Xeris Pharmaceuticals 424B5 Prospectus supplement for primary offering

As Filed Pursuant to Rule 424(b)(5)
Registration No. 333-233061

The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell, nor a solicitation of an offer to buy, the notes in any jurisdiction where the offer or sale is not permitted.

Subject to completion, dated June 24, 2020

Preliminary prospectus supplement

(To prospectus dated August 21, 2019)

$60,000,000

    % Convertible Senior Notes due 2025

We are offering $60,000,000 aggregate principal amount of our     % convertible senior notes due 2025. In addition, we have granted the underwriters an option, which is exercisable within 30 days after the date of this prospectus supplement, to purchase up to an additional $9,000,000 aggregate principal amount of notes, solely to cover over-allotments, if any.

We will pay interest on the notes at an annual rate of     %, payable semi-annually in arrears on January 15 and July 15 of each year, beginning on January 15, 2021. The notes will mature on July 15, 2025, unless earlier converted or redeemed or repurchased by us.

At any time before the close of business on the second scheduled trading day immediately before the maturity date, noteholders may convert their notes at their option into shares of our common stock, together, if applicable, with cash in lieu of any fractional share, at the then-applicable conversion rate. The initial conversion rate is                  shares per $1,000 principal amount of notes, which represents an initial conversion price of approximately $         per share, and is subject to adjustment as described in this prospectus supplement. If a “make-whole fundamental change” (as defined in this prospectus supplement) occurs, then we will in certain circumstances increase the conversion rate for a specified period of time.

The notes will be redeemable, in whole and not in part, at our option at any time, on or after July 20, 2023, at a cash redemption price equal to the principal amount of the notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date but only if the last reported sale price per share of our common stock exceeds 130% of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we send the related redemption notice; and (ii) the trading day immediately before the date we send such notice. In addition, calling any note for redemption will constitute a make-whole fundamental change with respect to that note, in which case the conversion rate applicable to the conversion of that note will be increased in certain circumstances for a specified period of time.

If a “fundamental change” (as defined in this prospectus supplement) occurs, then, except as described in this prospectus supplement, noteholders may require us to repurchase their notes at a cash repurchase price equal to the principal amount of the notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding the fundamental change repurchase date.

The notes will be our senior, unsecured obligations and will be equal in right of payment with our existing and future senior, unsecured indebtedness, senior in right of payment to our existing and future indebtedness that is expressly subordinated to the notes and effectively subordinated to our existing and future secured indebtedness, including borrowings under our loan and security agreement (our “Loan Agreement”), to the extent of the value of the collateral securing that indebtedness. The notes will be structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables, and (to the extent we are not a holder thereof) preferred equity, if any, of our subsidiaries.

Concurrently with this offering, we are offering $20.0 million of our common stock (or $23.0 million if the underwriters in that offering exercise their option to purchase additional shares in full) (the “Concurrent Common Stock Offering”) pursuant to a separate prospectus supplement and the accompanying prospectus (collectively, the “Common Stock Prospectus”). Neither the completion of the notes offering nor the Concurrent Common Stock Offering is contingent on the completion of the other, so it is possible that the notes offering occurs and the Concurrent Common Stock Offering does not occur, and vice versa. We cannot assure you that the Concurrent Common Stock Offering will be completed on the terms described herein, or at all. The Concurrent Common Stock Offering is being made pursuant to a separate prospectus supplement, and nothing contained herein shall constitute an offer to sell or the solicitation of an offer to buy shares of common stock to be issued in the Concurrent Common Stock Offering. See “Concurrent Common Stock Offering.”

No public market currently exists for the notes, and we do not intend to apply to list the notes on any securities exchange or for quotation on any inter-dealer quotation system. Our common stock is listed on The Nasdaq Global Select Market under the symbol “XERS.” On June 22, 2020, the last reported sale price of our common stock was $5.40 per share.

	PER NOTE	TOTAL
Public offering price(1)	$	$
Underwriting discounts and commissions(2)	$	$
Proceeds, before expenses, to us	$	$

(1) Plus accrued interest, if any, from                 , 2020.

(2) See “Underwriting (Conflicts of Interest)” for a description of compensation payable to the underwriters.

An investment in the notes involves risks. See “Risk Factors” beginning on page S-17.

Neither the Securities and Exchange Commission nor any state or foreign securities commission or regulatory authority has approved or disapproved of the notes or the shares of our common stock issuable upon the conversion of the notes or passed upon the adequacy or accuracy of this prospectus supplement. Any representation to the contrary is a criminal offense.

We expect to deliver the notes in book-entry form through the facilities of The Depository Trust Company on or about                 , 2020.

Joint Book-Running Managers

Jefferies SVB Leerink

Prospectus supplement dated June     , 2020

TABLE OF CONTENTS

PROSPECTUS SUPPLEMENT

	Page
ABOUT THIS PROSPECTUS SUPPLEMENT		S-1
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS		S-3
PROSPECTUS SUPPLEMENT SUMMARY		S-5
RISK FACTORS		S-17
USE OF PROCEEDS		S-29
DIVIDEND POLICY		S-31
CAPITALIZATION		S-32
DESCRIPTION OF NOTES		S-34
CONCURRENT COMMON STOCK OFFERING		S-66
MATERIAL UNITED STATES FEDERAL TAX CONSIDERATIONS		S-67
UNDERWRITING (CONFLICTS OF INTEREST)		S-74
LEGAL MATTERS		S-82
EXPERTS		S-82
WHERE YOU CAN FIND MORE INFORMATION		S-83
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE		S-84

PROSPECTUS

	Page
ABOUT THIS PROSPECTUS		1
RISK FACTORS		2
CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS		3
THE COMPANY		5
USE OF PROCEEDS		9
SECURITIES WE MAY OFFER		10
DESCRIPTION OF CAPITAL STOCK		11
DESCRIPTION OF DEBT SECURITIES		17
DESCRIPTION OF WARRANTS		25
DESCRIPTION OF UNITS		26
PLAN OF DISTRIBUTION		29
LEGAL MATTERS		32
EXPERTS		32
WHERE YOU CAN FIND MORE INFORMATION		33
INCORPORATION BY REFERENCE		34

ABOUT THIS PROSPECTUS SUPPLEMENT

This document is in two parts and is part of the registration statement that we filed with the Securities and Exchange Commission, or the SEC, using a “shelf” registration process. The first part is this prospectus supplement, which describes the specific terms of this notes offering and also adds to and updates information contained in the accompanying prospectus and the documents incorporated by reference herein. The second part, the accompanying prospectus, provides more general information. Generally, when we refer to this prospectus, we are referring to both parts of this document combined. To the extent there is a conflict between the information contained in this prospectus supplement and the information contained in the accompanying prospectus or any document incorporated by reference therein filed prior to the date of this prospectus supplement, you should rely on the information in this prospectus supplement; provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date—for example, a document incorporated by reference in the accompanying prospectus—the statement in the document having the later date modifies or supersedes the earlier statement.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference herein were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

Neither we nor the underwriters have authorized anyone to provide any information other than that contained or incorporated by reference in this prospectus supplement, the accompanying prospectus or in any free writing prospectus prepared by or on behalf of us or to which we have referred you. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. The information contained in this prospectus supplement or the accompanying prospectus, or incorporated by reference herein or therein is accurate only as of the respective dates thereof, regardless of the time of delivery of this prospectus supplement and the accompanying prospectus or of any sale of our securities. It is important for you to read and consider all information contained in this prospectus supplement and the accompanying prospectus, including the documents incorporated by reference herein and therein, in making your investment decision. You should also read and consider the information in the documents to which we have referred you in the sections entitled “Where You Can Find More Information” and “Incorporation of Certain Information by Reference” in this prospectus supplement and in the accompanying prospectus.

This prospectus supplement and the accompanying prospectus do not constitute an offer to sell, or a solicitation of an offer to purchase, the securities offered by this prospectus supplement and the accompanying prospectus in any jurisdiction to or from any person to whom or from whom it is unlawful to make such offer or solicitation of an offer in such jurisdiction. We are offering to sell, and seeking offers to buy, our securities only in jurisdictions where offers and sales are permitted. The distribution of this prospectus supplement and the accompanying prospectus and the offering of the securities in certain jurisdictions may be restricted by law. Persons outside the United States who come into possession of this prospectus supplement and the accompanying prospectus must inform themselves about, and observe any restrictions relating to, the offering of the securities and the distribution of this prospectus supplement and the accompanying prospectus outside the United States.

Unless otherwise stated, all references in this prospectus supplement and the accompanying prospectus to “we,” “us,” “our,” “Xeris,” “the Company” and similar designations refer, collectively, to Xeris Pharmaceuticals, Inc., a Delaware corporation.

The “Xeris” name, and the XeriJect, XeriSol, GVOKE, GVOKE HYPOPEN, and HYPOPEN names and related images, logos and symbols appearing in this prospectus supplement and the accompanying prospectus are our

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properties, trademarks and service marks. Other marks appearing in this prospectus supplement and the accompanying prospectus are the property of their respective owners. Solely for convenience, the trademarks and trade names in this prospectus supplement and the accompanying prospectus may be referred to without the ^® and ^™ symbols, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto. This prospectus supplement and the accompanying prospectus and the documents incorporated by reference herein also contain estimates, projections and other information concerning our industry, our business and the markets for our product candidates. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties and actual events or circumstances may differ materially from events and circumstances that are assumed in this information. Unless otherwise expressly stated, we obtained this industry, business, market and other data from our own internal estimates and research as well as from reports, research surveys, studies and similar data prepared by market research firms and other third parties, industry, medical and general publications, government data and similar sources.

No action is being taken in any jurisdiction outside the United States to permit a public offering of the securities or possession or distribution of this prospectus supplement or the accompanying prospectus in that jurisdiction. Persons who come into possession of this prospectus supplement or the accompanying prospectus in jurisdictions outside the United States are required to inform themselves about and to observe any restrictions as to this offering and the distribution of this prospectus supplement or the accompanying prospectus applicable to that jurisdiction.

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement and the accompanying prospectus, including the documents that we incorporate by reference, contain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. Any statements about our expectations, beliefs, plans, objectives, assumptions or future events or performance are not historical facts and may be forward-looking. These statements are often, but are not always, made through the use of words or phrases such as “may,” “will,” “could,” “should,” “expects,” “intends,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “projects,” “seeks,” “endeavor,” “potential,” “continue,” and similar expressions, or the negative of these terms, or similar expressions. Accordingly, these statements involve estimates, assumptions, risks and uncertainties which could cause actual results to differ materially from those expressed in them. Any forward-looking statements are qualified in their entirety by reference to the factors discussed throughout this prospectus supplement, and in particular those factors referenced in the section “Risk Factors.”

This prospectus supplement and the accompanying prospectus contain forward-looking statements that are based on our management’s belief and assumptions and on information currently available to our management. These statements relate to future events or our future financial performance, and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to be materially different from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Forward-looking statements include, but are not limited to, statements about:

• the rate and degree of market acceptance and clinical utility of Gvoke;

• our expectations related to the anticipated timing of the commercial launch of Gvoke HypoPen;

• our expectations related to the potential timing of the launch of ourready-to-use glucagon in certain European countries, if we receive marketing approval;

• our estimates regarding the market opportunities for Gvoke and our product candidates;

• the commercialization, marketing and manufacturing of Gvoke and our product candidates, if approved;

• our ability to manufacture, or the ability of third parties to deliver, sufficient quantities of components and drug product for commercialization of Gvoke or any of our product candidates, if approved;

• the pricing and reimbursement of Gvoke or any of our product candidates, if approved;

• the rate and degree of market acceptance and clinical utility of any of our product candidates for which we receive marketing approval in the future;

• the initiation, timing, progress and results of our research and development programs and future preclinical and clinical studies;

• our ability to advance any other product candidates into, and successfully complete, clinical studies and obtain regulatory approval for them;

• our ability to identify additional product candidates;

• the implementation of our strategic plans for our business, product candidates and technology;

• the scope of protection we are able to establish and maintain for intellectual property rights covering our product candidates and technology;

• the effect of uncertainties related to the current coronavirus pandemic, or any other health epidemic, on U.S. and global markets, our business, financial condition, operations, third-party suppliers or the global economy as a whole;

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• the Concurrent Common Stock Offering (as described in “Prospectus Supplement Summary – Concurrent Common Stock Offering”);

• our ability to use the proceeds of this offering, and the Concurrent Common Stock Offering, in ways that increase the value of your investment;

• our expectations related to the use of proceeds from this offering, and estimates of our expenses, future revenues, capital requirements and our needs for additional financing;

• our ability to maintain and establish collaborations;

• our financial performance;

• our ability to effectively manage our anticipated growth;

• developments relating to our competitors and our industry, including the impact of government regulation;

• our ability to avoid any findings of material weakness or significant deficiencies we may find in the future; and

• other risks and uncertainties, including those listed under the caption “Risk Factors.”

This prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein also contain estimates, projections and other information concerning our industry, our business and the markets for certain diseases, including data regarding the estimated size of those markets and the incidence and prevalence of certain medical conditions. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties and actual events or circumstances may differ materially from events and circumstances reflected in this information. Unless otherwise expressly stated, we obtained this industry, business, market and other data from reports, research surveys, studies and similar data prepared by market research firms and other third parties, industry, medical and general publications, government data and similar sources.

You should read this prospectus supplement, the accompanying prospectus and the documents that we incorporate by reference herein or therein completely and with the understanding that our actual future results may be materially different from what we expect. Such risks and uncertainties may be amplified by theCOVID-19 pandemic and its impact on our business and the global economy. The forward-looking statements in this prospectus supplement, the accompanying prospectus and the documents we incorporate by reference herein represent our views as of their respective dates. We anticipate that subsequent events and developments will cause our views to change. However, while we may elect to update these forward-looking statements at some point in the future, we have no current intention of doing so except to the extent required by applicable law. You should, therefore, not rely on these forward-looking statements as representing our views as of any date subsequent to the date of this prospectus supplement, the accompanying prospectus or the documents incorporated by reference herein, as applicable.

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PROSPECTUS SUPPLEMENT SUMMARY

This summary highlights selected information contained elsewhere in this prospectus supplement and the accompanying prospectus and in the documents we incorporate by reference. This summary does not contain all of the information you should consider before investing in our securities. You should read this entire prospectus supplement and the accompanying prospectus, including the documents incorporated by reference herein and therein, carefully, especially the risks of investing in our securities discussed under “Risk Factors” beginning on page S-17 of this prospectus supplement and under similar sections of the accompanying prospectus and other periodic reports incorporated herein and therein by reference, along with our consolidated financial statements and notes to those consolidated financial statements, before making an investment decision.

Company Overview

We are a specialty pharmaceutical company leveraging our novelnon-aqueous formulation technology platforms, XeriSol and XeriJect, to develop and commercializeready-to-use injectable and infusible drug formulations. We have developed and launched the firstready-to-use, room-temperature stable liquid glucagon formulation that, unlike the current standard of care, can be administered without any preparation or reconstitution. Our first product, Gvoke, deliversready-to-use glucagon via a commercially availablepre-filled syringe (“Gvoke PFS”) or auto-injector (“Gvoke HypoPen”) for the treatment of severe hypoglycemia, a potentially life-threatening condition, in people with diabetes. Gvoke was approved in September 2019 by the U.S. Food & Drug Administration (“FDA”) for the treatment of severe hypoglycemia in pediatric and adult patients with diabetes ages two years and older. We began the field launch of Gvoke PFS in January 2020. Gvoke PFS is available in two doses: a 0.5 mg/0.1 mL dose for pediatric patients and a 1 mg/0.2 mL dose for adolescent and adult patients. We expect Gvoke HypoPen will be commercially available in July 2020, in the same doses as the Gvoke PFS. Additionally, our Marketing Authorisation Application (“MAA”) for our novelready-to-use, room temperature stable liquid glucagon formulation for the treatment of severe hypoglycemia in people with diabetes is under review by the European Medicines Agency (“EMA”). We are also applying our novel liquid glucagon formulation to the management of hypoglycemia associated with additional intermittent and chronic conditions with significant unmet medical need. Finally, we are applying our technology platforms to other commercially available drugs to enable more convenient and patient-friendly subcutaneous (“SC”) and intramuscular (“IM”) routes of administration, including the development of products to address unmet needs in both diabetes and epilepsy. We own the rights to our proprietary formulation technology platforms, Gvoke, and our product candidates domestically and internationally, with 112 patents issued globally, including a composition of matter patent covering ourready-to-use glucagon formulation that expires in 2036.

Our proprietary XeriSol and XeriJectnon-aqueous formulation technology platforms allow for the SC and IM delivery of highly concentrated,ready-to-use formulations of peptides, small molecules, and proteins (including monoclonal antibodies) using commercially available syringes, auto-injectors, multi-dose pens and infusion pumps. Current aqueous formulations of certain drugs present numerous challenges for patients and caregivers, including multi-step reconstitution, refrigerated storage, reduced shelf life, large injection volumes, and intravenous (“IV”) administration over long periods of time. We believe our broadly applicable platforms can provide distinct advantages over existing formulations by eliminating reconstitution and refrigeration, enabling long-term room-temperature stability, significantly reducing injection volume and enabling patient-convenient SC or IM administration versus IV infusion. We believe that our technology platforms can lead to products that will improve outcomes and enable easier administration while reducing costs for payors and the healthcare system.

Our key priority is the commercialization of our first product, Gvoke, for the treatment of severe hypoglycemia in people with diabetes to address limitations of traditional glucagon kits. Hypoglycemia, a key concern of people with both Type 1 Diabetes (“T1D”) and Type 2 Diabetes (“T2D”), occurs when a person has a deficiency

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of glucose in their bloodstream, often as a result of insulin treatment. Symptoms of hypoglycemia include fatigue, shakiness, anxiety, headache, nausea and vomiting, and in severe cases, hypoglycemia can result in cardiovascular disease, seizure, coma, and, if left untreated, death. The current standard of care for severe hypoglycemia in the ambulatory setting is the emergency administration of glucagon, a hormone that raises the concentration of glucose in the bloodstream. Traditional glucagon kits consist of a glucagon powder that must be reconstituted with a liquid diluent and drawn into a syringe using a multi-step procedure that can be difficult to successfully administer, particularly in an emergency. In published comparative human factors studies with traditional glucagon kits, only 6% to 31% of users were able to successfully administer the full dose of glucagon. In other words, in these studies, test subjects failed to deliver the full dose of glucagon 69% to 94% of the time. The underuse or unsuccessful use of these traditional glucagon kits leaves people at risk of experiencing prolonged severe hypoglycemic events, which if left untreated, can lead to serious health consequences and death.

We believe Gvoke addresses the administration challenges of traditional glucagon kits and has the potential to be the preferred emergency glucagon product. Ourready-to-use Gvoke does not require reconstitution or refrigeration and featurestwo-year room-temperature stable liquid glucagon delivered in apre-filled syringe or an auto-injecting device with no visible needle. In our human factors studies, 99% of users were able to successfully administer the full dose with ourready-to-use Gvoke.

In addition to traditional glucagon kits, a nasally administered glucagon powder, Eli Lilly’s BAQSIMI^®, was approved by the FDA in July 2019 and was launched in August 2019. While BAQSIMI offers a novel route of administration, we believe patients and caregivers in the diabetic community want greater certainty that a full dose of glucagon will be delivered in an emergency situation and so will prefer Gvoke to BAQSIMI.

Our goal is to establish Gvoke as the preferred emergency glucagon product and drive greater adoption and penetration of emergency glucagon therapy by offering a glucagon product that better meets the needs of patients and caregivers. The American Diabetes Association recommends that glucagon be prescribed for all individuals at increased risk of clinically significant hypoglycemia for use in the event of an emergency. People with diabetes who are treated with insulin or substances that promote production of insulin are at increased risk of clinically significant hypoglycemia. There are an estimated 1.5 million people with T1D in the United States who are treated with insulin because their bodies do not naturally produce insulin, all of whom are clinically appropriate for glucagon. Approximately 4.7 million additional people with T2D in the United States are treated with insulin because their bodies do not use insulin properly, of which we estimate that approximately 50% are clinically appropriate for glucagon. Therefore, we estimate the potential target population for emergency glucagon therapy totals approximately 3.9 million people in the United States. Our commercial strategy, which we began to implement with our field launch of Gvoke PFS in January 2020, is to penetrate this market efficiently with a concentrated sales force by targeting high prescribers of glucagon and mealtime insulin and to activate demand through targeteddirect-to-patient promotion. We also are using our medical affairs and market access teams to actively drive market access and obtain payor coverage for Gvoke. The combination of our promotional efforts in this category and Eli Lilly’s in support of its BAQSIMI is expected to drive a significant increase in prescription activity for glucagon in general. In fact, from the introduction of Gvoke PFS in November 2019 until theCOVID-19 pandemic stay at home orders began in the U.S., total monthly glucagon prescriptions across all types and formulations were an average of 16% higher than the same month’s prior year totals. The growth trajectory has been adversely impacted recently as a result of theCOVID-19 pandemic and civil unrest.

Due to the limitations of traditional glucagon kits and other factors, only approximately 567,200 total prescriptions for traditional glucagon kits were written in 2019 in the United States. In the second half of 2019, both BAQSIMI, which Eli Lilly launched in August 2019, and Gvoke PFS, which we launched in November 2019, entered the market. According to IQVIA, total prescriptions written in 2019 for BAQSIMI and Gvoke PFS

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were approximately 40,900 and 600, respectively. Total units reported in 2019 were approximately 906,700 traditional glucagon kits, 106,100 units of BAQSIMI, and 2,300 Gvoke units as adjusted for a consistent unit of measure. Based on our market research, we are targeting our marketing to all 3.9 million people that we believe are clinically appropriate for glucagon. In 2019, U.S. sales for emergency glucagon products were approximately $259 million, but we believe that increasing penetration, including by new entrants that address unmet patient and caregiver needs, such as Gvoke, may result in a potential sales opportunity of up to $2.2 billion. Outside the United States, we estimate there are an additional 3.5 million people with diabetes in Europe and an additional 12.5 million people with diabetes in Japan and China that are clinically appropriate for emergency glucagon treatment. Our MAA for our liquid glucagon formulation for the treatment of severe hypoglycemia in people with diabetes is under review by the EMA. If our MAA is approved, we could potentially launch our liquid glucagon formulation in certain European countries in 2021. We plan to pursue development and commercialization collaborations for most, if not all, of thenon-U.S. markets we seek to enter.

We are also evaluating our glucagon formulation for certain intermittent and chronic use conditions with significant unmet medical need. We plan to continue to advance these programs going forward. These additional applications are:

• Exercise-Induced Hypoglycemia (“EIH”) in people with diabetes. Exercise, particularly aerobic exercise, often results in a significant drop in blood glucose levels for people on insulin.

• Post-Bariatric Hypoglycemia (“PBH”), a serious complication of bariatric surgery that can arise from excessive insulin, or hyperinsulinism, due to the change in gastric anatomy resulting from bariatric surgery.

• Management of diabetes via glucagon in a fully integrated,bi-hormonal artificial pancreas closed-loop system.

By applying ourready-to-use glucagon to treat multiple conditions, we expect to leverage operating efficiencies across our supply chain, research and development, and commercial and medical organizations.

We are also applying our technology platforms to develop additional product candidates, such as a fixed ratioco-formulation of pramlintide and insulin (“Pram-Insulin”) for the management of diabetes andready-to-use, liquid-stable diazepam for the emergency treatment of epileptic seizures. Additionally, based on the promising data seen in some of our early clinical trials as well as preclinical studies of formulations developed in our laboratory, we believe we have the potential to advance a number of additional programs in additional indications and that our strong product candidate portfolio, complemented by external expansion opportunities, will support our vision to effectively and efficiently meet the needs of our target markets.

The nature of our product candidates and target conditions provides us with a potentially faster and capital-efficient development and regulatory pathway to approval. The FDA has granted orphan drug status to several indications for our product candidates, including ourready-to-use glucagon for PBH and ourready-to-use, liquid-stable formulation of diazepam for the treatment of Dravet syndrome and acute repetitive seizures, or ARS, in patients with epilepsy. Additionally, we have received orphan drug designation from the EMA for Noninsulinoma Pancreatogenous Hypoglycaemia Syndrome (“NIPHS”), which includes patients with PBH.

In the United States, this designation provides us with research and development tax credits and exemption from FDA user fees, as well as seven years of orphan drug exclusivity upon product approval. In the European Union (“EU”), this designation provides us with ten years of market exclusivity upon product approval and a single MAA application to the EMA through centralized review and the potential for reduced regulatory review fees. In addition, because certain conditions that we intend to target are rare conditions, we believe our clinical trials may be of smaller size than studies for conditions that are not rare conditions. Furthermore, because the product

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candidates developed using our technology platforms are designed to be reformulations of currently approved products, in the United States we expect to utilize for many of our product candidates the FDA’s pathway under Section 505(b)(2) of the U.S. Federal Food, Drug and Cosmetic Act (“FDCA”) which permits submissions to rely, in part, on the safety and effectiveness of a previously approved product, which may potentially result in a more expeditious pathway to FDA approval.

Our management team includes veterans in drug development, discovery and commercialization, with executive experience in leading global pharmaceutical and healthcare companies, including Durata Therapeutics, Baxter Healthcare, Merck, Searle, Takeda, Warner Chilcott, MedPointe Healthcare, Amgen, Amylin Pharmaceuticals, PowderJect Technologies and Alpharma.

Recent Developments

Topline Results from Phase 2 Study of Mini-Dose Glucagon to Prevent EIH in T1D

On June 15, 2020, we announced topline results from the outpatient stage of our Phase 2 study of Gvokeready-to-use (RTU) Micro^TMfor the treatment of hypoglycemia during and aftermoderate-to-high intensity aerobic exercise in adults with T1D who use insulin pumps.

In the outpatient stage of this study, subjects were randomly assigned to RTU Glucagon with 50% insulin pump reduction (RTU Glucagon + standard of care), placebo injection with 50% insulin pump reduction (standard of care), or RTU Glucagon without insulin pump reduction (Open-Label RTU Glucagon). For persons with diabetes, standard of care for aerobic exercise includes 50% insulin pump reduction. Previous results showed that pretreatment with 150 µg of RTU glucagon was adequate to maintain normal blood glucose levels during prolonged,moderate-to-intense aerobic exercise.

During the12-week outpatient stage, 45 subjects completed 795 aerobic exercise sessions. Over this time, when individually compared to standard of care alone, the number of EIH episodes was significantly less with RTU Glucagon + standard of care (2.5±1.26 episodes versus 8.5±1.17 episodes, P=0.0016) and with Open-Label RTU Glucagon (3.9±1.37 episodes versus 8.5±1.17 episodes, P=0.0165). RTU Glucagon + standard of care resulted in an approximately 70% lower rate of EIH when compared to standard of care alone (12±14.1% versus 41±21.5%, P<0.0001). Additionally, Open-Label RTU Glucagon resulted in an approximately 54% lower rate of EIH when compared to standard of care alone (19±20.2% versus 41±21.5%, P=0.0032). The difference in the incidence rates of EIH between the two RTU Glucagon arms was not statistically significant.

Across all outpatient stage exercise sessions, the nominal use of oral glucose tablets during and after exercise, in order to treat hypoglycemia, was greater in the standard of care arm compared to RTU Glucagon + standard of care and Open Label RTU Glucagon. Consequently, the nominal incidence of hyperglycemia (blood glucose >180 mg/dL) episodes was observed to be greater(2.4-fold) in the standard of care arm when compared to RTU Glucagon + standard of care. RTU Glucagon did not appear to individually contribute to hyperglycemia. When hyperglycemia events did occur, the time duration and severity of events did not differ between treatment arms.

The incidence and severity of adverse events was comparable across all treatment arms. Nausea, vomiting, and injection site discomfort were the most commonly reported adverse events. RTU glucagon was observed to be generally safe and well tolerated in the enrolled population, and no serious adverse events were reported.

Topline Results from Phase 2 Comparative Study of Pram-InsulinCo-Formulation(XP-3924) in Adults with T1D Mellitus

On June 18, 2020, we announced topline results from aproof-of-concept Phase 2 study of a novel XeriSol^™ pramlintide-insulinco-formulation(XP-3924) in adults with T1D mellitus.

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XP-3924 is designed to improve the synergistic combination of two complementary therapies: pramlintide (an amylin-analog) and insulin. The separate administration of these existing therapies in combination reduces both post-prandial glucose excursions and glucose variability, as well as improves overall glycemic control. A pramlintide-insulinco-formulation may help reduce the daily burden associated with pramlintideco-administration (e.g., reduce the multiple additional injections needed per day). We believe this reduction in the multiple injection burden usingXP-3924 may also improve longer term pramlintide treatment adherence and persistency.

The completed Phase 2 study was a randomized, open-label, active comparator-controlled, three-period cross-over study, which enrolled 18 adult participants with T1D. This study aimed to investigate the pharmacokinetics, pharmacodynamics, and the safety and tolerability of a single dose ofXP-3924 (administered based upon the subjects’ insulin:carbohydrate ratio), when compared toco-administration of regular insulin (Humulin^® R) and pramlintide (Symlin^®), and to an injection of regular insulin alone (Humulin^® R). Subjects were randomly allocated to a sequence of three treatments:XP-3924 (with 50% insulin reduction), regular insulin, or regular insulin (with 50% insulin reduction) plus pramlintideco-administered as separate injections. The study drugs were administered subcutaneously before the intake of a standardized75-gram oral glucose challenge. The subjects’ blood glucose levels were monitored for 6 hours after drug dosing.

Treatment withXP-3924 resulted in a 62.3% reduction of hyperglycemia (blood glucose >180 mg/dL) after the glucose challenge when compared to Humulin^® R (p<0.001). Additionally,XP-3924 exhibited comparable postprandial glycemic control to that of theco-administered injections of Humulin^® R and Symlin^®. The mean absolute change in blood glucose was less inXP-3924 when compared to both Humulin^® R andco-administered injections of Humulin^® R and Symlin^® after the oral glucose challenge. The glucose variability after treatment withXP-3924 was less than both Humulin^® R andco-administered injections of Humulin^® R and Symlin^®, as defined by the comparison of the coefficient of variation of all plasma glucose readings across the6-hour duration of study treatments.

The incidence and severity of treatment emergent adverse events was comparable across all treatment arms, as were the overall number of hypoglycemic events during dosing visits. There were minimal gastrointestinal side effects reported in any treatment arm. There was a comparable incidence of injection site reactions and no edema was noted, across all treatment arms.XP-3924 was generally safe and well-tolerated by the enrolled population, and no serious adverse events occurred in this study.

Amendment to Loan Agreement

We have a senior secured loan facility with Oxford Finance LLC (“Oxford”) and Silicon Valley Bank (“SVB”) pursuant to our Amended and Restated Loan and Security Agreement, dated September 10, 2019, as amended by the First Amendment to Amended and Restated Loan and Security Agreement, dated April 21, 2020, between us, Oxford, as collateral agent and lender, and SVB (as amended, the “Loan Agreement”). We received a commitment from Oxford and SVB to amend the Loan Agreement to, among other things, provide the lenders’ consent to and allow for this offering, extend the principal maturity date under the Loan Agreement from June 1, 2023, to June 1, 2024 and extend the interest-only period under the Loan Agreement from April 2020 to December 2021 with the potential to extend the interest-only period to September 2022 upon achievement of a certain revenue milestone (the “Loan Agreement Amendment”). The completion of this offering is contingent upon the closing of the Loan Agreement Amendment. We cannot assure you that the Loan Agreement Amendment will be completed on the terms described herein, or at all.

In addition to the foregoing, the Loan Agreement Amendment, if it becomes effective, would include the following conditions: we are required to make a prepayment to lenders in an amount equal to $20.0 million plus accrued interest of approximately $140,000, a prepayment fee of $300,000 and a final payment fee of $600,000 at the closing of the Loan Agreement Amendment. We are also required to maintain a minimum balance of

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$5 million in unrestricted cash at all times and to pay an amendment fee of $100,000 due at the earlier of prepayment and the maturity date.

Impact ofCOVID-19

The current novel coronavirus(“COVID-19”) pandemic has presented a substantial public health and economic challenge around the world and has impacted our business operations, employees, patients and communities, as well as the global economy and financial markets. TheCOVID-19 pandemic continues to evolve and to date has led to the implementation of various responses, including government-imposed quarantines, stay at home orders, travel restrictions, mandated business closures and other public health safety measures.

To date, we and our suppliers and third-party manufacturing partners have been able to continue to supply our products to our patients and currently do not anticipate any interruptions in supply. Our third-party contract manufacturing partners continue to operate at or near normal levels, with enhanced safety measures intended to prevent the spread of the virus. While we currently do not anticipate any interruptions in our manufacturing process, it is possible that theCOVID-19 pandemic and response efforts may have an impact in the future on our third-party suppliers and contract manufacturing partners’ ability to supply and/or manufacture our products.

We believe that customer demand for Gvoke has been adversely impacted by theCOVID-19 pandemic. Initially, we suspendedin-person interactions by our sales and marketing personnel in healthcare settings. We are engaging with these customers remotely, via webinar programs and virtual meetings, as we seek to continue to support healthcare professionals and patient care. As parts of the country reopen, some of our sales and marketing personnel have begun to reengage with a limited number ofin-person interactions. In addition, several conferences and other programs at which we intended to market Gvoke have been postponed, canceled and/or transitioned to virtual meetings. Remote interactions may be less effective thanin-person interactions. We have also revised our patient copay assistance program to offer a $0 copay card for commercially eligible patients in response to theCOVID-19 pandemic.

As theCOVID-19 pandemic unfolded, we moved quickly to transition our employees to a remote work from home environment excluding essential services, such as personnel in our laboratory. For those employees, we have implemented safety measures designed to comply with applicable federal, state and local guidelines in response to theCOVID-19 pandemic. We may be required to take additional actions that may impact our operations as required by applicable laws or regulations, or which we determine to be in the best interests of our employees.

Concurrent Common Stock Offering

Concurrently with this offering, we are offering $20.0 million of our common stock (or $23.0 million if the underwriters in that offering exercise their option to purchase additional shares in full) (the “Concurrent Common Stock Offering”) pursuant to a separate prospectus supplement and the accompanying prospectus (collectively, the “Common Stock Prospectus”).

Neither the completion of this notes offering nor the Concurrent Common Stock Offering is contingent on the completion of the other, so it is possible that this notes offering occurs and the Concurrent Common Stock Offering does not occur, and vice versa. We cannot assure you that the Concurrent Common Stock Offering will be completed on the terms described herein, or at all. The Concurrent Common Stock Offering is being made pursuant to a separate prospectus supplement, and nothing contained herein shall constitute an offer to sell or the solicitation of an offer to buy shares of common stock to be issued in the Concurrent Common Stock Offering. See “Concurrent Common Stock Offering.”

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Company information

We were incorporated under the laws of the State of Delaware in 2005. Our principal offices are located at 180 N. LaSalle Street, Suite 1600, Chicago, Illinois 60601, and our telephone number is (844)445-5704. Our website address is www.xerispharma.com. We do not incorporate the information on or accessible through our website into this prospectus supplement, and you should not consider any information on, or that can be accessed through, our website as part of this prospectus supplement. You should not rely on any such information in making your decision whether to purchase the notes. Our common stock trades on The Nasdaq Global Select Market under the symbol “XERS”.

Implications of being an emerging growth company

We qualify as an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, as amended. As an emerging growth company, we may take advantage of specified reduced disclosure and other requirements that are otherwise applicable generally to public companies. These provisions include:

• Only two years of audited financial statements in addition to any required unaudited interim financial statements with correspondingly reduced “Management’s Discussion and Analysis of Financial Condition and Results of Operations” disclosure;

• Reduced disclosure about our executive compensation arrangements;

• No advisory votes on executive compensation or golden parachute arrangements; and

• Exemption from the auditor attestation requirement in the assessment of our internal control over financial reporting.

We may take advantage of these exemptions for up to five years or such earlier time that we are no longer an emerging growth company. We would cease to be an emerging growth company on the date that is the earliest of (i) the last day of the fiscal year in which we have total annual gross revenues of $1.07 billion or more; (ii) the last day of our fiscal year following the fifth anniversary of the date of the completion of our initial public offering; (iii) the date on which we have issued more than $1.0 billion in nonconvertible debt during the previous three years; or (iv) the date on which we are deemed to be a large accelerated filer under the rules of the Securities and Exchange Commission, or SEC. We may choose to take advantage of some but not all of these exemptions. We have taken advantage of reduced reporting requirements in this prospectus supplement. Accordingly, the information contained herein may be different from the information you receive from other public companies in which you hold stock.

We are also a “smaller reporting company” as defined in the Exchange Act. We may continue to be a smaller reporting company even after we are no longer an emerging growth company. We may take advantage of certain of the scaled disclosures available to smaller reporting companies until the fiscal year following the determination that our voting andnon-voting common stock held bynon-affiliates is more than $250 million measured on the last business day of our second fiscal quarter, or our annual revenues are more than $100 million during the most recently completed fiscal year and our voting andnon-voting common stock held bynon-affiliates is more than $700 million measured on the last business day of our second fiscal quarter.

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THE OFFERING

The summary below describes the principal terms of the notes. Certain of the terms of the notes described below are subject to important limitations and exceptions that are described in more detail under the “Description of Debt Securities” section of the accompanying prospectus, as supplemented by the “Description of Notes” section of this prospectus supplement. As used in this section, “we,” “our” and “us” refer to Xeris Pharmaceuticals, Inc. and not to its subsidiaries.

Issuer Xeris Pharmaceuticals, Inc.

Notes $60,000,000 aggregate principal amount of     % convertible senior notes due 2025. We have granted the underwriters an option, which is exercisable within 30 days after the date of this prospectus supplement, to purchase up to an additional $9,000,000 aggregate principal amount of notes, solely to cover over-allotments, if any

Ranking The notes will be our senior, unsecured obligations and will be:

�� • equal in right of payment with our existing and future senior, unsecured indebtedness;

• senior in right of payment to our existing and future indebtedness that is expressly subordinated to the notes;

• effectively subordinated to our existing and future secured indebtedness, including borrowings under our Loan Agreement, to the extent of the value of the collateral securing that indebtedness; and

• structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables, and (to the extent we are not a holder thereof) preferred equity, if any, of our subsidiaries.

As of March 31, 2020, we had $60.0 million principal amount of long-term indebtedness outstanding. In addition, our subsidiaries had $0.3 million of other liabilities (including trade payables, but excluding intercompany obligations and liabilities). After giving effect to this offering (assuming no exercise of the underwriters’ option to purchase additional notes) and the use of proceeds therefrom as described in “Use of Proceeds,” our total outstanding long-term indebtedness would have been $100.0 million, of which $40.0 million would have been secured and $60.0 million would have been unsecured.

Maturity July 15, 2025, unless earlier repurchased, redeemed or converted.

Interest     % per annum, payable semi-annually in arrears on January 15 and July 15 of each year, beginning on January 15, 2021. In addition, special interest, if any, will accrue on the notes, at our election, as the sole remedy relating to the failure to comply with our reporting obligations, as described in “Description of Notes—Events of Default—Special Interest as Sole Remedy for Certain Reporting Defaults.”

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Conversion Rights At any time before the close of business on the second scheduled trading day immediately before the maturity date, noteholders may convert their notes at their option into shares of our common stock, together, if applicable, with cash in lieu of any fractional share, at the then-applicable conversion rate. The initial conversion rate is             shares per $1,000 principal amount of notes, which represents an initial conversion price of approximately $             per share, and is subject to adjustment as described in this prospectus supplement.

If a “make-whole fundamental change” (as defined in this prospectus supplement) occurs, then we will in certain circumstances increase the conversion rate for a specified period of time.

Notwithstanding anything to the contrary herein, you will not be entitled to receive any shares of our common stock otherwise deliverable upon conversion of the notes to the extent, but only to the extent, that such receipt would cause you to become, directly or indirectly, a “beneficial owner” of shares of our common stock in excess of the beneficial ownership limits applicable to you at such time, as described under “Description of Notes—Conversion Rights—Limits on Issuance of Shares of Common Stock upon Conversion” and “Description of Notes—Conversion Rights—Waiver of Beneficial Ownership Limits.”

See “Description of Notes—Conversion Rights.”

Optional Redemption The notes will be redeemable, in whole and not in part, at our option at any time on or after July 20, 2023, at a cash redemption price equal to the principal amount of the notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date, but only if (1) the last reported sale price per share of our common stock exceeds 130% of the conversion price on (i) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we send the related redemption notice; and (ii) the trading day immediately before the date we send such notice. In addition, calling any note for redemption will constitute a make-whole fundamental change with respect to that note, in which case the conversion rate applicable to the conversion of that note will be increased in certain circumstances if it is converted after it is called for redemption for a specified period of time. See “Description of Notes—Optional Redemption.”

Repurchase at the Option of the Noteholders After a Fundamental Change If a “fundamental change” (as defined in this prospectus supplement) occurs, then, except as described in this prospectus supplement, noteholders may require us to repurchase their notes at a cash repurchase price equal to the principal amount of the notes to be repurchased, plus accrued and unpaid interest, if any, to, but

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excluding, the fundamental change repurchase date. See “Description of Notes—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes.”

Trustee, Paying Agent and Conversion Agent U.S. Bank National Association

Public Market The notes are a new class of securities for which no public market currently exists. We do not intend to apply to list the notes on any securities exchange or for quotation on any inter-dealer quotation system. Accordingly, a liquid market for the notes may never develop. The underwriters have advised us that they intend to make a market in the notes. However, they are not obligated to do so and may discontinue any market-making activity at any time and without notice.

The Nasdaq Global Select Market Symbol Our common stock is listed on The Nasdaq Global Select Market under the symbol “XERS.”

Concurrent Common Stock Offering Concurrently with this offering, we are offering $20.0 million of our common stock (or $23.0 million if the underwriters in that offering exercise their option to purchase additional shares in full) (the “Concurrent Common Stock Offering”) pursuant to a separate prospectus supplement and the accompanying prospectus (collectively, the “Common Stock Prospectus”).

Neither the completion of this notes offering nor the Concurrent Common Stock Offering is contingent on the completion of the other, so it is possible that this notes offering occurs and the Concurrent Common Stock Offering does not occur, and vice versa. We cannot assure you that the Concurrent Common Stock Offering will be completed on the terms described herein, or at all. The Concurrent Common Stock Offering is being made pursuant to a separate prospectus supplement, and nothing contained herein shall constitute an offer to sell or the solicitation of an offer to buy shares of common stock to be issued in the Concurrent Common Stock Offering. See “Concurrent Common Stock Offering.”

Use of Proceeds We estimate that the net proceeds to us from this offering will be approximately $56.3 million (or approximately $64.9 million if the underwriters fully exercise their option to purchase additional notes), after deducting the underwriters’ discounts and commissions and our estimated offering expenses.

We estimate that the net proceeds to us from the Concurrent Common Stock Offering will be approximately $18.6 million (or approximately $21.4 million if the underwriters fully exercise their option to purchase additional shares of common stock in such offering), after

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deducting underwriting discounts and commissions and our estimated offering expenses.

We intend to use the net proceeds from this offering and, if completed, the Concurrent Common Stock Offering, primarily (i) to fund sales and marketing costs to support commercialization of Gvoke; (ii) to repay $20.0 million of the borrowings under our Loan Agreement; (iii) to fund research and development activities relating to the advancement of our product candidates; (iv) for expansion of our technology or manufacturing infrastructure and capabilities; (v) for potential strategic acquisitions of complementary businesses, assets, services or technologies; and (vi) the remainder for working capital, capital expenditures, and other general corporate purposes.

An affiliate of SVB Leerink LLC is a lender under our Loan Agreement and may receive a portion of the net proceeds of this offering. Because of this relationship, SVB Leerink LLC is deemed to have a “conflict of interest” under the applicable provisions of FINRA Rule 5121. Accordingly, this offering is being conducted in accordance with the applicable provisions of FINRA Rule 5121, including the requirement that a “qualified independent underwriter” participate in the preparation of the prospectus supplement and exercise the usual standards of due diligence in respect thereto. Jefferies LLC has agreed to serve as the qualified independent underwriter for this offering and will not receive any additional fees for serving in that capacity. We have agreed to indemnify Jefferies LLC against liabilities incurred in connection with acting as a qualified independent underwriter, including liabilities under the Securities Act. In accordance with Rule 5121, SVB Leerink LLC will not make sales of the notes to discretionary accounts without the prior written consent of the account holder. See “Use of Proceeds” onpage S-29 of this prospectus supplement and “Underwriting (Conflicts of Interest)” on pageS-74 of this prospectus supplement.

Risk Factors Investing in the notes involves risks. See “Risk Factors.”

Material U.S. Federal Income Tax Considerations For a description of material U.S. federal income tax considerations of purchasing, owning, converting into shares of our common stock, and disposing of the notes and owning and disposing of shares of our common stock issuable upon the conversion of the notes, see “Material U.S. Federal Income Tax Considerations.”

Book-Entry Form We will initially issue the notes in the form of one or more global notes registered in the name of Cede & Co., as nominee of The Depository Trust Company (“DTC”), without interest coupons, which we will deposit with the trustee as custodian for DTC. Beneficial interests in global notes will be shown on, and transfers of global notes will be effected only through, the records maintained by DTC. Except in limited circumstances, we will not issue certificated notes. See “Description of Notes—Book Entry, Settlement and Clearance.”

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Unless otherwise indicated, all information in this prospectus supplement assumes:

• that the underwriters do not exercise their over-allotment option to purchase up to $9.0 million principal amount of additional notes; and

• that the underwriters in the Concurrent Common Stock Offering, if such offering is completed, do not exercise their option to purchase up to $3.0 million additional shares of our common stock.

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RISK FACTORS

Investing in our notes and our common stock potentially issuable upon the conversion of our notes involves a high degree of risk. Before making an investment decision, you should carefully consider the risks described below and in our most recent Annual Report on Form10-K and any subsequent Quarterly Reports on Form10-Q or Current Reports that are filed on Form8-K, as well as any amendments thereto reflected in subsequent filings with the SEC, each of which is incorporated by reference in this prospectus supplement, and all of the other information in this prospectus supplement, including our financial statements and related notes incorporated by reference herein. Our business, financial condition or results of operations could be materially adversely affected by the materialization of any of these risks. The trading price of our common stock could decline due to the materialization of any of these risks, and you may lose all or part of your investment. Additional risks and uncertainties that are not yet identified or that we currently believe to be immaterial may also materially harm our business, financial condition or results of operations and could result in a complete loss of your investment.

Risks Relating to the Notes

The notes will be effectively subordinated to our existing and future secured indebtedness and structurally subordinated to the liabilities of our subsidiaries.

The notes will be our senior, unsecured obligations and will rank equal in right of payment with our existing and future senior, unsecured indebtedness, senior in right of payment to our existing and future indebtedness that is expressly subordinated to the notes and effectively subordinated to our existing and future secured indebtedness, including borrowings under our Loan Agreement, to the extent of the value of the collateral securing that indebtedness. In addition, the notes will be structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables, and (to the extent we are not a holder thereof) preferred equity, if any, of our subsidiaries. As of March 31, 2020, we had $60.0 million principal amount of long-term indebtedness outstanding. In addition, our subsidiaries had $0.3 million of other liabilities (including trade payables, but excluding intercompany obligations and liabilities). After giving effect to this offering (assuming no exercise of the underwriters’ option to purchase additional notes) and the use of proceeds therefrom as described in “Use of Proceeds,” our total outstanding long-term indebtedness would have been $100.0 million, of which $40.0 million would have been secured and $60.0 million would have been unsecured. Additionally, On April 21, 2020, we entered into the U.S. Small Business Administration, or the SBA, Paycheck Protection Program, or PPP, Note with SVB for a loan in the amount of $5.1 million, or the PPP Loan, enabled by the Coronavirus Aid, Relief and Economic Security Act of 2020, or the CARES Act. We received the full amount of the PPP Loan on April 22, 2020. On May 4, 2020, we repaid $0.9 million of the PPP Loan, and we have used the remaining proceeds of $4.2 million to retain employees, maintain payroll and make lease and utility payments in accordance with the relevant terms and conditions of the CARES Act. The indenture governing the notes will not prohibit us or our subsidiaries from incurring additional indebtedness, including senior or secured indebtedness, in the future.

If a bankruptcy, liquidation, dissolution, reorganization or similar proceeding occurs with respect to us, then the holders of any of our secured indebtedness may proceed directly against the assets securing that indebtedness. Accordingly, those assets will not be available to satisfy any outstanding amounts under our unsecured indebtedness, including the notes, unless the secured indebtedness is first paid in full. The remaining assets, if any, would then be allocated pro rata among the holders of our senior, unsecured indebtedness, including the notes. There may be insufficient assets to pay all amounts then due.

If a bankruptcy, liquidation, dissolution, reorganization or similar proceeding occurs with respect to any of our subsidiaries, then we, as a direct or indirect common equity owner of that subsidiary (and, accordingly, holders of our indebtedness, including the notes), will be subject to the prior claims of that subsidiary’s creditors, including trade creditors and preferred equity holders. We may never receive any amounts from that subsidiary to satisfy amounts due under the notes.

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Our indebtedness and liabilities could limit the cash flow available for our operations, expose us to risks that could adversely affect our business, financial condition and results of operations and impair our ability to satisfy our obligations under the notes.

As of March 31, 2020, we had $60.0 million principal amount of long-term indebtedness outstanding. In addition, our subsidiaries had $0.3 million of other liabilities (including trade payables, but excluding intercompany obligations and liabilities). After giving effect to this offering (assuming no exercise of the underwriters’ option to purchase additional notes) and the use of proceeds therefrom as described in “Use of Proceeds,” our total outstanding long-term indebtedness would have been $100.0 million, of which $40.0 million would have been secured and $60.0 million would have been unsecured. Additionally, On April 21, 2020, we entered into the U.S. Small Business Administration, or the SBA, Paycheck Protection Program, or PPP, Note with SVB for a loan in the amount of $5.1 million, or the PPP Loan, enabled by the Coronavirus Aid, Relief and Economic Security Act of 2020, or the CARES Act. We received the full amount of the PPP Loan on April 22, 2020. On May 4, 2020, we repaid $0.9 million of the PPP Loan, and we have used the remaining proceeds of $4.2 million to retain employees, maintain payroll and make lease and utility payments in accordance with the relevant terms and conditions of the CARES Act. We may also incur additional indebtedness to meet future financing needs. Our indebtedness could have significant negative consequences for our security holders and our business, results of operations and financial condition by, among other things:

• increasing our vulnerability to adverse economic and industry conditions;

• limiting our ability to obtain additional financing;

• requiring the dedication of a substantial portion of our cash flow from operations to service our indebtedness, which will reduce the amount of cash available for other purposes;

• limiting our flexibility to plan for, or react to, changes in our business;

• diluting the interests of our existing stockholders as a result of issuing shares of our common stock upon conversion of the notes; and

• placing us at a possible competitive disadvantage with competitors that are less leveraged than us or have better access to capital.

Our business may not generate sufficient funds, and we may otherwise be unable to maintain sufficient cash reserves, to pay amounts due under our indebtedness, including the notes, and our cash needs may increase in the future. In addition, any future indebtedness that we may incur may contain financial and other restrictive covenants that limit our ability to operate our business, raise capital or make payments under our other indebtedness. If we fail to comply with these covenants or to make payments under our indebtedness when due, then we would be in default under that indebtedness, which could, in turn, result in that and our other indebtedness becoming immediately payable in full.

We may be unable to raise the funds necessary to repurchase the notes for cash following a fundamental change and our existing and future indebtedness may limit our ability to repurchase the notes.

Noteholders may require us to repurchase their notes following a fundamental change at a cash repurchase price generally equal to the principal amount of the notes to be repurchased, plus accrued and unpaid interest, if any. See “Description of Notes—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes.” We may not have enough available cash or be able to obtain financing at the time we are required to repurchase the notes. In addition, applicable law, regulatory authorities and the agreements governing our existing and future indebtedness may restrict our ability to repurchase the notes. Our failure to repurchase notes when required will constitute a default under the base and supplemental indentures that will govern the notes, which we refer to collectively as the “indenture”. A default under the indenture or the fundamental change itself could also lead to a default under agreements governing our future indebtedness, which may result in that other indebtedness becoming immediately payable in full. A fundamental change would constitute an event of default under our Loan Agreement. We may not have sufficient funds to satisfy all amounts due under the other indebtedness and the notes.

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Not all dilutive events will result in an adjustment to the conversion rate.

We will adjust the conversion rate of the notes for certain events, including:

• certain stock dividends, splits and combinations;

• the issuance of certain rights, options or warrants to holders of our common stock;

• certain distributions of assets, debt securities, capital stock or other property to holders of our common stock;

• cash dividends on our common stock; and

• certain tender or exchange offers.

See “Description of Notes—Conversion Rights—Conversion Rate Adjustments.” We are not required to adjust the conversion rate for other events, such as an issuance of common stock (or securities exercisable for, or convertible into, common stock) for cash, that may adversely affect the trading price of the notes and our common stock. An event may occur that adversely affects the noteholders and the trading price of the notes and the underlying shares of our common stock but that does not result in an adjustment to the conversion rate.

Not all significant restructuring transactions will constitute a fundamental change, in which case you will not have the right to require us to repurchase your notes for cash.

If certain corporate events called “fundamental changes” occur, you will have the right to require us to repurchase your notes for cash. See “Description of Notes—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes.” However, the definition of “fundamental change” is limited to specific corporate events and does not include all events that may adversely affect our financial condition or the trading price of the notes. For example, a leveraged recapitalization, refinancing, restructuring or acquisition by us may not constitute a fundamental change that would require us to repurchase the notes. Nonetheless, these events could significantly increase the amount of our indebtedness, harm our credit rating or adversely affect our capital structure and the trading price of the notes.

The increase to the conversion rate resulting from a make-whole fundamental change may not adequately compensate noteholders for the lost option value of their notes. In addition, a variety of transactions that do not constitute a make-whole fundamental change may significantly reduce the option value of the notes without a corresponding increase to the conversion rate.

If certain corporate events that constitute a “make-whole fundamental change” occur, then we will, in certain circumstances, temporarily increase the conversion rate. See “Description of Notes—Conversion Rights—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change.” The amount of the increase to the conversion rate will depend on the date on which the make-whole fundamental change becomes effective and the applicable “stock price.” While the increase to the conversion rate is designed to compensate noteholders for the lost option value of their notes resulting from a make-whole fundamental change, the increase is only an approximation and may not adequately compensate noteholders for the loss in option value. In addition, if the applicable “stock price” is greater than $                per share or less than $                per share (in each case, subject to adjustment), then we will not increase the conversion rate for the make-whole fundamental change. Moreover, we will not increase the conversion rate pursuant to these provisions to an amount that exceeds                shares per $1,000 principal amount of notes, subject to adjustment.

Furthermore, the definition of make-whole fundamental change is limited to certain specific transactions. Accordingly, the make-whole fundamental change provisions of the indenture will not protect noteholders from other transactions that could significantly reduce the option value of the notes. For example, aspin-off or sale of a subsidiary or business division with volatile earnings, or a change in our line of business, could significantly affect the trading characteristics of our common stock and reduce the option value of the notes without constituting a make-whole fundamental change that results in a temporary increase to the conversion rate.

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In addition, our obligation to increase the conversion rate in connection with a make-whole fundamental change could be considered a penalty, in which case its enforceability would be subject to general principles of reasonableness and equitable remedies.

There is currently no trading market for the notes. If an active trading market for the notes does not develop, then noteholders may be unable to sell their notes at desired times or prices, or at all.

The notes are a new class of securities for which no market currently exists. We do not intend to apply to list the notes on any securities exchange or for quotation on any inter-dealer quotation system. Although the underwriters have advised us that they intend to make a market in the notes, they are not obligated to do so and may discontinue any market-making activity at any time and without notice. Accordingly, an active market for the notes may never develop, and, even if one develops, it may not be maintained. If an active trading market for the notes does not develop or is not maintained, then the market price and liquidity of the notes will be adversely affected and noteholders may not be able to sell their notes at desired times or prices, or at all.

The liquidity of the trading market, if any, and future trading prices of the notes will depend on many factors, including, among other things, the trading price and volatility of our common stock, prevailing interest rates, our dividend yield, financial condition, results of operations, business, prospects and credit quality relative to our competitors, the market for similar securities and the overall securities market. Many of these factors are beyond our control. Historically, the market for convertible debt has been volatile. Market volatility could significantly harm the market for the notes, regardless of our financial condition, results of operations, business, prospects or credit quality.

The trading price of our common stock, the condition of the financial markets, prevailing interest rates and other factors could significantly affect the trading price of the notes.

We expect that the trading price of our common stock will significantly affect the trading price of the notes, which could result in greater volatility in the trading price of the notes than would be expected fornon-convertible securities. The trading price of our common stock will likely continue to fluctuate in response to the factors described or referred to elsewhere in this section and under the caption “Cautionary Note Regarding Forward-Looking Statements,” among others, many of which are beyond our control.

In addition, the condition of the financial markets and changes in prevailing interest rates can have an adverse effect on the trading price of the notes. For example, prevailing interest rates have fluctuated in the past and are likely to fluctuate in the future, and we would expect an increase in prevailing interest rates to depress the trading price of the notes.

The issuance or sale of shares of our common stock, or rights to acquire shares of our common stock, could depress the trading price of our common stock and the notes.

We may conduct future offerings of our common stock, preferred stock or other securities that are convertible into or exercisable for our common stock to finance our operations or fund acquisitions, or for other purposes. As of March 31, 2020, we had reserved an additional 7,406,314 shares of our common stock, including 95,431 shares to be issued upon the exercise of outstanding warrants and 7,310,883 shares to be issued upon exercise of outstanding options or vesting of restricted stock units or reserved for future issuance under our equity incentive plans. The indenture for the notes will not restrict our ability to issue additional equity securities in the future. If we issue additional shares of our common stock or rights to acquire shares of our common stock, if any of our existing stockholders sells a substantial amount of our common stock, or if the market perceives that such issuances or sales may occur, then the trading price of our common stock, and, accordingly, the notes may significantly decline. In addition, our issuance of additional shares of common stock will dilute the ownership interests of our existing common stockholders, including noteholders who have received shares of our common stock upon conversion of their notes.

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We will make only very limited covenants in the indenture, and these limited covenants may not protect your investment.

Many debt instruments contain provisions that are designed to restrict the borrower’s activities and operations in a manner that is designed to preserve the borrower’s ability to make payments on the related indebtedness when due. These provisions include financial and operating covenants and restrictions on the payments of dividends, the incurrence of indebtedness or the issuance or repurchase of securities by the borrower or any of its subsidiaries. The indenture for the notes will not contain any of these covenants or restrictions or otherwise place any meaningful restrictions on our ability to operate our business as management deems appropriate. As a result, your investment in the notes may not be as protected as an investment in an instrument that contains some or all of these types of covenants and restrictions.

Recent and future regulatory actions, changes in market conditions and other events may adversely affect the trading price and liquidity of the notes and the ability of investors to implement a convertible note arbitrage trading strategy.

We expect that many investors in the notes, including potential purchasers of the notes from investors in this offering, will seek to employ a convertible note arbitrage strategy. Under this strategy, investors typically short sell a certain number of shares of our common stock and adjust their short position over time while they continue to hold the notes. Investors may also implement this type of strategy by entering into swaps on our common stock in lieu of, or in addition to, short selling shares of our common stock.

The SEC and other regulatory authorities have implemented various rules and taken certain actions, and may in the future adopt additional rules and take other actions, that may impact those engaging in short selling activity involving equity securities (including our common stock). These rules and actions include Rule 201 of SEC Regulation SHO, the adoption by the Financial Industry Regulatory Authority, Inc., and the national securities exchanges of a “limitup-limit down” program, the imposition of market-wide circuit breakers that halt trading of securities for certain periods following specific market declines, and the implementation of certain regulatory reforms required by the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010. Any governmental or regulatory action that restricts investors’ ability to effect short sales of our common stock or enter into equity swaps on our common stock could depress the trading price of, and the liquidity of the market for, the notes.

In addition, the liquidity of the market for our common stock and other market conditions could deteriorate, which could reduce, or eliminate entirely, the number of shares available for lending in connection with short sale transactions and the number of counterparties willing to enter into an equity swap on our common stock with a note investor. These and other market events could make implementing a convertible note arbitrage strategy prohibitively expensive or infeasible. If investors in this offering or potential purchasers of the notes that seek to employ a convertible note arbitrage strategy are unable to do so on commercial terms, or at all, then the trading price of, and the liquidity of the market for, the notes may significantly decline.

You may be subject to tax if we adjust, or fail to adjust, the conversion rate of the notes, even though you will not receive a corresponding cash distribution.

We will adjust the conversion rate of the notes for certain events, including the payment of cash dividends. If we adjust the conversion rate as a result of a dividend that is taxable to our common stockholders, such as a cash dividend, then you may be deemed, for U.S. federal income tax purposes, to have received a taxable dividend to the extent of your share of our earnings and profits, without the receipt of any cash. In addition, if we do not adjust (or do not adequately adjust) the conversion rate after an event that increases your proportionate interest in us, then you could be treated as having received a deemed taxable dividend. If a make-whole fundamental change occurs prior to the maturity date, under some circumstances, we will increase the conversion rate for notes converted in connection with that make-whole fundamental change. Such increase may also be treated as a

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distribution subject to U.S. federal income tax as a dividend. If you are anon-U.S. holder (as defined in “Material U.S. Federal Income Tax Considerations”), then any deemed dividend may be subject to U.S. federal withholding tax at a 30% rate, or such lower rate as may be specified by an applicable treaty, which may be withheld from or set off against payments on the notes or our common stock owned by you or from any proceeds of any subsequent sale, exchange, or other disposition, by you, of our notes (including the retirement of such note) or our common stock. The Internal Revenue Service has issued proposed regulations addressing the amount and timing of deemed distributions, obligations of withholding agents and filing and notice obligations of issuers, which, if adopted, could affect the U.S. federal income tax treatment of a holder of notes deemed to receive such a distribution. See “Description of Notes— Conversion Rights—Conversion Rate Adjustments” and “Material U.S. Federal Income Tax Considerations.”

A rating agency may not rate the notes or may assign a rating that is lower than expected.

We do not intend to seek to have the notes rated by any rating agency. However, if one or more rating agencies rate the notes and assign a rating that is lower than the rating that investors expect, or reduce their rating in the future, then the trading price of our common stock and the notes could significantly decline.

In addition, market perceptions of our creditworthiness will directly affect the trading price of the notes. Accordingly, if a ratings agency rates any of our indebtedness in the future or downgrades or withdraws the rating, or puts us on credit watch, then the trading price of the notes will likely decline.

Provisions in the indenture could delay or prevent an otherwise beneficial takeover of us.

Certain provisions in the notes and the indenture could make a third-party attempt to acquire us more difficult or expensive. For example, if a takeover constitutes a fundamental change, then noteholders will have the right to require us to repurchase their notes for cash. In addition, if a takeover constitutes a make-whole fundamental change, then we may be required to temporarily increase the conversion rate. In either case, and in other cases, our obligations under the notes and the indenture could increase the cost of acquiring us or otherwise discourage a third party from acquiring us or removing incumbent management, including in a transaction that noteholders or holders of our common stock may view as favorable.

Your investment in the notes may be harmed if we redeem the notes.

We will have the right to redeem notes in certain circumstances on or after July 20, 2023. See “Description of Notes—Optional Redemption.” If we redeem your notes, then you may not be entitled to benefit from potential future appreciation in the trading price of our common stock, and you may be unable to reinvest any proceeds from the redemption in comparable investments at favorable interest rates.

Our management may spend the proceeds of this offering and, if completed, the Concurrent Common Stock Offering, in ways with which you may disagree or that may not be profitable.

We currently intend to use the net proceeds from this offering and, if completed, the Concurrent Common Stock Offering, primarily (i) to fund sales and marketing costs to support commercialization of Gvoke; (ii) to repay $20.0 million of the borrowings under our Loan Agreement; (iii) to fund research and development activities relating to the advancement of our product candidates; (iv) for expansion of our technology or manufacturing infrastructure and capabilities; (v) for potential strategic acquisitions of complementary businesses, assets, services or technologies; and (vi) the remainder for working capital, capital expenditures, and other general corporate purposes. However, our management will have broad discretion to apply the net proceeds, and investors will rely on our management’s judgment in spending the net proceeds. Our management may use the proceeds in ways that do not earn a profit or otherwise result in the creation of stockholder value. In addition, pending our use of the proceeds, we may invest the proceeds primarily in instruments that do not produce significant income or that may lose value.

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Because the notes will initially be held in book-entry form, noteholders must rely on DTC’s procedures to receive communications relating to the notes and exercise their rights and remedies.

We will initially issue the notes in the form of one or more “global notes” registered in the name of Cede & Co., as nominee of DTC. Beneficial interests in global notes will be shown on, and transfers of global notes will be effected only through, the records maintained by DTC. Except in limited circumstances, we will not issue certificated notes. See “Description of Notes—Book Entry, Settlement and Clearance.” Accordingly, if you own a beneficial interest in a global note, then you will not be considered an owner or holder of the notes. Instead, DTC or its nominee will be the sole holder of the notes. Payments of principal, interest and other amounts on global notes will be made to the paying agent, who will remit the payments to DTC. We expect that DTC will then credit those payments to the DTC participant accounts that hold book-entry interests in the global notes and that those participants will credit the payments to indirect DTC participants. Unlike persons who have certificated notes registered in their names, owners of beneficial interests in global notes will not have the direct right to act on our solicitations for consents or requests for waivers or other actions from noteholders. Instead, those beneficial owners will be permitted to act only to the extent that they have received appropriate proxies to do so from DTC or, if applicable, a DTC participant. The applicable procedures for the granting of these proxies may not be sufficient to enable owners of beneficial interests in global notes to vote on any requested actions on a timely basis. In addition, notices and other communications relating to the notes (including any notice of redemption) will be sent to DTC. We expect DTC will forward any such communications to DTC participants, which in turn would forward such communications to indirect DTC participants, but we can make no assurances that you will timely receive any such communications.

Holding notes will not, in itself, confer any rights with respect to our common stock.

Noteholders will generally not be entitled to any rights with respect to our common stock (including voting rights and rights to receive any dividends or other distributions on our common stock). However, noteholders will be subject to all changes affecting our common stock to the extent the trading price of the notes depends on the market price of our common stock and to the extent they receive shares of our common stock upon conversion of their notes. For example, if we propose an amendment to our charter documents that requires stockholder approval, then a noteholder will not, as such, be entitled to vote on the amendment, although the noteholder will be subject to any changes implemented by that amendment in the powers, preferences or special rights of our common stock.

Risks Related to Our Concurrent Common Stock Offering and Our Common Stock

Our stock price has been and will likely continue to be volatile, and you may not be able to resell shares of our common stock at or above the price you paid.

The trading price of our common stock historically has been highly volatile and could continue to be subject to large fluctuations in response to various factors. The market price of our common stock has varied between a high price of $27.98 on September 12, 2018 and a low price of $1.42 on March 19, 2020. This volatility may affect the price at which you could sell the shares of our common stock, and the sale of substantial amounts of our common stock could adversely affect the price of our common stock. Our stock price is likely to continue to be volatile and subject to significant price and volume fluctuations in response to market and other factors, including:

• our ability to successfully commercialize Gvoke;

• regulatory actions with respect to our products and product candidates;

• regulatory actions with respect to our competitors’ products and product candidates;

• the success of existing or new competitive products or technologies;

• results of clinical trials of product candidates of our competitors;

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• announcements by us or our competitors of significant acquisitions, strategic partnerships, joint ventures, collaborations or capital commitments;

• the timing and results of clinical trials of our pipeline product candidates;

• commencement or termination of collaborations for our development programs;

• the results of our efforts to develop additional product candidates or products;

• the level of expenses related to any of our product candidates or clinical development programs;

• failure or discontinuation of any of our development programs;

• the pricing and reimbursement of Gvoke as well as any of our product candidates that may be approved;

• regulatory or legal developments in the United States and other countries;

• developments or disputes concerning patent applications, issued patents or other proprietary rights;

• the recruitment or departure of key personnel;

• actual or anticipated changes in estimates as to financial results or development timelines;

• announcement or expectation of additional financing efforts;

• sales of our common stock by us, our insiders or other stockholders;

• variations in our financial results or those of companies that are perceived to be similar to us;

• changes in estimates or recommendations by securities analysts, if any, that cover our stock;

• changes in the structure of healthcare payment systems;

• market conditions in the pharmaceutical and biotechnology sectors;

• general economic, industry and market conditions;

• global health concerns, such as theCOVID-19 pandemic; and

• the other factors described in this “Risk Factors” section.

In recent years, the stock markets, and particularly the stock of smaller pharmaceutical and biotechnology companies, at times have experienced price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of affected companies. Broad market and industry factors may significantly affect the market price of our common stock unrelated to our actual operating performance. Since shares of our common stock were sold in our IPO in June 2018 at a price of $15.00 per share, our stock price has fluctuated significantly.

In addition, in the past, class action litigation has often been instituted against companies whose securities have experienced periods of volatility in market price. Securities litigation brought against us following volatility in our stock price, regardless of the merit or ultimate results of such litigation, could result in substantial costs, which would hurt our financial condition and operating results and divert management’s attention and resources from our business.

This offering is not conditioned on the consummation of any other financing, including the Concurrent Common Stock Offering.

We currently intend to use the net proceeds of this offering, together with the proceeds from the Concurrent Common Stock Offering, as described in “Use of Proceeds” herein. However, neither the completion of this offering nor of the Concurrent Common Stock Offering is contingent on the completion of the other, so it is

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possible that this offering occurs and the Concurrent Common Stock Offering does not occur, and vice versa. This prospectus supplement is not an offer to sell or a solicitation of an offer to buy any securities being offered in the Concurrent Common Stock Offering. We cannot assure you that the Concurrent Common Stock Offering will be completed on the terms described herein, or at all.

The Concurrent Common Stock Offering and any future sales and issuances of our common stock, equity-linked securities or rights to purchase common stock, including, pursuant to our equity incentive plans, as a result of the issuance of the notes offered hereby or any additional equity-linked securities or the conversion of any existing equity-linked securities, including the notes offered hereby, could result in additional dilution of the percentage ownership of our stockholders and could cause our stock price to fall.

Additional capital will be needed in the future to continue our planned operations. To the extent we raise additional capital by issuing equity securities or equity-linked securities, our stockholders may experience substantial dilution. We may sell common stock, convertible securities or other equity-linked securities in one or more transactions at prices and in a manner we determine from time to time. If we sell common stock, convertible securities or other equity-linked securities in more than one transaction, investors may be materially diluted by subsequent sales. These sales may also result in material dilution to our existing stockholders, and new investors could gain rights superior to our existing stockholders. The conversion of some or all of the notes offered hereby will dilute ownership interests of existing stockholders.

In addition, sales of a substantial number of shares of our outstanding common stock in the public market could occur at any time. These sales, or the perception in the market that the holders of a large number of shares of common stock intend to sell shares, could reduce the market price of our common stock. Persons who were our stockholders prior to our IPO continue to hold a substantial number of shares of our common stock that many of them are now able to sell in the public market. Significant portions of these shares are held by a relatively small number of stockholders. Sales by our stockholders of a substantial number of shares, or the expectation that such sales may occur, could significantly reduce the market price of our common stock.

In addition, holders of an aggregate of approximately 683,221 shares of our common stock are entitled, subject to some conditions, to require us to file registration statements covering their shares or to include their shares in registration statements that we may file for ourselves or other stockholders.

We have registered the shares of common stock issuable upon exercise or settlement of all equity awards issued or reserved for issuance under our 2018 Stock Option and Incentive Plan, 2018 Employee Stock Purchase Plan and our Inducement Equity Plan under a Registration Statement on FormS-8. These shares can be freely sold in the public market upon issuance and once vested, subject to thelock-up agreements described above and Rule 144 in the case of our affiliates.

We are an “emerging growth company” and a “smaller reporting company,” and the reduced disclosure requirements applicable to “emerging growth companies” and “smaller reporting companies” may make our common stock less attractive to investors.

We are an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act, and we have elected to take advantage of certain exemptions and relief from various reporting requirements that are applicable to other public companies that are not “emerging growth companies.” In particular, while we are an “emerging growth company,” (i) we will not be required to comply with the auditor attestation requirements of Section 404(b) of the Sarbanes-Oxley Act, (ii) we will be exempt from any rules that may be adopted by the Public Company Accounting Oversight Board requiring mandatory audit firm rotations or a supplement to the auditor’s report on financial statements, (iii) we will be subject to reduced disclosure obligations regarding executive compensation in our periodic reports and proxy statements and (iv) we will not be required to hold nonbinding advisory votes on executive compensation or stockholder approval of any golden parachute payments not previously approved.

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As a result, our public filings may not be comparable to companies that are not “emerging growth companies”. We may remain an “emerging growth company” until the fiscalyear-end following the fifth anniversary of the completion of our IPO, though we may cease to be an “emerging growth company” earlier under certain circumstances, including (i) if the market value of our common stock that is held bynon-affiliates exceeds $700 million as of any June 30, in which case we would cease to be an “emerging growth company” as of the following January 1, (ii) the date on which we have issued more than $1.0 billion innon-convertible debt during the previous three years, or (iii) if our gross revenue exceeds $1.07 billion in any fiscal year.

In addition, the JOBS Act provides that an emerging growth company can take advantage of an extended transition period for complying with new or revised accounting standards. This allows an emerging growth company to delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. In addition, we qualify as a “smaller reporting company,” which allows us to take advantage of many of the same exemptions from disclosure requirements, including not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act and reduced disclosure obligations regarding executive compensation in our periodic reports and proxy statements. Even after we no longer qualify as an “emerging growth company,” we may still qualify as a “smaller reporting company” if the market value of our common stock that is held by nonaffiliates is below $250 million (or $700 million if our annual revenue is less than $100 million) as of June 30 in any given year, which would allow us to continue to take advantage of these exemptions.

Investors may find our common stock less attractive if we rely on these exemptions and relief granted by the JOBS Act. If some investors find our common stock less attractive as a result, there may be a less active trading market for our common stock and our stock price may decline and/or become more volatile.

We do not anticipate paying any cash dividends in the foreseeable future, and accordingly, our stockholders’ ability to achieve a return on their investment will depend on appreciation in the price of our common stock.

We do not anticipate declaring any cash dividends to holders of our common stock in the foreseeable future. In addition, under our Loan Agreement, we are restricted from paying any dividends or making any distributions on account of our capital stock. Our ability to pay cash dividends also may be prohibited by future loan agreements. Consequently, investors must rely on sales of their common stock after price appreciation, which may never occur, as the only way to realize any future gains on their investment. Investors seeking cash dividends should not invest in our common stock.

We might not be able to utilize a significant portion of our net operating loss carryforwards and research and development tax credit carryforwards.

As of December 31, 2019, we had federal net operating loss carryforwards of $215.3 million and various state net operating loss carryforwards of $147.5 million. If not utilized, the federal net operating losses generated in taxable years beginning on or before December 31, 2017 will expire at various dates between 2025 and 2037 and these net operating loss carryforwards could expire unused and be unavailable to offset future income tax liabilities. Federal net operating losses generated in taxable years beginning after December 31, 2017 can be carried forward indefinitely; however, such net operating losses may only offset up to 80% of taxable income in taxable years beginning after December 31, 2020. As of December 31, 2019, we had $8.3 million and $1.0 million of federal and state income tax credits, respectively, to reduce future tax liabilities. If not utilized, these carryforwards will expire at various dates between 2025 and 2038 and these tax credit carryforwards could expire unused and be unavailable to offset future income tax liabilities. In addition, under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, or the Code, and corresponding provisions of state law, if a corporation undergoes an “ownership change,” which is generally defined as a greater than 50% change, by value, in its equity ownership over a three-year period, the corporation’s ability to use itspre-change net operating loss carryforwards and otherpre-change tax attributes to offset its post-change income may be limited.

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Our existing net operating losses or credits may be subject to limitations arising from previous ownership changes, and if we undergo future ownership changes, many of which may be outside of our control, our ability to utilize our net operating losses or credits could be further limited by Sections 382 and 383 of the Code. Accordingly, we may not be able to utilize a material portion of our net operating losses or credits.

Provisions in our corporate charter documents and under Delaware law may prevent or frustrate attempts by our stockholders to change our management or hinder efforts to acquire a controlling interest in us.

Provisions in our corporate charter and our bylaws may discourage, delay or prevent a merger, acquisition or other change in control of us that stockholders may consider favorable, including transactions in which you might otherwise receive a premium for your shares. These provisions could also limit the price that investors might be willing to pay in the future for shares of our common stock, thereby depressing the market price of our common stock. In addition, because our board of directors is responsible for appointing the members of our management team, these provisions may frustrate or prevent any attempts by our stockholders to replace or remove our current management by making it more difficult for stockholders to replace members of our board of directors. Among other things, these provisions:

• establish a classified board of directors such that all members of the board are not elected at one time; allow the authorized number of our directors to be changed only by resolution of our board of directors; and limit the manner in which stockholders can remove directors from the board;

• establish advance notice requirements for nominations for election to the board of directors or for proposing matters that can be acted on at stockholder meetings;

• require that stockholder actions must be effected at a duly called stockholder meeting and prohibit actions by our stockholders by written consent;

• limit who may call a special meeting of stockholders;

• authorize our board of directors to issue preferred stock without stockholder approval, which could be used to institute a “poison pill” that would work to dilute the stock ownership of a potential hostile acquirer, effectively preventing acquisitions that have not been approved by our board of directors;

• require the approval of the holders of at leasttwo-thirds of the votes that all our stockholders would be entitled to cast to amend or repeal certain provisions of our charter or bylaws; and

• provide that the Court of Chancery of the State of Delaware will be the exclusive forum for any state law derivative action or proceeding brought on our behalf, any action asserting a breach of fiduciary duty by one or more of our directors, officers or employees, any action asserting a claim against us pursuant to the Delaware General Corporation Law, or any action asserting a claim against us that is governed by the internal affairs doctrine, and that the United States District Court for the District of Illinois will be the exclusive forum for claims arising under the Securities Act of 1933, as amended.

Moreover, because we are incorporated in Delaware, we are governed by the provisions of Section 203 of the General Corporation Law of the State of Delaware, which prohibits a person who owns in excess of 15% of our outstanding voting stock from merging or combining with us for a period of three years after the date of the transaction in which the person acquired in excess of 15% of our outstanding voting stock, unless the merger or combination is approved in a prescribed manner. This could discourage, delay or prevent someone from acquiring us or merging with us, whether or not it is desired by, or beneficial to, our stockholders. This could also have the effect of discouraging others from making tender offers for our common stock, including transactions that may be in our stockholders’ best interests. These provisions may also prevent changes in our management or limit the price that investors are willing to pay for our stock.

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Our bylaws designate certain courts as the sole and exclusive forums for certain types of actions and proceedings that may be initiated by our stockholders, which could limit our stockholders’ ability to obtain a favorable judicial forum for disputes with us or our directors, officers or employees and may discourage such lawsuits with respect to such claims.

Our amended and restated bylaws provide that, unless we consent in writing to an alternative forum, the Court of Chancery of the State of Delaware will be the sole and exclusive forum for any state law claim for (i) any derivative action or proceeding brought on our behalf, (ii) any action asserting a claim of breach of or based on a fiduciary duty owed by any of our directors, officers and employees to us or our stockholders, (iii) any action asserting a claim arising pursuant to any provision of the Delaware General Corporation Law, our certificate of incorporation or our bylaws, or (iv) any action asserting a claim that is governed by the internal affairs doctrine, in each case subject to the Court of Chancery having personal jurisdiction over the indispensable parties named as defendants therein (the “Delaware Forum Provision”). The Delaware Forum Provision will not apply to any causes of action arising under the Securities Act of 1933, as amended (the “Securities Act”) or the Securities Exchange Act of 1934. In addition, our amended and restated bylaws further provide that the United States District Court for the Northern District of Illinois will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act (the “Federal Forum Provision”). We have chosen the United States District Court for the Northern District of Illinois as the exclusive forum for Securities Act causes of action because our principal executive offices are located in Chicago, Illinois. Our amended and restated bylaws also provide that any person or entity purchasing or otherwise acquiring any interest in shares of our common stock is deemed to have notice of and consented to the Delaware Forum Provision and the Federal Forum Provision.

On December 19, 2018, inSciabacucchi v. Salzberg, C.A. No.2017-0931-JTL (Del. Ch.), the Delaware Court of Chancery issued a decision declaring that federal forum selection provisions purporting to require claims under the Securities Act be brought in federal court are ineffective and invalid under Delaware law. However, that decision was appealed to the Delaware Supreme Court and on March 18, 2020, the Delaware Supreme Court reversed the Court of Chancery and ruled that such federal forum selection provisions are “facially valid” under Delaware law. In light of the Delaware Supreme Court’s ruling, we intend to enforce our Federal Forum Provision designating the Northern District of Illinois as the exclusive forum for Securities Act claims.

We also recognize that the Delaware Forum Provision and the Federal Forum Provision in our bylaws may impose additional litigation costs on stockholders in pursuing any such claims, particularly if the stockholders do not reside in or near the State of Delaware or the Northern District of Illinois. Additionally, the Delaware Forum Provision and/or the Federal Forum Provision may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or our directors, officers or employees, which may discourage such lawsuits against us and our directors, officers and employees even though an action, if successful, might benefit our stockholders. The Federal Forum Provision may also impose additional litigation costs on stockholders who assert the provision is not enforceable. The Court of Chancery of the State of Delaware or the United States District Court for the Northern District of Illinois may also reach different judgments or results than would other courts, including courts where a stockholder considering an action may be located or would otherwise choose to bring the action, and such judgments or results may be more favorable to us than to our stockholders.

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USE OF PROCEEDS

We estimate that the net proceeds from this offering, after deducting underwriting discounts and commissions and estimated offering expenses payable by us, will be approximately $56.3 million, or $64.9 million if the underwriters exercise in full their option to purchase additional notes.

In addition, cconcurrently with this offering of notes, we are offering $20.0 million of our common stock (or $23.0 million if the underwriters in that offering exercise their over-allotment option to purchase additional shares in full) in an underwritten offering pursuant to a separate prospectus supplement, or the Concurrent Common Stock Offering. We estimate that the net proceeds to us from the Concurrent Common Stock Offering, after deducting underwriting discounts and commissions and estimated expenses payable by us, will be approximately $18.6 million (or approximately $21.4 million if the underwriters in the Concurrent Common Stock Offering exercise in full their over-allotment option to purchase additional shares).

The principal purpose of this offering of notes and, if completed, the Concurrent Common Stock Offering, is to obtain additional capital to support our operations. We expect to use the net proceeds of this offering and, if completed, the Concurrent Common Stock Offering, in addition to our existing cash resources, as follows:

• to fund sales and marketing costs to support commercialization of Gvoke;

• to repay $20.0 million of the borrowings under our Loan Agreement;

• to fund research and development activities relating to the advancement of our product candidates;

• for expansion of our technology or manufacturing infrastructure and capabilities;

• for potential strategic acquisitions of complementary businesses, assets, services or technologies; and

• the remainder for working capital, capital expenditures, and other general corporate purposes.

Our Loan Agreement, which is scheduled to mature on June 1, 2023, or June 1, 2024 upon effectiveness of the Loan Agreement Amendment, generally bears interest at a floating per annum rate in an amount equal to the sum of 6.25% plus the greater of (a) 2.43% and (b) thethirty-day U.S. Dollar LIBOR rate. As of June 23, 2020, the actual interest rate on borrowings under our Loan Agreement was 8.68%.

An affiliate of SVB Leerink LLC is a lender under our Loan Agreement and may receive a portion of the net proceeds of this offering. See “Underwriting (Conflicts of Interest)” on pageS-74 of this prospectus supplement.

Our expected use of net proceeds from this offering of notes and, if completed, the Concurrent Common Stock Offering, is based on our current plans and business conditions, which could change in the future as our plans and business conditions evolve. The amounts and timing of our actual expenditures may vary significantly depending on numerous factors, including the progress of our commercialization and development activities, feedback from regulatory authorities, the status of and results from clinical trials, any collaborations that we may enter into with third parties for our drug candidates, and any unforeseen cash needs. As of the date of this prospectus supplement, we cannot specify with certainty all of the particular uses for the remaining net proceeds to us from this offering of notes and, if completed, the Concurrent Common Stock Offering. Accordingly, our management will retain broad discretion over the allocation of the net proceeds from this offering of notes and, if completed, the Concurrent Common Stock Offering. We may find it necessary or advisable to use the net proceeds from this offering of notes for other purposes, and we will have broad discretion in the application of net proceeds.

Neither the completion of this offering nor of the Concurrent Common Stock Offering is contingent on the completion of the other, so it is possible that this offering occurs and the Concurrent Common Stock Offering does not occur, and vice versa. This prospectus supplement is not an offer to sell or a solicitation of an offer to buy any securities being offered in the Concurrent Common Stock Offering. We cannot assure you that the Concurrent Common Stock Offering will be completed on the terms described herein, or at all. If this offering occurs, but the Concurrent Common Stock Offering does not, we will use the proceeds of this offering for working capital and other general corporate purposes.

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Pending use of the proceeds as described above, we intend to invest the proceeds in a variety of capital preservation instruments, including high quality, investment grade instruments, certificates of deposit or direct or guaranteed obligations of the U.S. government, or may hold such proceeds as cash, in a manner that permits us to maintain our exemption from registration under the Investment Company Act of 1940, as amended, until they are used for their stated purpose.

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DIVIDEND POLICY

We have not declared or paid any cash dividends on our capital stock since our inception. We currently intend to retain all of our future earnings, if any, to finance the growth and development of our business. We do not intend to pay cash dividends to our stockholders in the foreseeable future. Payment of future dividends, if any, will be at the discretion of our board of directors and will depend on our financial condition, results of operations, capital requirements, restrictions contained in current or future financing instruments, provisions of applicable law and other factors the board deems relevant.

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CAPITALIZATION

The following table sets forth our cash, cash equivalents, investments and capitalization as of March 31, 2020:

• on an actual basis;

• on an as adjusted basis to give effect to (i) the sale of $60.0 million aggregate principal amount of notes by us in this offering (assuming the underwriters do not exercise their over-allotment option to purchase additional notes), after deducting the underwriters’ discounts and commissions and our estimated offering expenses, (ii) the use of $20.0 million of the net proceeds from this offering to repay a portion of our borrowings under our Loan Agreement as described in “Use of Proceeds” and (iii) assuming the remaining net proceeds are held as cash or cash equivalents; and

• on an as further adjusted basis to give effect to the sale of 3,703,703 shares of common stock by us in the Concurrent Common Stock Offering (assuming the underwriters in the Concurrent Common Stock Offering do not exercise their option to purchase additional shares of common stock), based on an assumed public offering price of $5.40 per share (the last reported sale price of our common stock on the Nasdaq Global Select Market on June 22, 2020), and after deducting the underwriting discounts and commissions and estimated offering expenses payable by us and assuming the net proceeds from the Concurrent Common Stock Offering are held as cash or cash equivalents.

You should read this table in conjunction with “Use of Proceeds” as well as our “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and our consolidated financial statements, including the related notes, incorporated by reference into this prospectus supplement and the accompanying prospectus from our annual report onForm 10-K for the fiscal year ended December 31, 2019 and our Quarterly Report on Form10-Q for the three months ended March 31, 2020.

	As of March 31, 2020
	Actual			As Adjusted	As Further Adjusted for the Concurrent Common Stock Offering
	(unaudited) (in thousands of dollars)
Cash and cash equivalents	$	39,244		$	$
Short-term investments		57,698
Long-term investments		2,992
Long-term debt, net of unamortized deferred costs
Loan Agreement		58,485
% convertible senior notes due 2025 offered hereby, net of unamortized costs		—
Total long-term debt, net of unamortized deferred costs(1)		58,485
Stockholders’ equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized and no shares issued and outstanding as of March 31, 2020		—
Common stock—par value $0.0001, 150,000,000 shares authorized as of March 31, 2020; 37,541,037 shares issued and outstanding as of March 31, 2020, actual and as adjusted, 41,244,740 shares issued and outstanding as further adjusted(2)		4
Additional paid in capital		302,434
Accumulated deficit		(275,429	)
Accumulated other comprehensive gain		60
Total stockholders’ equity		27,069
Total capitalization	$	85,554		$	$

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Each $0.25 increase in the assumed public offering price of $5.40 per share (the last reported sale price of our common stock on the Nasdaq Global Select Market on June 22, 2020) in the Concurrent Common Stock Offering would decrease the number of shares of common stock to be issued by us in the Concurrent Common Stock Offering by approximately 163,880 shares, assuming we do not change the aggregate dollar amount of shares offered by us in the Concurrent Common Stock Offering. Each $0.25 decrease in the assumed public offering price of $5.40 per share (the last reported sale price of our common stock on the Nasdaq Global Select Market on June 22, 2020) in the Concurrent Common Stock Offering would increase the number of shares of common stock to be issued by us in the Concurrent Common Stock Offering by approximately 179,792 shares, assuming we do not change the aggregate dollar amount of shares offered by us in the Concurrent Common Stock Offering. We may also increase or decrease the aggregate dollar amount of shares we are offering in the Concurrent Common Stock Offering. The as adjusted and as further adjusted information above is illustrative only, and will be adjusted based on the actual public offering price and other terms of this offering and the Concurrent Common Stock Offering determined at pricing.

(1) The actual, as adjusted and as further adjusted long-term debt, net of unamortized deferred costs does not reflect the $4.2 million PPP Loan currently outstanding as this PPP Loan was entered into in April 2020.

(2) The number of shares issued and outstanding in the actual, as adjusted and as further adjusted for the Concurrent Common Stock Offering columns in the table above excludes:

• 2,187,555 shares of common stock issuable upon exercise of options issued under our 2011 Stock Option/Stock Issuance Plan at a weighted-average exercise price of $4.46 per share;

• 2,854,831 shares of common stock issuable upon exercise of options issued under our 2018 Stock Option and Incentive Plan and Inducement Equity Plan at a weighted-average exercise price of $12.41 per share;

• 661,250 shares of common stock issuable upon vesting of restricted stock units;

• 21,148 shares of unvested restricted stock;

• 1,419 shares of common stock issuable upon the exercise of warrants to purchase common stock at an exercise price of $5.91 per share and 94,012 shares of common stock issuable upon the exercise of warrants to purchase common stock at an exercise price of $11.17 per share;

• 676,777 shares of common stock reserved for issuance under our 2018 Stock Option and Incentive Plan;

• 600,470 shares of common stock reserved for future issuance under our 2018 Employee Stock Purchase Plan;

• 330,000 shares of common stock reserved for future issuance under our Inducement Equity Plan; and

• shares of common stock reserved for issuance upon conversion of the notes.

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DESCRIPTION OF NOTES

We will issue the notes under an indenture and a supplemental indenture (together, the “indenture”), each to be dated as of the initial closing date of this offering and between us and U.S. Bank National Association, as trustee (the “trustee”).

The following is a summary of certain provisions of the notes and the indenture. It is only a summary and is not complete. We qualify this summary by referring you to the indenture and the notes, because they, and not this summary, define your rights as a holder of the notes. We will provide you with a copy of the indenture, which includes the form of the notes, as provided under the caption “Where You Can Find Additional Information.”

In addition, the indenture and the notes will be deemed to include certain terms that are made a part of the indenture and the notes pursuant to the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”).

Certain terms used in this summary are defined below under the caption “—Definitions.” Certain other terms used in this summary are defined in the indenture.

This “Description of Notes” section supplements and, to the extent inconsistent therewith, supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities.”

References to “we,” “us” and “our” in this section refer to Xeris Pharmaceuticals, Inc. only and not to any of its subsidiaries. References to any “note” in this section refer to any authorized denomination of a note, unless the context requires otherwise.

Generally

The notes will:

• be our senior, unsecured obligations;

• initially be limited to an aggregate principal amount of $60,000,000 (or $69,000,000, if the underwriters fully exercise their option to purchase additional notes);

• bear interest from, and including,                    , 2020, at an annual rate of    %, payable semi-annually in arrears on January 15 and July 15 of each year, beginning on January 15, 2021;

• bear special interest in the circumstances described below under the caption “Events of Default—Special Interest as Sole Remedy for Certain Reporting Defaults”;

• mature on July 15, 2025, unless earlier repurchased, redeemed or converted;

• be redeemable, in whole and not in part, at our option, in the circumstances and at the times, and at the redemption price, described below under the caption “—Optional Redemption”;

• be subject to repurchase by us at the noteholders’ option if a “fundamental change” (as defined below under the caption “—Definitions”) occurs, at a cash repurchase price equal to the principal amount of the notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date (subject to the right of noteholders on a regular record date to receive the related interest payment), as described, and subject to the limited exception set forth, below under the caption “—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes”;

• be convertible, at the noteholders’ option, into shares of our common stock (together with cash in lieu of any fractional share, if applicable), at an initial conversion rate of                shares per $1,000 principal amount of notes (which represents an initial conversion price of approximately $    per share), under the conditions, and subject to the adjustments, described below under the caption “—Conversion Rights”;

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• be issued in principal amount denominations of $1,000 or any integral multiple of $1,000 in excess thereof, which we refer to as an “authorized denomination”; and

• initially be represented by one or more registered notes in global form, but may, in certain circumstances, be exchanged for notes in definitive form, as described below under the caption “—Book Entry, Settlement and Clearance.”

The indenture will not contain any financial covenants and will not limit us or our subsidiaries from incurring additional indebtedness, paying dividends or issuing or repurchasing any securities. Except to the extent described below under the captions “—Conversion Rights—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change,” “—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes” and “—Consolidation, Merger and Asset Sale,” the indenture will not contain any provisions designed to protect noteholders upon a highly leveraged transaction involving us or a decline in our credit rating as a result of a recapitalization, takeover, highly leveraged transaction or other restructuring involving us.

You will not be entitled to receive any shares of our common stock otherwise deliverable upon conversion of the notes to the extent, but only to the extent, that such receipt would cause you to become, directly or indirectly, a “beneficial owner” of shares of our common stock in excess of the beneficial ownership limits applicable to you at such time.

Without the consent of any noteholder, we may issue additional notes under the indenture with the same terms as the notes we are offering (except for certain differences, such as the date as of which interest begins to accrue and the first interest payment date for such additional notes). However, such additional notes must be identified by a separate CUSIP number or by no CUSIP number if they are not fungible, for federal income tax or federal securities laws purposes, with other notes we issue under the indenture.

We do not intend to list the notes on any securities exchange or include them in any automated inter-dealer quotation system.

Absent manifest error, a person in whose name a note is registered on the registrar’s books will be considered to be the holder of that note for all purposes, and only registered noteholders (which, in the case of notes held through DTC, will initially be DTC’s nominee, Cede & Co.) will have rights under the indenture as noteholders.

Subject to applicable law, we or our subsidiaries may directly or indirectly repurchase notes in the open market or otherwise, whether through private or public tender or exchange offers, cash-settled swaps or other cash-settled derivatives. The indenture requires us to promptly deliver to the trustee for cancellation all notes that we or our subsidiaries have purchased or otherwise acquired.

Payments on the Notes

For purposes of the notes, the description below under this section titled “—Payments on the Notes” supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities—Payment and Paying Agents.”

We will pay (or cause the paying agent to pay) the principal of, and interest on, any global note by wire transfer of immediately available funds. We will pay (or cause the paying agent to pay) the principal of, and interest on, any physical note as follows:

• if the principal amount of such note is at least $1.0 million (or such lower amount as we may choose in our sole and absolute discretion) and the holder of such note entitled to such payment has delivered to the paying agent or the trustee, no later than the time set forth below, a written request to receive payment by wire transfer to an account of such holder within the United States, by wire transfer of immediately available funds to such account; and

• in all other cases, by check mailed to the address of such holder set forth in the note register.

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To be timely, a written request referred to in the first bullet point above must be delivered no later than the “close of business” (as defined below under the caption “—Definitions”) on the following date: (i) with respect to the payment of any interest due on an interest payment date, the immediately preceding regular record date; and (ii) with respect to any other payment, the date that is 15 calendar days immediately before the date such payment is due.

If the due date for a payment on a note is not a “business day” (as defined below under the caption “—Definitions”), then such payment may be made on the immediately following business day and no interest will accrue on such payment as a result of the related delay.

Registrar, Paying Agent and Conversion Agent

We will maintain one or more offices or agencies in the continental United States where notes may be presented for registration of transfer or for exchange, payment and conversion, which we refer to as the “registrar,” “paying agent” and “conversion agent,” respectively. We have appointed the trustee as the initial registrar, paying agent and conversion agent and its office in the United States as a place where notes may be presented for payment. However, we may change the registrar, paying agent and conversion agent, and we or any of our subsidiaries may choose to act in that capacity as well, without prior notice to the noteholders.

Transfers and Exchanges

For purposes of the notes, the description below under this section titled “—Transfers and Exchanges” supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities—Form, Exchange and Transfer.”

A noteholder may transfer or exchange its notes at the office of the registrar in accordance with the indenture. We, the trustee and the registrar may require the noteholder to, among other things, deliver appropriate endorsements or transfer instruments, and such certificates or other documentation or evidence as we or they may reasonably require to determine that such transfer or exchange complies with applicable securities laws. In addition, we, the trustee and the registrar may refuse to register the transfer or exchange of any note that is subject to conversion, redemption or required repurchase.

We have appointed the trustee’s office in the United States as a place where notes may be presented for registration of transfer or for exchange. However, we may change the registrar or act as the registrar ourselves without prior notice to the noteholders.

Interest

The notes will bear cash interest at an annual rate of    %, payable semi-annually in arrears on January 15 and July 15 of each year, beginning on January 15, 2021, to the noteholders of record of the notes as of the close of business on the immediately preceding January 1 and July 1, respectively. Interest will accrue from, and including, the last date to which interest has been paid or duly provided for (or, if no interest has been paid or duly provided for, from, and including, the date the notes are initially issued) to, but excluding, the next interest payment date. Interest will be computed on the basis of a360-day year comprised of twelve30-day months.

In addition to the stated interest on the notes referred to above, special interest will accrue on the notes in the circumstances described below under the caption “—Events of Default—Special Interest as Sole Remedy for Certain Reporting Defaults.” All references in this prospectus supplement to interest on the notes include any special interest payable on the notes, unless the context requires otherwise.

Ranking

The notes will be our senior, unsecured obligations and will be:

• equal in right of payment with our existing and future senior, unsecured indebtedness;

• senior in right of payment to our existing and future indebtedness that is expressly subordinated to the notes;

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• effectively subordinated to our existing and future secured indebtedness, including borrowings under our Loan Agreement, to the extent of the value of the collateral securing that indebtedness; and

• structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables, and (to the extent we are not a holder thereof) preferred equity, if any, of our subsidiaries.

The indenture will not prohibit us from incurring additional indebtedness, including secured indebtedness, which would be effectively senior to the notes to the extent of the value of the collateral securing that indebtedness, or indebtedness that would rank equal in right of payment with the notes. The indenture will also not prohibit our subsidiaries from incurring any additional indebtedness or other liabilities that would be structurally senior to our obligations under the notes.

In the event of our bankruptcy, liquidation, reorganization or other winding up, our assets that secure any indebtedness will not be available to make payments under the notes unless all of that indebtedness is first paid in full. We advise you that there may not be sufficient assets remaining to pay amounts due on any or all of the notes then outstanding. In the event of the bankruptcy, liquidation, reorganization or other winding up of any of our subsidiaries, we, as a common equity holder of that subsidiary, and, therefore, the noteholders, will rank behind that subsidiary’s creditors, including that subsidiary’s trade creditors, and (to the extent we are not a holder thereof) that subsidiary’s preferred equity holders. Even if we were a creditor of any of our subsidiaries, our rights as a creditor would be effectively subordinated to any security interest of others in the assets of that subsidiary, to the extent of the value of those assets, and would be subordinated to any indebtedness of that subsidiary that is senior in right of payment to that held by us.

Our subsidiaries will have no obligations under the notes. The ability of our subsidiaries to pay dividends or make other payments to us is restricted by, among other things, corporate and other laws and by agreements to which our subsidiaries may become a party. Accordingly, we may be unable to gain access to the cash flow or assets of our subsidiaries to enable us to make payments on the notes.

As of March 31, 2020, we had $60.0 million principal amount of long-term indebtedness outstanding. In addition, our subsidiaries had $0.3 million of other liabilities (including trade payables, but excluding intercompany obligations and liabilities). After giving effect to this offering (assuming no exercise of the underwriters’ option to purchase additional notes) and the use of proceeds therefrom as described in “Use of Proceeds,” our total outstanding long-term indebtedness would have been $100.0 million, of which $40.0 million would have been secured and $60.0 million would have been unsecured.

See “Risk Factors—The notes will be effectively subordinated to our existing and future secured indebtedness and structurally subordinated to the liabilities of our subsidiaries.”

Optional Redemption

We may not redeem the notes at our option at any time before July 20, 2023. Subject to the terms of the indenture, we have the right, at our election, to redeem all, but not less than all, of the notes, at any time, on a redemption date occurring on or after July 20, 2023, for cash, but only if the “last reported sale price” (as defined below under the caption “—Definitions”) per share of common stock exceeds 130% of the “conversion price” (as defined below under the caption “—Definitions”) on (i) each of at least 20 “trading days” (as defined below under the caption “—Definitions”), whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date we send the related redemption notice; and (ii) the trading day immediately before the date we send such notice. In addition, calling any note for redemption will constitute a “make-whole fundamental change” (as defined below under the caption “—Definitions”) with respect to that note, in which case the conversion rate applicable to the conversion of that note will be increased in certain circumstances if the conversion date for such note occurs during the period from, and including, the date we give the related redemption notice to, and including, the close of business on the second business day preceding the redemption date. The redemption date will be a business day of our choosing that is no more than 60, nor less than 30 calendar days after the date we send the related redemption notice, as described below.

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The redemption price for any note called for redemption will be the principal amount of such note plus accrued and unpaid interest on such note to, but excluding, the redemption date. However, if the redemption date is after a regular record date and on or before the next interest payment date, then (i) the holder of such note at the close of business on such regular record date will be entitled, notwithstanding such redemption, to receive, on or, at our election, before such interest payment date, the unpaid interest that would have accrued on such note to, but excluding, such interest payment date; and (ii) the redemption price will not include accrued and unpaid interest on such note to, but excluding, such redemption date.

We will send to each noteholder, the trustee and conversion agent (if other than the trustee) notice of the redemption containing certain information set forth in the indenture, including the redemption price and the redemption date.

Notes called for redemption must be delivered to the paying agent (in the case of certificated notes) or the “depositary procedures” (as defined below under the caption “—Definitions”) must be complied with (in the case of global notes) for the holder of those notes to be entitled to receive the redemption price.

Notwithstanding anything to the contrary above, we may not redeem any notes if the principal amount of the notes has been accelerated (except in the case of an acceleration resulting from a default by us in the payment of the related redemption price and any related interest described above on the redemption date) and such acceleration has not been rescinded on or before the redemption date.

Conversion Rights

Generally

Noteholders will have the right to convert their notes (or any portion of a note in an authorized denomination) into shares of our common stock (together with cash in lieu of any fractional share, if applicable), at an initial conversion rate of                  shares per $1,000 principal amount of notes (which represents an initial conversion price of approximately $         per share).

Noteholders may convert their notes at any time until the close of business on the second scheduled trading day (as defined below under the caption “—Definitions”) immediately before the maturity date. However, if we call the notes for redemption, then the holders of such notes may not convert such notes after the close of business on the second business day immediately before the applicable redemption date, except to the extent we fail to pay the redemption price for such notes in accordance with the indenture.

Treatment of Interest upon Conversion

We will not adjust the conversion rate to account for any accrued and unpaid interest on any note being converted, and, except as described below, our delivery of the consideration due in respect of the conversion will be deemed to fully satisfy and discharge our obligation to pay the principal of, and accrued and unpaid interest, if any, on, such note. As a result, except as described below, any accrued and unpaid interest on a converted note will be deemed to be paid in full rather than cancelled, extinguished or forfeited.

Notwithstanding anything to the contrary above, if the conversion date of a note is after a regular record date and before the next interest payment date, then:

• the holder of such note at the close of business on such regular record date will be entitled, notwithstanding such conversion, to receive, on or, at our election, before such interest payment date, the unpaid interest that would have accrued on such note to, but excluding, such interest payment date; and

• the noteholder surrendering such note for conversion must deliver, at the time it surrenders such note, an amount of cash equal to the amount of such interest.

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However, such noteholder need not deliver such cash:

• if we have specified a redemption date that is after such regular record date and on or before the business day immediately after such interest payment date;

• if such conversion date occurs after the regular record date immediately before the maturity date;

• if we have specified a “fundamental change repurchase date” (as defined below under the caption “—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes”) that is after such regular record date and on or before the business day immediately after such interest payment date; or

• to the extent of any overdue interest or interest that has accrued on any overdue interest.

Accordingly, for the avoidance of doubt, all noteholders as of the close of business on the regular record date immediately before the maturity date will receive the full interest payment that would have been due on the maturity date regardless of whether their notes have been converted after such regular record date.

Conversion Procedures

To convert a beneficial interest in a global note, the owner of the beneficial interest must:

• comply with the depositary procedures for converting the beneficial interest (at which time such conversion will become irrevocable);

• if applicable, pay any interest payable on the next interest payment date, as described above under the caption “—Treatment of Interest upon Conversion”; and

• if applicable, pay any documentary or other taxes as described below.

To convert all or a portion of a physical note, the holder of such note must:

• complete, manually sign and deliver to the conversion agent the conversion notice attached to such note or a facsimile of such conversion notice;

• deliver such note to the conversion agent (at which time such conversion will become irrevocable);

• furnish any endorsements and transfer documents that we or the conversion agent may require;

• if applicable, pay any interest payable on the next interest payment date, as described above under the caption “—Treatment of Interest upon Conversion”; and

• if applicable, pay any documentary or other taxes as described below.

Notes may be surrendered for conversion only after the “open of business” (as defined below under the caption “—Definitions”) and before the close of business on a day that is a business day.

We will pay any documentary, stamp or similar issue or transfer tax or duty due on the issue of any shares of our common stock upon conversion, except any tax or duty that is due because the converting noteholder requests those shares to be registered in a name other than the noteholder’s name.

We refer to the first business day on which the requirements described above to convert a note are satisfied as the “conversion date.”

If a noteholder has validly delivered a “fundamental change repurchase notice” (as defined below under the caption “—Fundamental Change Permits Noteholders to Require Us to Repurchase Notes”) with respect to a note, then such note may not be converted, except to the extent (i) such notice is withdrawn in accordance with the procedures described below; or (ii) we fail to pay the related fundamental change repurchase price for such note.

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Limits on Issuance of Shares of Common Stock upon Conversion

Notwithstanding anything to the contrary herein, no person will be entitled to receive any shares of our common stock otherwise deliverable upon conversion of the notes to the extent, but only to the extent, that such receipt would cause such person to become, directly or indirectly, a “beneficial owner” (as defined below) of more than 9.99% of the shares of our common stock outstanding at such time (such restriction, the “general beneficial ownership limit”).

In addition, a holder of notes at its option may elect a beneficial ownership limit as to such holder (but not as to any other holder) that is less than or equal to the general beneficial ownership limit then applicable to the holders in general upon written notice delivered to us prior to the issuance of the notes or, if thereafter, at least 61 days prior to the date of effectiveness of such lower beneficial ownership limit, specifying the percentage of shares of our common stock for the beneficial ownership limit that shall apply to such holder (such beneficial ownership limit, a “holder beneficial ownership limit” and together with the general beneficial ownership limit, the “beneficial ownership limits”).

Any purported delivery of shares of our common stock upon conversion of the notes shall be void and have no effect to the extent, but only to the extent, that such delivery would result in any person becoming the beneficial owner of shares of our common stock outstanding at such time in excess of the beneficial ownership limits applicable to such person.

Unless we have waived the general beneficial ownership limit as described below under “—Conversion Rights—Waiver of Beneficial Ownership Limits” and there is no holder beneficial ownership limit applicable to a holder, when such holder tenders notes for conversion, that holder must provide a certification to us as to whether the person (or persons) receiving shares of our common stock upon conversion is, or would, as a result of such conversion, become the beneficial owner of shares of our common stock outstanding at such time in excess of any beneficial ownership limit then applicable to such person (or persons).

If any delivery of shares of our common stock otherwise owed to any person (or persons) upon conversion of the notes is not made, in whole or in part, as a result of the applicable beneficial ownership limits, our obligation to make such delivery shall not be extinguished and, such holder may certify to us that the person (or persons) receiving shares of our common stock upon conversion is not, and would not, as a result of such conversion, become the beneficial owner of shares of our common stock outstanding at such time in excess of the applicable beneficial ownership limits, after which we shall deliver any such shares of our common stock withheld on account of such applicable beneficial ownership limits by the later of (i) the date such shares were otherwise due to such person (or persons) and (ii) two trading days after receipt of such certification; provided, however, until such time as the affected holder gives such notice, no person shall be deemed to be the stockholder of record with respect to the shares of our common stock otherwise deliverable upon conversion in excess of any applicable beneficial ownership limit. Upon delivery of such notice, the provisions under “Conversion Rights—Settlement upon Conversion,” shall apply to the shares of common stock to be delivered pursuant to such notice.

For purposes of this section only, a person shall be deemed the “beneficial owner” of and shall be deemed to beneficially own any shares of our common stock that such person or any of such person’s affiliates (as defined in Rule 12b-2 under the Exchange Act) or associates (as defined in Rule 12b-2 under the Exchange Act) is deemed to beneficially own, together with any shares of our common stock beneficially owned by any other persons whose beneficial ownership would be aggregated with such person for purposes of Section 13(d) of the Exchange Act. Subject to the following proviso, for purposes of the this section only, beneficial ownership shall be determined in accordance with Section 13(d) of the Exchange Act and the rules and regulations promulgated thereunder as in effect on the first date of original issuance of the notes; provided that the number of shares of our common stock beneficially owned by such person and its affiliates and associates and any other persons whose beneficial ownership would be aggregated with such person for purposes of Section 13(d) of the Exchange Act shall include the number of shares of our common stock issuable upon exercise or conversion of any of our

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securities or rights to acquire our common stock, whether or not such securities or rights are currently exercisable or convertible or are exercisable or convertible only after the passage of time (including the number of shares of our common stock issuable upon conversion of the notes in respect of which the beneficial ownership determination is being made), but shall exclude the number of shares of our common stock that would be issuable upon (A) conversion of the remaining, unconverted portion of any notes beneficially owned by such person or any of its affiliates or associates and any other persons whose beneficial ownership would be aggregated with such person for purposes of Section 13(d) of the Exchange Act and (B) exercise or conversion of the unexercised or unconverted portion of any of our other securities subject to a limitation on conversion or exercise analogous to the limitation contained herein beneficially owned by such person or any of its affiliates or associates and any other persons whose beneficial ownership would be aggregated with such person for purposes of Section 13(d) of the Exchange Act. For the avoidance of doubt, the term “beneficial owner” as used in this section shall not include (i) with respect to any global note, the nominee of the depositary or any person having an account with the depositary or its nominee or (ii) with respect to any certificated note, the holder of such certificated note unless, in each case, such nominee, account holder or holder shall also be a beneficial owner of such note.

Waiver of Beneficial Ownership Limits

We may, at our option with the approval of our board of directors and subject to the applicable listing standards of The Nasdaq Global Select Market, waive the general beneficial ownership limit (as to a particular person or as to all persons). In the event that we exercise our right to waive the general beneficial ownership limit to all persons, we or, at our written request and our expense, the trustee, shall deliver or cause to be delivered to each holder 61 days prior to the effective waiver date an irrevocable notice stating that as of an effective date specified therein, we waive any restrictions that limit a holder from converting its notes in the event that such holder is, or would, as a result of a conversion of notes, become, a restricted converting holder. Any such waiver of the general beneficial ownership limit would not effect a waiver of any holder beneficial ownership limit. Neither the trustee nor the conversion agent shall have any obligation to monitor the general beneficial ownership limit (as to a particular person or as to all persons).

Settlement upon Conversion

Upon conversion of any note, we will deliver, for each $1,000 principal amount being converted, a number of shares of our common stock equal to the conversion rate in effect on the conversion date for such conversion. However, in lieu of delivering any fractional share of common stock otherwise due upon conversion, we will pay cash based on the last reported sale price per share of our common stock on the conversion date for such conversion (or, if such conversion date is not a trading day, the immediately preceding trading day).

Except as described below under the caption “—Special Provisions for Adjustments that Are Not Yet Effective and Where Converting Noteholders Participate in the Relevant Transaction or Event,” we will pay or deliver, as applicable, the consideration due upon conversion on or before the second business day immediately after the conversion date for such conversion.

If a noteholder converts more than one note on a conversion date, then the consideration due upon such conversion will (in the case of any global note, to the extent permitted by, and practicable under, the depositary procedures) be computed based on the total principal amount of notes converted on such conversion date by that noteholder.

When Converting Noteholders Become Stockholders of Record

The person in whose name any share of common stock is issuable upon conversion of any note will be deemed to become the holder of record of that share as of the close of business on the conversion date for such conversion.

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Conversion Rate Adjustments

Generally

The conversion rate will be adjusted for the events described below. However, we are not required to adjust the conversion rate for these events (other than a stock split or combination or a tender or exchange offer) if each noteholder participates, at the same time and on the same terms as holders of our common stock, and solely by virtue of being a holder of notes, in such transaction or event without having to convert such noteholder’s notes and as if such noteholder held a number of shares of our common stock equal to the product of (i) the conversion rate in effect on the related record date; and (ii) the aggregate principal amount (expressed in thousands) of notes held by such noteholder on such date.

(1) Stock Dividends, Splits and Combinations. If we issue solely shares of our common stock as a dividend or distribution on all or substantially all shares of our common stock, or if we effect a stock split or a stock combination of our common stock (in each case excluding an issuance solely pursuant to a common stock change event, as to which the provisions described below under the caption “—Effect of Common Stock Change Event” will apply), then the conversion rate will be adjusted based on the following formula:

CR1  =  CR0  X	OS1
	OS0

where:

CR₀   = the conversion rate in effect immediately before the open of business on theex-dividend date for such dividend or distribution, or immediately before the open of business on the effective date of such stock split or stock combination, as applicable;

CR₁   = the conversion rate in effect immediately after the open of business on suchex-dividend date or effective date, as applicable;

OS₀   = the number of shares of our common stock outstanding immediately before the open of business on suchex-dividend date or effective date, as applicable, without giving effect to such dividend, distribution, stock split or stock combination; and

OS₁   = the number of shares of our common stock outstanding immediately after giving effect to such dividend, distribution, stock split or stock combination.

If any dividend, distribution, stock split or stock combination of the type described in this paragraph (1) is declared or announced, but not so paid or made, then the conversion rate will be readjusted, effective as of the date our board of directors determines not to pay such dividend or distribution or to effect such stock split or stock combination, to the conversion rate that would then be in effect had such dividend, distribution, stock split or stock combination not been declared or announced.

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(2) Rights, Options and Warrants. If we distribute, to all or substantially all holders of our common stock, rights, options or warrants (other than rights issued or otherwise distributed pursuant to a stockholder rights plan, as to which the provisions described below in paragraph (3)(a) and under the caption “—Stockholder Rights Plans” will apply) entitling such holders, for a period of not more than 60 calendar days after the record date of such distribution, to subscribe for or purchase shares of our common stock at a price per share that is less than the average of the last reported sale prices per share of our common stock for the 10 consecutive trading days ending on, and including, the trading day immediately before the date such distribution is announced, then the conversion rate will be increased based on the following formula:

CR1  =  CR0  X	OS + X
	OS + Y

where:

CR₀   = the conversion rate in effect immediately before the open of business on theex-dividend date for such distribution;

CR₁   = the conversion rate in effect immediately after the open of business on suchex-dividend date;

OS   = the number of shares of our common stock outstanding immediately before the open of business on suchex-dividend date;

X   = the total number of shares of our common stock issuable pursuant to such rights, options or warrants; and

Y   = a number of shares of our common stock obtained by dividing (x) the aggregate price payable to exercise such rights, options or warrants by (y) the average of the last reported sale prices per share of our common stock for the 10 consecutive trading days ending on, and including, the trading day immediately before the date such distribution is announced.

To the extent such rights, options or warrants are not so distributed, the conversion rate will be readjusted to the conversion rate that would then be in effect had the increase to the conversion rate for such distribution been made on the basis of only the rights, options or warrants, if any, actually distributed. In addition, to the extent that shares of our common stock are not delivered after the expiration of such rights, options or warrants (including as a result of such rights, options or warrants not being exercised), the conversion rate will be readjusted to the conversion rate that would then be in effect had the increase to the conversion rate for such distribution been made on the basis of delivery of only the number of shares of our common stock actually delivered upon exercise of such rights, option or warrants.

For purposes of this paragraph (2), in determining whether any rights, options or warrants entitle holders of our common stock to subscribe for or purchase shares of our common stock at a price per share that is less than the average of the last reported sale prices per share of our common stock for the 10 consecutive trading days ending on, and including, the trading day immediately before the date the distribution of such rights, options or warrants is announced, and in determining the aggregate price payable to exercise such rights, options or warrants, there will be taken into account any consideration we receive for such rights, options or warrants and any amount payable on exercise thereof, with the value of such consideration, if not cash, to be determined by us in good faith.

(3) Spin-Offs and Other Distributed Property.

(a) Distributions Other than Spin-Offs. If we distribute shares of our “capital stock” (as defined below under the caption “—Definitions”), evidences of our indebtedness or other assets or property of ours, or rights, options or warrants to acquire our capital stock or other securities, to all or substantially all holders of our common stock, excluding:

• dividends, distributions, rights, options or warrants for which an adjustment to the conversion rate is required (or would be required without regard to the “deferral exception” (as defined below under the caption “—the Deferral Exception”)) pursuant to paragraph (1) or (2) above;

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• dividends or distributions paid exclusively in cash for which an adjustment to the conversion rate is required pursuant (or would be required without regard to the deferral exception) to paragraph (4) below;

• rights issued or otherwise distributed pursuant to a stockholder rights plan, except to the extent provided below under the caption “—Stockholder Rights Plans”;

• spin-offs for which an adjustment to the conversion rate is required (or would be required without regard to the deferral exception) pursuant to paragraph (3)(b) below;

• a distribution solely pursuant to a tender offer or exchange offer for shares of our common stock, as to which the provisions described below in paragraph (5) will apply; and

• a distribution solely pursuant to a common stock change event, as to which the provisions described below under the caption “—Effect of Common Stock Change Event” will apply,

then the conversion rate will be increased based on the following formula:

CR1  =  CR0  X	SP
	SP – FMV

where:

CR₀ = the conversion rate in effect immediately before the open of business on theex-dividend date for such distribution;

CR₁ = the conversion rate in effect immediately after the open of business on suchex-dividend date;

SP = the average of the last reported sale prices per share of our common stock for the 10 consecutive trading days ending on, and including, the trading day immediately before suchex-dividend date; and

FMV = the fair market value (as determined by us in good faith), as of suchex-dividend date, of the shares of capital stock, evidences of indebtedness, assets, property, rights, options or warrants distributed per share of our common stock pursuant to such distribution.

However, ifFMV is equal to or greater thanSP, then, in lieu of the foregoing adjustment to the conversion rate, each noteholder will receive, for each $1,000 principal amount of notes held by such noteholder on the record date for such distribution, at the same time and on the same terms as holders of our common stock, the amount and kind of shares of capital stock, evidences of indebtedness, assets, property, rights, options or warrants that such noteholder would have received if such noteholder had owned, on such record date, a number of shares of our common stock equal to the conversion rate in effect on such record date.

To the extent such distribution is not so paid or made, the conversion rate will be readjusted to the conversion rate that would then be in effect had the adjustment been made on the basis of only the distribution, if any, actually made or paid.

(b) Spin-Offs. If we distribute or dividend shares of capital stock of any class or series, or similar equity interests, of or relating to an “affiliate” or “subsidiary” (as those terms are defined below under the caption “—Definitions”) or other business unit of ours to all or substantially all holders of our common stock (other than solely pursuant to (x) a common stock change event, as to which the provisions described below under the caption “—Effect of Common Stock Change Event” will apply; or (y) a tender offer or exchange offer for shares of our common stock, as to which the provisions described below in paragraph (5) will apply), and such capital stock or equity interests are listed or quoted (or will be listed or quoted upon the consummation of the transaction) on a U.S. national securities exchange (a“spin-off”), then the conversion rate will be increased based on the following formula:

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CR1  =  CR0  X	FMV + SP
	SP

where:

CR₀   = the conversion rate in effect immediately before the close of business on the last trading day of the“spin-off valuation period” (as defined below) for suchspin-off;

CR₁   = the conversion rate in effect immediately after the close of business on the last trading day of thespin-off valuation period;

FMV   = the product of (x) the average of the last reported sale prices per share or unit of the capital stock or equity interests distributed in suchspin-off over the 10 consecutive trading day period (the“spin-off valuation period”) beginning on, and including, theex-dividend date for suchspin-off (such average to be determined as if references to our common stock in the definitions of “last reported sale price,” “trading day” and “market disruption event” were instead references to such capital stock or equity interests); and (y) the number of shares or units of such capital stock or equity interests distributed per share of our common stock in suchspin-off; and

SP   = the average of the last reported sale prices per share of our common stock for each trading day in thespin-off valuation period.

Notwithstanding anything to the contrary, if the conversion date for a note occurs during thespin-off valuation period for suchspin-off, then, solely for purposes of determining the consideration due in respect of such conversion, suchspin-off valuation period will be deemed to consist of the trading days occurring in the period from, and including, theex-dividend date for suchspin-off to, and including, such conversion date.

To the extent any dividend or distribution of the type described above in this paragraph (3)(b) is declared but not made or paid, the conversion rate will be readjusted to the conversion rate that would then be in effect had the adjustment been made on the basis of only the dividend or distribution, if any, actually made or paid.

(4) Cash Dividends or Distributions. If any cash dividend or distribution is made to all or substantially all holders of our common stock, then the conversion rate will be increased based on the following formula:

CR1  =  CR0  X	SP
	SP – D

where:

CR₀   = the conversion rate in effect immediately before the open of business on theex-dividend date for such dividend or distribution;

CR₁   = the conversion rate in effect immediately after the open of business on suchex-dividend date;

SP   = the last reported sale price per share of our common stock on the trading day immediately before suchex-dividend date; and

D   = the cash amount distributed per share of our common stock in such dividend or distribution.

However, if D is equal to or greater than SP, then, in lieu of the foregoing adjustment to the conversion rate, each noteholder will receive, for each $1,000 principal amount of notes held by such noteholder on the record date for such dividend or distribution, at the same time and on the same terms as holders of our common stock, the amount of cash that such noteholder would have received if such noteholder had owned, on such record date, a number of shares of our common stock equal to the conversion rate in effect on such record date, then no adjustment to the conversion rate will be made. To the extent such dividend or

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distribution is declared but not made or paid, the conversion rate will be readjusted to the conversion rate that would then be in effect had the adjustment been made on the basis of only the dividend or distribution, if any, actually made or paid.

(5) Tender Offers or Exchange Offers. If we or any of our subsidiaries makes a payment in respect of a tender offer or exchange offer for shares of our common stock that is subject to the then-applicable tender offer rules under the Exchange Act (other than anodd-lot tender offer that satisfies the requirements of Rule13e-4(h)(5), or any successor rule), and the value (determined as of the expiration time by us in good faith) of the cash and other consideration paid per share of our common stock in such tender or exchange offer exceeds the last reported sale price per share of our common stock on the trading day immediately after the last date (the “expiration date”) on which tenders or exchanges may be made pursuant to such tender or exchange offer (as it may be amended), then the conversion rate will be increased based on the following formula:

CR1  =  CR0  X	AC + (SP X OS1)
	SP x OS0

where:

CR₀   = the conversion rate in effect immediately before the close of business on the last trading day of the “tender/exchange offer valuation period” (as defined below) for such tender or exchange offer;

CR₁   = the conversion rate in effect immediately after the close of business on the last trading day of the tender/exchange offer valuation period;

AC   = the aggregate value (determined as of the time (the “expiration time”) such tender or exchange offer expires by our board of directors) of all cash and other consideration paid for shares of our common stock purchased or exchanged in such tender or exchange offer;

OS₀   = the number of shares of our common stock outstanding immediately before the expiration time (including all shares of our common stock accepted for purchase or exchange in such tender or exchange offer);

OS₁   = the number of shares of our common stock outstanding immediately after the expiration time (excluding all shares of our common stock accepted for purchase or exchange in such tender or exchange offer); and

SP   = the average of the last reported sale prices per share of our common stock over the 10 consecutive trading day period (the “tender/exchange offer valuation period”) beginning on, and including, the trading day immediately after the expiration date;

provided,however, that the conversion rate will in no event be adjusted down pursuant to the provisions described in this paragraph (5), except to the extent provided in the immediately following paragraph. Notwithstanding anything to the contrary, if the conversion date for a note occurs during the tender/exchange offer valuation period for such tender or exchange offer, then, solely for purposes of determining the consideration due in respect of such conversion, such tender/exchange offer valuation period will be deemed to consist of the trading days occurring in the period from, and including, the trading day immediately after the expiration date to, and including, such conversion date.

To the extent such tender or exchange offer is announced but not consummated (including as a result of being precluded from consummating such tender or exchange offer under applicable law), or any purchases or exchanges of shares of common stock in such tender or exchange offer are rescinded, the conversion rate will be readjusted to the conversion rate that would then be in effect had the adjustment been made on the basis of only the purchases or exchanges of shares of common stock, if any, actually made, and not rescinded, in such tender or exchange offer.

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We will not be required to adjust the conversion rate except as described above or below under the caption “—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change.” Without limiting the foregoing, we will not be required to adjust the conversion rate on account of:

• except as described above, the sale of shares of our common stock for a purchase price that is less than the market price per share of our common stock or less than the conversion price;

• the issuance of any shares of our common stock pursuant to any present or future plan providing for the reinvestment of dividends or interest payable on our securities and the investment of additional optional amounts in shares of our common stock under any such plan;

• the issuance of any shares of our common stock or options or rights to purchase shares of our common stock pursuant to any present or future employee, director or consultant benefit or incentive plan or program of, or assumed by, us or any of our subsidiaries;

• the issuance of any shares of our common stock pursuant to any option, warrant, right or convertible or exchangeable security of ours outstanding as of the date we first issue the notes;

• a third-party tender offer, other than a tender offer that is subject to clause (5) above;

• the repurchase of any of shares of our common stock pursuant to an open market share purchase program or other buyback transaction, including structured or derivative transactions such as accelerated share repurchase transactions or similar forward derivatives, or other buyback transaction, in each case that is not subject to clause (5) above;

• solely a change in the par value of our common stock; or

• accrued and unpaid interest on the notes.

The Deferral Exception

If an adjustment to the conversion rate otherwise required by the provisions described above would result in a change of less than 1% to the conversion rate, then, notwithstanding anything to the contrary described above, we may, at our election, defer and carry forward such adjustment, except that all such deferred adjustments must be given effect immediately upon the earliest to occur of the following: (i) when all such deferred adjustments would result in an aggregate change of at least 1% to the conversion rate; (ii) the conversion date of any note; (iii) the date a fundamental change or make-whole fundamental change occurs; and (iv) the date we call any notes for redemption. We refer to our ability to defer adjustments as described above as the “deferral exception.”

Notice of Conversion Rate Adjustments

Upon the effectiveness of any adjustment to the conversion rate pursuant to the provisions described above under the caption “—Conversion Rate Adjustments—Generally,” we will promptly send notice to the noteholders, the trustee and the conversion agent (if other than the trustee) containing (i) a brief description of the transaction or other event on account of which such adjustment was made; (ii) the conversion rate in effect immediately after such adjustment; and (iii) the effective time of such adjustment.

Voluntary Conversion Rate Increases

To the extent permitted by law and applicable stock exchange rules, we, from time to time, may (but are not required to) increase the conversion rate by any amount if (i) our board of directors determines that such increase is in our best interest or that such increase is advisable to avoid or diminish any income tax imposed on holders of our common stock or rights to purchase our common stock as a result of any dividend or distribution of shares (or rights to acquire shares) of our common stock or any similar event; (ii) such increase is in effect for a period of at least 20 business days; and (iii) such increase is irrevocable during such period.

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Tax Considerations

A holder or beneficial owner of the notes may, in some circumstances, including a cash distribution or dividend on our common stock, be deemed to have received a distribution that is subject to U.S. federal income tax as a result of an adjustment or thenon-occurrence of an adjustment to the conversion rate. Applicable withholding taxes (including backup withholding) may be withheld from interest and payments upon conversion, repurchase, redemption or maturity of the notes. In addition, if any withholding taxes (including backup withholding) are paid on behalf of a holder or beneficial owner, then those withholding taxes may be withheld from or set off against payments of cash or the delivery of shares of common stock in respect of the notes (or, in some circumstances, any payments on our common stock) or sales proceeds received by, or other funds or assets of, that holder or beneficial owner. For a discussion of the U.S. federal income tax treatment of an adjustment to the conversion rate, see “Material U.S. Federal Income Tax Considerations.”

Special Provisions for Adjustments that Are Not Yet Effective and Where Converting Noteholders Participate in the Relevant Transaction or Event

Notwithstanding anything to the contrary, if:

• a note is to be converted;

• the record date, effective date or expiration time for any event that requires an adjustment to the conversion rate pursuant to the provisions described above under the caption “—Conversion Rate Adjustments—Generally” has occurred on or before the conversion date for such conversion, but an adjustment to the conversion rate for such event has not yet become effective as of such conversion date;

• the consideration due upon such conversion includes any whole shares of our common stock; and

• such shares are not entitled to participate in such event (because they were not held on the related record date or otherwise),

then, solely for purposes of such conversion, we will, without duplication, give effect to such adjustment on such conversion date. In such case, if the date we are otherwise required to deliver the consideration due upon such conversion is before the first date on which the amount of such adjustment can be determined, then we will delay the settlement of such conversion until the second business day after such first date.

Notwithstanding anything to the contrary, if:

• a conversion rate adjustment for any dividend or distribution becomes effective on anyex-dividend date pursuant to the provisions described above under the caption “—Conversion Rate Adjustments—Generally”;

• a note is to be converted;

• the conversion date for such conversion occurs on or after suchex-dividend date and on or before the related record date;

• the consideration due upon such conversion includes any whole shares of our common stock based on a conversion rate that is adjusted for such dividend or distribution; and

• such shares would be entitled to participate in such dividend or distribution,

then (x) such conversion rate adjustment will not be given effect for such conversion; (y) the shares of common stock issuable upon such conversion based on such unadjusted conversion rate will not be entitled to participate in such dividend or distribution; and (z) there will be added, to the consideration otherwise due upon such conversion, the same kind and amount of consideration that would have been delivered in such dividend or distribution with respect to such shares had such shares been entitled to participate in such dividend or distribution.

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Stockholder Rights Plans

If any shares of our common stock are to be issued upon conversion of any note and, at the time of such conversion, we have in effect any stockholder rights plan, then the holder of that note will be entitled to receive, in addition to, and concurrently with the delivery of, the consideration otherwise due upon such conversion, the rights set forth in such stockholder rights plan, unless such rights have separated from our common stock at such time, in which case, and only in such case, the conversion rate will be adjusted pursuant to the provisions described above in paragraph (3) (a) under the caption “—Conversion Rate Adjustments—Generally” on account of such separation as if, at the time of such separation, we had made a distribution of the type referred to in such paragraph to all holders of our common stock, subject to readjustment as described above if such rights expire, terminate or are redeemed. We currently do not have a stockholder rights plan in effect.

Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change

Generally

If a make-whole fundamental change occurs and the conversion date for the conversion of a note occurs during the related “make-whole fundamental change conversion period” (as defined below under the caption “—Definitions”), then, subject to the provisions described below, the conversion rate applicable to such conversion will be increased by a number of shares (the “additional shares”) set forth in the table below corresponding (after interpolation as described below) to the “make-whole fundamental change effective date” (as defined below under the caption “—Definitions”) and the “stock price” (as defined below under the caption “—Definitions”) of such make-whole fundamental change:

	Stock Price
Make-Whole Fundamental Change Effective Date	$	$	$	$	$	$	$	$	$	$
, 2020
July 15, 2021
July 15, 2022
July 15, 2023
July 15, 2024
July 15, 2025

If such make-whole fundamental change effective date or stock price is not set forth in the table above, then:

• if such stock price is between two stock prices in the table above or the make-whole fundamental change effective date is between two dates in the table above, then the number of additional shares will be determined by straight-line interpolation between the numbers of additional shares set forth for the higher and lower stock prices in the table above or the earlier and later dates in the table above, based on a365- or366-day year, as applicable; and

• if the stock price is greater than $         (subject to adjustment in the same manner as the stock prices set forth in the column headings of the table above are adjusted, as described below under the caption “—Adjustment of Stock Prices and Number of Additional Shares”), or less than $         (subject to adjustment in the same manner), per share, then no additional shares will be added to the conversion rate.

Notwithstanding anything to the contrary, in no event will the conversion rate be increased to an amount that exceeds              shares of our common stock per $1,000 principal amount of notes, which amount is subject to adjustment in the same manner as, and at the same time and for the same events for which, the conversion rate is required to be adjusted pursuant to the provisions described above under the caption “—Conversion Rate Adjustments—Generally.”

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As set forth in the definition of “make-whole fundamental change conversion period” below under the caption “—Definitions,” if the conversion date for the conversion of a note occurs during a make-whole fundamental change conversion period relating to both a make-whole fundamental change resulting from our calling notes for redemption and another make-whole fundamental change, then, solely for purposes of that conversion, such conversion date will be deemed to occur only during the period relating to the make-whole fundamental change with the earlier make-whole fundamental change effective date. In that circumstance, the make-whole fundamental change with the later make-whole fundamental change effective date will be deemed not to occur for purposes of such conversion.

Adjustment of Stock Prices and Number of Additional Shares

The stock prices in the first row (i.e., the column headers) of the table above will be adjusted in the same manner as, and at the same time and for the same events for which, the conversion price is adjusted as a result of the operation of the provisions described above under the caption “—Conversion Rate Adjustments—Generally.” The numbers of additional shares in the table above will be adjusted in the same manner as, and at the same time and for the same events for which, the conversion rate is adjusted pursuant to the provisions described above under the caption “—Conversion Rate Adjustments—Generally.”

Notice of Make-Whole Fundamental Change

If a make-whole fundamental change occurs pursuant to clause (i) of the definition thereof, then, promptly and in no event later than the business day immediately after the make-whole fundamental change effective date of such make-whole fundamental change, we will notify the noteholders, the trustee and the conversion agent (if other than the trustee) of the occurrence of such make-whole fundamental change and of such make-whole fundamental change effective date. We will provide notice of a make-whole fundamental change that occurs pursuant to clause (ii) of the definition thereof in the manner described above under the caption “—Optional Redemption.”

Enforceability

Our obligation to increase the conversion rate as described above in connection with a make-whole fundamental change could be considered a penalty, in which case its enforceability would be subject to general principles of reasonableness and equitable remedies.

Effect of Common Stock Change Event

Generally

If there occurs any:

• recapitalization, reclassification or change of our common stock, other than (x) changes solely resulting from a subdivision or combination of our common stock, (y) a change only in par value or from par value to no par value or no par value to par value or (z) stock splits and stock combinations that do not involve the issuance of any other series or class of securities;

• consolidation, merger, combination or binding or statutory share exchange involving us;

• sale, lease or other transfer of all or substantially all of the assets of us and our subsidiaries, taken as a whole, to any person; or

• other similar event,

and, as a result of which, our common stock is converted into, or is exchanged for, or represents solely the right to receive, other securities, cash or other property, or any combination of the foregoing (such an event, a

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“common stock change event,” and such other securities, cash or property, the “reference property,” and the amount and kind of reference property that a holder of one share of our common stock would be entitled to receive on account of such common stock change event (without giving effect to any arrangement not to issue or deliver a fractional portion of any security or other property), a “reference property unit”), then, notwithstanding anything to the contrary,

• from and after the effective time of such common stock change event, (i) the consideration due upon conversion of any note will be determined in the same manner as if each reference to any number of shares of common stock in the provisions described under this “—Conversion Rights” section (or in any related definitions) were instead a reference to the same number of reference property units; (ii) for purposes of the redemption provisions described above under the caption “—Optional Redemption,” each reference to any number of shares of our common stock in such provisions (or in any related definitions) will instead be deemed to be a reference to the same number of reference property units; and (iii) for purposes of the definition of “fundamental change” and “make-whole fundamental change,” the terms “common stock” and “common equity” will be deemed to mean the common equity, if any, forming part of such reference property;

• if such reference property unit consists entirely of cash, then we will pay the cash due in respect of all conversions whose conversion date occurs on or after the effective date of such common stock change event no later than the second business day after the relevant conversion date; and

• for these purposes, the last reported sale price of any reference property unit or portion thereof that does not consist of a class of securities will be the fair value of such reference property unit or portion thereof, as applicable, determined in good faith by us (or, in the case of cash denominated in U.S. dollars, the face amount thereof).

If the reference property consists of more than a single type of consideration to be determined based in part upon any form of stockholder election, then the composition of the reference property unit will be deemed to be the weighted average of the types and amounts of consideration actually received, per share of our common stock, by the holders of our common stock. We will notify the noteholders, the trustee and the conversion agent (if other than the trustee) of such weighted average as soon as practicable after such determination is made.

We will not become a party to any common stock change event unless its terms are consistent with the provisions described under this “—Effect of Common Stock Change Event” caption.

Execution of Supplemental Indenture

At or before the effective time of the common stock change event, we and the resulting, surviving or transferee person (if not us) of such common stock change event (the “successor person”) will execute and deliver to the trustee a supplemental indenture that (i) provides for subsequent adjustments to the conversion rate in a manner consistent with the provisions described above; and (ii) contains such other provisions, if any, that we reasonably determine are appropriate to preserve the economic interests of the noteholders and to give effect to the provisions described above. If the reference property includes shares of stock or other securities or assets (other than cash) of a person other than the successor person (that are not then owned by such successor person), then such other person will also execute such supplemental indenture and such supplemental indenture will contain such additional provisions, if any, that we reasonably determine are appropriate to preserve the economic interests of noteholders.

Notice of Common Stock Change Event

We will provide notice of each common stock change event to noteholders, the trustee and the conversion agent (if other than the trustee) no later than the business day after the effective date of the common stock change event.

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Equitable Adjustments to Prices

Whenever the indenture requires us to calculate the average of the last reported sale prices, or any function thereof, over a period of multiple days (including to calculate the stock price or an adjustment to the conversion rate), we will make proportionate adjustments to those calculations to account for any adjustment to the conversion rate pursuant to paragraph (1) above under the caption “—Conversion Rights—Conversion Rate Adjustments—Generally” that becomes effective, or any event requiring such an adjustment to the conversion rate where theex-dividend date or effective date, as applicable, of such event occurs, at any time during such period.

Fundamental Change Permits Noteholders to Require Us to Repurchase Notes

Generally

If a fundamental change occurs, then each noteholder will have the right (the “fundamental change repurchase right”) to require us to repurchase its notes (or any portion thereof in an authorized denomination) for cash on a date (the “fundamental change repurchase date”) of our choosing, which must be a business day that is no more than 35, nor less than 20, business days after the date we send the related fundamental change notice, as described below.

The repurchase price (the “fundamental change repurchase price”) for a note tendered for repurchase will be the principal amount of such note plus accrued and unpaid interest on such note to, but excluding, the fundamental change repurchase date. However, if the fundamental change repurchase date is after a regular record date and on or before the next interest payment date, then (i) the holder of such note at the close of business on such regular record date will be entitled, notwithstanding such repurchase, to receive, on or, at our election, before such interest payment date, the unpaid interest that would have accrued on such note to, but excluding, such interest payment date; and (ii) the fundamental change repurchase price will not include accrued and unpaid interest on such note to, but excluding, the fundamental change repurchase date.

Notwithstanding anything to the contrary above, we may not repurchase any notes if the principal amount of the notes has been accelerated and such acceleration has not been rescinded on or before the fundamental change repurchase date (except in the case of an acceleration resulting from a default by us in the payment of the related fundamental change repurchase price and any related interest described above on the fundamental change repurchase date).

Notice of Fundamental Change

On or before the 20th calendar day after the effective date of a fundamental change, we will send to each noteholder, the trustee and the paying agent notice of such fundamental change containing certain information set forth in the indenture, including the fundamental change repurchase date, the fundamental change repurchase price and the procedures noteholders must follow to tender their notes for repurchase.

Procedures to Exercise the Fundamental Change Repurchase Right

To exercise its fundamental change repurchase right with respect to a note, the holder thereof must deliver a notice (a “fundamental change repurchase notice”) to the paying agent before the close of business on the business day immediately before the related fundamental change repurchase date (or such later time as may be required by law).

The fundamental change repurchase notice must contain certain information set forth in the indenture, including the certificate number of any physical notes to be repurchased, or must otherwise comply with the depositary procedures in the case of a global note.

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A noteholder that has delivered a fundamental change repurchase notice with respect to a note may withdraw that notice by delivering a withdrawal notice to the paying agent at any time before the close of business on the business day immediately before the fundamental change repurchase date. The withdrawal notice must contain certain information set forth in the indenture, including the certificate number of any physical notes with respect to which the withdrawal notice is being delivered, or must otherwise comply with the depositary procedures in the case of a global note.

Notes to be repurchased must be delivered to the paying agent (in the case of physical notes) or the depositary procedures must be complied with (in the case of global notes) for the holder of those notes to be entitled to receive the fundamental change repurchase price.

Repurchase by Third Party

Notwithstanding anything to the contrary, we will be deemed to satisfy our obligations to repurchase notes pursuant to the provisions described above if (i) one or more third parties conduct the repurchase offer and repurchase tendered notes in a manner that would have satisfied our obligations to do the same if conducted directly by us; and (ii) an owner of a beneficial interest in the notes would not receive a lesser amount (as a result of taxes, additional expenses or for any other reason) than such owner would have received had we repurchased the notes.

No Repurchase Right in Certain Circumstances

Notwithstanding anything to the contrary, we will not be required to send a fundamental change notice, or offer to repurchase or repurchase any notes, as described above, in connection with a fundamental change occurring pursuant to clause (ii)(2) (or pursuant to clause (i) that also constitutes a fundamental change occurring pursuant to clause (ii)(2)) of the definition thereof, if:

• such fundamental change constitutes a common stock change event whose reference property consists entirely of cash in U.S. dollars;

• immediately after such fundamental change, the notes become convertible (pursuant to the provisions described above under the captions “—Conversion Rights—Effect of Common Stock Change Event” and, if applicable, “—Conversion Rights—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change”) into consideration that consists solely of U.S. dollars in an amount per $1,000 principal amount of notes that equals or exceeds the fundamental change repurchase price per $1,000 principal amount of notes (calculated assuming that the same includes the maximum amount of accrued interest payable as part of the related fundamental change repurchase price); and

• we timely send the notice relating to the make-whole fundamental change related to such fundamental change that is required pursuant to the provisions described above under the caption “—Conversion Rights—Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change—Notice of Make-Whole Fundamental Change.”

We refer to any fundamental change with respect to which, in accordance with the provisions described above, we do not offer to repurchase any notes as an “exempted fundamental change.”

Compliance with Securities Laws

We will comply in all material respects with all federal and state securities laws in connection with a repurchase following a fundamental change (including complying with Rules13e-4 and14e-1 under the Exchange Act and filing any required Schedule TO, to the extent applicable) so as to permit effecting such repurchase in the manner described above. However, to the extent that our obligations to offer to repurchase and to repurchase notes

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pursuant to the provisions described above conflict with any law or regulation that is applicable to us and enacted after the date we initially issue the notes, our compliance with such law or regulation will not be considered to be a default of those obligations.

Consolidation, Merger and Asset Sale

For purposes of the notes, the description below under this section titled “—Consolidation, Merger and Asset Sale” supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities—Merger, Consolidation or Sale of Assets.”

We will not consolidate with or merge with or into, or (directly, or indirectly through one or more of our subsidiaries) sell, lease or otherwise transfer, in one transaction or a series of transactions, all or substantially all of the assets of us and our subsidiaries, taken as a whole, to another person (a “business combination event”), unless:

• the resulting, surviving or transferee person is us or, if not us, is a corporation (the “successor corporation”) duly organized and existing under the laws of the United States of America, any State thereof or the District of Columbia that expressly assumes (by executing and delivering to the trustee, at or before the effective time of such business combination event, a supplemental indenture) all of our obligations under the indenture and the notes;

• immediately after giving effect to such business combination event, no default or event of default will have occurred and be continuing; and

• We have delivered to the trustee certain officer’s certificates and opinions as set forth in the indenture.

At the effective time of a business combination event that complies with the provisions described above, the successor corporation (if not us) will succeed to, and may exercise every right and power of, us under the indenture and the notes, and, except in the case of a lease, the predecessor company will be discharged from its obligations under the indenture and the notes.

The definition of “business combination event” includes a reference to “all or substantially all” of our and our subsidiaries’ assets. There is no precise, established definition of the phrase “all or substantially all” under applicable law. Accordingly, there may be uncertainty as to whether the provisions described above would apply to a sale, lease or transfer of less than all of our and our subsidiaries’ assets.

Events of Default

For purposes of the notes, the description below under this section titled “—Events of Default” supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities—Events of Default, Notice and Waiver.”

Generally

An “event of default” means the occurrence of any of the following:

(1) a default in the payment when due (whether at maturity, upon redemption or repurchase upon fundamental change or otherwise) of the principal of, or the redemption price or fundamental change repurchase price for, any note;

(2) a default for 30 days in the payment when due of interest on any note;

(3) our failure to deliver, when required by the indenture, a fundamental change notice or a notice of a make-whole fundamental change pursuant to the provisions described above under the caption “—Conversion

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Rights— Increase in Conversion Rate in Connection with a Make-Whole Fundamental Change—Notice of Make-Whole Fundamental Change;

(4) a default in our obligation to convert a note in accordance with the indenture upon the exercise of the conversion right with respect thereto and such failure continues for three business days;

(5) a default in our obligations described above under the caption “—Consolidation, Merger and Asset Sale”;

(6) a default in any of our obligations or agreements under the indenture or the notes (other than a default set forth in paragraphs (1), (2), (3), (4) or (5) above) where such default is not cured or waived within 60 days after notice to us by the trustee, or to us and the trustee by holders of at least 25% of the aggregate principal amount of notes then outstanding, which notice must specify such default, demand that it be remedied and state that such notice is a “notice of default”;

(7) a default by us or any of our significant subsidiaries with respect to any one or more mortgages, agreements or other instruments under which there is outstanding, or by which there is secured or evidenced, any indebtedness for money borrowed of at least $10,000,000 (or its foreign currency equivalent) in the aggregate of us or any of our significant subsidiaries, whether such indebtedness exists as of the date we first issue the notes or is thereafter created, where such default:

• constitutes a failure to pay the principal of such indebtedness when due and payable (after the expiration of all applicable grace periods) at its stated maturity, upon required repurchase, upon declaration of acceleration or otherwise; or

• results in such indebtedness becoming or being declared due and payable before its stated maturity,

in each case, where such acceleration has not been rescinded or annulled or such failure to pay or default is not cured or waived, or such indebtedness is not paid or discharged in full, within 30 days after notice to us by the trustee or to us and the trustee by holders of at least 25% of the aggregate principal amount of notes then outstanding;

(8) one or more final judgments being rendered against us or any of our significant subsidiaries for the payment of at least $10,000,000 (or its foreign currency equivalent) in the aggregate (excluding any amounts covered by insurance), where such judgment is not discharged or stayed within 60 days after (i) the date on which the right to appeal the same has expired, if no such appeal has commenced; or (ii) the date on which all rights to appeal have been extinguished; and

(9) certain events of bankruptcy, insolvency and reorganization with respect to us or any of our significant subsidiaries.

Acceleration

If an event of default described in paragraph (9) above occurs with respect to us (and not solely with respect to a significant subsidiary of ours), then the principal amount of, and all accrued and unpaid interest on, all of the notes then outstanding will immediately become due and payable without any further action or notice by any person. If an event of default (other than an event of default described in paragraph (9) above with respect to us and not solely with respect to a significant subsidiary of ours) occurs and is continuing, then, except as described below under the caption “—Special Interest as Sole Remedy for Certain Reporting Defaults,” the trustee, by notice to us, or noteholders of at least 25% of the aggregate principal amount of notes then outstanding, by notice to us and the trustee, may declare the principal amount of, and all accrued and unpaid interest on, all of the notes then outstanding to become due and payable immediately.

Noteholders of a majority in aggregate principal amount of the notes then outstanding, by notice to us and the trustee, may, on behalf of all noteholders, rescind any acceleration of the notes and its consequences if (i) such rescission would not conflict with any judgment or decree of a court of competent jurisdiction; and (ii) all existing events of default (except thenon-payment of principal of, or interest on, the notes that has become due solely because of such acceleration) have been cured or waived. No such rescission will affect any subsequent default or impair any right consequent thereto.

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If any portion of the amount payable on the notes upon acceleration is considered by a court to be unearned interest (through the allocation of the value of the instrument to the embedded warrant or otherwise), then the court could disallow recovery of any such portion.

Waiver of Past Defaults

An event of default pursuant to paragraph (1), (2), (4) or (6) above (that, in the case of paragraph (6) only, results from a default under any covenant that cannot be amended without the consent of each affected noteholder), and a default that could lead to such an event of default, can be waived only with the consent of each affected noteholder. Each other default or event of default may be waived, on behalf of all noteholders, by noteholders of a majority in aggregate principal amount of the notes then outstanding.

Notice of Defaults

If a default or event of default occurs, then, within 30 days after its occurrence, we will notify the trustee in writing, setting forth what action we are taking or propose to take with respect thereto, except that we are not required to deliver such notice if such default or event of default has been cured. We must also provide the trustee, within 120 days after the end of each fiscal year, a certificate as to whether any defaults or events of default have occurred or are continuing during such year. If a default or event of default occurs and is continuing and is known to the trustee, then the trustee must notify the noteholders of the same within 90 days after it occurs or, if it is not known to a responsible officer of the trustee at such time, promptly (and in any event within 10 business days) after it becomes known to a responsible officer of the trustee. However, except in the case of a default or event of default in the payment of the principal of, or interest on, any note, the trustee may withhold such notice if and for so long as it in good faith determines that withholding such notice is in the interests of the noteholders.

Limitation on Suits; Absolute Rights of Noteholders

Except with respect to the rights referred to below, no noteholder may pursue any remedy with respect to the indenture or the notes, unless:

• such noteholder has previously delivered to the trustee notice that an event of default is continuing;

• noteholders of at least 25% in aggregate principal amount of the notes then outstanding deliver a written request to the trustee to pursue such remedy;

• such noteholder(s) offer and, if requested, provide to the trustee security and indemnity satisfactory to the trustee against any loss, liability or expense to the trustee that may result from the trustee’s following such request;

• the trustee does not comply with such request within 60 calendar days after its receipt of such request and such offer of security or indemnity; and

• during such 60 calendar day period, noteholders of a majority in aggregate principal amount of the notes then outstanding do not deliver to the trustee a direction that is inconsistent with such request.

However, notwithstanding anything to the contrary, but without limiting the provisions described in the third paragraph under the caption “—Modification and Amendment,” the right of each holder of a note to bring suit for the enforcement of any payment or delivery, as applicable, of the principal of, or the redemption price or fundamental change repurchase price for, or any interest on, or the consideration due upon conversion of, such note on or after the respective due dates therefor, will not be impaired or affected without the consent of such holder.

Noteholders of a majority in aggregate principal amount of the notes then outstanding may direct the time, method and place of conducting any proceeding for exercising any remedy available to the trustee or exercising

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any trust or power conferred on it. However, the trustee may refuse to follow any direction that conflicts with law, the indenture or the notes, or that, subject to the terms of the indenture, the trustee determines may be unduly prejudicial to the rights of other noteholders or may involve the trustee in liability, unless the trustee is offered, and, if requested, provided, security and indemnity satisfactory to the trustee against any loss, liability or expense to the trustee that may result from the trustee’s following such direction.

Default Interest

Payments of any amounts due on the notes that are not made when due will accrue interest at a rate per annum equal to the stated interest on the notes.

Special Interest as Sole Remedy for Certain Reporting Defaults

Notwithstanding anything to the contrary described above, we may elect that the sole remedy for any event of default (a “reporting event of default”) pursuant to paragraph (6) above arising from our failure to comply with our obligations described below under the caption “—Exchange Act Reports” (including our obligations under Section 314(a)(1) of the Trust Indenture Act) will, for each of the first 360 calendar days on which a reporting event of default has occurred and is continuing, consist exclusively of the accrual of special interest on the notes. If we have made such an election, then (i) the notes will be subject to acceleration as described above on account of the relevant reporting event of default from, and including, the 361st calendar day on which a reporting event of default has occurred and is continuing or if we fail to pay any accrued and unpaid special interest when due; and (ii) special interest will cease to accrue on any notes from, and including, the earlier of (x) the date such event of default is cured or waived and (y) such 361st calendar day.

Any special interest that accrues on a note will be payable on the same dates and in the same manner as the stated interest on such note and will accrue at a rate per annum equal to 0.25% of the principal amount thereof for the first 180 days on which special interest accrues and, thereafter, at a rate per annum equal to 0.50% of the principal amount thereof from the 181st day to, and including, the 360th day on which special interest accrues. However, in no event will special interest accrue on any day on a note at a rate per annum that exceeds 0.50%, regardless of the number of events or circumstances giving rise to the accrual of special interest. For the avoidance of doubt, any special interest that accrues on a note will be in addition to the stated interest that accrues on such note.

To make the election to pay special interest as described above, we must provide notice of such election to noteholders, the trustee and the paying agent before the date on which each reporting event of default first occurs. The notice will also, among other things, briefly describe the periods during which and rate at which special interest will accrue and the circumstances under which the notes will be subject to acceleration on account of such reporting event of default.

Modification and Amendment

For purposes of the notes, the description below under this section titled “—Modification and Amendment” supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities—Modification of Indentures.”

We and the trustee may, with the consent of holders of a majority in aggregate principal amount of the notes then outstanding, amend or supplement the indenture or the notes or waive compliance with any provision of the indenture or the notes. However, without the consent of each affected noteholder, no amendment or supplement to the indenture or the notes, or waiver of any provision of the indenture or the notes, may:

• reduce the principal, or extend the stated maturity, of any note;

• reduce the redemption price or fundamental change repurchase price for any note or change the times at which, or the circumstances under which, the notes may or will be redeemed or repurchased by us;

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• reduce the rate, or extend the time for the payment, of interest on any note;

• make any change that adversely affects the conversion rights of any note;

• impair the absolute rights of any holder of a note to bring suit for the enforcement of any payment or delivery, as applicable, of the principal of, or the redemption price or fundamental change repurchase price for, or any interest on, or the consideration due upon conversion of, such note on or after the respective due dates therefor;

• change the ranking of the notes;

• make any note payable in money, or at a place of payment, other than that stated in the indenture or the note;

• reduce the amount of notes whose holders must consent to any amendment, supplement, waiver or other modification; or

• make any direct or indirect change to any amendment, supplement, waiver or modification provision of the indenture or the notes that requires the consent of each affected noteholder.

For the avoidance of doubt, pursuant to the first four bullet points above, no amendment or supplement to the indenture or the notes, or waiver of any provision of the indenture or the notes, may change the amount or type of consideration due on any note (whether on an interest payment date, redemption date, fundamental change repurchase date or the maturity date or upon conversion, or otherwise), or the date(s) or time(s) such consideration is payable or deliverable, as applicable, without the consent of each affected noteholder.

Notwithstanding anything to the contrary above, we and the trustee may amend or supplement the indenture or the notes without the consent of any noteholder to:

• cure any ambiguity or correct any omission, defect or inconsistency in the indenture or the notes;

• add guarantees with respect to our obligations under the indenture or the notes;

• secure the notes;

• add to our covenants or events of default for the benefit of noteholders or surrender any right or power conferred on us;

• provide for the assumption of our obligations under the indenture and the notes pursuant to, and in compliance with, the provisions described above under the caption “—Consolidation, Merger and Asset Sale”;

• enter into supplemental indentures pursuant to, and in accordance with, the provisions described above under the caption “—Conversion Rights—Effect of Common Stock Change Event” in connection with a common stock change event;

• evidence or provide for the acceptance of the appointment of a successor trustee;

• conform the provisions of the indenture and the notes to the “Description of Notes” section of the preliminary prospectus supplement, as supplemented by the related pricing term sheet;

• provide for or confirm the issuance of additional notes in accordance with the limitations set forth in the indenture;

• increase the conversion rate as provided in the indenture;

• comply with any requirement of the SEC in connection with any qualification of the indenture or any supplemental indenture under the Trust Indenture Act; or

• to make any other change to the indenture or the forms or terms of the notes; provided that no such change individually, or in the aggregate with all other such changes, adversely affect the rights of noteholders.

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Exchange Act Reports

We will send to the trustee copies of all reports that we are required to file with or furnish to the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act within 15 calendar days after the date that we are required to so file or furnish the same (after giving effect to all applicable grace periods under the Exchange Act). However, we need not send to the trustee any material for which we have received, or are seeking in good faith and have not been denied, confidential treatment by the SEC. Any report that we file with or furnish to the SEC through the EDGAR system (or any successor thereto) will be deemed to be sent to the trustee at the time such report is so filed or furnished via the EDGAR system (or such successor), it being understood that the trustee shall have no obligation to determine whether such filings have been made. Upon the request of any noteholder, the company will provide to the noteholder a copy of any report that we have sent the trustee pursuant to the provisions described above, other than a report that is deemed to be sent to the trustee pursuant to the preceding sentence. We will also comply with our other obligations under Section 314(a)(1) of the Trust Indenture Act. Delivery of reports, information and documents to the trustee under the indenture is for informational purposes only and the information and the trustee’s receipt of the foregoing shall not constitute actual or constructive notice of any information contained therein, or determinable from information contained therein our compliance with any of its covenants thereunder (as to which the trustee is entitled to rely exclusively on an officer’s certificate).

Discharge

For purposes of the notes, the description below under this section titled “—Discharge” supersedes the information in the accompanying prospectus under the caption “Description of Debt Securities— Discharge, Defeasance and Covenant Defeasance.”

Subject to the terms of the indenture, our obligations with respect to the notes under the indenture will be discharged if we deliver all outstanding notes to the trustee for cancellation, or if all outstanding notes have become due and payable (including upon conversion, if the consideration due upon such conversion has been determined) and we have irrevocably deposited with the trustee, or caused to be delivered to noteholders, sufficient cash or other consideration to satisfy all such amounts that have become due and payable.

Calculations

Except as otherwise provided in the indenture, we will be responsible for making all calculations called for under the indenture or the notes, including determinations of the last reported sale price, the stock price, accrued interest on the notes and the conversion rate. We will make all calculations in good faith, and, absent manifest error, our calculations will be final and binding on all noteholders. We will provide a schedule of our calculations to the trustee, and we will promptly forward a copy of each such schedule to any noteholder upon written request.

Trustee

The trustee under the indenture is U.S. Bank National Association. The trustee assumes no responsibility for the accuracy or completeness of the information contained in this prospectus supplement or the related documents. The trustee and its affiliates have in the past provided and may from time to time in the future provide banking and other services to us in the ordinary course of business.

Notices

We will send all notices or communications to noteholders pursuant to the indenture in writing by first class mail, certified or registered, return receipt requested, or by overnight air courier guaranteeing next day delivery, to the noteholders’ respective addresses shown on the register for the notes. However, in the case of global notes, we are permitted to send notices or communications to noteholders pursuant to the depositary procedures, and notices and communications that we send in this manner will be deemed to have been properly sent to such noteholders in writing.

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No Personal Liability of Directors, Officers, Employees and Stockholders

No past, present or future director, officer, employee, incorporator or stockholder of ours, as such, will have any liability for any obligations of ours under the indenture or the notes or for any claim based on, in respect of, or by reason of, such obligations or their creation. By accepting any note, each noteholder will be deemed to waive and release all such liability, and such waiver and release are part of the consideration for the issuance of the notes.

Governing Law; Waiver of Jury Trial

The indenture and the notes, and any claim, controversy or dispute arising under or related to the indenture or the notes, will be governed by and construed in accordance with the laws of the state of New York. The indenture will provide that we and the trustee will irrevocably waive, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to the indenture, the notes or the transactions contemplated by the indenture or the notes.

Submission to Jurisdiction

Any legal suit, action or proceeding arising out of or based upon the indenture or the transactions contemplated by the indenture may be instituted in the federal courts of the United States of America located in the City of New York or the courts of the State of New York, in each case located in the City of New York (collectively, the “specified courts”), and each party will be deemed to irrevocably submit to thenon-exclusive jurisdiction of those courts in any such suit, action or proceeding. Service of any process, summons, notice or document by mail (to the extent allowed under any applicable statute or rule of court) to any party’s address as provided in the indenture will be effective service of process for any such suit, action or proceeding brought in any such court. Each of us, the trustee and each noteholder (by its acceptance of any note) will be deemed to irrevocably and unconditionally waive any objection to the laying of venue of any suit, action or other proceeding in the specified courts and to irrevocably and unconditionally waive and agree not to plead or claim any such suit, action or other proceeding has been brought in an inconvenient forum.

Definitions

“Affiliate” has the meaning set forth in Rule 144 under the Securities Act as in effect on the date we first issue the notes.

“Board of directors” means our board of directors or a committee of such board duly authorized to act on behalf of such board.

“Business day” means any day other than a Saturday, a Sunday or any day on which the Federal Reserve Bank of New York (or, for purposes of the provision described in the last sentence under the caption “—Payments on the Notes” above, the applicable place of payment) is authorized or required by law or executive order to close or be closed.

“Capital stock” of any person means any and all shares of, interests in, rights to purchase, warrants or options for, participations in, or other equivalents of, in each case however designated, the equity of such person, but excluding any debt securities convertible into such equity.

“Close of business” means 5:00 p.m., New York City time.

“Conversion price” means, as of any time, an amount equal to (i) $1,000divided by (ii) the conversion rate in effect at such time.

“Conversion rate” initially means                  shares of our common stock per $1,000 principal amount of notes, which amount is subject to adjustment as described above under the caption “—Conversion Rights.” Whenever

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in this prospectus supplement we refer to the conversion rate as of a particular date without setting forth a particular time on such date, such reference will be deemed to be to the conversion rate immediately after the close of business on such date.

“Depositary procedures” means, with respect to any transfer, exchange or transaction involving a global note or any beneficial interest therein, the rules and procedures of the depositary applicable to such transfer, exchange or transaction.

“DTC” means The Depository Trust Company or its successor.

“Ex-dividend date” means, with respect to an issuance, dividend or distribution on our common stock, the first date on which shares of our common stock trade on the applicable exchange or in the applicable market, regular way, without the right to receive such issuance, dividend or distribution (including pursuant to due bills or similar arrangements required by the relevant stock exchange). For the avoidance of doubt, any alternative trading convention on the applicable exchange or market in respect of our common stock under a separate ticker symbol or CUSIP number will not be considered “regular way” for this purpose.

“Exchange Act” means the U.S. Securities Exchange Act of 1934, as amended.

“Fundamental change” means any of the following events:

(i) a “person” or “group” (within the meaning of Section 13(d)(3) of the Exchange Act), other than us or any of our “wholly owned subsidiaries” (as defined below), or any employee benefit plans of ours or any of our wholly owned subsidiaries, has become and files any report with the SEC that discloses that such person or group, has become the direct or indirect “beneficial owner” (as defined below) of shares of our common stock representing more than 50% of the voting power of all of our then-outstanding common stock; provided, however, that, for these purposes, no “person” or “group” will be deemed to be the beneficial owner of any securities tendered pursuant to a tender or exchange offer made by or on behalf of such “person” or “group” until such tendered securities are accepted for purchase or exchange under such offer;

(ii) the consummation of: (1) any sale, lease or other transfer, in one transaction or a series of transactions, of all or substantially all of the assets of us and our subsidiaries, taken as a whole, to any person, other than one or more of our wholly owned subsidiaries; or (2) any transaction or series of related transactions in connection with which (whether by means of merger, consolidation, share exchange, combination, reclassification, recapitalization, acquisition, liquidation or otherwise) all of our common stock is exchanged for, converted into, acquired for, or constitutes solely the right to receive, other securities, cash or other property (other than changes resulting solely from a subdivision or combination, or a change in par value, of our common stock);provided,however, that any merger, consolidation, share exchange, combination, reclassification or recapitalization of us pursuant to which the persons that directly or indirectly “beneficially owned” (as defined below) all classes of our common equity immediately before such transaction directly or indirectly “beneficially own,” immediately after such transaction, more than 50% of all classes of common equity of the surviving, continuing or acquiring company or other transferee, as applicable, or the parent thereof, in substantially the same proportionsvis-à-vis each other as immediately before such transaction will be deemed not to be a fundamental change pursuant to this clause (ii);

(iii) our stockholders approve any plan or proposal for our liquidation or dissolution; or

(iv) our common stock ceases to be listed on any of The New York Stock Exchange, The NYSE American, The NASDAQ Capital Market, The NASDAQ Global Market or The NASDAQ Global Select Market (or any of their respective successors);

provided,however, that a transaction or event described in clause (i) or (ii) above will not constitute a fundamental change if at least 90% of the consideration received or to be received by the holders of our common

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stock (excluding cash payments for fractional shares or pursuant to dissenters rights), in connection with such transaction or event, consists of shares of common stock listed on any of The New York Stock Exchange, The NYSE American, The NASDAQ Capital Market, The NASDAQ Global Market or The NASDAQ Global Select Market (or any of their respective successors), or that will be so listed when issued or exchanged in connection with such transaction or event, and such transaction or event constitutes a common stock change event whose reference property consists of such consideration.

For the purposes of this definition, (x) any transaction or event that constitutes a fundamental change pursuant to both clause (i) and clause (ii) above (without regard to the proviso in clause (ii)) will be deemed to occur solely pursuant to clause (ii) above (subject to such proviso); and (y) whether a person is a “beneficial owner” or whether shares are “beneficially owned” will be determined in accordance with Rule13d-3 under the Exchange Act, subject to the proviso to clause (i) above.

“Holder” and “noteholder” mean a person in whose name a note is registered in the register for the notes.

“Last reported sale price” of our common stock for any trading day means the closing sale price per share (or, if no closing sale price is reported, the average of the last bid price and the last ask price per share or, if more than one in either case, the average of the average last bid prices and the average last ask prices per share) of our common stock on such trading day as reported in composite transactions for the principal U.S. national or regional securities exchange on which our common stock is then listed. If our common stock is not listed on a U.S. national or regional securities exchange on such trading day, then the last reported sale price will be the last quoted bid price per share of our common stock on such trading day in theover-the-counter market as reported by OTC Markets Group Inc. or a similar organization. If our common stock is not so quoted on such trading day, then the last reported sale price will be the average of themid-point of the last bid price and the last ask price per share of our common stock on such trading day from each of at least three nationally recognized independent investment banking firms we select, which may include any of the underwriters. The “last reported sale price” will be determined without regard to after-hours trading or any other trading outside of the regular trading session hours.

“Make-whole fundamental change” means (i) a fundamental change (determined after giving effect to the proviso immediately after clause (iv) of the definition thereof, but without regard to the proviso to clause (ii)(2) of such definition); or (ii) the sending of any notice of redemption pursuant to the provisions described above under the caption “—Optional Redemption”.

“Make-whole fundamental change conversion period” has the following meaning:

(i) in the case of a make-whole fundamental change pursuant to clause (i) of the definition thereof, the period from, and including, the make-whole fundamental change effective date of such make-whole fundamental change to, and including, the 35th trading day after such make-whole fundamental change effective date (or, if such make-whole fundamental change also constitutes a fundamental change (other than an exempted fundamental change), to, but excluding, the close of business on the business day immediately preceding the related fundamental change repurchase date); and

(ii) in the case of a make-whole fundamental change pursuant to clause (ii) of the definition thereof, the period from, and including, the date we send the redemption notice for the related redemption to, and including, the close of business on the second business day immediately before the related redemption date;

provided, however, that if the conversion date for the conversion of a note occurs during the make-whole fundamental change conversion period for both a make-whole fundamental change occurring pursuant to clause (i) of the definition of “make-whole fundamental change” and a make-whole fundamental change occurring pursuant to clause (ii) of such definition, then, solely for purposes of such conversion, (x) such conversion date will be deemed to occur solely during the make-whole fundamental change conversion period for the make-

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whole fundamental change with the earlier make-whole fundamental change effective date; and (y) the make-whole fundamental change with the later make-whole fundamental change effective date will be deemed not to have occurred.

“Make-whole fundamental change effective date” means (i) with respect to a make-whole fundamental change pursuant to clause (i) of the definition thereof, the date on which such make-whole fundamental change occurs or becomes effective; and (ii) with respect to a make-whole fundamental change pursuant to clause (ii) of the definition thereof, the applicable “redemption notice date” (as defined below).

“Market disruption event” means, with respect to any date, the occurrence or existence, during theone-half hour period ending at the scheduled close of trading on such date on the principal U.S. national or regional securities exchange or other market on which our common stock is listed for trading or trades, of any material suspension or limitation imposed on trading (by reason of movements in price exceeding limits permitted by the relevant exchange or otherwise) in our common stock or in any options contracts or futures contracts relating to our common stock.

“Maturity date” means July 15, 2025.

“Open of business” means 9:00 a.m., New York City time.

“Person” means any individual, corporation, partnership, limited liability company, joint venture, association, joint-stock company, trust, unincorporated organization or government or other agency or political subdivision thereof. Any division or series of a limited liability company, limited partnership or trust will constitute a separate “person.”

“Redemption notice date” means, with respect to a redemption, the date on which we send the related redemption notice pursuant to the provisions described above under the caption “—Optional Redemption.”

“Scheduled trading day” means any day that is scheduled to be a trading day on the principal U.S. national or regional securities exchange on which our common stock is then listed or, if our common stock is not then listed on a U.S. national or regional securities exchange, on the principal other market on which our common stock is then traded. If our common stock is not so listed or traded, then “scheduled trading day” means a business day.

“SEC” means the Securities and Exchange Commission.

“Securities Act” means the U.S. Securities Act of 1933, as amended.

“Significant subsidiary” of any person means any subsidiary of that person that constitutes, or any group of subsidiaries of that person that, in the aggregate, would constitute, a “significant subsidiary” (as defined in Rule1-02(w) of RegulationS-X under the Exchange Act) of that person.

“Stock price” has the following meaning for any make-whole fundamental change: (i) if the holders of our common stock receive only cash in consideration for their shares of common stock in such make-whole fundamental change and such make-whole fundamental change is pursuant to clause (ii) of the definition of “fundamental change,” then the stock price is the amount of cash paid per share of our common stock in such make-whole fundamental change; and (ii) in all other cases, the stock price is the average of the last reported sale prices per share of common stock for the five consecutive trading days ending on, and including, the trading day immediately before the make-whole fundamental change effective date of such make-whole fundamental change.

“Subsidiary” means, with respect to any person, (i) any corporation, association or other business entity (other than a partnership or limited liability company) of which more than 50% of the total voting power of the capital stock entitled (without regard to the occurrence of any contingency, but after giving effect to any voting

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agreement or stockholders’ agreement that effectively transfers voting power) to vote in the election of directors, managers or trustees, as applicable, of such corporation, association or other business entity is owned or controlled, directly or indirectly, by such person or one or more of the other subsidiaries of such person; and (ii) any partnership or limited liability company where (x) more than 50% of the capital accounts, distribution rights, equity and voting interests, or of the general and limited partnership interests, as applicable, of such partnership or limited liability company are owned or controlled, directly or indirectly, by such person or one or more of the other subsidiaries of such person, whether in the form of membership, general, special or limited partnership or limited liability company interests or otherwise; and (y) such person or any one or more of the other subsidiaries of such person is a controlling general partner of, or otherwise controls, such partnership or limited liability company.

“Trading day” means any day on which (i) trading in our common stock generally occurs on the principal U.S. national or regional securities exchange on which our common stock is then listed or, if our common stock is not then listed on a U.S. national or regional securities exchange, on the principal other market on which our common stock is then traded; and (ii) there is no “market disruption event” (as defined above in this “—Definitions” section). If our common stock is not so listed or traded, then “trading day” means a business day.

“Wholly owned subsidiary” of a person means any subsidiary of such person all of the outstanding capital stock or other ownership interests of which (other than directors’ qualifying shares) are owned by such person or one or more wholly owned subsidiaries of such person.

Book Entry, Settlement and Clearance

Global Notes

The notes will be initially issued in the form of one or more notes registered in the name of Cede & Co., as nominee of DTC, without interest coupons (the “global notes”), and will be deposited with the trustee as custodian for DTC.

Only persons who have accounts with DTC (“DTC participants”) or persons who hold interests through DTC participants may own beneficial interests in a global note. We expect that, under procedures established by DTC:

• upon deposit of a global note with DTC’s custodian, DTC will credit portions of the principal amount of the global note to the accounts of the DTC participants designated by the underwriters; and

• ownership of beneficial interests in a global note will be shown on, and transfers of such interests will be effected only through, records maintained by DTC (with respect to interests of DTC participants) and the records of DTC participants (with respect to other owners of beneficial interests in the global note).

Book-Entry Procedures for Global Notes

All interests in a global note will be subject to the operations and procedures of DTC. Accordingly, you must allow for sufficient time in order to comply with those operations and procedures if you wish to exercise any of your rights with respect to the notes. The operations and procedures of DTC are controlled by DTC and may be changed at any time. None of us, the trustee or any of the underwriters will be responsible for those operations or procedures.

DTC has advised us that it is:

• a limited purpose trust company organized under the laws of the State of New York;

• a “banking organization” within the meaning of the New York State Banking Law;

• a member of the Federal Reserve System;

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• a “clearing corporation” within the meaning of the Uniform Commercial Code; and

• a “clearing agency” registered under Section 17A of the Exchange Act.

DTC was created to hold securities for its participants and to facilitate the clearance and settlement of securities transactions between its participants through electronic book-entry changes to the accounts of its participants. DTC’s participants include securities brokers and dealers (including the underwriters), banks and trust companies, clearing corporations and other organizations. Indirect access to DTC’s book-entry system is also available to other “indirect participants,” such as banks, brokers, dealers and trust companies, who directly or indirectly clear through or maintain a custodial relationship with a DTC participant. Purchasers of notes who are not DTC participants may beneficially own securities held by or on behalf of DTC only through DTC participants or indirect participants in DTC.

So long as DTC or its nominee is the registered owner of a global note, DTC or that nominee will be considered the sole owner or holder of the notes represented by that global note for all purposes under the indenture. Except as provided below, owners of beneficial interests in a global note:

• will not be entitled to have notes represented by the global note registered in their names;

• will not receive or be entitled to receive physical, certificated notes; and

• will not be considered the owners or holders of the notes under the indenture for any purpose.

As a result, each investor who owns a beneficial interest in a global note must rely on the procedures of DTC (and, if the investor is not a participant or an indirect participant in DTC, on the procedures of the DTC participant through whom the investor owns its interest) to exercise any rights of a noteholder under the indenture.

Payments on any global notes will be made to DTC’s nominee as the registered holder of the global note. Neither we nor the trustee (including in its capacity as paying agent) will have any responsibility or liability for the payment of amounts to owners of beneficial interests in a global note, for any aspect of the records relating to, or payments made on account of, those interests by DTC or for maintaining, supervising or reviewing any records of DTC relating to those interests. Payments by participants and indirect participants in DTC to the owners of beneficial interests in a global note will be governed by standing instructions and customary industry practice and will be the responsibility of those participants or indirect participants and DTC.

Transfers between participants in DTC will be effected under DTC’s procedures and will be settled insame-day funds.

Certificated Notes

A global note will be exchanged, pursuant to customary procedures, for one or more physical notes only if:

• DTC notifies us or the trustee that it is unwilling or unable to continue as depositary for such global note or DTC ceases to be a “clearing agency” registered under Section 17A of the Exchange Act and, in each case, we fail to appoint a successor depositary within 90 days of such notice or cessation;

• an event of default has occurred and is continuing and we, the trustee or the registrar has received a written request from DTC, or from a holder of a beneficial interest in such global note, to exchange such global note or beneficial interest, as applicable, for one or more physical notes; or

we, in our sole discretion, permit the exchange of any beneficial interest in such global note for one or more physical notes at the request of the owner of such beneficial interest.

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CONCURRENT COMMON STOCK OFFERING

Concurrently with this offering, we are offering $20.0 million of our common stock (or $23.0 million if the underwriters in that offering exercise their option to purchase additional shares in full) (the “Concurrent Common Stock Offering”) pursuant to a separate prospectus supplement and the accompanying prospectus (collectively, the “Common Stock Prospectus”).

Neither the completion of this notes offering nor the Concurrent Common Stock Offering is contingent on the completion of the other, so it is possible that this notes offering occurs and the Concurrent Common Stock Offering does not occur, and vice versa. We cannot assure you that the Concurrent Common Stock Offering will be completed on the terms described herein, or at all. The Concurrent Common Stock Offering is being made pursuant to a separate prospectus supplement, and nothing contained herein shall constitute an offer to sell or the solicitation of an offer to buy shares of common stock to be issued in the Concurrent Common Stock Offering.

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CERTAIN MATERIAL UNITED STATES FEDERAL INCOME TAX CONSIDERATIONS

The following discussion is a summary of the material U.S. federal income tax considerations relating to the purchase, ownership and disposition of the notes and any common stock received on conversion thereof, but does not purport to be a complete analysis of all potential tax effects and does not address the effects of any state, local, alternative minimum, estate, gift ornon-U.S. tax laws. This discussion is based upon the U.S. Internal Revenue Code of 1986, as amended (the “Code”), Treasury regulations issued thereunder, and judicial and administrative interpretations thereof, each as in effect on the date hereof, and all of which are subject to change, possibly with retroactive effect and to differing interpretations, all of which could result in U.S. federal income tax considerations different from those described below. No rulings from the Internal Revenue Service (“IRS”) have been or are expected to be sought with respect to the matters discussed below. The discussion below is not binding on the IRS or the courts. Accordingly, there can be no assurance that the IRS will not take a different position concerning the tax consequences of the purchase, ownership or disposition of the notes or that any such position would not be sustained.

This discussion does not address all of the U.S. federal income tax considerations that might be relevant to a beneficial owner in light of such beneficial owner’s particular circumstances or to beneficial owners subject to special treatment under the U.S. federal income tax laws, including:

• a dealer in securities;

• a financial institution;

• a regulated investment company;

• a real estate investment trust;

• atax-exempt organization;

• an insurance company;

• a person holding the notes or common stock as part of a hedging, integrated, or conversion transaction or a straddle, or a person deemed to sell notes or common stock under the constructive sale provisions of the Code;

• a trader in securities that has elected themark-to-market method of tax accounting for securities;

• an entity that is treated as a partnership for U.S. federal income tax purposes;

• a person who is a partner or investor in a partnership or other pass-through entity that holds the notes or common stock;

• a U.S. person whose “functional currency” is not the U.S. dollar;

• a controlled foreign corporation;

• a passive foreign investment company;

• a qualified foreign pension fund;

• a person required under Section 451(b) of the Code to conform the timing of income accruals with respect to the notes to their financial statements; or

• a U.S. expatriate.

In addition, this discussion is limited to persons who purchase the notes for cash at original issue and at their “issue price” (the first price at which a substantial amount of the notes is sold to the public for cash, excluding sales to bond houses, brokers or similar persons or organizations acting in the capacity of underwriters, placement agents or wholesalers) and who hold the notes as capital assets within the meaning of Section 1221 of the Code.

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For purposes of this discussion, a “U.S. holder” is a beneficial owner of a note or a share of common stock received upon conversion of the note that is, for U.S. federal income tax purposes:

• an individual who is a citizen or resident of the United States;

• a corporation (or any other entity treated as a corporation for U.S. federal income tax purposes) created or organized in or under the laws of the United States, any state thereof or the District of Columbia;

• an estate the income of which is subject to U.S. federal income taxation regardless of its source; or

• a trust if (1) it is subject to the primary supervision of a court within the United States and one or more U.S. persons have the authority to control all substantial decisions of the trust or (2) it has a valid election in effect under applicable U.S. Treasury regulations to be treated as a U.S. person.

For purposes of this discussion, a“non-U.S. holder” is a beneficial owner (other than a partnership or other pass-through entity) that is not a U.S. holder. Such entities should consult their own tax advisors to determine the U.S. federal, state, local and other tax consequences that may be relevant to them.

If a partnership holds the notes or shares of common stock received on conversion thereof, the tax treatment of a partner will generally depend upon the status of the partner and the activities of the partnership. A partnership holding the notes or shares of common stock or a partner therein should consult its own tax advisors as to the tax consequences of holding and disposing of the notes or shares of common stock received on conversion thereof.

Prospective investors considering the purchase of notes should consult their own tax advisors concerning the particular U.S. federal income tax consequences to them of the ownership of the notes or shares of common stock received on conversion thereof in light of their specific situation, as well as the consequences to them arising under the laws of any other taxing jurisdiction.

U.S. Holders

The following discussion is a summary of certain U.S. federal income tax considerations applicable to a U.S. holder of notes or shares of common stock received on conversion.

Payment of Interest. Payments of stated interest on the notes generally will be taxable to a U.S. holder as ordinary income at the time that such payments are received or accrued, in accordance with such U.S. holder’s method of accounting for U.S. federal income tax purposes.

This discussion assumes that the notes will be issued with less than a de minimis amount of original issue discount. If, however, the notes’ principal amount exceeds the issue price by at least a de minimis amount, as determined under applicable Treasury regulations, a U.S. holder will be required to include such excess of principal amount over issue price in income as original issue discount, as it accrues, in accordance with a constant yield method based on a compounding of interest before the receipt of cash payments attributable to this income.

Additional Interest. As described under the heading “Description of Notes–Events of Default” we may be required to pay additional interest on the notes in certain circumstances. We intend to take the position that the notes should not be treated as contingent payment debt instruments because the anticipated possibility of such additional payments is remote. Assuming such position is respected, any additional interest paid to a U.S. holder would be taxable as additional ordinary income when received or accrued, in accordance with the U.S. holder’s method of accounting for U.S. federal income tax purposes. However, the IRS may take a position contrary to our position, which could materially and adversely affect the timing and character of income with respect to the notes. In particular, if the notes were treated as contingent payment debt instruments, U.S. holders would be required to accrue interest income at a higher rate on the notes and to treat any gain recognized on the sale or other disposition of a note (including any gain realized on the conversion or redemption of a note) as ordinary

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income rather than as capital gain. The remainder of the discussion assumes that the notes are not treated as contingent payment debt instruments.

Sale, Exchange, Redemption, or Other Taxable Disposition of Notes. A U.S. holder will generally recognize gain or loss upon the sale, exchange, redemption, or other taxable disposition of a note equal to the difference between the amount realized upon the sale, exchange, redemption, or other taxable disposition (less an amount equal to any accrued but unpaid interest, which will be taxable as interest income as discussed above to the extent not previously included in income by the U.S. holder) and the U.S. holder’s adjusted U.S. federal income tax basis in the note. A U.S. holder’s adjusted tax basis in a note will generally be its cost for that note plus the amount, if any, included in income on an adjustment to the conversion rate of the notes. Any such gain or loss generally will be capital gain or loss. Capital gains ofnon-corporate U.S. holders (including individuals) derived in respect of capital assets held for more than one year currently are eligible for reduced rates of taxation. The deductibility of capital losses is subject to limitations under the Code.

Conversion of Notes into Common Stock. A U.S. holder who receives solely stock and cash in lieu of a fractional share of common stock upon conversion will generally not recognize any gain or loss, except to the extent of cash received in lieu of a fractional share, which will be taxable as a gain or loss as described below, and except to the extent of the fair market value of common stock received with respect to accrued interest, which will be taxable as interest income as discussed above to the extent not previously included in income by the U.S. holder.

A U.S. holder’s tax basis in the shares of common stock received upon a conversion (other than common stock attributable to accrued interest, the tax basis of which will equal its fair market value) will equal the tax basis in the note that was converted (excluding the portion of the tax basis that is allocable to any fractional share). A U.S. holder’s holding period for shares of common stock will include the period during which the U.S. holder held the notes, except that the holding period of any common stock received with respect to accrued interest will commence on the day after the date of receipt.

The amount of gain or loss recognized on the receipt of cash in lieu of a fractional share will be equal to the difference between the amount of cash a U.S. holder receives in respect of the fractional share and the portion of the U.S. holder’s tax basis in the note that is allocable to the fractional share. Any gain recognized on conversion generally will be capital gain and will be long-term capital gain if, at the time of the conversion, the note has been held for more than one year.

Constructive Distribution. Under Section 305(c) of the Code, depending upon the particular circumstances, certain adjustments (or failures to make adjustments) in the conversion rate of the notes that have the effect of increasing a U.S. holder’s proportionate interest in our assets or earnings may result in a deemed distribution for U.S. federal income tax purposes equal to the fair market value of such increase. In addition, a failure to adjust (or to adjust adequately) the conversion rate after an event that increases a U.S. holder’s proportionate interest could be treated as a deemed distribution. If such adjustment is made pursuant to a bona fide reasonable adjustment formula that has the effect of preventing the dilution of the interest of the beneficial owners of the notes, it generally will not result in a deemed distribution. Any deemed distribution would be taxable as a dividend, return of capital, or capital gain in accordance with the rules discussed below under “Common Stock” regarding distributions. It is not clear whether a constructive dividend deemed paid would be eligible for the preferential rates of U.S. federal income tax applicable to certain dividends paid tonon-corporate beneficial owners. It is also not clear whether corporate beneficial owners would be entitled to claim the dividends-received deduction with respect to any such constructive dividends.

The conversion rate of the notes will be adjusted in certain circumstances, including upon the payment of certain cash distributions and in connection with a make-whole fundamental change. Certain of the possible conversion rate adjustments provided in the notes (including, without limitation, upon the payments of cash distributions to holders of common stock or in connection with a make-whole fundamental change) will not qualify as being pursuant to a bona fide reasonable adjustment formula. If such adjustments are made, depending on the facts at the time, a U.S. holder may be deemed to have received a distribution even though it has not received any cash or

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property because of such adjustments. We do not currently anticipate paying cash distributions for the foreseeable future that could have the result of a U.S. holder receiving a deemed distribution as a result of an adjustment to the conversion rate of the notes, although there can be no assurance in this regard.

We are required to determine the date and amount of any constructive distributions. Proposed Treasury Regulations, on which we may rely prior to the issuance of final Treasury Regulations, specify how the date and amount of constructive distributions are determined, and provide that our determination of those items will generally control the timing and amount of any constructive distributions (or portions thereof) you would be required to include your taxable income.

Common Stock. Distributions, if any, made on our common stock generally will be included in a U.S. holder’s income as ordinary dividend income to the extent of our current or accumulated earnings and profits. However, for individual U.S. holders, such dividends currently are generally taxed at the lower applicable long-term capital gains rates, provided certain holding period and other requirements are satisfied. Distributions in excess of our current and accumulated earnings and profits will be treated as a return of capital to the extent of a U.S. holder’s tax basis in the common stock and thereafter as capital gain from the sale or exchange of such common stock. For corporate holders, dividends received may be eligible for the dividends-received deduction, subject to applicable limitations.

Upon the sale, exchange, or other taxable disposition of our common stock, a U.S. holder generally will recognize capital gain or loss equal to the difference between (i) the amount of cash and the fair market value of any property received upon such taxable disposition and (ii) the U.S. holder’s tax basis in the common stock. Such capital gain or loss will be long-term capital gain or loss if a U.S. holder’s holding period in the common stock is more than one year at the time of the taxable disposition. Long-term capital gains recognized by certainnon-corporate U.S. holders (including individuals) are generally subject to a reduced rate of U.S. federal income tax. The deductibility of capital losses is subject to certain limits under the Code.

Unearned Income Medicare Contribution Tax. Certain U.S. holders who are individuals, estates or trusts will be required to pay an additional 3.8% tax on, among other things, interest and dividends and capital gains from the sale, exchange, redemption, retirement or other taxable disposition of notes and our common stock.

Information Reporting and Backup Withholding. Information reporting requirements generally will apply to payments of interest on the notes, distributions on shares of common stock (including constructive distributions deemed paid) and to the proceeds of a sale of a note or shares of common stock received on conversion thereof unless a U.S. holder is an exempt recipient, such as a corporation. Backup withholding will apply to those payments if a U.S. holder fails to provide its correct taxpayer identification number and certification of exempt status or fails to report in full interest and dividend income. Any amounts withheld under the backup withholding rules will be allowed as a refund or a credit against U.S. federal income tax liability, provided the required information is timely furnished to IRS.

Non-U.S. Holders

The following is a summary of the U. S. federal income tax considerations applicable to anon-U.S. holder (as defined above) of notes or shares of common stock received on conversion thereof.

Payments of Interest. The gross amount of payments to anon-U.S. holder of interest that does not qualify for the portfolio interest exemption and that is not effectively connected with the conduct by suchnon-U.S. holder of a trade or business within the United States (or, if required by an applicable income tax treaty, is not attributable to a permanent establishment of suchnon-U.S. holder in the United States) will be subject to U.S. withholding tax at the rate of 30%, unless a U.S. income tax treaty applies to reduce or eliminate such withholding tax. The 30% U. S. federal withholding tax will not apply to any payment to anon-U.S. holder of interest on a note under the “portfolio interest exemption” provided thenon-U.S. holder:

• does not actually (or constructively) own 10% or more of the total combined voting power of all of our stock entitled to vote;

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• is not a “controlled foreign corporation” with respect to which we are a “related person” within the meaning of the Code; and

• either (1) provides thenon-U.S. holder’s name and address on an IRS FormW-8BEN orW-8BEN-E (or other applicable or successor form), and certifies under penalties of perjury that it is not a U.S. person or (2) owns through a securities clearing organization, bank or other financial institution that holds customers’ securities in the ordinary course of its trade or business that certifies, under penalties of perjury, that such a form has been received from thenon-U.S. holder by it or by a financial institution between it and thenon-U.S. holder.

If anon-U.S. holder is engaged in a trade or business in the United States and interest paid on the note constitutes income that is effectively connected with the conduct of that trade or business (and, if required by an applicable income tax treaty, is attributable to a permanent establishment of thatnon-U.S. holder), or U.S. Trade or Business Income, such interest will be taxed on a net basis at regular graduated U.S. income tax rates rather than the 30% gross rate. In the case of anon-U.S. holder that is a corporation, such U.S. Trade or Business Income may also be subject to the branch profits tax at a 30% rate (or lower applicable income tax treaty rate).

To claim the benefit of a tax treaty exemption from or reduction in withholding, or to claim exemption from withholding because the income is U.S. Trade or Business Income, anon-U.S. holder must provide a properly executed IRS FormW-8BEN,W-8BEN-E orW-8ECI (or such successor forms as the IRS designates), as applicable. Thenon-U.S. holder must provide the form to its withholding agent. These forms must be periodically updated. Anon-U.S. holder who is claiming the benefits of a treaty may be required in certain instances to obtain a U.S. taxpayer identification number and to provide certain documentary evidence issued by foreign governmental authorities to prove residence in the foreign country.

Dividends and Constructive Dividends. Any dividends paid to anon-U.S. holder with respect to shares of our common stock received on conversion of a note (and any deemed dividends resulting from certain adjustments, or failure to make adjustments, to the conversion rate including, without limitation, for cash dividends paid to holders of our common stock, see “—U.S. Holders—Constructive Distribution” above) will be subject to withholding tax at a 30% rate (or lower applicable treaty rate). Because any constructive dividend anon-U.S. holder is deemed to receive would not give rise to any cash from which any applicable withholding tax could be satisfied, this tax would be withheld from any amount owed to thenon-U.S. holder, including, but not limited to, interest payments, cash or shares of common stock otherwise due on conversion, or dividends or sales proceeds subsequently paid or credited to thenon-U.S. holder. Dividends and constructive dividends that constitute U.S. Trade or Business Income and are attributable to a U.S. permanent establishment or a fixed base, are not subject to the withholding tax, but instead are subject to U.S. federal income tax on a net income basis at applicable graduated individual or corporate rates. Certain certification requirements and disclosure requirements must be complied with in order for effectively connected income to be exempt from withholding. Any such effectively connected income received by a foreign corporation may, under certain circumstances, be subject to an additional branch profits tax at a 30% rate (or lower applicable income tax treaty rate). We are required to determine the date and amount of any constructive distributions. Proposed Treasury Regulations, on which we may rely prior to the issuance of final Treasury Regulations, specify how the date and amount of constructive distributions are determined, and provide that our determination of those items will generally control the timing and amount of any constructive distributions (or portions thereof) you would be required to include your taxable income.

Anon-U.S. holder of shares of our common stock who wishes to claim the benefit of an applicable treaty rate is required to satisfy applicable certification and other requirements.Non-U.S. holders eligible for a reduced rate of U.S. withholding tax pursuant to an income tax treaty may obtain a refund of any excess amounts withheld by filing an appropriate claim for refund with the IRS.

Sale, Exchange, Redemption, Conversion or Other Disposition of Notes or Shares of Common Stock. Anon-U.S. holder will recognize gain on the sale, exchange, redemption, or other taxable disposition of notes or shares of

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common stock received on conversion thereof. Nevertheless, such gain generally will not be subject to U.S. federal income tax unless:

• such gain is U.S. Trade or Business Income (as defined above);

• in the case of any gain recognized by an individualnon-U.S. holder, suchnon-U.S. holder is present in the United States for 183 days or more in the taxable year of such sale, exchange, redemption, retirement, conversion, or other disposition and certain other conditions are met; or

• we are or have been a “United States real property holding corporation” for U.S. federal income tax purposes at any time during the shorter of thenon-U.S. holder’s holding period in our common stock or notes and the5-year period ending on the date of such sale, exchange, redemption, retirement, conversion or other disposition of our common stock or notes.

An individualnon-U.S. holder described in the first bullet point above will be subject to tax on the net gain derived from the sale, exchange, redemption, conversion or other taxable disposition under regular U.S. federal income tax rates. An individualnon-U.S. holder described in the second bullet point above will be subject to a flat 30% tax on the gain derived from the sale, exchange, redemption, conversion or other taxable disposition, which may be offset by U.S. source capital losses, even though suchnon-U.S. holder is not considered a resident of the United States. A corporatenon-U.S. holder that falls under the first bullet point above will be subject to tax on any net gain in the same manner as if suchnon-U.S. holder was a U.S. person as defined under the Code and, in addition, may be subject to the branch profits tax equal to 30% of suchnon-U.S. holder’s U.S. Trade or Business Income or at such lower rate as may be specified by an applicable income tax treaty.

We believe that we are not and do not anticipate becoming a “United States real property holding corporation” for U.S. federal income tax purposes.

Any stock that anon-U.S. holder receives on the sale, exchange, redemption, conversion or other disposition of a note that is attributable to accrued interest will not give rise to gain, as described above, but will instead generally be subject to the rules for taxation of interest described above under “—Payments of Interest.”

Information Reporting and Backup Withholding. The amount of interest and distributions paid (including distributions deemed paid) and the amount of tax, if any, withheld with respect to those payments will be reported to thenon-U.S. holder and the IRS. Copies of the information returns reporting such interest and distributions and any withholding may also be made available to the tax authorities in the country in which anon-U.S. holder resides, under the provisions of an applicable income tax treaty.

In general, anon-U.S. holder will not be subject to backup withholding with respect to payments of interest or dividends, provided that the withholding agent does not have actual knowledge or reason to know that suchnon-U.S. holder is a U.S. person, as defined under the Code, and has received the statement described above in the third bullet point under “—Payments of Interest.” In addition, information returns will not be filed with the IRS in connection with the payment of proceeds from a sale or other disposition of the notes or the shares of our common stock unless made within the United States or through certain U.S. related payors. In the case of a payment made within the United States, unless the withholding agent has received the statement described above in the third bullet point under “—Payments of Interest,” anon-U.S. holder may also be subject to U.S. backup withholding on such proceeds.

Any amounts withheld under the backup withholding rules will be allowed as a refund or a credit against anon-U.S. holder’s U.S. federal income tax liability, provided the required information is timely furnished to the IRS.

Withholding on Foreign Accounts. Legislation known as the Foreign Account Tax Compliance Act and guidance issued thereunder (“FATCA”) imposes withholding taxes on certain types of payments made to “foreign

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financial institutions” and certain other foreign entities (including financial intermediaries). FATCA generally imposes withholding at a rate of 30% on payments to certain foreign entities of interest on the notes and dividends on our common stock, unless various U.S. information reporting and due diligence requirements (generally relating to ownership by U.S. persons of interests in or accounts with those entities) have been satisfied or the entity otherwise qualifies for an exemption. An intergovernmental agreement between the United States and an applicable foreign country may modify these requirements. These withholding rules generally apply to payments of interest on the notes and dividends on common stock. Currently proposed regulations provide that FATCA withholding does not apply to gross proceeds from the disposition of property of a type that can produce U.S. source interest or dividends, such as the notes or our common stock; although prior versions of the rules would have made such gross proceeds subject to FATCA withholding. Taxpayers (including withholding agents) can currently rely on the proposed regulations until final regulations are issued. You should consult your tax advisor regarding the application of FATCA.

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UNDERWRITING (CONFLICTS OF INTEREST)

Subject to the terms and conditions set forth in the underwriting agreement, dated June                , 2020, among us and Jefferies LLC and SVB Leerink LLC, as the representatives of the underwriters named below, we have agreed to sell to the underwriters, and each of the underwriters have agreed, severally and not jointly, to purchase from us, the principal amount of notes shown opposite its name below.

UNDERWRITER	PRINCIPAL AMOUNT OF NOTES
Jefferies LLC
SVB Leerink LLC
Total	$	60,000,000

The underwriting agreement provides that the obligations of the several underwriters are subject to certain conditions precedent such as the receipt by the underwriters of officers’ certificates and legal opinions and approval of certain legal matters by their counsel. The underwriting agreement provides that the underwriters will purchase all of the notes offered by us if any of them are purchased. If an underwriter defaults, the underwriting agreement provides that the purchase commitments of thenon-defaulting underwriters may be increased or the underwriting agreement may be terminated. We have agreed to indemnify the underwriters and certain of their controlling persons against certain liabilities, including liabilities under the Securities Act, and to contribute to payments that the underwriters may be required to make in respect of those liabilities.

The notes will constitute a new class of securities with no established trading market. We do not intend to apply for the notes to be listed on any securities exchange or to arrange for the notes to be quoted on any automated quotation system.

The underwriters have advised us that, following the completion of this offering, they currently intend to make a market in the notes, as permitted by applicable laws and regulations. However, the underwriters are not obligated to do so, and the underwriters may discontinue any market-making activities at any time without notice in their sole discretion. Accordingly, no assurance can be given as to the liquidity of the trading market for the notes, that you will be able to sell any of the notes held by you at a particular time or that the prices that you receive when you sell will be favorable.

The underwriters are offering the notes subject to their acceptance of the notes from us and subject to prior sale. The underwriters reserve the right to withdraw, cancel or modify offers to the public and to reject orders in whole or in part.

Commission and Expenses

The underwriters have advised us that they propose to offer the notes to the public at the public offering price set forth on the cover page of this prospectus supplement and to certain dealers, which may include the underwriters, at that price less a concession not in excess of $                per $1,000 principal amount of notes. After the offering, the initial public offering price and concession may be reduced by the underwriters. No such reduction will change the amount of proceeds to be received by us as set forth on the cover page of this prospectus supplement.

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The following table shows the public offering price, the underwriting discounts and commissions that we are to pay the underwriters and the proceeds, before expenses, to us in connection with this offering. Such amounts are shown assuming both no exercise and full exercise of the underwriters’ option to purchase additional notes.

	Per Note		Total
	Without Option to Purchase Additional Notes	With Option to Purchase Additional Notes	Without Option to Purchase Additional Notes	With Option to Purchase Additional Notes
Public offering price	$	$	$	$
Underwriting discounts and commissions paid by us	$	$	$	$
Proceeds to us, before expenses	$	$	$	$

We estimate expenses payable by us in connection with this offering, other than the underwriting discounts and commissions referred to above, will be approximately $0.6 million. We have also agreed to pay the filing fees incident to, and the fees and disbursements of counsel for the underwriters in connection with, the required review by the Financial Industry Regulatory Authority, Inc.

Listing

Our common stock is listed on The Nasdaq Global Select Market under the symbol “XERS.”

Option to Purchase Additional Notes

We have granted to the underwriters an option, exercisable for 30 days from the date of this prospectus supplement, to purchase, from time to time, in whole or in part, up to an additional $9,000,000 principal amount of additional notes from us at the public offering price set forth on the cover page of this prospectus supplement, less underwriting discounts and commissions.

Concurrent Common Stock Offering

Concurrently with the offering of notes being made by this prospectus supplement, we are conducting a public offering of                 shares of common stock (the “Concurrent Common Stock Offering”) (or                shares of common stock if the underwriters in the Concurrent Common Stock Offering exercise their30-day option to purchase up to                 additional shares of common stock in full).

Neither the completion of the offering of notes being made hereby nor the Concurrent Common Stock Offering is contingent on the completion of the other, so it is possible that the notes offering occurs and the Concurrent Common Stock Offering does not occur, and vice versa. We cannot assure you that the Concurrent Common Stock Offering will be completed on the terms described herein, or at all. The Concurrent Common Stock Offering is being made pursuant to a separate prospectus supplement, and nothing contained herein shall constitute an offer to sell or the solicitation of an offer to buy shares of common stock to be issued in the Concurrent Common Stock Offering.

No Sales of Similar Securities

We, our officers and our directors have agreed, subject to specified exceptions, not to directly or indirectly:

• sell, offer, contract or grant any option to sell (including any short sale), pledge, transfer, or establish an open “put equivalent position” within the meaning of Rule16a-l(h) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”);

• otherwise dispose of any shares of common stock, options or warrants to acquire shares of common stock, or securities exchangeable or exercisable for or convertible into shares of common stock currently or hereafter owned either of record or beneficially; or

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• publicly announce an intention to do any of the foregoing for a period of 90 days after the date of this prospectus supplement without the prior written consent of the representatives.

These restrictions terminate after the close of trading of the common stock on and including the 90th day after the date of this prospectus supplement.

The representatives may, in their sole discretion and at any time or from time to time before the termination of the90-day period, release all or any portion of the securities subject tolock-up agreements. There are no existing agreements between the underwriters and any of our shareholders who will execute alock-up agreement providing consent to the sale of shares prior to the expiration of thelock-up period.

Stabilization

In connection with the offering of the notes, the underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the notes. Specifically, the underwriters may over-allot in connection with the offering of the notes, creating a syndicate short position. In addition, the underwriters may bid for, and purchase, notes in the open market to cover syndicate short positions or to stabilize the price of the notes. Finally, the underwriting syndicate may reclaim selling concessions allowed for distributing the notes in the offering, if the syndicate repurchases previously distributed notes in syndicate covering transactions, stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the notes above independent market levels. The underwriters are not required to engage in any of these activities and may end any of them at any time. Neither we nor the underwriters make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of the notes. In addition, neither we nor the underwriters make any representation that the underwriters will engage in such transactions or that such transactions, once commenced, will not be discontinued without notice.

Electronic Distribution

A prospectus supplement and the accompanying prospectus in electronic format may be made available bye-mail or on the web sites or through online services maintained by the underwriters or its affiliates. In those cases, prospective investors may view offering terms online and may be allowed to place orders online. The underwriters may agree with us to allocate a specific number of notes for sale to online brokerage account holders. Any such allocation for online distributions will be made by the underwriters on the same basis as other allocations. Other than the prospectus supplement and the accompanying prospectus in electronic format, the information on the underwriters’ web sites and any information contained in any other web site maintained by the underwriters is not part of this prospectus supplement and the accompanying prospectus, has not been approved and/or endorsed by us or the underwriters and should not be relied upon by investors.

Conflicts of Interest

An affiliate of SVB Leerink LLC is a lender under our Loan Agreement and may receive a portion of the net proceeds of this offering. Because of this relationship, SVB Leerink LLC is deemed to have a “conflict of interest” under the applicable provisions of FINRA Rule 5121. Accordingly, this offering is being conducted in accordance with the applicable provisions of FINRA Rule 5121, including the requirement that a “qualified independent underwriter” participate in the preparation of the prospectus supplement and exercise the usual standards of due diligence in respect thereto. Jefferies LLC has agreed to serve as the qualified independent underwriter for this offering and will not receive any additional fees for serving in that capacity. We have agreed to indemnify Jefferies LLC against liabilities incurred in connection with acting as a qualified independent underwriter, including liabilities under the Securities Act. In accordance with Rule 5121, SVB Leerink LLC will not make sales of the notes to discretionary accounts without the prior written consent of the account holder.

Other Activities and Relationships

The underwriters and certain of their respective affiliates are full-service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory,

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investment management, investment research, principal investment, hedging, financing and brokerage activities. The underwriters are also acting underwriters in the Concurrent Common Stock Offering, for which they will receive fees for acting in that role. Additionally, the underwriters and certain of their respective affiliates have, from time to time, performed, and may in the future perform, various commercial and investment banking and financial advisory services for us and our affiliates, for which they received or may in the future receive customary fees and expenses.

In the ordinary course of their various business activities, the underwriters and certain of their respective affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers, and such investment and securities activities may involve securities and/or instruments issued by us and our affiliates. If the underwriters or their respective affiliates have a lending relationship with us, they may hedge their credit exposure to us consistent with their customary risk management policies. The underwriters and their respective affiliates may hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities or the securities of our affiliates, including potentially the notes offered hereby. Any such short positions could adversely affect future trading prices of the notes offered hereby. The underwriters and certain of their respective affiliates may also communicate independent investment recommendations, market color or trading ideas or publish or express independent research views in respect of such securities or instruments and may at any time hold, or recommend to clients that they acquire, long or short positions in such securities and instruments.

Other than in the United States, no action has been taken by us or the underwriters that would permit a public offering of the securities offered by this prospectus in any jurisdiction where action for that purpose is required. The securities offered by this prospectus supplement may not be offered or sold, directly or indirectly, nor may this prospectus supplement or any other offering material or advertisements in connection with the offer and sale of any such securities be distributed or published in any jurisdiction, except under circumstances that will result in compliance with the applicable rules and regulations of that jurisdiction. Persons into whose possession this prospectus supplement comes are advised to inform themselves about and to observe any restrictions relating to the offering and the distribution of this prospectus supplement. This prospectus supplement does not constitute an offer to sell or a solicitation of an offer to buy any securities offered by this prospectus supplement in any jurisdiction in which such an offer or a solicitation is unlawful.

Disclaimers AboutNon-U.S. Jurisdictions

Canada

A.Resale Restrictions. The distribution of the notes in Canada is being made only in the provinces of Ontario, Quebec, Alberta and British Columbia on a private placement basis exempt from the requirement that we prepare and file a prospectus with the securities regulatory authorities in each province where trades of these securities are made. Any resale of the notes in Canada must be made under applicable securities laws which may vary depending on the relevant jurisdiction, and which may require resales to be made under available statutory exemptions or under a discretionary exemption granted by the applicable Canadian securities regulatory authority. Purchasers are advised to seek legal advice prior to any resale of the securities.

B.Representations of Canadian Purchasers. By purchasing notes in Canada and accepting delivery of a purchase confirmation, a purchaser is representing to and the dealer from whom the purchase confirmation is received that:

• the purchaser is entitled under applicable provincial securities laws to purchase the notes without the benefit of a prospectus qualified under those securities laws as it is an “accredited investor” as defined under NationalInstrument 45-106 — Prospectus Exemptions;

• the purchaser is a “permitted client” as defined in NationalInstrument 31-103 — Registration Requirements, Exemptions and Ongoing Registrant Obligations;

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• where required by law, the purchaser is purchasing as principal and not as agent; and

• the purchaser has reviewed the text above under Resale Restrictions.

C.Conflicts of Interest. Canadian purchasers are hereby notified that the underwriters are relying on the exemption set out in section 3A.3 or 3A.4, if applicable, of NationalInstrument 33-105 — Underwriting Conflicts from having to provide certain conflict of interest disclosure in this document.

D.Statutory Rights of Action. Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

E.Enforcement of Legal Rights. All of our directors and officers as well as the experts named herein may be located outside of Canada and, as a result, it may not be possible for Canadian purchasers to effect service of process within Canada upon us or those persons. All or a substantial portion of our assets and the assets of those persons may be located outside of Canada and, as a result, it may not be possible to satisfy a judgment against us or those persons in Canada or to enforce a judgment obtained in Canadian courts against us or those persons outside of Canada.

F.Taxation and Eligibility for Investment. Canadian purchasers of notes should consult their own legal and tax advisors with respect to the tax consequences of an investment in the company in their particular circumstances and about the eligibility of the notes for investment by the purchaser under relevant Canadian legislation.

Australia

This prospectus supplement is not a disclosure document for the purposes of Australia’s Corporations Act 2001 (Cth) of Australia, or Corporations Act, has not been lodged with the Australian Securities & Investments Commission and is only directed to the categories of exempt persons set out below. Accordingly, if you receive this prospectus supplement in Australia, you confirm and warrant that you are either:

• a “sophisticated investor” under section 708(8)(a) or (b) of the Corporations Act;

• a “sophisticated investor” under section 708(8)(c) or (d) of the Corporations Act and that you have provided an accountant’s certificate to the company which complies with the requirements of section 708(8)(c)(i) or (ii) of the Corporations Act and related regulations before the offer has been made;

• a person associated with the Company under Section 708(12) of the Corporations Act; or

• a “professional investor” within the meaning of section 708(11)(a) or (b) of the Corporations Act.

To the extent that you are unable to confirm or warrant that you are an exempt sophisticated investor, associated person or professional investor under the Corporations Act, any offer made to you under this prospectus supplement is void and incapable of acceptance.

You warrant and agree that you will not offer any of the securities issued to you pursuant to this prospectus supplement for resale in Australia within 12 months of those securities being issued unless any such resale offer is exempt from the requirement to issue a disclosure document under section 708 of the Corporations Act.

European Economic Area

In relation to each Member State of the European Economic Area (each, a “Relevant Member State”), no offer of notes may be made to the public in that Relevant Member State other than:

(a) to any legal entity which is a “qualified investor” as defined in the Prospectus Directive;

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(b) to fewer than 100 or, if the Relevant Member State has implemented the relevant provision of the 2010 PD Amending Directive, 150 natural or legal persons (other than qualified investors as defined in the Prospectus Directive), as permitted under the Prospectus Directive, subject to obtaining the prior consent of the underwriters; or

(c) in any other circumstances falling within Article 3(2) of the Prospectus Directive, provided that no such offer of notes shall require the Company or the underwriters to publish a prospectus pursuant to Article 3 of the Prospectus Directive or supplement a prospectus pursuant to Article 16 of the Prospectus Directive.

Each person in a Relevant Member State who initially acquires any notes or to whom any offer is made will be deemed to have represented, acknowledged and agreed to and with each of the underwriters and the Company that it is a “qualified investor” within the meaning of the law in that Relevant Member State implementing Article 2(1)(e) of the Prospectus Directive. In the case of any notes being offered to a financial intermediary as that term is used in Article 3(2) of the Prospectus Directive, each such financial intermediary will be deemed to have represented, acknowledged and agreed that the notes acquired by it in the offer have not been acquired on anon-discretionary basis on behalf of, nor have they been acquired with a view to their offer or resale to, persons in circumstances which may give rise to an offer of any notes to the public other than their offer or resale in a Relevant Member State to qualified investors as so defined or in circumstances in which the prior consent of the underwriters has been obtained to each such proposed offer or resale.

For the purposes of this provision, the expression an “offer of notes to the public” in relation to any notes in any Relevant Member State means the communication in any form and by any means of sufficient information on the terms of the offer and the notes to be offered so as to enable an investor to decide to purchase or to subscribe the notes, as the same may be varied in the Relevant Member State by any measure implementing the Prospectus Directive in the Relevant Member State. The expression “Prospectus Directive” means Directive 2003/71/EC (as amended by Directive 2010/73/EU), and includes any relevant implementing measure in the Relevant Member State.

Hong Kong

No securities have been offered or sold, and no securities may be offered or sold, in Hong Kong, by means of any document, other than to persons whose ordinary business is to buy or sell securities, whether as principal or agent; or to “professional investors” as defined in the Securities and Futures Ordinance (Cap. 571) of Hong Kong, or the SFO, and any rules made under that Ordinance; or in other circumstances which do not result in the document being a “prospectus” as defined in the Companies Ordinance (Cap. 32) of Hong Kong, or the CO, or which do not constitute an offer or invitation to the public for the purpose of the CO or the SFO. No document, invitation or advertisement relating to the securities has been issued or may be issued or may be in the possession of any person for the purpose of issue (in each case whether in Hong Kong or elsewhere), which is directed at, or the contents of which are likely to be accessed or read by, the public of Hong Kong (except if permitted under the securities laws of Hong Kong) other than with respect to securities which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” as defined in the SFO and any rules made under that Ordinance.

This prospectus supplement has not been registered with the Registrar of Companies in Hong Kong. Accordingly, this prospectus supplement may not be issued, circulated or distributed in Hong Kong, and the securities may not be offered for subscription to members of the public in Hong Kong. Each person acquiring the securities will be required, and is deemed by the acquisition of the securities, to confirm that he is aware of the restriction on offers of the securities described in this prospectus supplement and the relevant offering documents and that he is not acquiring, and has not been offered any securities in circumstances that contravene any such restrictions.

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Israel

This document does not constitute a prospectus under the Israeli Securities Law, 5728-1968, or the Securities Law, and has not been filed with or approved by the Israel Securities Authority. In Israel, this prospectus is being distributed only to, and is directed only at, and any offer of the notes is directed only at, (i) a limited number of persons in accordance with the Israeli Securities Law and (ii) investors listed in the first addendum, or the Addendum, to the Israeli Securities Law, consisting primarily of joint investment in trust funds, provident funds, insurance companies, banks, portfolio managers, investment advisors, members of the Tel Aviv Stock Exchange, underwriter, venture capital funds, entities with equity in excess of NIS 50 million and “qualified individuals,” each as defined in the Addendum (as it may be amended from time to time), collectively referred to as qualified investors (in each case, purchasing for their own account or, where permitted under the Addendum, for the accounts of their clients who are investors listed in the Addendum). Qualified investors are required to submit written confirmation that they fall within the scope of the Addendum, are aware of the meaning of same and agree to it.

Japan

This offering has not been and will not be registered under the Financial Instruments and Exchange Law of Japan (Law No. 25 of 1948 of Japan, as amended), or FIEL, and the underwriters will not offer or sell any securities, directly or indirectly, in Japan or to, or for the benefit of, any resident of Japan (which term as used herein means any person resident in Japan, including any corporation or other entity organized under the laws of Japan), or to others forre-offering or resale, directly or indirectly, in Japan or to, or for the benefit of, any resident of Japan, except pursuant to an exemption from the registration requirements of, and otherwise in compliance with, the FIEL and any other applicable laws, regulations and ministerial guidelines of Japan.

Singapore

This prospectus supplement has not been and will not be lodged or registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus supplement and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the notes may not be circulated or distributed, nor may the notes be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore, or the SFA, (ii) to a relevant person pursuant to Section 275(1), or any person pursuant to Section 275(1A), and in accordance with the conditions specified in Section 275, of the SFA, or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA.

Where the notes are subscribed or purchased under Section 275 of the SFA by a relevant person which is:

(a) a corporation (which is not an accredited investor (as defined in Section 4A of the SFA)) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor; or

(b) a trust (where the trustee is not an accredited investor) whose sole purpose is to hold investments and each beneficiary of the trust is an individual who is an accredited investor, securities (as defined in Section 239(1) of the SFA) of that corporation or the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferred within six months after that corporation or that trust has acquired the notes pursuant to an offer made under Section 275 of the SFA except:

(i) to an institutional investor or to a relevant person defined in Section 275(2) of the SFA, or to any person arising from an offer referred to in Section 275(1A) or Section 276(4)(i)(B) of the SFA;

(ii) where no consideration is or will be given for the transfer;

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(iii) where the transfer is by operation of law;

(iv) as specified in Section 276(7) of the SFA; or

(v) as specified in Regulation 32 of the Securities and Futures (Offers of Investments) (Shares and Debentures) Regulations 2005 of Singapore.

Switzerland

The securities may not be publicly offered in Switzerland and will not be listed on the SIX Swiss Exchange, or the SIX, or on any other stock exchange or regulated trading facility in Switzerland. This prospectus supplement has been prepared without regard to the disclosure standards for issuance prospectuses under art. 652a or art. 1156 of the Swiss Code of Obligations or the disclosure standards for listing prospectuses under art. 27 ff. of the SIX Listing Rules or the listing rules of any other stock exchange or regulated trading facility in Switzerland. Neither this prospectus supplement nor any other offering or marketing material relating to the securities or this offering may be publicly distributed or otherwise made publicly available in Switzerland.

Neither this prospectus supplement nor any other offering or marketing material relating to this offering, the company or the securities have been or will be filed with or approved by any Swiss regulatory authority. In particular, this prospectus supplement will not be filed with, and the offer of securities will not be supervised by, the Swiss Financial Market Supervisory Authority FINMA, and the offer of securities has not been and will not be authorized under the Swiss Federal Act on Collective Investment Schemes, or the CISA. The investor protection afforded to acquirers of interests in collective investment schemes under the CISA does not extend to acquirers of securities.

United Kingdom

This prospectus supplement is only being distributed to, and is only directed at, persons in the United Kingdom that are qualified investors within the meaning of Article 2(1)(e) of the Prospectus Directive that are also (i) investment professionals falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005, as amended, or the Order, and/or (ii) high net worth entities falling within Article 49(2)(a) to (d) of the Order and other persons to whom it may lawfully be communicated (each such person being referred to as a relevant person).

This prospectus supplement and its contents are confidential and should not be distributed, published or reproduced (in whole or in part) or disclosed by recipients to any other persons in the United Kingdom. Any person in the United Kingdom that is not a relevant person should not act or rely on this document or any of its contents.

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LEGAL MATTERS

The validity of the notes offered hereby and the shares of common stock issuable upon conversion of the notes will be passed upon for us by Goodwin Procter LLP, Boston, Massachusetts. Certain legal matters with respect to this offering will be passed upon for the underwriters by Wilmer Cutler Pickering Hale and Dorr LLP, New York, New York.

EXPERTS

The consolidated financial statements of Xeris Pharmaceuticals, Inc. as of December 31, 2019 and 2018 and for each of the years in thetwo-year period ended December 31, 2019, have been incorporated by reference herein in reliance upon the report of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

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WHERE YOU CAN FIND MORE INFORMATION

We are subject to the information requirements of the Exchange Act and, in accordance therewith, file annual, quarterly and special reports, proxy statements and other information with the SEC. These documents may be accessed through the SEC’s electronic data gathering, analysis and retrieval system, or EDGAR, via electronic means, including the SEC’s home page on the Internet (www.sec.gov). Copies of certain information filed by us with the SEC are also available on our website athttp://www.xerispharma.com.The information contained on our website is not incorporated by reference into this prospectus supplement and, therefore, is not part of this prospectus supplement.

This prospectus supplement is part of a registration statement that we have filed with the SEC. Certain information in the registration statement has been omitted from this prospectus supplement in accordance with SEC rules and regulations. For more detail about us and any securities that may be offered by this prospectus supplement, you may examine the registration statement on FormS-3 and the exhibits filed with it at the locations listed in the previous paragraph. Please be aware that statements in this prospectus supplement referring to a contract or other document are summaries and you should refer to the exhibits that are part of the registration statement for a copy of the contract or document.

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INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to incorporate by reference the information and reports we file with it, which means that we can disclose important information to you by referring you to these documents. The information incorporated by reference is considered to be a part of this prospectus supplement, and the information that we file later with the SEC will automatically update and, where applicable, supersede the information already incorporated by reference. We incorporate by reference the documents listed below that we filed with the SEC:

• our Annual Report onForm10-K for the year ended December 31, 2019 filed with the SEC on March 12, 2020;

• the information specifically incorporated by reference into our Annual Report on Form10-K for the year ended December 31, 2019 from our definitive proxy statement onSchedule 14A (other than information furnished rather than filed) filed with the SEC on April 24, 2020;

• our Quarterly Report onForm10-Q for the quarter ended March 31, 2020 filed with the SEC on May 7, 2020;

• our Current Reports on Form8-K filed with the SEC onFebruary 11, 2020 (only with respect to Item 8.01),February  13, 2020,April  10, 2020 (only with respect to Item 5.02),April  24, 2020, andJune 4, 2020;

• the description of our common stock contained in our registration statement onForm8-A filed with the SEC on June 18, 2018, including any amendments or reports filed for the purposes of updating this description; and

• all future documents filed by us with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, including all filings made after the date of the filing of this registration statement and prior to the effectiveness of this registration statement or prior to the termination of the offering of the underlying securities; provided, however, that we are not incorporating by reference any additional documents or information furnished and not filed with the SEC.

Upon request, either orally or in writing, we will provide, without charge, to each person, including any beneficial owner, to whom a copy of this prospectus supplement is delivered, a copy of the documents incorporated by reference into this prospectus supplement but not delivered with the prospectus. You may request a copy of these filings, and any exhibits we have specifically incorporated by reference as an exhibit in this prospectus supplement, at no cost by writing us at the following address: Xeris Pharmaceuticals, Inc., 180 N. LaSalle Street, Suite 1600, Chicago, IL 60601.

You should rely only on the information incorporated by reference or provided in this prospectus supplement. We have not authorized anyone to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus supplement or in the documents incorporated by reference is accurate as of any date other than the date on the front of this prospectus supplement or those documents.

S-84

PROSPECTUS

$250,000,000

Common Stock

Preferred Stock

Debt Securities

Warrants

Units

We may from time to time issue, in one or more series or classes, up to $250.0 million in aggregate principal amount of our common stock, preferred stock, debt securities, warrants and/or units, in any combination, together or separately, in one or more offerings in amounts, at prices and on the terms that we will determine at the time of the offering and which will be set forth in a prospectus supplement and any related free writing prospectus.

We may offer these securities separately or together in units. Each time we sell securities described herein, we will provide prospective investors with a supplement to this prospectus that will specify the terms of the securities being offered. We may sell these securities to or through underwriters or dealers and also to other purchasers or through agents. We will set forth the names of any underwriters or agents, and any fees, conversions, or discount arrangements, in the accompanying prospectus supplement. We may not sell any securities under this prospectus without delivery of the applicable prospectus supplement. You should read this document and any prospectus supplement or amendment carefully before you invest in our securities.

Our common stock is listed on The Nasdaq Global Select Market under the symbol “XERS.” On August 2, 2019, the closing price for our common stock, as reported on The Nasdaq Global Select Market, was $10.75 per share. Our principal executive offices are located at 180 N. LaSalle Street, Suite 1600, Chicago, IL 60601.

Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” contained in this prospectus beginning on page 2 and any applicable prospectus supplement, and under similar headings in the other documents that are incorporated by reference into this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this Prospectus is August 21, 2019

TABLE OF CONTENTS

	Page
ABOUT THIS PROSPECTUS		1
RISK FACTORS		2
CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS		3
THE COMPANY		5
USE OF PROCEEDS		9
SECURITIES WE MAY OFFER		10
DESCRIPTION OF CAPITAL STOCK		11
DESCRIPTION OF DEBT SECURITIES		17
DESCRIPTION OF WARRANTS		25
DESCRIPTION OF UNITS		26
PLAN OF DISTRIBUTION		29
LEGAL MATTERS		32
EXPERTS		32
WHERE YOU CAN FIND MORE INFORMATION		33
INCORPORATION BY REFERENCE		34

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, or the SEC, using a “shelf” registration process. Under this shelf registration process, we may from time to time sell any combination of the securities described in this prospectus in one or more offerings for an aggregate initial offering price of up to $250.0 million.

This prospectus provides you with a general description of the securities we may offer. Each time we sell securities described herein, we will provide one or more prospectus supplements that will contain specific information about the terms of the offering. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and the accompanying prospectus supplement together with the additional information described under the heading “Where You Can Find More Information” and “Incorporation By Reference.”

You should rely only on the information contained in or incorporated by reference in this prospectus or any accompanying prospectus supplement or in any related free writing prospectus filed by us with the SEC. We have not authorized anyone to provide you with different information. This prospectus and the accompanying prospectus supplement do not constitute an offer to sell or the solicitation of an offer to buy any securities other than the securities described in the accompanying prospectus supplement or an offer to sell or the solicitation of an offer to buy such securities in any circumstances in which such offer or solicitation is unlawful. You should assume that the information appearing in this prospectus, any prospectus supplement, the documents incorporated by reference and any related free writing prospectus is accurate only as of their respective dates. Our business, financial condition, results of operations and prospects may have changed materially since those dates.

THIS PROSPECTUS MAY NOT BE USED TO OFFER AND SELL SECURITIES UNLESS IT IS ACCOMPANIED BY AN ADDITIONAL PROSPECTUS OR A PROSPECTUS SUPPLEMENT.

As used in this prospectus, unless the context otherwise requires, references to the “company,” “we,” “us” and “our” refer to Xeris Pharmaceuticals, Inc., and, where appropriate, our subsidiary.

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RISK FACTORS

Investing in our securities involves a high degree of risk. You should carefully consider the risks described in the documents incorporated by reference in this prospectus and any prospectus supplement, as well as other information we include or incorporate by reference into this prospectus and any applicable prospectus supplement, before making an investment decision. Our business, financial condition or results of operations could be materially adversely affected by the materialization of any of these risks. The trading price of our securities could decline due to the materialization of any of these risks, and you may lose all or part of your investment. This prospectus and the documents incorporated herein by reference also contain forward-looking statements that involve risks and uncertainties. Actual results could differ materially from those anticipated in these forward-looking statements as a result of certain factors, including the risks described in the documents incorporated herein by reference, including (i) our annual report onForm 10-K for the fiscal year ended December 31, 2018, which is on file with the SEC and is incorporated herein by reference, (ii) our quarterly report on Form10-Q for the fiscal quarters ended March 31, 2019 and June 30, 2019, respectively, which are on file with the SEC and are incorporated herein by reference and (iii) other documents we file with the SEC that are deemed incorporated by reference into this prospectus.

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CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, including the documents that we incorporate by reference, contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. Any statements about our expectations, beliefs, plans, objectives, assumptions or future events or performance are not historical facts and may be forward-looking. These statements are often, but are not always, made through the use of words or phrases such as “may,” “will,” “could,” “should,” “expects,” “intends,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “projects,” “seeks,” “endeavor,” “potential,” “continue,” and similar expressions, or the negative of these terms, or similar expressions. Accordingly, these statements involve estimates, assumptions, risks and uncertainties which could cause actual results to differ materially from those expressed in them. Any forward-looking statements are qualified in their entirety by reference to the factors discussed throughout this prospectus, and in particular those factors referenced in the section “Risk Factors.”

This prospectus contains forward-looking statements that are based on our management’s belief and assumptions and on information currently available to our management. These statements relate to future events or our future financial performance, and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to be materially different from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Forward-looking statements include, but are not limited to, statements about:

• the timing or likelihood of approval by the U.S. Food and Drug Administration of our New Drug Application for Gvoke;

• our estimates regarding the market opportunities for our product candidates;

• the commercialization, marketing and manufacturing of our product candidates, if approved;

• the pricing and reimbursement of Gvoke or any other of our product candidates, if approved;

• the rate and degree of market acceptance and clinical utility of Gvoke or any other of our product candidates for which we receive marketing approval;

• the initiation, timing, progress and results of our research and development programs and future preclinical and clinical studies;

• our ability to advance any other product candidates into, and successfully complete, clinical studies and obtain regulatory approval for them;

• our ability to identify additional product candidates;

• the implementation of our strategic plans for our business, product candidates and technology;

• the scope of protection we are able to establish and maintain for intellectual property rights covering our product candidates and technology;

• our ability to use the proceeds of this offering in ways that increase the value of your investment;

• our expectations related to the use of proceeds from this offering, and estimates of our expenses, future revenues, capital requirements and our needs for additional financing;

• our ability to manufacture, or the ability of third parties to deliver, sufficient quantities of components and drug product for commercialization of Gvoke or any other of our product candidates;

• our ability to maintain and establish collaborations;

• our financial performance;

• our ability to effectively manage our anticipated growth;

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• developments relating to our competitors and our industry, including the impact of government regulation;

• our ability to avoid any findings of material weakness or significant deficiencies we may find in the future; and

• other risks and uncertainties, including those listed under the caption “Risk Factors.”

This prospectus and the documents incorporated by reference also contain estimates, projections and other information concerning our industry, our business and the markets for certain diseases, including data regarding the estimated size of those markets and the incidence and prevalence of certain medical conditions. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties and actual events or circumstances may differ materially from events and circumstances reflected in this information. Unless otherwise expressly stated, we obtained this industry, business, market and other data from reports, research surveys, studies and similar data prepared by market research firms and other third parties, industry, medical and general publications, government data and similar sources.

You should read this prospectus and the documents that we incorporate by reference in this prospectus completely and with the understanding that our actual future results may be materially different from what we expect. The forward-looking statements in this prospectus and the documents we incorporate by reference herein represent our views as of their respective dates. We anticipate that subsequent events and developments will cause our views to change. However, while we may elect to update these forward-looking statements at some point in the future, we have no current intention of doing so except to the extent required by applicable law. You should, therefore, not rely on these forward-looking statements as representing our views as of any date subsequent to the date of this prospectus.

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THE COMPANY

We are a specialty pharmaceutical company leveraging our novelnon-aqueous formulation technology platforms, XeriSol and XeriJect, to develop and commercializeready-to-use injectable and infusible drug formulations. We have developed aready-to-use, room-temperature stable liquid glucagon formulation that, unlike any currently available products, can be administered without any preparation or reconstitution. Our lead product candidate, Gvoke, deliversready-to-use glucagon via a commercially available auto-injector orpre-filled syringe for the treatment of severe hypoglycemia, a potentially life-threatening condition, in people with diabetes. We have completed three Phase 3 clinical trials for Gvoke for our New Drug Application, or NDA, which we submitted in August 2018 to the U.S. Food & Drug Administration, or the FDA. The FDA set June 10, 2019 as the Prescription Drug User Fee Act, or PDUFA, action goal date for our NDA, which date was extended to September 10, 2019. If our NDA is approved at that time, we believe we will have the firstready-to-use, room-temperature stable liquid glucagon formulation that can be administered without any preparation or reconstitution. Additionally, based on our interactions with the European Medicines Agency, or EMA, regarding our development path in Europe, we completed a requisite Phase 3 trial to support our European Marketing Authorization Application, or MAA, which we plan to submit in the second half of 2019. We also are applying our novelready-to-use, room-temperature stable liquid glucagon formulation for the management of hypoglycemia associated with additional intermittent and chronic conditions with significant unmet medical need. In addition, we are applying our technology platforms to convert other commercially-available drugs intoready-to-use, room-temperature stable liquid formulations to address the needs in multiple therapeutic areas and conditions, including epilepsy and diabetes. We own the worldwide rights to our proprietary formulation technology platforms and our product candidates, with 108 patents issued globally, including a composition of matter patent covering ourready-to-use glucagon formulation that expires in 2036.

Our proprietary XeriSol and XeriJectnon-aqueous formulation technologies allow for the subcutaneous, or SC, and intramuscular, or IM, delivery of highly-concentrated,ready-to-use formulations of peptides, small molecules, proteins, and antibodies using commercially-available syringes, auto-injectors, multi-dose pens and infusion pumps. Current aqueous formulations of certain drugs present numerous challenges for patients and care providers, including multi-step reconstitution, refrigeration requirements, large injection volumes and intravenous, or IV, administration over several hours. Our broadly-applicable platforms offer the opportunity to eliminate reconstitution and refrigeration, enable long-term room-temperature stability, significantly reduce injection volume and allow for a more convenient SC or IM administration as opposed to IV infusion, all of which we believe are distinct advantages over these existing aqueous formulations. We believe that our technology platforms can lead to products that will improve outcomes and enable easier administration while reducing costs for payors and the healthcare system.

Our key priority is developing and commercializing our lead product candidate, Gvoke, for the treatment of severe hypoglycemia in people with diabetes to address limitations of currently marketed emergency glucagon kits. Hypoglycemia, a key concern of people with both Type 1 Diabetes, or T1D, and Type 2 Diabetes, or T2D, occurs when a person has a deficiency of glucose in their bloodstream, often as a result of insulin treatment. Symptoms of hypoglycemia include fatigue, shakiness, anxiety, headache, nausea and vomiting, and in severe cases, hypoglycemia can result in cardiovascular disease, seizure, coma, and, if left untreated, death. The current standard of care for severe hypoglycemia in the ambulatory setting is the emergency administration of glucagon, a hormone that raises the concentration of glucose in the bloodstream. Currently marketed emergency glucagon kits consist of a glucagon powder that must be reconstituted with a liquid diluent and drawn into a syringe using a multi-step procedure that can be difficult to successfully administer, particularly in an emergency. In published comparative human factors studies with currently marketed kits, only 6% to 31% of users were able to successfully administer the full dose of glucagon. In other words, in these studies, test subjects failed to deliver the full dose of glucagon 69% to 94% of the time. The underuse or unsuccessful use of currently marketed kits leaves people at risk of experiencing prolonged severe hypoglycemic events, which if left untreated, can lead to serious health consequences and death.

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We believe Gvoke addresses the administration challenges of currently marketed products, and, if approved, has the potential to be the preferred emergency glucagon product. Ourready-to-use Gvoke does not require reconstitution or refrigeration and featurestwo-year room-temperature stable liquid glucagon delivered in an auto-injecting device with no visible needle or apre-filled syringe. In our human factors studies 99% of users were able to successfully administer the full dose with ourready-to-use Gvoke.

Our goal is to establish Gvoke, if approved, as the preferred emergency glucagon product and drive greater adoption and penetration of emergency glucagon therapy by offering a glucagon product that better meets the needs of patients and caregivers. The American Diabetes Association, or ADA, recommends that glucagon be prescribed for all individuals at increased risk of clinically significant hypoglycemia for use in the event of an emergency. People with diabetes who are treated with insulin or substances that promote production of insulin are at increased risk of clinically significant hypoglycemia. There are an estimated 1.3 million people with T1D who are treated with insulin because their bodies do not naturally produce insulin, all of whom are clinically appropriate for glucagon. Approximately 4.3 million additional people with T2D are treated with insulin because their bodies do not use insulin properly, of which we estimate that approximately 50% are clinically appropriate for glucagon. Therefore, we estimate the potential target population for emergency glucagon therapy totals approximately 3.5 million people in the United States. Our commercial strategy is to penetrate this market efficiently with a concentrated sales force by targeting high prescribers of glucagon and mealtime insulin and activate demand through targeteddirect-to-patient promotion. We also plan to use our medical affairs team to actively drive market access and obtain payor coverage for Gvoke.

Due to the limitations of currently marketed products, only approximately 662,000 total prescriptions for emergency glucagon kits were written in 2018 in the United States, resulting in the purchase of approximately 978,000 single-dose kits. Based on our market research, we intend to market two Gvokes per package and to target all 3.5 million people that we believe are clinically appropriate for glucagon. In 2018, U.S. sales for emergency glucagon kits were approximately $246 million, but we believe that increasing penetration, including by new entrants that address unmet patient and caregiver needs such as Gvoke, may result in a potential sales opportunity totaling up to $2.0 billion. Outside the United States, we estimate there are an additional 3.5 million people with diabetes in Europe and an additional 12.5 million people with diabetes in Japan and China that are clinically appropriate for emergency glucagon treatment. Following the receipt of EMA scientific advice, in the first half of 2019 we completed a requisite Phase 3 trial of our glucagon auto-injector to support our European MAA and plan to submit the MAA for approval in the second half of 2019. We plan to pursue development and commercialization collaborations for all thenon-U.S. markets we seek to enter.

We are also applying our glucagon formulation to five intermittent and chronic use conditions with significant unmet medical need. In 2018 and 2019, all five development programs either produced positive clinical trial results or advanced into clinical trials. We plan to continue to advance all five of these programs going forward. These additional applications are:

• Post-Bariatric Hypoglycemia, or PBH, a serious complication of bariatric surgery that can arise from excessive insulin, or hyperinsulinism, due to the change in gastric anatomy resulting from bariatric surgery.

• Congenital Hyperinsulinism, or CHI, a condition caused by several genetic defects that result in severe, persistent hypoglycemia in infants and children, which can lead to brain damage and death.

• Hypoglycemia-Associated Autonomic Failure, or HAAF, in which chronic hypoglycemia impairs the body’s natural response to restore blood sugar levels and can lead to an individual becoming unaware of the onset of a severe hypoglycemic event and result in cardiovascular disease, seizure, coma, and, if left untreated, death.

• Exercise-Induced Hypoglycemia, or EIH, in people with diabetes. Exercise, particularly aerobic exercise, often results in a significant drop in blood glucose levels for people on insulin.

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• Management of diabetes via glucagon in a fully-integrated,bi-hormonal artificial pancreas closed-loop system.

By applying ourready-to-use glucagon to treat multiple conditions, we expect to leverage operating efficiencies across our supply chain, research and development, and commercial and medical organizations.

We also are applying our technology platforms to develop additional product candidates, such asready-to-use, liquid-stable diazepam delivered via a commercially-available auto-injector for the emergency treatment of epileptic seizures, for which we have completed a Phase 1 study and plan to initiate a Phase 2 study in the second half of 2019, and a fixed-doseco-formulation of pramlintide and insulin, or Pram-Insulin, for the management of diabetes. Additionally, based on the promising data seen in some of our early clinical trials as well as formulations in our laboratory, we believe we have the potential to advance a number of additional programs in additional indications and that our strong product candidate portfolio, complemented by external expansion opportunities, will support our vision to effectively and efficiently meet the needs of our target markets.

The nature of our product candidates and target conditions provides us with a potentially faster and capital-efficient development and regulatory pathway to approval. The FDA has granted orphan drug status to four indications for our product candidates, which are ourready-to-use glucagon for PBH and CHI and ourready-to-use, liquid-stable formulation of diazepam for the treatment of Dravet Syndrome and acute repetitive seizures, or ARS, in patients with epilepsy. Additionally, we have received orphan drug designation from the EMA for CHI and Noninsulinoma Pancreatogenous Hypoglycaemia Syndrome, or NIPHS, which includes patients with PBH.

In the United States, this designation provides us with research and development tax credits and exemption from FDA user fees, as well as seven years of orphan drug exclusivity upon product approval. In the EU, this designation provides us with ten years of market exclusivity upon product approval (although it may be reduced to six years if, at the end of the fifth year, it is established that the criteria for orphan drug designation are no longer met; in other words, when it is shown on the basis of available evidence that the product is sufficiently profitable not to justify maintenance of market exclusivity); a single MAA application to the EMA through centralized review; and the potential for reduced regulatory review fees. In addition, because certain conditions that we intend to target are rare conditions, we believe our clinical trials may be of smaller size than studies for conditions that are not rare conditions. Furthermore, because the product candidates developed using our technology platforms are designed to be reformulations of currently approved products, in the United States we expect to utilize the FDA’s pathway under Section 505(b)(2) of the U.S. Federal Food, Drug and Cosmetic Act, or the FDCA, which permits submissions to rely, in part, on the safety and effectiveness of a previously approved product, which may potentially result in a more expeditious pathway to FDA approval. Similarly, in the EU, we intend to submit an MAA through the Centralised Procedure via Article 8(3) - Full Mixed Dossier, which offers data protection and market exclusivity for up to 11 years.

Our management team includes veterans in drug development, discovery and commercialization, with executive experience in leading global pharmaceutical and healthcare companies, including Durata Therapeutics, Baxter Healthcare, Merck, Searle, Takeda, Warner Chilcott, MedPointe Healthcare, Amylin Pharmaceuticals, PowderJect Technologies and Alpharma.

We qualify as an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act, and we have elected to take advantage of specified reduced disclosure and other requirements that are otherwise applicable generally to public companies. We may remain an “emerging growth company” until the fiscalyear-end following the fifth anniversary of the completion of our IPO, though we may cease to be an “emerging growth company” earlier under certain circumstances, including (i) if the market value of our common stock that is held by non-affiliates exceeds $700 million as of any June 30, in which case we would cease to be an “emerging growth company” as of the following January 1, or (ii) if our gross revenue exceeds $1.07 billion in any fiscal year.

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We were incorporated under the laws of the State of Delaware in 2005. Our principal offices are located at 180 N. LaSalle Street, Suite 1600, Chicago, Illinois 60601, and our telephone number is (844)445-5704. Our common stock is listed on The Nasdaq Global Select Market under the symbol “XERS.” Our website and the information contained on, or that can be accessed through, the website will not be deemed to be incorporated by reference in, and are not considered part of, this prospectus.

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USE OF PROCEEDS

We intend to use the net proceeds from the sale of any securities offered under this prospectus for general corporate purposes unless otherwise indicated in the applicable prospectus supplement. General corporate purposes may include research and development costs, including the conduct of one or more clinical trials and process development and manufacturing of our product candidates, sales and marketing expenses to support commercialization of Gvoke, potential strategic acquisitions of complementary businesses, services or technologies, expansion of our technology infrastructure and capabilities, working capital, capital expenditures and other general corporate purposes. We may temporarily invest the net proceeds in a variety of capital preservation instruments, including investment grade, interest bearing instruments and U.S. government securities, until they are used for their stated purpose. We have not determined the amount of net proceeds to be used specifically for such purposes. As a result, management will retain broad discretion over the allocation of net proceeds.

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SECURITIES WE MAY OFFER

This prospectus contains summary descriptions of the securities we may offer from time to time. These summary descriptions are not meant to be complete descriptions of each security. The particular terms of any security will be described in the applicable prospectus supplement. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities described herein, we will provide prospective investors with a supplement to this prospectus that will contain specific information about the terms of that offering, including the specific amounts, prices and terms of the securities offered.

We may sell the securities to or through underwriters, dealers or agents, directly to purchasers or through a combination of any of these methods of sale or as otherwise set forth below under “Plan of Distribution.” We, as well as any agents acting on our behalf, reserve the sole right to accept and to reject in whole or in part any proposed purchase of securities. Any prospectus supplement will set forth the names of any underwriters, dealers, agents or other entities involved in the sale of securities described in that prospectus supplement and any applicable fee, commission or discount arrangements with them.

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DESCRIPTION OF CAPITAL STOCK

The following description of our common stock and preferred stock, together with the additional information we include in any applicable prospectus supplements, summarizes the material terms and provisions of the common stock and preferred stock that we may offer under this prospectus. The following description of our capital stock does not purport to be complete and is subject to, and qualified in its entirety by, our amended and restated certificate of incorporation, or our charter, and amended and restatedby-laws, or ourby-laws, which are exhibits to the registration statement of which this prospectus forms a part, and by applicable law. The terms of our common stock and preferred stock may also be affected by Delaware law.

Authorized Capital Stock

Our authorized capital stock consists of 150,000,000 shares of common stock, par value $0.0001 per share, and 10,000,000 shares of preferred stock, par value $0.0001 per share, all of which shares of preferred stock are undesignated.

As of August 2, 2019, 26,987,351 shares of our common stock were outstanding and held by 68 stockholders of record.

Common Stock

Holders of our common stock are entitled to one vote for each share of common stock held of record for the election of directors and on all matters submitted to a vote of the stockholders. Holders of our common stock are entitled to receive dividends ratably, if any, as may be declared by our board of directors out of legally available funds, subject to any preferential dividend rights of any preferred stock then outstanding. The holders of our common stock do not have any cumulative voting rights. Holders of our common stock have no preemptive, subscription, redemption or conversion rights, and no sinking fund provisions are applicable to our common stock.

In the event of our dissolution, liquidation or winding up, holders of our common stock are entitled to share ratably in our net assets legally available after the payment of all our debts and other liabilities, subject to the preferential rights of any preferred stock then outstanding. The rights, preferences and privileges of holders of common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future.

All outstanding shares are fully paid andnon-assessable. When we issue shares of common stock under this prospectus, the shares will fully be paid andnon-assessable and will not have, or be subject to, any preemptive or similar rights.

Preferred Stock

Our board of directors is authorized, without further action by the stockholders, to designate and issue up to an aggregate of 10,000,000 shares of preferred stock in one or more series and to fix the rights, preferences, privileges and restrictions thereof. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting, or the designation of, such series, any or all of which may be greater than the rights of common stock. Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of common stock and the likelihood that such holders will receive dividend payments and payments upon our liquidation.

The purpose of authorizing our board of directors to issue preferred stock in one or more series and determine the number of shares in the series and its rights, preferences, privileges and restrictions is to eliminate

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delays associated with a stockholder vote on specific issuances. The issuance of preferred stock, while providing flexibility in connection with possible future financings and acquisitions and other corporate purposes, could, under certain circumstances, have the effect of delaying, deferring or preventing a change in control of our company, as further discussed below under “—Anti-Takeover Effects of Delaware Law and Provisions of our Charter and ourBy-laws—Provisions of our Charter and ourBy-laws—Undesignated Preferred Stock.”

When we issue shares of preferred stock under this prospectus, the shares will be fully paid andnon-assessable and will not be subject to any preemptive or similar rights.

Registration Rights

Pursuant to the terms of our investors’ rights agreement, dated as of December 31, 2015, certain of our stockholders are entitled to rights with respect to the registration of their shares under the Securities Act until the earliest of the fifth (5^th) anniversary of our initial public offering, or such holder’s registrable securities could be sold without any restriction on volume or manner of sale on any90-day period under Rule 144 or any successor rule, as described below. We refer to these shares collectively as registrable securities.

Demand Registration Rights

The holders of 533,714 shares of our common stock are entitled to demand registration rights. Under the terms of the investors’ rights agreement, we will be required, upon the written request of holders of at least 20% of the securities eligible for registration then outstanding or such lesser percentage that would result in an aggregate offering price of at least $10.0 million, to file a registration statement and use commercially reasonable efforts to effect the registration of all or a portion of these shares for public resale. We are required to effect only two registrations pursuant to this provision of the investors’ rights agreement.

Short-Form Registration Rights

Pursuant to the investors’ rights agreement, if we are eligible to file a registration statement on FormS-3, upon the written request of majority in interest of these holders to sell registrable securities at an aggregate price of at least $1.0 million, we will be required to use commercially reasonable efforts to effect a registration of such shares. We are not required to effect more than two registrations that have been declared or ordered effective by the SEC pursuant to this provision of the investors’ rights agreement. The right to have such shares registered on FormS-3 is further subject to other specified conditions and limitations.

Piggyback Registration Rights

Pursuant to the investors’ rights agreement, if we register any of our securities either for our own account or for the account of other security holders, the holders of 533,714 shares of our common stock are entitled to include their shares in the registration. Subject to certain exceptions contained in the investors’ rights agreement, we and the underwriters may limit the number of shares included in the underwritten offering to the number of shares which we and the underwriters determine in our sole discretion will not jeopardize the success of the offering.

Indemnification

Our investors’ rights agreement contains customary cross-indemnification provisions, under which we are obligated to indemnify holders of registrable securities in the event of material misstatements or omissions in the registration statement attributable to us, and they are obligated to indemnify us for material misstatements or omissions attributable to them.

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Expiration of Registration Rights

The demand registration rights and short form registration rights granted under the investors’ rights agreement will terminate on the fifth anniversary of the completion of our initial public offering or at such time after this offering when the holders’ shares may be sold without restriction pursuant to Rule 144 within a90-day period.

Anti-Takeover Effects of Delaware Law and Provisions of our Certificate of Incorporation and ourBy-laws

Our certificate of incorporation and bylaws include a number of provisions that may have the effect of delaying, deferring or preventing another party from acquiring control of us and encouraging persons considering unsolicited tender offers or other unilateral takeover proposals to negotiate with our board of directors rather thanpursue non-negotiated takeover attempts. These provisions include the items described below.

Delaware Anti-Takeover Statute

We are subject to the provisions of Section 203 of the Delaware General Corporation Law. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a three-year period following the time that this stockholder becomes an interested stockholder, unless the business combination is approved in a prescribed manner. Under Section 203, a business combination between a corporation and an interested stockholder is prohibited unless it satisfies one of the following conditions:

• before the stockholder became interested, our board of directors approved either the business combination or the transaction which resulted in the stockholder becoming an interested stockholder;

• upon consummation of the transaction which resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction commenced, excluding for purposes of determining the voting stock outstanding, shares owned by persons who are directors and also officers, and employee stock plans, in some instances, but not the outstanding voting stock owned by the interested stockholder; or

• at or after the time the stockholder became interested, the business combination was approved by our board of directors and authorized at an annual or special meeting of the stockholders by the affirmative vote of at leasttwo-thirds of the outstanding voting stock which is not owned by the interested stockholder.

Section 203 defines a business combination to include:

• any merger or consolidation involving the corporation and the interested stockholder;

• any sale, transfer, lease, pledge or other disposition involving the interested stockholder of 10% or more of the assets of the corporation;

• subject to exceptions, any transaction that results in the issuance or transfer by the corporation of any stock of the corporation to the interested stockholder;

• subject to exceptions, any transaction involving the corporation that has the effect of increasing the proportionate share of the stock of any class or series of the corporation beneficially owned by the interested stockholder; and

• the receipt by the interested stockholder of the benefit of any loans, advances, guarantees, pledges or other financial benefits provided by or through the corporation.

In general, Section 203 defines an interested stockholder as any entity or person beneficially owning 15% or more of the outstanding voting stock of the corporation and any entity or person affiliated with or controlling or controlled by the entity or person.

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Choice of Forum

Our bylaws provide that the Court of Chancery of the State of Delaware will be the exclusive forum for state law claims for (i) any derivative action or proceeding brought on our behalf, (ii) any action asserting a breach of fiduciary duty by one or more of our directors, officers or employees, (iii) any action asserting a claim against us arising pursuant to the Delaware General Corporation Law or (iv) any action asserting a claim against us that is governed by the internal affairs doctrine (the “Delaware Forum Provision”). The Delaware Forum Provision will not apply to any causes of action arising under the Securities Act of 1933, as amended (the “Securities Act”), and the Securities Exchange Act of 1934. Our bylaws further provide that, unless we consent in writing to an alternate forum, the United States District Court for the Northern District of Illinois will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act (the “Federal Forum Provision”). Any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock shall be deemed to have notice of and consented to the foregoing Delaware Forum Provision and Federal Forum Provision.

In Sciabacucchi v. Salzberg, C.A. No.2017-0931-JTL (Del. Ch.), the Court of Chancery of the State of Delaware issued a decision declaring that federal forum selection provisions that purport to require claims under the Securities Act be brought in federal court are ineffective and invalid under Delaware law. On January 17, 2019, the decision was appealed to the Delaware Supreme Court. While the Delaware Supreme Court dismissed the appeal on jurisdictional grounds, we expect that the appeal will bere-filed. Unless and until the Court of Chancery’s decision in Sciabacucchi is reversed by the Delaware Supreme Court or otherwise abrogated, we do not intend to enforce its Federal Forum Provision designating the District for the Northern District of Illinois as the exclusive forum for Securities Act claims. In the event that the Delaware Supreme Court affirms the Court of Chancery’s Sciabacucchi decision or otherwise makes a determination that provisions such as the Federal Forum Provision are invalid, our Board of Directors intends to amend promptly our bylaws to remove the Federal Forum Provision. Such amendment could cause us to incur additional costs, which could have an adverse effect on our business, financial condition or results of operations.

We recognize that the Delaware Forum Provision and the Federal Forum Provision may impose additional litigation costs on stockholders in pursuing any such claims, particularly if the stockholders do not reside in or near the State of Delaware or Illinois. Additionally, the forum selection clauses in ourby-laws may limit our stockholders’ ability to bring a claim in a judicial forum that they find favorable for disputes with us or our directors, officers or employees, which may discourage the filing of lawsuits against us and our directors, officers and employees even though an action, if successful, might benefit our stockholders. Alternatively, if the Federal Forum Provision is found inapplicable to, or unenforceable in respect of, one or more of the specified types of actions or proceedings, we may incur additional costs associated with resolving such matters in other jurisdictions, which could have an adverse effect on our business, financial condition or results of operations. The Court of Chancery of the State of Delaware or the United States District Court for the Northern District of Illinois may also reach different judgments or results than would other courts, including courts where a stockholder considering an action may be located or would otherwise choose to bring the action, and such judgments may be more or less favorable to us than our stockholders.

Provisions of our Charter and ourBy-laws

Our certificate of incorporation and bylaws include a number of provisions that may have the effect of delaying, deferring or preventing another party from acquiring control of us and encouraging persons considering unsolicited tender offers or other unilateral takeover proposals to negotiate with our board of directors rather thanpursue non-negotiated takeover attempts. These provisions include the items described below.

Board Composition and Filling Vacancies.Our certificate of incorporation provides for the division of our board of directors into three classes serving staggered three-year terms, with one class being elected each year. Our certificate of incorporation also provides that directors may be removed only for cause and then only by the

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affirmative vote of the holdersof two-thirds or more of the shares then entitled to vote at an election of directors. Furthermore, any vacancy on our board of directors, however occurring, including a vacancy resulting from an increase in the size of our board, may only be filled by the affirmative vote of a majority of our directors then in office even if less than a quorum. The classification of directors, together with the limitations on removal of directors and treatment of vacancies, has the effect of making it more difficult for stockholders to change the composition of our board of directors.

No Written Consent of Stockholders.Our certificate of incorporation provides that all stockholder actions are required to be taken by a vote of the stockholders at an annual or special meeting, and that stockholders may not take any action by written consent in lieu of a meeting. This limit may lengthen the amount of time required to take stockholder actions and would prevent the amendment of our bylaws or removal of directors by our stockholders without holding a meeting of stockholders.

Meetings of Stockholders.Our certificate of incorporation and bylaws provide that only a majority of the members of our board of directors then in office may call special meetings of stockholders and only those matters set forth in the notice of the special meeting may be considered or acted upon at a special meeting of stockholders. Our bylaws limit the business that may be conducted at an annual meeting of stockholders to those matters properly brought before the meeting.

Advance Notice Requirements.Our bylaws establish advance notice procedures with regard to stockholder proposals relating to the nomination of candidates for election as directors or new business to be brought before meetings of our stockholders. These procedures provide that notice of stockholder proposals must be timely given in writing to our corporate secretary prior to the meeting at which the action is to be taken. Generally, to be timely, notice must be received at our principal executive offices not less than 90 days nor more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. Our bylaws specify the requirements as to form and content of all stockholders’ notices. These requirements may preclude stockholders from bringing matters before the stockholders at an annual or special meeting.

Amendment to Charter and By-laws. Any amendment of our certificate of incorporation must first be approved by a majority of our board of directors, and if required by law or our certificate of incorporation, must thereafter be approved by a majority of the outstanding shares entitled to vote on the amendment and a majority of the outstanding shares of each class entitled to vote thereon as a class, except that the amendment of the provisions relating to stockholder action, board composition, limitation of liability and the amendment of our bylaws and certificate of incorporation must be approved by not lessthan two-thirds of the outstanding shares entitled to vote on the amendment, and not lessthan two-thirds of the outstanding shares of each class entitled to vote thereon as a class. Our bylaws may be amended by the affirmative vote of a majority of the directors then in office, subject to any limitations set forth in the bylaws; and may also be amended by the affirmative vote of atleast two-thirds of the outstanding shares entitled to vote on the amendment, or, if our board of directors recommends that the stockholders approve the amendment, by the affirmative vote of the majority of the outstanding shares entitled to vote on the amendment, in each case voting together as a single class.

Undesignated Preferred Stock. Our certificate of incorporation provides for 10,000,000 authorized shares of preferred stock. The existence of authorized but unissued shares of preferred stock may enable our board of directors to discourage an attempt to obtain control of us by means of a merger, tender offer, proxy contest or otherwise. For example, if in the due exercise of its fiduciary obligations, our board of directors were to determine that a takeover proposal is not in the best interests of our stockholders, our board of directors could cause shares of preferred stock to be issued without stockholder approval in one or more private offerings or other transactions that might dilute the voting or other rights of the proposed acquirer or insurgent stockholder or stockholder group. In this regard, our certificate of incorporation grants our board of directors broad power to establish the rights and preferences of authorized and unissued shares of preferred stock. The issuance of shares of preferred stock could decrease the amount of earnings and assets available for distribution to holders of shares of common stock. The issuance may also adversely affect the rights and powers, including voting rights, of these holders and may have the effect of delaying, deterring or preventing a change in control of us.

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Nasdaq Global Select Market Listing

Our common stock is listed on The Nasdaq Global Select Market under the symbol “XERS.”

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A. The transfer agent and registrar’s address is 250 Royall Street, Canton, Massachusetts 02021, and its telephone number is (800)962-4284.

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DESCRIPTION OF DEBT SECURITIES

We may offer debt securities which may be senior or subordinated. We refer to senior debt securities and subordinated debt securities collectively as debt securities. Each series of debt securities may have different terms. The following description summarizes the general terms and provisions of the debt securities. We will describe the specific terms of the debt securities and the extent, if any, to which the general provisions summarized below apply to any series of debt securities in the prospectus supplement relating to the series and any applicable free writing prospectus that we authorize to be delivered.

We may issue senior debt securities from time to time, in one or more series under a senior indenture to be entered into between us and a senior trustee to be named in a prospectus supplement, which we refer to as the senior trustee. We may issue subordinated debt securities from time to time, in one or more series under a subordinated indenture to be entered into between us and a subordinated trustee to be named in a prospectus supplement, which we refer to as the subordinated trustee. The forms of senior indenture and subordinated indenture are filed as exhibits to the registration statement of which this prospectus forms a part. Together, the senior indenture and the subordinated indenture are referred to as the indentures and, together, the senior trustee and the subordinated trustee are referred to as the trustees. This prospectus briefly outlines some of the provisions of the indentures. The following summary of the material provisions of the indentures is qualified in its entirety by the provisions of the indentures, including definitions of certain terms used in the indentures. Wherever we refer to particular sections or defined terms of the indentures, those sections or defined terms are incorporated by reference in this prospectus or the applicable prospectus supplement. You should review the indentures that are filed as exhibits to the registration statement of which this prospectus forms a part for additional information. As used in this prospectus, the term “debt securities” includes the debt securities being offered by this prospectus and all other debt securities issued by us under the indentures.

General

The indentures:

• do not limit the amount of debt securities that we may issue;

• allow us to issue debt securities in one or more series;

• do not require us to issue all of the debt securities of a series at the same time; and

• allow us to reopen a series to issue additional debt securities without the consent of the holders of the debt securities of such series.

Unless otherwise provided in the applicable prospectus supplement, the senior debt securities will be unsubordinated obligations and will rank equally with all of our other unsecured and unsubordinated indebtedness. Payments on the subordinated debt securities will be subordinated to the prior payment in full of all of our senior indebtedness, as described under “—Subordination” and in the applicable prospectus supplement.

Each indenture provides that we may, but need not, designate more than one trustee under an indenture. Any trustee under an indenture may resign or be removed and a successor trustee may be appointed to act with respect to the series of debt securities administered by the resigning or removed trustee. If two or more persons are acting as trustee with respect to different series of debt securities, each trustee shall be a trustee of a trust under the applicable indenture separate and apart from the trust administered by any other trustee. Except as otherwise indicated in this prospectus, any action described in this prospectus to be taken by each trustee may be taken by each trustee with respect to, and only with respect to, the one or more series of debt securities for which it is trustee under the applicable indenture.

The prospectus supplement for each offering will provide the following terms, where applicable:

• the title of the debt securities and whether they are senior or subordinated;

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• the aggregate principal amount of the debt securities being offered, the aggregate principal amount of the debt securities outstanding as of the most recent practicable date and any limit on their aggregate principal amount, including the aggregate principal amount of debt securities authorized;

• the price at which the debt securities will be issued, expressed as a percentage of the principal and, if other than the principal amount thereof, the portion of the principal amount thereof payable upon declaration of acceleration of the maturity thereof or, if applicable, the portion of the principal amount of such debt securities that is convertible into common stock or other securities of ours or the method by which any such portion shall be determined;

• if convertible, the terms on which such debt securities are convertible, including the initial conversion price or rate and the conversion period and any applicable limitations on the ownership or transferability of common stock or other securities of ours received on conversion;

• the date or dates, or the method for determining the date or dates, on which the principal of the debt securities will be payable;

• the fixed or variable interest rate or rates of the debt securities, or the method by which the interest rate or rates is determined;

• the date or dates, or the method for determining the date or dates, from which interest will accrue;

• the dates on which interest will be payable;

• the record dates for interest payment dates, or the method by which such dates will be determined;

• the persons to whom interest will be payable;

• the place or places where the principal of, and any premium or make-whole amount, and interest on, the debt securities will be payable;

• where the debt securities may be surrendered for registration of transfer or conversion or exchange;

• the times, prices and other terms and conditions upon which we may redeem the debt securities;

• any obligation we have to redeem, repay or repurchase the debt securities pursuant to any sinking fund or analogous provision or at the option of holders of the debt securities, and the times and prices at which we must redeem, repay or repurchase the debt securities as a result of such obligation;

• the currency or currencies in which the debt securities are denominated and payable if other than United States dollars, which may be a foreign currency or units of two or more foreign currencies or a composite currency or currencies and the terms and conditions relating thereto, and the manner of determining the equivalent of such foreign currency in United States dollars;

• whether the principal of, and any premium or make-whole amount, or interest on, the debt securities of the series are to be payable, at our election or at the election of a holder, in a currency or currencies other than that in which the debt securities are denominated or stated to be payable, and other related terms and conditions;

• whether the debt securities will be in registered form, bearer form, or both, and (i) if in registered form, the person to whom any interest shall be payable, if other than the person in whose name the security is registered at the close of business on the regular record date for such interest, or (ii) if in bearer form, the manner in which, or the person to whom, any interest on the security shall be payable if otherwise than upon presentation and surrender upon maturity;

• any restrictions applicable to the offer, sale or delivery of securities in bearer form and the terms upon which securities in bearer form of the series may be exchanged for securities in registered form of the series and vice versa, if permitted by applicable laws and regulations;

• whether any debt securities of the series are to be issuable initially in temporary global form and whether any debt securities of the series are to be issuable in permanent global form with or without

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coupons and, if so, whether beneficial owners of interests in any such permanent global security may, or shall be required to, exchange their interests for other debt securities of the series, and the manner in which interest shall be paid;

• the identity of the depositary for securities in registered form, if such series are to be issuable as a global security;

• the applicability, if any, of the defeasance and covenant defeasance provisions described in this prospectus or in the applicable indenture;

• whether and under what circumstances we will pay any additional amounts on the debt securities in respect of any tax, assessment or governmental charge;

• whether and under what circumstances the debt securities being offered are convertible into common stock or other securities of ours, as the case may be, including the conversion price or rate and the manner or calculation thereof;

• the name of the applicable trustee and the nature of any material relationship with us or any of our affiliates, and the percentage of debt securities of the class necessary to require the trustee to take action; and

• any other terms of such debt securities not inconsistent with the provisions of the applicable indenture.

We may issue debt securities that provide for less than the entire principal amount thereof to be payable upon declaration of acceleration of the maturity of the debt securities. We refer to any such debt securities throughout this prospectus as “original issue discount securities.” The applicable prospectus supplement will describe the United States federal income tax consequences and other relevant considerations applicable to original issue discount securities.

Except as described under “—Merger, Consolidation or Sale of Assets” or as may be set forth in any prospectus supplement, the debt securities will not contain any provisions that (i) would limit our ability to incur indebtedness or (ii) would afford holders of debt securities protection in the event of (a) a highly leveraged or similar transaction involving us, or (b) a change of control or reorganization, restructuring, merger or similar transaction involving us that may adversely affect the holders of the debt securities. In the future, we may enter into transactions, such as the sale of all or substantially all of our assets or a merger or consolidation, that may have an adverse effect on our ability to service our indebtedness, including the debt securities, by, among other things, substantially reducing or eliminating our assets.

Our governing instruments do not define the term “substantially all” as it relates to the sale of assets. Additionally, Delaware cases interpreting the term “substantially all” rely upon the facts and circumstances of each particular case. Consequently, to determine whether a sale of “substantially all” of our assets has occurred, a holder of debt securities must review the financial and other information that we have disclosed to the public.

We will provide you with more information in the applicable prospectus supplement regarding any deletions, modifications, or additions to the events of default or covenants that are described below, including any addition of a covenant or other provision providing event risk or similar protection.

Payment

Unless otherwise provided in the applicable prospectus supplement, the principal of, and any premium or make-whole amount, and interest on, any series of the debt securities will be payable by mailing a check to the address of the person entitled to it as it appears in the applicable register for the debt securities or by wire transfer of funds to that person at an account maintained within the United States.

All monies that we pay to a paying agent or a trustee for the payment of the principal of, and any premium or make-whole amount, or interest on, any debt security will be repaid to us if unclaimed at the end of

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two years after the obligation underlying payment becomes due and payable. After funds have been returned to us, the holder of the debt security may look only to us for payment, without payment of interest for the period which we hold the funds.

Denomination, Interest, Registration and Transfer

Unless otherwise provided in the applicable prospectus supplement, the debt securities of any series will be issuable in denominations of $1,000 and integral multiples of $1,000.

Interest on the debt securities shall be computed on the basis of a360-day year composed of twelve30-day months.

Subject to the limitations imposed upon debt securities that are evidenced by a computerized entry in the records of a depository company rather than by physical delivery of a note, a holder of debt securities of any series may:

• exchange them for any authorized denomination of other debt securities of the same series and of a like aggregate principal amount and kind upon surrender of such debt securities at the corporate trust office of the applicable trustee or at the office of any transfer agent that we designate for such purpose; and

• surrender them for registration of transfer or exchange at the corporate trust office of the applicable trustee or at the office of any transfer agent that we designate for such purpose.

Every debt security surrendered for registration of transfer or exchange must be accompanied by a written instrument of transfer satisfactory to the applicable trustee or transfer agent. Payment of a service charge will not be required for any registration of transfer or exchange of any debt securities, but we or the trustee may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith. We may at any time designate additional transfer agents for any series of debt securities.

Neither we, nor any trustee, will be required to:

• issue, register the transfer of or exchange debt securities of any series during a period beginning at the opening of business 15 days before the day that the notice of redemption of any debt securities selected for redemption is mailed and ending at the close of business on the day of such mailing;

• register the transfer of or exchange any debt security, or portion thereof, so selected for redemption, in whole or in part, except the unredeemed portion of any debt security being redeemed in part; and

• issue, register the transfer of or exchange any debt security that has been surrendered for repayment at the option of the holder, except the portion, if any, of such debt security not to be so repaid.

Merger, Consolidation or Sale of Assets

The indentures provide that we may, without the consent of the holders of any outstanding debt securities, (i) consolidate with, (ii) sell, lease or convey all or substantially all of our assets to, or (iii) merge with or into, any other entity provided that:

• either we are the continuing entity, or the successor entity, if other than us, assumes the obligations (a) to pay the principal of, and any premium or make-whole amount, and interest on, all of the debt securities and (b) to duly perform and observe all of the covenants and conditions contained in the applicable indenture;

• after giving effect to the transaction, there is no event of default under the applicable indentures and no event which, after notice or the lapse of time, or both, would become such an event of default, occurs and continues; and

• an officers’ certificate and legal opinion covering such conditions are delivered to each applicable trustee.

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Events of Default, Notice and Waiver

Unless the applicable prospectus supplement states otherwise, when we refer to “events of default” as defined in the indentures with respect to any series of debt securities, we mean:

• default in the payment of any installment of interest on any debt security of such series continuing for 90 days unless such date has been extended or deferred;

• default in the payment of principal of, or any premium or make-whole amount on, any debt security of such series when due and payable unless such date has been extended or deferred;

• default in the performance or breach of any covenant or warranty in the debt securities or in the indenture by us continuing for 90 days after written notice described below;

• bankruptcy, insolvency or reorganization, or court appointment of a receiver, liquidator or trustee of us; and

• any other event of default provided with respect to a particular series of debt securities.

If an event of default occurs and is continuing with respect to debt securities of any series outstanding, then the applicable trustee or the holders of 25% or more in principal amount of the debt securities of that series will have the right to declare the principal amount of all the debt securities of that series to be due and payable. If the debt securities of that series are original issue discount securities or indexed securities, then the applicable trustee or the holders of 25% or more in principal amount of the debt securities of that series will have the right to declare the portion of the principal amount as may be specified in the terms thereof to be due and payable. However, at any time after such a declaration of acceleration has been made, but before a judgment or decree for payment of the money due has been obtained by the applicable trustee, the holders of at least a majority in principal amount of outstanding debt securities of such series or of all debt securities then outstanding under the applicable indenture may rescind and annul such declaration and its consequences if:

• we have deposited with the applicable trustee all required payments of the principal, any premium or make-whole amount, interest and, to the extent permitted by law, interest on overdue installment of interest, plus applicable fees, expenses, disbursements and advances of the applicable trustee; and

• all events of default, other than thenon-payment of accelerated principal, or a specified portion thereof, and any premium or make-whole amount, have been cured or waived.

The indentures require each trustee to give notice to the holders of debt securities within the later of 90 days after an event of default and 30 days after the event of default is actually known to a responsible officer of such trustee, unless such default has been cured or waived. However, the trustee may withhold notice if specified persons of such trustee consider such withholding to be in the interest of the holders of debt securities.

The indentures provide that holders of debt securities of any series may not institute any proceedings, judicial or otherwise, with respect to such indenture or for any remedy under the indenture, unless the trustee fails to act for a period of 90 days after the trustee has received a written request to institute proceedings in respect of an event of default from the holders of 25% or more in principal amount of the outstanding debt securities of such series, as well as an offer of indemnity reasonably satisfactory to the trustee. However, this provision will not prevent any holder of debt securities from instituting suit for the enforcement of payment of the principal of, and any premium or make-whole amount, and interest on, such debt securities at the respective due dates thereof.

The indentures provide that, subject to provisions in each indenture relating to its duties in the case of a default, a trustee has no obligation to exercise any of its rights or powers at the request or direction of any holders of any series of debt securities then outstanding under the indenture, unless the holders have offered to the trustee reasonable security or indemnity. The holders of at least a majority in principal amount of the outstanding debt securities of any series or of all debt securities then outstanding under an indenture shall have the right to direct

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the time, method and place of conducting any proceeding for any remedy available to the applicable trustee, or of exercising any trust or power conferred upon such trustee. However, a trustee may refuse to follow any direction which:

• is in conflict with any law or the applicable indenture;

• may involve the trustee in personal liability; or

• may be unduly prejudicial to the holders of debt securities of the series not joining the proceeding.

Within 120 days after the close of each fiscal year, we will be required to deliver to each trustee a certificate, signed by one of our several specified officers, stating whether or not that officer has knowledge of any default under the applicable indenture. If the officer has knowledge of any default, the notice must specify the nature and status of the default.

Modification of the Indentures

The indentures provide that modifications and amendments may be made only with the consent of the affected holders of a majority in principal amount of all outstanding debt securities issued under that indenture:

We and our respective trustee may make modifications and amendments of an indenture without the consent of any holder of debt securities for any of the following purposes:

• to evidence the succession of another person to us as obligor under such indenture;

• to provide for uncertificated debt securities in addition to or in place of certificated debt securities;

• to add to our covenants for the benefit of the holders of all or any series of debt securities or to surrender any right or power conferred upon us in such indenture;

• to add events of default for the benefit of the holders of all or any series of debt securities;

• to add to, delete from, or revise the conditions, limitations, and restrictions on the authorized amount, terms, or purposes of issue, authentication, and delivery of debt securities;

• to make any change that does not adversely affect the rights of any securityholder in any material respect;

• to establish the form or terms of debt securities of any series;

• to provide for the acceptance of appointment by a successor trustee or facilitate the administration of the trusts under an indenture by more than one trustee; or

• to cure any ambiguity, defect or inconsistency in an indenture, provided that such action shall not adversely affect the interests of holders of debt securities of any series issued under such indenture.

Voting

The indentures provide that in determining whether the holders of the requisite principal amount of outstanding debt securities of a series have given any request, demand, authorization, direction, notice, consent or waiver under the indentures or whether a quorum is present at a meeting of holders of debt securities, the principal amount of an original issue discount security that shall be deemed to be outstanding shall be the amount of the principal thereof that would be due and payable as of the date of such determination upon declaration of acceleration of the maturity thereof.

Subordination

Unless otherwise provided in the applicable prospectus supplement, subordinated debt securities will be subject to the following subordination provisions.

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Upon any distribution to our creditors in a liquidation, dissolution or reorganization, the payment of the principal of and interest on any subordinated debt securities will be subordinated to the extent provided in the applicable indenture in right of payment to the prior payment in full of all senior debt. However, our obligation to make payments of the principal of and interest on such subordinated debt securities otherwise will not be affected. No payment of principal or interest will be permitted to be made on subordinated debt securities at any time if a default on senior debt exists that permits the holders of such senior debt to accelerate its maturity and the default is the subject of judicial proceedings or we receive notice of the default. After all senior debt is paid in full and until the subordinated debt securities are paid in full, holders of subordinated debt securities will be subrogated to the rights of holders of senior debt to the extent that distributions otherwise payable to holders of subordinated debt securities have been applied to the payment of senior debt. The subordinated indenture will not restrict the amount of senior debt or other indebtedness of ours. As a result of these subordination provisions, in the event of a distribution of assets upon insolvency, holders of subordinated debt securities may recover less, ratably, than our general creditors.

No restrictions will be included in any indenture relating to subordinated debt securities upon the creation of additional senior debt.

If this prospectus is being delivered in connection with the offering of a series of subordinated debt securities, the accompanying prospectus supplement or the information incorporated in this prospectus by reference will set forth the approximate amount of senior debt outstanding as of the end of our most recent fiscal quarter.

Discharge, Defeasance and Covenant Defeasance

Unless otherwise provided in the applicable prospectus supplement, the indentures allow us to discharge our obligations to holders of any series of debt securities issued under any indenture when:

• either (i) all securities of such series have already been delivered to the applicable trustee for cancellation; or (ii) all securities of such series have not already been delivered to the applicable trustee for cancellation but (a) have become due and payable, (b) will become due and payable within one year, or (c) if redeemable at our option, are to be redeemed within one year, and we have irrevocably deposited with the applicable trustee, in trust, funds in such currency or currencies, currency unit or units or composite currency or currencies in which such debt securities are payable, an amount sufficient to pay the entire indebtedness on such debt securities in respect of principal and any premium or make-whole amount, and interest to the date of such deposit if such debt securities have become due and payable or, if they have not, to the stated maturity or redemption date;

• we have paid or caused to be paid all other sums payable; and

• an officers’ certificate and an opinion of counsel stating the conditions to discharging the debt securities have been satisfied have been delivered to the trustee.

Unless otherwise provided in the applicable prospectus supplement, the indentures provide that, upon our irrevocable deposit with the applicable trustee, in trust, of an amount, in such currency or currencies, currency unit or units or composite currency or currencies in which such debt securities are payable at stated maturity, or government obligations, or both, applicable to such debt securities, which through the scheduled payment of principal and interest in accordance with their terms will provide money in an amount sufficient to pay the principal of, and any premium or make-whole amount, and interest on, such debt securities, and any mandatory sinking fund or analogous payments thereon, on the scheduled due dates therefor, the issuing company shall be released from its obligations with respect to such debt securities under the applicable indenture or, if provided in the applicable prospectus supplement, its obligations with respect to any other covenant, and any omission to comply with such obligations shall not constitute an event of default with respect to such debt securities.

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Notwithstanding the above, we may not elect to defease and be discharged from the obligation to pay any additional amounts upon the occurrence of particular events of tax, assessment or governmental charge with respect to payments on such debt securities and the obligations to register the transfer or exchange of such debt securities, to replace temporary or mutilated, destroyed, lost or stolen debt securities, to maintain an office or agency in respect of such debt securities, or to hold monies for payment in trust.

The applicable prospectus supplement may further describe the provisions, if any, permitting such defeasance or covenant defeasance, including any modifications to the provisions described above, with respect to the debt securities of or within a particular series.

Conversion Rights

The terms and conditions, if any, upon which the debt securities are convertible into common stock or other securities of ours will be set forth in the applicable prospectus supplement. The terms will include whether the debt securities are convertible into shares of common stock or other securities of ours, the conversion price, or manner of calculation thereof, the conversion period, provisions as to whether conversion will be at the issuing company’s option or the option of the holders, the events requiring an adjustment of the conversion price and provisions affecting conversion in the event of the redemption of the debt securities and any restrictions on conversion.

No Recourse

No recourse shall be had under any obligation, covenant or agreement of ours in the senior indenture or any supplemental indenture, or in any of the debt securities or because of the creation of any indebtedness represented thereby, against any of our incorporators, stockholders, officers or directors, past, present or future, or of any predecessor or successor entity thereof under any law, statute or constitutional provision or by the enforcement of any assessment or by any legal or equitable proceeding or otherwise. Each holder, by accepting the debt securities, waives and releases all such liability.

Governing Law

The indentures and the debt securities will be governed by and construed in accordance with the laws of the State of New York, except to the extent that the Trust Indenture Act is applicable.

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DESCRIPTION OF WARRANTS

The following description, together with the additional information we may include in any applicable prospectus supplements, summarizes the material terms and provisions of the warrants that we may offer under this prospectus and the related warrant agreements and warrant certificates. While the terms summarized below will apply generally to any warrants that we may offer, we will describe the particular terms of any series of warrants in more detail in the applicable prospectus supplement. If we indicate in the prospectus supplement, the terms of any warrants offered under that prospectus supplement may differ from the terms described below. Specific warrant agreements will contain additional important terms and provisions and will be incorporated by reference as an exhibit to the registration statement, which includes this prospectus.

General

We may issue warrants for the purchase of common stock, preferred stock and/or debt securities in one or more series. We may issue warrants independently or together with common stock, preferred stock and/or debt securities, and the warrants may be attached to or separate from these securities.

We will evidence each series of warrants by warrant certificates that we will issue under a separate warrant agreement. We will enter into the warrant agreement with a warrant agent. We will indicate the name and address of the warrant agent in the applicable prospectus supplement relating to a particular series of warrants.

We will describe in the applicable prospectus supplement the terms of the series of warrants, including:

• the offering price and aggregate number of warrants offered;

• the currency for which the warrants may be purchased;

• if applicable, the designation and terms of the securities with which the warrants are issued and the number of warrants issued with each such security or each principal amount of such security;

• if applicable, the date on and after which the warrants and the related securities will be separately transferable;

• in the case of warrants to purchase debt securities, the principal amount of debt securities purchasable upon exercise of one warrant and the price at, and currency in which, this principal amount of debt securities may be purchased upon such exercise;

• in the case of warrants to purchase common stock or preferred stock, the number of shares of common stock or preferred stock, as the case may be, purchasable upon the exercise of one warrant and the price at which these shares may be purchased upon such exercise;

• the effect of any merger, consolidation, sale or other disposition of our business on the warrant agreement and the warrants;

• the terms of any rights to redeem or call the warrants;

• any provisions for changes to or adjustments in the exercise price or number of securities issuable upon exercise of the warrants;

• the periods during which, and places at which, the warrants are exercisable;

• the manner of exercise;

• the dates on which the right to exercise the warrants will commence and expire;

• the manner in which the warrant agreement and warrants may be modified;

• federal income tax consequences of holding or exercising the warrants;

• the terms of the securities issuable upon exercise of the warrants; and

• any other specific terms, preferences, rights or limitations of or restrictions on the warrants.

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DESCRIPTION OF UNITS

We may issue units comprised of shares of common stock, shares of preferred stock, debt securities and warrants in any combination. We may issue units in such amounts and in as many distinct series as we wish. This section outlines certain provisions of the units that we may issue. If we issue units, they will be issued under one or more unit agreements to be entered into between us and a bank or other financial institution, as unit agent. The information described in this section may not be complete in all respects and is qualified entirely by reference to the unit agreement with respect to the units of any particular series. The specific terms of any series of units offered will be described in the applicable prospectus supplement. If so described in a particular supplement, the specific terms of any series of units may differ from the general description of terms presented below. We urge you to read any prospectus supplement related to any series of units we may offer, as well as the complete unit agreement and unit certificate that contain the terms of the units. If we issue units, forms of unit agreements and unit certificates relating to such units will be incorporated by reference as exhibits to the registration statement, which includes this prospectus.

Each unit that we may issue will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security. The unit agreement under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately, at any time or at any time before a specified date. The applicable prospectus supplement may describe:

• the designation and terms of the units and of the securities comprising the units, including whether and under what circumstances those securities may be held or transferred separately;

• any provisions of the governing unit agreement;

• the price or prices at which such units will be issued;

• the applicable United States federal income tax considerations relating to the units;

• any provisions for the issuance, payment, settlement, transfer or exchange of the units or of the securities comprising the units; and

• any other terms of the units and of the securities comprising the units.

The provisions described in this section, as well as those described under “Description of Capital Stock,” “Description of Debt Securities” and “Description of Warrants” will apply to the securities included in each unit, to the extent relevant and as may be updated in any applicable prospectus supplements.

Issuance in Series

We may issue units in such amounts and in as many distinct series as we wish. This section summarizes terms of the units that apply generally to all series. Most of the financial and other specific terms of a particular series of units will be described in the applicable prospectus supplement.

Unit Agreements

We will issue the units under one or more unit agreements to be entered into between us and a bank or other financial institution, as unit agent. We may add, replace or terminate unit agents from time to time. We will identify the unit agreement under which each series of units will be issued and the unit agent under that agreement in the applicable prospectus supplement.

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The following provisions will generally apply to all unit agreements unless otherwise stated in the applicable prospectus supplement:

Modification without Consent

We and the applicable unit agent may amend any unit or unit agreement without the consent of any holder:

• to cure any ambiguity, including modifying any provisions of the governing unit agreement that differ from those described below;

• to correct or supplement any defective or inconsistent provision; or

• to make any other change that we believe is necessary or desirable and will not adversely affect the interests of the affected holders in any material respect.

We do not need any approval to make changes that affect only units to be issued after the changes take effect. We may also make changes that do not adversely affect a particular unit in any material respect, even if they adversely affect other units in a material respect. In those cases, we do not need to obtain the approval of the holder of the unaffected unit; we need only obtain any required approvals from the holders of the affected units.

Modification with Consent

We may not amend any particular unit or a unit agreement with respect to any particular unit unless we obtain the consent of the holder of that unit, if the amendment would:

• impair any right of the holder to exercise or enforce any right under a security included in the unit if the terms of that security require the consent of the holder to any changes that would impair the exercise or enforcement of that right; or

• reduce the percentage of outstanding units or any series or class the consent of whose holders is required to amend that series or class, or the applicable unit agreement with respect to that series or class, as described below.

Any other change to a particular unit agreement and the units issued under that agreement would require the following approval:

• If the change affects only the units of a particular series issued under that agreement, the change must be approved by the holders of a majority of the outstanding units of that series; or

• If the change affects the units of more than one series issued under that agreement, it must be approved by the holders of a majority of all outstanding units of all series affected by the change, with the units of all the affected series voting together as one class for this purpose.

These provisions regarding changes with majority approval also apply to changes affecting any securities issued under a unit agreement, as the governing document.

In each case, the required approval must be given by written consent.

Unit Agreements Will Not Be Qualified under Trust Indenture Act

No unit agreement will be qualified as an indenture, and no unit agent will be required to qualify as a trustee, under the Trust Indenture Act. Therefore, holders of units issued under unit agreements will not have the protections of the Trust Indenture Act with respect to their units.

Mergers and Similar Transactions Permitted; No Restrictive Covenants or Events of Default

The unit agreements will not restrict our ability to merge or consolidate with, or sell our assets to, another corporation or other entity or to engage in any other transactions. If at any time we merge or consolidate with, or

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sell our assets substantially as an entirety to, another corporation or other entity, the successor entity will succeed to and assume our obligations under the unit agreements. We will then be relieved of any further obligation under these agreements.

The unit agreements will not include any restrictions on our ability to put liens on our assets, nor will they restrict our ability to sell our assets. The unit agreements also will not provide for any events of default or remedies upon the occurrence of any events of default.

Governing Law

The unit agreements and the units will be governed by Delaware law.

Form, Exchange and Transfer

We will issue each unit in global—i.e., book-entry—form only. Units in book-entry form will be represented by a global security registered in the name of a depositary, which will be the holder of all the units represented by the global security. Those who own beneficial interests in a unit will do so through participants in the depositary’s system, and the rights of these indirect owners will be governed solely by the applicable procedures of the depositary and its participants. We will describe book-entry securities, and other terms regarding the issuance and registration of the units in the applicable prospectus supplement.

Each unit and all securities comprising the unit will be issued in the same form.

If we issue any units inregistered, non-global form, the following will apply to them.

The units will be issued in the denominations stated in the applicable prospectus supplement. Holders may exchange their units for units of smaller denominations or combined into fewer units of larger denominations, as long as the total amount is not changed.

• Holders may exchange or transfer their units at the office of the unit agent. Holders may also replace lost, stolen, destroyed or mutilated units at that office. We may appoint another entity to perform these functions or perform them ourselves.

• Holders will not be required to pay a service charge to transfer or exchange their units, but they may be required to pay for any tax or other governmental charge associated with the transfer or exchange. The transfer or exchange, and any replacement, will be made only if our transfer agent is satisfied with the holder’s proof of legal ownership. The transfer agent may also require an indemnity before replacing any units.

• If we have the right to redeem, accelerate or settle any units before their maturity, and we exercise our right as to less than all those units or other securities, we may block the exchange or transfer of those units during the period beginning 15 days before the day we mail the notice of exercise and ending on the day of that mailing, in order to freeze the list of holders to prepare the mailing. We may also refuse to register transfers of or exchange any unit selected for early settlement, except that we will continue to permit transfers and exchanges of the unsettled portion of any unit being partially settled. We may also block the transfer or exchange of any unit in this manner if the unit includes securities that are or may be selected for early settlement.

Only the depositary will be entitled to transfer or exchange a unit in global form, since it will be the sole holder of the unit.

Payments and Notices

In making payments and giving notices with respect to our units, we will follow the procedures as described in the applicable prospectus supplement.

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PLAN OF DISTRIBUTION

We may sell the securities offered through this prospectus and any accompanying prospectus supplement, if required, in any of the following ways: (i) to or through underwriters or dealers, (ii) directly to purchasers, including our affiliates, (iii) through agents, or (iv) through a combination of any of these methods. The securities may be distributed at a fixed price or prices, which may be changed, market prices prevailing at the time of sale, prices related to the prevailing market prices, or negotiated prices, either:

• on or through the facilities of The Nasdaq Global Select Market or any other securities exchange or quotation or trading service on which such securities may be listed, quoted or traded at the time of sale; and/or

• to or through a market maker otherwise than on The Nasdaq Global Select Market or such other securities exchanges or quotation or trading services.

In addition, we may issue the securities as a dividend or distribution or in a subscription rights offering to our existing security holders.

We may directly solicit offers to purchase securities, or agents may be designated to solicit such offers. In the prospectus supplement relating to such offering, we will name any agent that could be viewed as an underwriter under the Securities Act and describe any commissions that we must pay to any such agent. Any such agent will be acting on a best efforts basis for the period of its appointment or, if indicated in the applicable prospectus supplement, on a firm commitment basis. This prospectus may be used in connection with any offering of our securities through any of these methods or other methods described in the applicable prospectus supplement.

Each prospectus supplement will describe the method of distribution of the securities and any applicable restrictions.

The prospectus supplement with respect to the securities of a particular series will describe the terms of the offering of the securities, including the following:

• the name of the agent or any underwriters;

• the public offering or purchase price;

• any discounts and commissions to be allowed or paid to the agent or underwriters;

• all other items constituting underwriting compensation;

• any discounts and commissions to be allowed or paid to dealers; and

• any exchanges on which the securities will be listed.

If any underwriters or agents are used in the sale of the securities in respect of which this prospectus is delivered, we will enter into an underwriting agreement, sales agreement or other agreement with them at the time of sale to them, and we will set forth in the prospectus supplement relating to such offering the names of the underwriters or agents and the terms of the related agreement with them.

In connection with the offering of securities, we may grant to the underwriters an option to purchase additional securities with an additional underwriting commission, as may be set forth in the accompanying prospectus supplement. If we grant any such option, the terms of such option will be set forth in the prospectus supplement for such securities.

If a dealer is used in the sale of the securities in respect of which the prospectus is delivered, we will sell such securities to the dealer, as principal. The dealer, who may be deemed to be an “underwriter” as that term is defined in the Securities Act, may then resell such securities to the public at varying prices to be determined by such dealer at the time of resale.

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If we offer securities in a subscription rights offering to our existing security holders, we may enter into a standby underwriting agreement with dealers, acting as standby underwriters. We may pay the standby underwriters a commitment fee for the securities they commit to purchase on a standby basis. If we do not enter into a standby underwriting arrangement, we may retain a dealer-manager to manage a subscription rights offering for us.

Agents, underwriters, dealers and other persons may be entitled under agreements which they may enter into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, and may be customers of, engage in transactions with or perform services for us in the ordinary course of business.

If so indicated in the applicable prospectus supplement, we will authorize underwriters or other persons acting as our agents to solicit offers by certain institutions to purchase securities from us pursuant to delayed delivery contracts providing for payment and delivery on the date stated in the prospectus supplement. Each contract will be for an amount not less than, and the aggregate amount of securities sold pursuant to such contracts shall not be less nor more than, the respective amounts stated in the prospectus supplement. Institutions with whom the contracts, when authorized, may be made include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and other institutions, but shall in all cases be subject to our approval. Delayed delivery contracts will not be subject to any conditions except that:

• the purchase by an institution of the securities covered under that contract shall not at the time of delivery be prohibited under the laws of the jurisdiction to which that institution is subject; and

• if the securities are also being sold to underwriters acting as principals for their own account, the underwriters shall have purchased such securities not sold for delayed delivery. The underwriters and other persons acting as our agents will not have any responsibility in respect of the validity or performance of delayed delivery contracts.

Offered securities may also be offered and sold, if so indicated in the prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more remarketing firms, acting as principals for their own accounts or as agents for us. Any remarketing firm will be identified and the terms of its agreement, if any, with us and its compensation will be described in the applicable prospectus supplement. Remarketing firms may be deemed to be underwriters in connection with their remarketing of offered securities.

Certain agents, underwriters and dealers, and their associates and affiliates, may be customers of, have borrowing relationships with, engage in other transactions with, or perform services, including investment banking services, for us or one or more of our respective affiliates in the ordinary course of business.

In order to facilitate the offering of the securities, any underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the securities or any other securities the prices of which may be used to determine payments on such securities. Specifically, any underwriters may over allot in connection with the offering, creating a short position for their own accounts. In addition, to cover overallotments or to stabilize the price of the securities or of any such other securities, the underwriters may bid for, and purchase, the securities or any such other securities in the open market. Finally, in any offering of the securities through a syndicate of underwriters, the underwriting syndicate may reclaim selling concessions allowed to an underwriter or a dealer for distributing the securities in the offering if the syndicate repurchases previously distributed securities in transactions to cover syndicate short positions, in stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the securities above independent market levels. Any such underwriters are not required to engage in these activities and may end any of these activities at any time.

We may engage in at the market offerings into an existing trading market in accordance with Rule 415(a)(4) under the Securities Act. In addition, we may enter into derivative transactions with third parties, or sell

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securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement so indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities pledged by us or borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in such sale transactions will be an underwriter and, if not identified in this prospectus, will be named in the applicable prospectus supplement (or a post-effective amendment). In addition, we may otherwise loan or pledge securities to a financial institution or other third party that in turn may sell the securities short using this prospectus and an applicable prospectus supplement. Such financial institution or other third party may transfer its economic short position to investors in our securities or in connection with a concurrent offering of other securities.

Under Rule15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in two business days, unless the parties to any such trade expressly agree otherwise. The applicable prospectus supplement may provide that the original issue date for your securities may be more than two scheduled business days after the trade date for your securities. Accordingly, in such a case, if you wish to trade securities on any date prior to the second business day before the original issue date for your securities, you will be required, by virtue of the fact that your securities initially are expected to settle in more than two scheduled business days after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

The securities may be new issues of securities and may have no established trading market. The securities may or may not be listed on a national securities exchange. We can make no assurance as to the liquidity of or the existence of trading market for any of the securities.

The specific terms of anylock-up provisions in respect of any given offering will be described in the applicable prospectus supplement.

The underwriters, dealers and agents may engage in transactions with us, or perform services for us, in the ordinary course of business for which they receive compensation.

The anticipated date of delivery of offered securities will be set forth in the applicable prospectus supplement relating to each offer.

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LEGAL MATTERS

Certain legal matters in connection with this offering will be passed upon for us by Goodwin Procter LLP, Boston, Massachusetts. Any underwriters will also be advised about the validity of the securities and other legal matters by their own counsel, which will be named in the prospectus supplement.

EXPERTS

The financial statements of Xeris Pharmaceuticals, Inc. as of December 31, 2018 and 2017 and for each of the years in the two-year period ended December 31, 2018, have been incorporated by reference herein in reliance upon the reports of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

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WHERE YOU CAN FIND MORE INFORMATION

We are subject to the information requirements of the Exchange Act and, in accordance therewith, file annual, quarterly and special reports, proxy statements and other information with the SEC. These documents may be accessed through the SEC’s electronic data gathering, analysis and retrieval system, or EDGAR, via electronic means, including the SEC’s home page on the Internet (www.sec.gov). Copies of certain information filed by us with the SEC are also available on our website athttp://www.xerispharma.com.The information contained on our website is not incorporated by reference into this prospectus and, therefore, is not part of this prospectus or any accompanying prospectus supplement.

This prospectus is part of a registration statement that we have filed with the SEC. Certain information in the registration statement has been omitted from this prospectus in accordance with SEC rules and regulations. For more detail about us and any securities that may be offered by this prospectus, you may examine the registration statement on FormS-3 and the exhibits filed with it at the locations listed in the previous paragraph. Please be aware that statements in this prospectus referring to a contract or other document are summaries and you should refer to the exhibits that are part of the registration statement for a copy of the contract or document.

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INCORPORATION BY REFERENCE

The SEC allows us to incorporate by reference the information and reports we file with it, which means that we can disclose important information to you by referring you to these documents. The information incorporated by reference is considered to be a part of this prospectus, and the information that we file later with the SEC will automatically update and, where applicable, supersede the information already incorporated by reference. We incorporate by reference the documents listed below that we filed with the SEC:

• our Annual Report onForm10-K for the year ended December 31, 2018 filed with the SEC on March 6, 2019;

• the information specifically incorporated by reference into our Annual Report on Form10-K for the year ended December 31, 2018 from our definitive proxy statement onSchedule 14A (other than information furnished rather than filed) filed with the SEC on March 26, 2019;

• our Quarterly Reports on Form10-Q for the quarter ended March 31, 2019 filed with the SEC onMay 9, 2019 and for the quarter ended June  30, 2019 filed with the SEC onAugust 6, 2019;

• our Current Reports on Form8-K filed with the SEC onJanuary 22, 2019,February 14, 2019,March 26, 2019 (only with respect to Item 5.02),May  8, 2019, andJune 6, 2019;

• the description of our common stock contained in our registration statement onForm8-A filed with the SEC on June 18, 2018, including any amendments or reports filed for the purposes of updating this description; and

• all future documents filed by us with the SEC pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act, including all filings made after the date of the filing of this registration statement and prior to the effectiveness of this registration statement, prior to the termination of the offering of the underlying securities; provided, however, that we are not incorporating by reference any additional documents or information furnished and not filed with the SEC.

Upon request, either orally or in writing, we will provide, without charge, to each person, including any beneficial owner, to whom a copy of this prospectus is delivered, a copy of the documents incorporated by reference into this prospectus but not delivered with the prospectus. You may request a copy of these filings, and any exhibits we have specifically incorporated by reference as an exhibit in this prospectus, at no cost by writing us at the following address: Xeris Pharmaceuticals, Inc., 180 N. LaSalle Street, Suite 1600, Chicago, IL 60601.

You should rely only on the information incorporated by reference or provided in this prospectus or any prospectus supplement. We have not authorized anyone to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus or in the documents incorporated by reference is accurate as of any date other than the date on the front of this prospectus or those documents.

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$60,000,000

    % Convertible Senior Notes due 2025

Preliminary Prospectus Supplement

Joint Book-Running Managers

Jefferies

SVB Leerink

June     , 2020