Apollo Endosurgery (APEN) 424B5 Prospectus supplement for primary offering

Filed Pursuant to Rule 424(b)(5)
Registration No. 333-255786

Prospectus Supplement

(To Prospectus dated May 19, 2021)

8,400,000 Shares

Common Stock

We are offering 8,400,000 shares of common stock.

Our common stock is listed on The Nasdaq Global Market under the symbol “APEN.” On October 12, 2021, the last reported sale price of our common stock on The Nasdaq Global Market was $8.48 per share.

Investing in shares of our common stock involves a high degree of risk. You should carefully read and consider the “Risk Factors” beginning on page S-11 of this prospectus supplement and in our other filings with the Securities and Exchange Commission incorporated by reference in this prospectus supplement and accompanying prospectus before investing.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus supplement or accompanying prospectus. Any representation to the contrary is a criminal offense.

	Per Share		Total
Public offering price	$	7.750	$	65,100,000
Underwriting discounts and commissions(1)	$	0.465	$	3,906,000
Proceeds to Apollo Endosurgery before expenses	$	7.285	$	61,194,000

⁽¹⁾ See “Underwriting” for a description of the compensation payable to the underwriters.

We have granted the underwriters an option to purchase up to 1,260,000 additional shares of common stock from us at the public offering price, less underwriting discounts and commissions. The underwriters can exercise this right at any time within 30 days after the date of this prospectus supplement.

We anticipate that delivery of the common stock against payment will be made on or about October 15, 2021.

Joint Book-Running Managers

Piper Sandler Cowen Stifel

Co-Managers

Craig-Hallum Lake Street

The date of this prospectus supplement is October 12, 2021.

TABLE OF CONTENTS

PROSPECTUS SUPPLEMENT

ABOUT THIS PROSPECTUS SUPPLEMENT	S-iii
PROSPECTUS SUPPLEMENT SUMMARY	S-1
RISK FACTORS	S-11
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS	S-13
MARKET AND INDUSTRY DATA	S-15
USE OF PROCEEDS	S-16
DIVIDEND POLICY	S-17
CAPITALIZATION	S-18
DILUTION	S-20
MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES TO NON-U.S. HOLDERS	S-22
UNDERWRITING	S-26
LEGAL MATTERS	S-37
EXPERTS	S-37
WHERE YOU CAN FIND MORE INFORMATION	S-37
INCORPORATION BY REFERENCE	S-38

PROSPECTUS

	Page
ABOUT THIS PROSPECTUS		ii
PROSPECTUS SUMMARY		1
RISK FACTORS		5
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS		6
USE OF PROCEEDS		8
DESCRIPTION OF CAPITAL STOCK		9
DESCRIPTION OF DEBT SECURITIES		17
DESCRIPTION OF WARRANTS		24
LEGAL OWNERSHIP OF SECURITIES		26
PLAN OF DISTRIBUTION		30
LEGAL MATTERS		32
EXPERTS		32
WHERE YOU CAN FIND ADDITIONAL INFORMATION		32
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE		33

We and the underwriters have not authorized anyone to provide any information or to make any representations other than those contained in or incorporated by reference in this prospectus supplement, the accompanying prospectus or any free writing prospectuses 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. This prospectus is an offer to sell only the shares offered hereby, but only

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under circumstances and in jurisdictions where it is lawful to do so. The information contained in or incorporated by reference in this prospectus supplement, the accompanying prospectus and any free writing prospectuses that we may authorize for use in connection with this offering is accurate only as of its date regardless of the time of delivery of this prospectus supplement, the accompanying prospectus or any such free writing prospectuses or of any sale of common stock.

Neither we nor the underwriters have done anything that would permit this offering or possession or distribution of this prospectus supplement, the accompanying prospectus and any free writing prospectuses that we may authorize for use in connection with this offering in any jurisdiction where action for that purpose is required, other than in the United States. Persons who come into possession of this prospectus supplement, the accompanying prospectus and any free writing prospectuses that we may authorize for use in connection with this offering 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, the accompanying prospectus and any free writing prospectuses that we may authorize for use in connection with this offering applicable to that jurisdiction.

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ABOUT THIS PROSPECTUS SUPPLEMENT

This document consists of two parts. The first part is this prospectus supplement, which describes the terms of this offering of common stock and also adds to and updates information contained in the accompanying prospectus and the documents incorporated by reference into this prospectus supplement. The second part is the accompanying prospectus which includes the documents incorporated by reference therein and provides more general information. To the extent the information contained in this prospectus supplement differs or varies from the information contained in the accompanying prospectus or the documents incorporated by reference herein or therein, you should rely on the information in this prospectus supplement. You should read both this prospectus supplement and the accompanying prospectus, together with additional information described in the section titled “Where You Can Find More Information,” in their entirety before making an investment decision.

“Apollo Endosurgery,” the Apollo Endosurgery logo and other trademarks or service marks of Apollo Endosurgery, Inc. appearing in this prospectus supplement and accompanying prospectus are the property of Apollo Endosurgery, Inc. Other trademarks, service marks or trade names appearing in this prospectus supplement and accompanying prospectus are the property of their respective owners. We do not intend our use or display of other companies’ trade names, trademarks or service marks to imply a relationship with, or endorsement or sponsorship of us by, these other companies.

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PROSPECTUS SUPPLEMENT SUMMARY

This summary highlights certain information about us, this offering and selected information contained elsewhere in this prospectus supplement, the accompanying prospectus or any free writing prospectus and in the documents incorporated by reference. This summary is not complete and does not contain all of the information that you should consider before deciding whether to invest in our securities. For a more complete understanding of our company and this offering, we encourage you to read and consider carefully the more detailed information contained in or incorporated by reference in this prospectus supplement and accompanying prospectus, including the information contained under the heading “Risk Factors” beginning on page S-11 of this prospectus supplement and in the documents incorporated by reference herein, and the information included in any free writing prospectus that we have authorized for use in connection with this offering.

Throughout this prospectus supplement, the terms “Apollo,” “we,” “us,” “our,” and “our company” refer to Apollo Endosurgery, Inc. and its consolidated subsidiaries.

Overview

We are a medical technology company primarily focused on the development of next-generation, less invasive medical devices to advance gastrointestinal therapeutic endoscopy. Our Endoscopy product portfolio consists of the OverStitchTM Endoscopic Suturing System, the OverStitch SxTM Endoscopic Suturing System, X-Tack^® Endoscopic HeliX Tacking System and Orbera^® Intragastric Balloon. Our products are used by gastroenterologists and bariatric surgeons in a variety of settings to treat multiple gastrointestinal conditions including closure of acute perforations and chronic fistulas; tissue closure after the removal of abnormal lesions in the esophagus, stomach or colon (also known as endoscopic submucosal dissections, endoscopic mucosal resections and endoscopic full thickness resections); treatment of swallowing disorders (peroral endoscopic myotomy); and esophageal stent fixation and obesity.

Apollo Products

OverStitch Endoscopic Suturing System

The OverStitch Endoscopic Suturing System and the OverStitch Sx Endoscopic Suturing System, which we refer to collectively as Overstitch, enable advanced endoscopic procedures from within the GI tract, or endolumenally, by allowing physicians to pass suture in order to approximate tissue. OverStitch and OverStitch Sx are currently the only U.S. cleared flexible endoscopic suturing devices capable of full-thickness suturing of tissue. The OverStitch Endoscopic Suturing System received 510(k) clearance in 2008. The OverStitch Sx Endoscopic Suturing System received 510(k) clearance in June 2018 from the U.S. Food and Drug Administration, or FDA, and a CE Mark in November 2018.

Since its market introduction in 2008, over 60,000 OverStitch units have been sold for procedures worldwide. We estimate that approximately 60% of OverStitch uses in the United States were for advanced gastrointestinal therapies. The other uses were for endoscopic sleeve gastroplasty, or ESG, approximately 25%, and bariatric revision, approximately 15%. Outside the United States, we estimate that the majority of OverStitch uses, approximately 65%, were for ESG. The other uses outside the United States were for bariatric revision, approximately 20%, and for advanced gastrointestinal therapies, approximately 15%.

Recent research suggests that there may be a significant untapped market for applying Overstitch to obesity treatments, including endoscopic revisions of bariatric surgeries. In the aggregate, over 200 published investigator-initiated clinical trials, involving over 6,500 ESG procedures and conducted by a variety of physicians around the world, have consistently demonstrated clinically significant excess body weight loss (in excess of 50%) and low complication rates (0.8%). In another recently conducted study, participants were assigned to take semaglutide following their ESG procedures. In the study, initial outcomes of 25.2% total body weight loss at 12 months approached bariatric surgery outcomes as compared to outcomes of 18.7% total body weight loss with ESG alone. We believe these results demonstrate the potential for a meaningfully expanded

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market opportunity for obesity treatment given the currently limited use in the United States of Overstitich for ESG and bariatric revision, as well as the ability for ESG to be performed in individuals with lower body mass indices, or BMI, thereby making the option available to more people.

To address this opportunity, in September 2021, we submitted a De Novo classification request to the FDA seeking FDA 510(k) classification and clearance for the Apollo ESG and Apollo REVISE systems, which consist of the OverStitch Endoscopic Suturing System and related components (such as tissue helix, sutures, cinches). Apollo ESG is intended for use in the ESG procedure for weight loss and Apollo REVISE is intended for use in revision of bariatric surgery procedures. Pending FDA approval of the Apollo ESG and Apollo REVISE devices, we expect to begin education and marketing programs to expand visibility of the ESG procedures and thereby increase the use of OverStitch.

In 2017, we entered into a clinical trial agreement with The Mayo Clinic in Rochester, Minnesota to undertake the MERIT trial to evaluate the long-term safety and efficacy of ESG compared to efficacy endpoints set forth in a consensus statement of the American Society for Gastrointestinal Endoscopy and the American Society of Metabolic Bariatric Surgery and its impact on obesity related comorbidities in patients with an obesity and BMI range of 30 to 45. The MERIT-Trial was designed to enroll patients across nine sites, stratified into three groups (Obesity, Obesity with hypertension, Obesity with diabetes). The study’s primary efficacy endpoint is to achieve at least 25% excess body weight loss, or EBWL, at 12 months and at least 15% EBWL versus control at 12 months, and the primary safety endpoint is a serious adverse event rate of less than 5%. Additionally, patients undergoing ESG are being evaluated for improvement in hypertension and type 2 diabetes at 24 months. The MERIT trial subsequently received an Investigational Device Exemption from the FDA in 2019. We anticipate that the full MERIT trial results, including patient follow-up to two years, will be published in the first half of 2022.

X-Tack Endoscopic HeliX Tacking System

The X-Tack Endoscopic HeliX Tacking System, or X-Tack, is a novel through-the-scope, suture-based device designed specifically for closing and healing defects in the lower gastrointestinal tract. It also has application in the upper gastrointestinal tract. The X-Tack closure device is intended to resolve the limitations of TTS clips, OTSC and endoscopic suturing by offering functionality through the working channel of any standard gastroscope or colonoscope with precise HeliX Tack placement and tight closure of sites of varying shapes and sizes. The X-Tack device enables physicians to address the challenges commonly encountered when closing large or irregularly shaped defects. We believe X-Tack fulfills a need for advanced closure devices to improve healing and address potential adverse events that can occur following standard colonic polypectomy and endoscopic mucosal resection of complex polyps, such as delayed bleeding or perforation. In addition, based on published research and management’s estimates, we believe that we have currently penetrated fewer than 7% of our target United States accounts, and as a result, there is a significant market opportunity to expand the use of the X-tack device by these accounts and others. X-Tack received FDA 510(k) classification and clearance on December 15, 2020 and the first clinical cases were successfully completed in January 2021. We anticipate launching the X-Tack system outside the United States in 2022.

Orbera Intragastric Balloon System

The intragastric balloon system, which we refer to as the Orbera System or Orbera, is currently marketed under three brands depending on geography: the Orbera Intragastric Balloon System, the BIB, and the Orbera365 Managed Weight Loss System, or Orbera365. Orbera is a non-surgical alternative for interventional weight loss. Orbera is the global market leader among intragastric balloons. It is available in over 75 countries and more than 300,000 units have been sold worldwide.

There is a substantial and increasing body of evidence that shows that the level of weight loss with Orbera is highly effective in the treatment of comorbidities associated with obesity. The clinical effectiveness and safety profile of the Orbera System as a non-ulcerogenic weight loss device has been reported in over 230

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peer reviewed publications, which have consistently reported total body weight loss, or TBWL, greater than 10%. Although not specifically indicated for the treatment of any individual obesity-related comorbidities, studies have consistently reported resolution or improvement in a patient’s pre-existing comorbidities at the time of Orbera removal. Orbera is currently the only balloon or other endoscopic product that has been recognized in the ASGE Preservation and Incorporation of Valuable Endoscopic Innovations assessment to have met its threshold safety and efficacy standards for the treatment of obesity. The meta-analysis performed by the ASGE was based on the aggregation of certain clinical studies conducted outside the United States and reported an estimated TBWL at six months of approximately 13.2%.

In March 2021, the FDA granted a Breakthrough Device Designation for the Orbera Intragastric Balloon specifically for use in treating patients with BMI between 30-40 kg/m2 with NASH with liver fibrosis. In addition, the American Medical Association recently assigned, effective January 2023, new Category 1 Current Procedural Terminology (CPT) code to intragastric balloon procedures.

Market Overview

Our Endoscopy products are designed to treat a variety of gastrointestinal conditions including closure of gastrointestinal defects, managing gastrointestinal complications and the treatment of obesity. For the year ended December 31, 2020, 64% of our total Endoscopy sales related to the OverStitch Endoscopic Suturing System and 36% related to the Orbera Intragastric Balloon System products.

Interventional and therapeutic gastroenterology is a high growth area within medicine and our suturing products are used in both the upper and lower GI tract. Examples of upper GI applications include fistula closure, esophageal stent fixation and tunnel closure for peroral endoscopic myotomy.

In the lower GI tract, there are over 21 million colonoscopies performed annually in the United States alone. Cancer screening followed by the endoscopic resection of complex flat and large polyps can provide patients with an alternative to surgical resections.

Obesity as a disease is increasing worldwide. In the United States, it is estimated that 93 million adults are obese or clinically obese with a BMI of 30 or more. Worldwide, over 650 million people are considered obese. Traditional obesity intervention has been bariatric surgery (gastric bypass, sleeve gastrectomy and gastric banding), which is mostly performed laparoscopically. Today, based on U.S. population demographics and physician society reported bariatric procedure volumes, less than 1% of the population eligible for bariatric surgery elect to have a procedure each year. Based on published surveys, the eligible patient’s primary detraction from bariatric surgery is fear of surgery in general, and more specifically fear associated with the invasive nature of bariatric surgery, permanent anatomical alteration, potential for non-permanent results and the post-operative severe complications that have been reported with bariatric surgery. We believe the application of Overstitch to endoscopic revisions of bariatric surgeries would address many of these concerns.

Based on public research and management estimates, we believe that our historical addressable market for our Endoscopy products is approximately $215 million, consisting of a $175 million primarily U.S. market for advanced upper gastrointestinal defect closure and a $40 million global market for intragastric balloons. We hope to expand our future potential addressable market through new indications for our current products, new applications for existing solutions, increased clinical support and increased reimbursement.

We believe that, through the development of our current endoscopic suturing system, the advanced gastrointestinal procedures market, which includes clip replacements and polyp removal defect closures in both the upper and lower gastrointestinal tracts, presents an aggregate global market opportunity of approximately $850 million, including the U.S. market for polyp removal defect closures which is expected to be in excess of $500 million. Additionally, we aim to expand the indications for our Orbera and Overstitch products to address the approximately $3.9 billion global endobariatric weight loss market.

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In addition, we believe that endoscopic revisions of bariatric surgeries present another market for application of our Overstitch products with over 70% of our top 100 Overstitch accounts in the United States already performing revision procedures. In 2019, 43,000 revision procedures were performed in the United States. Between 2011 and 2019, over 1.4 million laparoscopic sleeve and gastric bypasses were performed in the United States alone, and we estimate that 30% to 50% of these are potential revision candidates. Moreover, in a peer-reviewed study that compared results at five years, endoscopic revision demonstrated equivalent efficacy and an improved safety profile as compared to surgical revision, suggesting that endoscopic revision has the potential to increase in relative share of the market for revisions of bariatric surgeries.

Our development strategy is to further establish the medical relevancy of Orbera in areas of unmet medical need, such as addressing the needs of the approximately 10 million U.S. patients with non-alcoholic steatohepatitis, or NASH. NASH is the leading cause of liver transplants in women and patients over the age of 65. NASH treatment presents a large and growing market opportunity, having grown from $1.9 billion in 2019 to $2.9 billion in 2021 and projected to reach $54 billion by 2027, representing a 59% estimated compound annual growth rate.

Preliminary Estimated Unaudited Financial Information

Presented below are certain estimated preliminary financial results as of and for the three months ended September 30, 2021. These ranges are based on the information available to us at this time and reflect our management’s best estimate of the impact of events during the three months ended September 30, 2021. We have provided estimated ranges, rather than specific amounts, because these results are preliminary and subject to change. We have not yet completed our closing procedures for the three months ended September 30, 2021. As such, our actual results may differ materially from the estimated preliminary financial results presented here and will not be finalized until after we close this offering and complete our normal quarter-end accounting procedures, including the execution of our internal controls over financial reporting.

These estimates should not be viewed as a substitute for our full interim or annual financial statements prepared in accordance with U.S. generally accepted accounting principles, or GAAP. Accordingly, you should not place undue reliance on these estimated financial results. These estimated preliminary financial results should be read in conjunction with our audited annual consolidated financial statements and our unaudited interim condensed consolidated financial statements, each incorporated herein by reference, and the sections titled “Special Note Regarding Forward-Looking Statements” and “Risk Factors” found elsewhere in this prospectus supplement.

The estimated preliminary financial results have been prepared by our management team. Our independent registered public accounting firm, Moss Adams LLP, has not audited, reviewed, compiled, or applied any procedures with respect to these estimated financial results. Accordingly, Moss Adams LLP does not express an opinion or any other form of assurance with respect thereto.

The following are our estimated preliminary financial results for the three months ended September 30, 2021. The comparative figures for the three months ended September 30, 2020 have been derived from our condensed consolidated financial statements and other information as previously reported.

	Three Months Ended September 30,
	2020			2021 Estimated
	Actual			Low			High
	($ in thousands, except percentages)
Revenue	$	12,826		$	16,000		$	16,400
Gross margin		55	%		54	%		56	%
Loss from operations		(1,574	)		(4,100	)		(5,200	)
Net loss		(2,597	)		(6,100	)		(7,300	)
Adjusted EBITDA (non-GAAP)		(172	)		(2,100	)		(3,000	)

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To supplement our financial statements presented in accordance with GAAP, we report non-GAAP Adjusted EBITDA. We believe that Adjusted EBITDA provides investors with an additional tool for evaluating our core performance, which our management uses in its own evaluation of continuing operating performance, and a baseline for assessing our future earnings potential. Adjusted EBITDA may not provide information that is directly comparable to that provided by other companies in our industry, as other companies in the industry may calculate this measure differently. Adjusted EBITDA should be considered in addition to, and not as a substitute for, or superior to, financial measures calculated in accordance with GAAP. The following table provides a reconciliation of our preliminary estimated ranges of Adjusted EBITDA for the three months ended September 30, 2021 to net loss for the same period, the most comparable GAAP measure, as well as a reconciliation of actual Adjusted EBITDA for the three months ended September 30, 2020 to net loss for the same period.

	Three Months Ended September 30,
	2020			2021 Estimated
	Actual			Low			High
	($ in thousands)
Net loss	$	(2,597	)	$	(6,100	)	$	(7,300	)
Depreciation and amortization		921			800			800
Interest expense, net		1,335			1,300			1,300
Income tax expense		41			—			100
EBITDA		(300	)		(4,000	)		(5,100	)
Stock-based compensation		586			1,400			1,500
Unrealized foreign exchange		(458	)		500			600
Adjusted EBITDA	$	(172	)	$	(2,100	)	$	(3,000	)

Risks Associated with Our Business

Our business is subject to numerous risks and uncertainties, including those highlighted in the section titled “Risk Factors” immediately following this prospectus supplement summary and those incorporated by reference in this prospectus supplement and accompanying prospectus.

• Our business has been and likely will continue to be adversely affected by the ongoing COVID-19 pandemic.

• We have incurred significant operating losses since inception and may not be able to achieve profitability.

• Our long-term growth depends on our ability to successfully develop the market for our Endoscopy products.

• A weakening of U.S. and international economic conditions may reduce consumer demand for our products, causing our sales and profitability to suffer.

• Our future growth depends on physician adoption and recommendation of procedures utilizing our products.

• Our future growth depends on patient awareness of and demand for procedures that use our products.

• Our future growth depends on developing clinical data that demonstrates the safety and efficacy of our products and the procedures that use our products.

• Our future growth depends on obtaining and maintaining adequate coverage and reimbursement for procedures performed with our products.

• If our products contribute to a serious injury or death, or malfunction in certain ways, we may be subject to liability claims and will be subject to medical device reporting regulations, which can result in voluntary corrective actions or agency enforcement actions.

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• The misuse or off-label use of our products may harm our image in the marketplace, result in injuries that lead to product liability suits or result in costly investigations and sanctions by regulatory bodies if we are deemed to have engaged in the promotion of these uses, any of which could be costly to our business.

• We are dependent on certain suppliers, vendors and manufacturers, and supply or service disruptions could materially adversely affect our business and future growth.

• We compete or may compete in the future against other companies, some of which have longer operating histories, more established products and greater resources, which may prevent us from achieving significant market penetration or improved operating results.

• If our facilities or the facility of a supplier become inoperable, we will be unable to continue to research, develop, manufacture and commercialize our products and, as a result, our business will be harmed.

• Our products are subject to extensive regulation by the U.S. Food and Drug Administration (“FDA”) and foreign regulatory authorities, including the requirement to obtain premarket approval and the requirement to report adverse events and violations of the U.S. Federal Food, Drug and Cosmetic Act that could present significant risk of injury to patients. Even though we have received FDA approval of our PMA applications, 510(k) clearances and foreign regulatory approvals to commercially market our products, we will continue to be subject to extensive regulatory oversight from the FDA and foreign regulatory authorities.

• If we or our suppliers fail to comply with local, state or federal laws, rules or regulations, or with ongoing FDA or foreign regulatory authority requirements, or if we experience unanticipated problems with our products, these products could be subject to restrictions or withdrawal from the market.

• Intellectual property rights may not provide adequate protection, which may permit third parties to compete against us more effectively.

• We may in the future be a party to patent and other intellectual property litigation and administrative proceedings that could be costly and could interfere with our ability to sell our products.

• We have substantial indebtedness which contain restrictive covenants that may limit our operating flexibility and our failure to comply with the covenants and payment requirements of our indebtedness may subject us to increased interest expenses, lender consent and amendment costs or adverse financial consequences.

• We may need substantial additional funding and may be unable to raise capital when needed, which would force us to delay, reduce, eliminate or abandon our commercialization efforts or product development programs.

• Our stock price may be volatile, and you may not be able to resell shares of our common stock at or above the price you paid.

• Our business and operations would suffer in the event of system failures, security breaches or cyber-attacks.

Corporate Background

Apollo was founded in 2005 and is incorporated in Delaware with headquarters in Austin, Texas. Our company was founded to develop and commercialize innovations originating from a collaboration of physicians from the Mayo Clinic, Johns Hopkins University, Medical University of South Carolina, the University of Texas Medical Branch and the Chinese University of Hong Kong, who called themselves the Apollo Group. The work

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of the Apollo Group resulted in a significant portfolio of patents in the field of flexible endoscopy and minimally invasive surgery aimed at minimizing the trauma of surgical access by taking advantage of natural orifices to deliver surgical tools to targeted areas.

In December 2016, we completed a business combination with Lpath, Inc., a publicly traded company. Following the Merger, Lpath, Inc. was renamed “Apollo Endosurgery, Inc.” and our common stock began trading on The Nasdaq Global Market under the symbol “APEN.”

Today, we have offices in the United Kingdom and Italy that oversee commercial activities outside the United States and a manufacturing facility in Costa Rica. All other activities are managed and operated from our facilities in Austin, Texas. Our principal executive offices are located at 1120 S. Capital of Texas Highway, Building 1, Suite 300, Austin, Texas 78746. Our telephone number is (512) 279-5100. Our website address is www.apolloendosurgery.com. The information contained on, or that can be accessed through, our website is not part of, and is not incorporated by reference into this prospectus supplement and should not be considered to be part of this prospectus supplement. Investors should not rely on any such information in deciding whether to purchase our common stock.

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THE OFFERING

Common stock offered by us	8,400,000 shares
Common stock to be outstanding after this offering	37,024,979 shares (or 38,284,979 shares if the underwriters exercise their option to purchase additional shares in full)
Option to purchase additional shares	We may sell up to 1,260,000 additional shares of common stock if the underwriters exercise their option to purchase additional shares in full.
Use of proceeds	We estimate that the net proceeds from this offering will be approximately $60.7 million, or approximately $69.9 million if the underwriters exercise their option to purchase additional shares in full, after deducting underwriting discounts and commissions and offering expenses payable by us.
	We intend to use the net proceeds from this offering to invest in opportunities to drive growth, such as expanding sales and marketing programs, expanding the indications of certain of our products and developing new products, to potentially refinance or partially pay down existing indebtedness under our term loan with Solar Capital, and for working capital and other general corporate purposes. Borrowings under the term loan bear interest at LIBOR, subject to a minimum floor, plus 7.5%. The term loan has a scheduled maturity date of March 1, 2025. See the section titled “Use of Proceeds” found on page S-16 of this prospectus supplement.
Risk factors	See “Risk Factors” beginning on page S-11 of this prospectus supplement, as well as other information included and incorporated by reference in this prospectus supplement and accompanying prospectus, for a discussion of factors you should read and consider carefully before investing in our common stock.
Nasdaq Global Market symbol	“APEN”

The number of shares of common stock to be outstanding after this offering is based on 28,624,979 shares of common stock outstanding as of June 30, 2021, and excludes:

• 3,851,739 shares issuable upon the exercise of outstanding stock options with a weighted-average exercise price of $4.70 per share;

• 1,269,200 shares issuable upon settlement of outstanding restricted stock units and performance stock units;

• 924,022 shares available for future issuance under our 2017 Equity Incentive Plan;

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• 14,573,379 shares issuable upon the exercise of outstanding pre-funded warrants with a weighted-average exercise price of $0.28 per share; and

• 6,290,932 shares issuable upon the conversion of $20,445,500 aggregate principal amount of outstanding convertible debentures, assuming a conversion price of $3.25 per share.

Subsequent to June 30, 2021, and through September 30, 2021:

• we granted stock options to purchase 150,000 shares of common stock with a weighted-average exercise price of $8.69 per share;

• we granted 200,000 performance stock units;

• we issued 71,609 shares of common stock to holders of our convertible debentures in fulfillment of accrued interest payable in kind on such convertible debentures; and

• we issued 624,436 shares of common stock upon the exercise of outstanding pre-funded warrants.

As of September 30, 2021, there were 29,829,697 shares of common stock outstanding.

Unless otherwise stated, information in this prospectus supplement assumes:

• no exercise of outstanding options or warrants, conversion of outstanding debentures or settlement of outstanding restricted stock units; and

• no exercise by the underwriters of their option to purchase additional shares.

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SUMMARY SELECTED CONSOLIDATED FINANCIAL DATA

You should read the summary selected consolidated financial data below in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” included in our Annual Report on Form 10-K for the year ended December 31, 2020 filed with the Securities and Exchange Commission, or the SEC, on February 25, 2021 and our Quarterly Report on Form 10-Q for the three months ended June 30, 2021 filed with the SEC on August 3, 2021, and the consolidated financial statements, related notes and other financial information incorporated by reference in this prospectus supplement and accompanying prospectus. The summary selected consolidated financial data in this section are not intended to replace the consolidated financial statements and are qualified in their entirety by the consolidated financial statements and related notes incorporated by reference in this prospectus supplement and accompanying prospectus.

The following consolidated statements of operations and comprehensive loss data for the years ended December 31, 2020 and 2019 and the consolidated balance sheet data as of December 31, 2020 and 2019 have been derived from our audited consolidated financial statements incorporated by reference in this prospectus supplement and accompanying prospectus. The condensed consolidated statements of operations and comprehensive loss data for the six months ended June 30, 2021 and 2020 and the condensed consolidated balance sheet data as of June 30, 2021 are derived from our unaudited interim condensed consolidated financial statements incorporated by reference in this prospectus supplement and accompanying prospectus. Our unaudited interim condensed consolidated financial statements were prepared on a basis consistent with our audited consolidated financial statements and include, in our opinion, all adjustments, consisting only of normal recurring adjustments that we consider necessary for a fair presentation of the financial information set forth in those statements. Our historical results are not necessarily indicative of the results that may be expected in the future and the results of interim periods are not necessarily indicative of the results for an entire year.

	Six Months Ended June 30,						Year Ended December 31,
	2021			2020			2020			2019
Consolidated Statements of Operations and Comprehensive Loss Data:	(in thousands)
Revenues	$	30,467		$	16,362		$	42,048		$	50,713
Cost of sales		13,837			8,296			19,806			25,038
Gross margin		16,630			8,066			22,242			25,675
Total operating expenses		25,625			19,039			38,036			49,188
Loss from operations		(8,995	)		(10,973	)		(15,794	)		(23,513	)
Interest expense, net		2,686			2,560			5,251			4,052
Gain on forgiveness of PPP loan		(2,852	)		—			—			—
Other (income) expense, net		(1,339	)		2,927			1,424			(408	)
Income tax expense		130			49			142			275
Net loss	$	(7,620	)	$	(16,509	)	$	(22,611	)	$	(27,432	)
Foreign currency translation		(1,402	)		2,403			1,299			(871	)
Comprehensive loss	$	(9,022	)	$	(14,106	)	$	(21,312	)	$	(28,303	)

	As of June 30,			As of December 31,
	2021			2020			2019
	(in thousands)
Consolidated Balance Sheet Data:
Cash, cash equivalents and restricted cash	$	31,242		$	37,200		$	30,921
Total assets		74,419			77,437			74,582
Long-term debt		35,516			37,192			—
Total liabilities		71,705			70,686			72,459
Accumulated deficit		(280,393	)		(272,773	)		(250,162	)
Total stockholders’ equity		2,714			6,751			2,123

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RISK FACTORS

An investment in our securities involves a high degree of risk. You should carefully consider the risks described below and discussed in the section titled “Risk Factors” contained in our Annual Report on Form 10-K for the year ended December 31, 2020, as updated by our subsequent filings under the Securities Exchange Act of 1934, as amended, or the Exchange Act, including our Quarterly Report on Form 10-Q for the three months ended June 30, 2021, each of which is incorporated by reference in this prospectus supplement and accompanying prospectus in its entirety, together with other information in this prospectus supplement and accompanying prospectus, and the information and documents incorporated by reference in this prospectus supplement, the accompanying prospectus and any free writing prospectuses that we may authorize for use in connection with this offering, before making a decision to invest in shares of our common stock.

Our business faces significant risks and the risks described below and in the documents incorporated by reference herein may not be the only risks we face. Additional risks not presently known to us or that we currently believe are immaterial may also significantly impair our business operations. If any of these risks occur, our business, results of operations or financial condition and prospects could be materially and adversely affected. In that event, the market price of our common stock could decline, and you could lose all or part of your investment. Please also read carefully the section below titled “Special Note Regarding Forward-Looking Statements.”

Risks Related to this Offering

Management will have broad discretion as to the use of the net proceeds from this offering, and we may not use these proceeds effectively.

We have not designated any portion of the net proceeds from this offering to be used for any particular purposes. Our management will have broad discretion in the application of the net proceeds from this offering and could spend the proceeds in ways that do not improve our results of operations or enhance the value of our common stock. Accordingly, you will be relying on the judgment of our management with regard to the use of these net proceeds, and you will not have the opportunity, as part of your investment decision, to assess whether the proceeds are being used appropriately. Our failure to apply these funds effectively could harm our business, delay the development of our products and cause the price of our common stock to decline.

Future sales and issuances of substantial amounts of our common stock could adversely affect the market price of our common stock.

We may choose to raise additional capital due to market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. If additional capital is raised through the sale of equity or convertible debt securities, or perceptions that those sales could occur, the issuance of these securities could result in further dilution to investors purchasing our common stock in this offering or result in downward pressure on the price of our common stock, and our ability to raise capital in the future.

In addition, the conversion or exercise of some or all of our outstanding convertible debt and pre-funded warrants, respectively, may also dilute the ownership interests of existing stockholders. Any sales in the public market of any shares of our common stock issuable upon such conversion or exercise, as applicable, including pursuant to our registration statements on Form S-3 with respect to shares underlying these convertible securities, could negatively impact prevailing market prices of our common stock.

Purchasers in this offering will experience immediate and substantial dilution in the tangible net book value of their investment.

If you purchase our common stock in this offering, you will incur an immediate dilution of $6.32 in net tangible book value (deficit) per share from the price you paid, based on the public offering price of $7.75 per share. The exercise of outstanding options or warrants, or the conversion of outstanding convertible

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debentures, will result in further dilution. For a further description of the dilution that you will experience immediately after this offering, see the section titled “Dilution.”

Future sales of our common stock could depress the market price of our common stock.

Sales of a substantial number of shares of our common stock in the public market following this offering, or the perception that such sales might occur, could cause the market price of our common stock to decline and make it more difficult for you to sell your common stock at a time that you deem appropriate. In addition, any future sales of securities by us or existing stockholders, particularly our director, executive officers or significant stockholders, could have a material adverse effect on the market price of our common stock. Further, we have a significant number of stock options and restricted stock units outstanding. If a substantial number of shares of common stock underlying these options and restricted stock units are sold, or if it is perceived that they will be sold, in the public market, it could have a material adverse effect on the market price of our common stock.

There may be a limited market for investors in our industry.

Our common stock is held by a relatively small number of stockholders. Investors may have limited funds to invest in the obesity focused medical devices sector, and investors who have purchased or may in the future purchase securities in this sector may choose to sell our securities that they have already purchased in favor of other companies, and/or choose to invest in other companies, including our competitors. As a result, demand for our common stock could decline, which would result in a corresponding decline in our stock price.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement, the accompanying prospectus and the documents we have filed with the SEC that are incorporated 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 Exchange Act. These statements relate to future events or to our future operating or financial performance and involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements to be materially different from any future results, performances or achievements expressed or implied by the forward-looking statements. Forward-looking statements may include, but are not limited to, statements about:

• our ability to become profitable and generate consistent cash flows to remain profitable;

• our plans to develop and commercialize additional products and product features;

• our plans to grow our customer base, both domestically and internationally;

• our expectations regarding potential market opportunity for our products;

• our ability to attract and retain highly qualified personnel;

• our ability to develop, expand and manage a worldwide sales organization;

• our ability to protect and enhance our products and intellectual property;

• our expectations concerning our relationships and actions with third parties;

• our ability to obtain and maintain approvals to sell existing and future products from domestic and international regulatory bodies;

• future regulatory, judicial and legislative changes in our industry;

• the results of our ongoing or future clinical trials of our products and product features;

• our ability to maintain and operate our business in light of the COVID-19 pandemic;

• our use of proceeds from offerings of our securities under this prospectus supplement;

• our financial performance; and

• developments and projections relating to our competitors, our industry and the general economy.

In some cases, you can identify forward-looking statements by terms such as “anticipates,” “believes,” “could,” “estimates,” “expects,” “intends,” “may,” “plans,” “potential,” “predicts,” “projects,” “should,” “will,” “would,” or the negative of these terms and other similar expressions. These statements reflect our current views with respect to future events and are based on assumptions and are subject to risks and uncertainties. Given these uncertainties, you should not place undue reliance on these forward-looking statements. We discuss in greater detail many of these risks in the section titled “Risk Factors” contained in this prospectus supplement, the accompanying prospectus, in any free writing prospectuses we may authorize for use in connection with this offering, and in our Annual Report on Form 10-K for the year ended December 31, 2020 and Quarterly Report on Form 10-Q for the three months ended June 30, 2021 and in subsequent filings with the SEC, which are incorporated by reference herein. Also, these forward-looking statements represent our estimates and assumptions only as of the date of the document containing the applicable statement. Unless required by law, we undertake no obligation to update or revise any forward-looking statements to reflect new information or future events or developments.

In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this prospectus supplement, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have

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conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.

You should read this prospectus supplement and accompanying prospectus together with the documents we have filed with the SEC that are incorporated by reference and any free writing prospectus that we may authorize for use in connection with this offering completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of the forward-looking statements in the foregoing documents by these cautionary statements.

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MARKET AND INDUSTRY DATA

This prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein contain market data and industry statistics and forecasts that are based on independent industry publications and other publicly available information. Although we believe that these sources are reliable, we do not guarantee the accuracy or completeness of this information and we have not independently verified this information. Although we are not aware of any misstatements regarding the market and industry data presented or incorporated by reference in this prospectus, these estimates involve risks and uncertainties and are subject to change based on various factors, including those discussed in the section titled “Risk Factors” contained in this prospectus supplement and accompanying prospectus and in our Annual Report on Form 10-K for the year ended December 31, 2020, our Quarterly Report on Form 10-Q for the three months ended June 30, 2021 and in subsequent filings with the SEC, which are incorporated by reference herein, and any related free writing prospectus that we may authorize for use in connection with this offering. Accordingly, investors should not place undue reliance on this information.

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USE OF PROCEEDS

We estimate that the net proceeds of this offering will be approximately $60.7 million, after deducting underwriting discounts and commissions and estimated expenses payable by us. If the underwriters exercise their option to purchase additional shares in full, we estimate that the net proceeds will be approximately $69.9 million, after deducting underwriting discounts and commissions and estimated offering expenses payable by us.

We intend to use the net proceeds from this offering to invest in opportunities to drive growth, such as expanding sales and marketing programs, expanding the indications of certain of our products and developing new products, to potentially refinance or partially pay down existing indebtedness under our term loan with Solar Capital, and for working capital and other general corporate purposes. Borrowings under the term loan bear interest at LIBOR, subject to a minimum floor, plus 7.5%. The term loan has a scheduled maturity date of March 1, 2025. We may also use a portion of the net proceeds from this offering to acquire or invest in complementary businesses, assets, technologies or intellectual property, although we have no present commitments or agreements to do so.

We cannot specify with certainty the particular uses of the net proceeds that we will receive from this offering. Accordingly, we will have broad discretion in using these proceeds. Pending the use of the proceeds from this offering as described above, we intend to invest the net proceeds in interest-bearing investment-grade securities or government securities.

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DIVIDEND POLICY

We have never paid or declared any cash dividends on our common stock. We do not anticipate paying any cash dividends on our common stock in the foreseeable future, and we intend to retain all available funds and any future earnings to fund the development and expansion of our business. In addition, covenants in the agreement governing our senior secured credit facility do not allow for the payment of any cash dividends. Any future determination to pay dividends will be at the discretion of our board of directors and will depend upon a number of factors, including our results of operations, financial condition, future prospects, contractual restrictions (including under our agreements with Solar Capital), restrictions imposed by applicable law and other factors our board of directors deems relevant.

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CAPITALIZATION

The following table shows our cash, cash equivalents and restricted cash and our capitalization as of June 30, 2021 on:

• an actual basis; and

• an as adjusted basis to reflect the sale by us of 8,400,000 shares of common stock in this offering at the public offering price of $7.75 per share, after deducting underwriting discounts and commissions and estimated offering expenses payable by us.

The following information should be read in conjunction with the section titled “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and financial statements and related notes in our Annual Report on Form 10-K for the year ended December 31, 2020, our Quarterly Report on Form 10-Q for the three months ended June 30, 2021 and the other documents incorporated by reference in this prospectus supplement and accompanying prospectus. For more details on how you can obtain our periodic reports and other information, see “Where You Can Find More Information” elsewhere in this prospectus supplement.

	As of June 30, 2021
	Actual			As Adjusted
	(in thousands, except share and per share data)
Cash, cash equivalents and restricted cash	$	31,242		$	91,986
Long-term debt	$	35,516		$	35,516
Stockholders’ equity:
Preferred stock, $0.001 par value, 15,000,000 shares authorized, no shares issued and outstanding, actual and as adjusted		—			—
Common stock, $0.001 par value, 100,000,000 shares authorized, 28,624,979 shares issued and outstanding, actual; 37,024,979 shares issued and outstanding, as adjusted		29			29
Additional paid-in capital		281,551			342,295
Accumulated other comprehensive income		1,527			1,527
Accumulated deficit		(280,393	)		(280,393	)
Total stockholders’ equity		2,714			63,458
Total capitalization	$	38,230		$	98,974

The number of shares of common stock to be outstanding after this offering is based on 28,624,979 shares of common stock outstanding as of June 30, 2021, and excludes:

• 3,851,739 shares issuable upon the exercise of outstanding stock options with a weighted-average exercise price of $4.70 per share;

• 1,269,200 shares issuable upon settlement of outstanding restricted stock units and performance stock units;

• 924,022 shares available for future issuance under our 2017 Equity Incentive Plan;

• 14,573,379 shares issuable upon the exercise of outstanding pre-funded warrants with a weighted-average exercise price of $0.28 per share; and

• 6,290,932 shares issuable upon the conversion of $20,445,500 aggregate principal amount of outstanding convertible debentures, assuming a conversion price of $3.25 per share.

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Subsequent to June 30, 2021, and through September 30, 2021:

• we granted stock options to purchase 150,000 shares of common stock with a weighted-average exercise price of $8.69 per share;

• we granted 200,000 performance stock units;

• we issued 71,609 shares of common stock to holders of our convertible debentures in fulfillment of accrued interest payable in kind on such convertible debentures; and

• we issued 624,436 shares of common stock upon the exercise of outstanding pre-funded warrants.

As of September 30, 2021, there were 29,829,697 shares of common stock outstanding.

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DILUTION

If you invest in our common stock, your interest will be diluted to the extent of the difference between the public offering price per share and the as adjusted net tangible book value (deficit) per share of our common stock after this offering.

As of June 30, 2021, our net tangible book value (deficit) was $(7.8) million, or $(0.27) per share. Net tangible book value (deficit) is total tangible assets less total liabilities divided by the total number of outstanding shares of common stock.

After giving effect to the sale of 8,400,000 shares of common stock in this offering, after deducting the underwriting discounts and commissions and estimated offering expenses payable by us, our as adjusted net tangible book value as of June 30, 2021 would have been $53.0 million, or $1.43 per share. This represents an immediate increase in as adjusted net tangible book value of $1.70 per share to our existing stockholders and immediate dilution in net tangible book value of $6.32 per share to investors participating in this offering. The following table illustrates this dilution per share to investors participating in this offering:

Public offering price per share				$	7.75
Net tangible book value (deficit) per share as of June 30, 2021	$	(0.27	)
Increase in net tangible book value per share attributable to new investors in this offering		1.70
As adjusted net tangible book value (deficit) per share after giving effect to this offering					1.43
Dilution in net tangible book value (deficit) per share to new investors in this offering				$	6.32

If the underwriters exercise in full their option to purchase additional shares from us, the adjusted net tangible book value per share after giving effect to this offering would be $1.62 per share, representing an immediate increase to existing stockholders of $1.89 per share, and immediate dilution to investors in this offering of $6.13 per share.

The number of shares of common stock to be outstanding after this offering is based on 28,624,979 shares of common stock outstanding as of June 30, 2021, and excludes:

• 3,851,739 shares issuable upon the exercise of outstanding stock options with a weighted-average exercise price of $4.70 per share;

• 1,269,200 shares issuable upon settlement of outstanding restricted stock units and performance stock units;

• 924,022 shares available for future issuance under our 2017 Equity Incentive Plan;

• 14,573,379 shares issuable upon the exercise of outstanding pre-funded warrants with a weighted-average exercise price of $0.28 per share; and

• 6,290,932 shares issuable upon the conversion of $20,445,500 aggregate principal amount of outstanding convertible debentures, assuming a conversion price of $3.25 per share.

Subsequent to June 30, 2021, and through September 30, 2021:

• we granted stock options to purchase 150,000 shares of common stock with a weighted-average exercise price of $8.69 per share;

• we granted 200,000 performance stock units;

• we issued 71,609 shares of common stock to holders of our convertible debentures in fulfillment of accrued interest payable in kind on such convertible debentures; and

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• we issued 624,436 shares of common stock upon the exercise of outstanding pre-funded warrants.

As of September 30, 2021, there were 29,829,697 shares of common stock outstanding.

The above illustration of dilution per share to investors participating in this offering assumes no exercise of outstanding options or warrants to purchase our common stock or settlement of outstanding restricted stock units. To the extent that any outstanding options or warrants are exercised or restricted stock units are settled, there will be further dilution to new investors.

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MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES TO NON-U.S. HOLDERS

The following summary describes the material U.S. federal income tax consequences of the acquisition, ownership and disposition of our common stock acquired in this offering by Non-U.S. Holders (as defined below). This discussion does not address all aspects of U.S. federal income taxes and does not deal with foreign, state and local consequences that may be relevant to Non-U.S. Holders in light of their particular circumstances, nor does it address U.S. federal tax consequences other than income taxes (not addressed, for instance, are gift and estate taxes). Special rules different from those described below may apply to certain Non-U.S. Holders that are subject to special treatment under the Code, such as financial institutions, insurance companies, tax-exempt organizations, tax-qualified retirement plans, broker-dealers and traders in securities, commodities or currencies, U.S. expatriates and certain former citizens and other long-term residents of the United States, “controlled foreign corporations,” “passive foreign investment companies,” corporations that accumulate earnings to avoid U.S. federal income tax, persons that hold our common stock as part of a “straddle,” “hedge,” “conversion transaction,” “synthetic security” or integrated investment or other risk reduction strategy, persons that are deemed to sell our common stock under the constructive sale provisions of the Code, persons who hold or receive our common stock pursuant to the exercise of options or otherwise as compensation, persons that own or are deemed to own more than 5% of our common stock (except as specifically set forth below), persons subject to the alternative minimum tax or federal Medicare contribution tax on net investment income, persons who are subject to Section 451(b) of the Internal Revenue Code of 1986, as amended, or the Code, partnerships and other pass-through entities, and investors in such pass-through entities. Such Non-U.S. Holders are urged to consult their own tax advisors to determine the U.S. federal, state, local and other tax consequences that may be relevant to them. Furthermore, the discussion below is based upon the provisions of the Code, and Treasury regulations, rulings and judicial decisions thereunder as of the date hereof, and such authorities may be repealed, revoked or modified, perhaps retroactively, so as to result in U.S. federal income tax consequences different from those discussed below. We have not requested a ruling from the U.S. Internal Revenue Service, or IRS, with respect to the statements made and the conclusions reached in the following summary, and there can be no assurance that the IRS will agree with such statements and conclusions. This discussion assumes that the Non-U.S. Holder holds our common stock as a “capital asset” within the meaning of Section 1221 of the Code (generally, property held for investment).

In addition, this discussion does not address the tax treatment of partnerships (or entities or arrangements that are treated as partnerships for U.S. federal income tax purposes) or persons that hold their common stock through such partnerships or such entities or arrangements. If a partnership, including any entity or arrangement treated as a partnership for U.S. federal income tax purposes, holds shares of our common stock, the U.S, federal income tax treatment of a partner in such partnership will generally depend upon the status of the partner, the activities of the partnership and certain determinations made at the partner level. Such partners and partnerships should consult their own tax advisors regarding the tax consequences of the purchase, ownership and disposition of our common stock.

Persons considering the purchase of our common stock pursuant to this offering should consult their own tax advisors concerning the U.S. federal income, estate, and other tax consequences of acquiring, owning and disposing of our common stock in light of their particular situations as well as any consequences arising under the laws of any other taxing jurisdiction, including any state, local or foreign tax consequences.

For the purposes of this discussion, a “Non-U.S. Holder” is, for U.S. federal income tax purposes, a beneficial owner of common stock that is neither a U.S. Holder nor a partnership (or other entity treated as a partnership for U.S. federal income tax purposes regardless of its place of organization or formation). A “U.S. Holder” means a beneficial owner of our common stock that is for U.S. federal income tax purposes (1) an individual who is a citizen or resident of the U.S., (2) a corporation or other entity treated as a corporation created or organized in or under the laws of the U.S., any state thereof or the District of Columbia, (3) an estate the income of which is subject to U.S. federal income taxation regardless of its source or (4) a trust if it (a) is subject to the primary supervision of a court within the U.S. and one or more U.S. persons have the authority to

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control all substantial decisions of the trust or (b) has a valid election in effect under applicable U.S. Treasury regulations to be treated as a U.S. person.

Distributions

Distributions, if any, made on our common stock to a Non-U.S. Holder to the extent made out of our current or accumulated earnings and profits (as determined under U.S. federal income tax principles) generally will constitute dividends for U.S. federal income tax purposes. Subject to the discussion below regarding backup withholding and FATCA withholding, dividends will be subject to withholding tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty. To obtain a reduced rate of withholding under a treaty, a Non-U.S. Holder generally will be required to provide us or our paying agent with a properly executed IRS Form W-8BEN (in the case of individuals), IRS Form W-8BEN-E (in the case of entities), or other appropriate form, including a U.S. taxpayer identification number, and certifying the Non-U.S. Holder’s entitlement to benefits under that treaty. This certification must be provided to us or our paying agent prior to the payment of dividends. In the case of a Non-U.S. Holder that is an entity, Treasury Regulations and the relevant tax treaty provide rules to determine whether, for purposes of determining the applicability of a tax treaty, dividends will be treated as paid to the entity or to those holding an interest in that entity. If a Non-U.S. Holder holds stock through a financial institution or other agent acting on the holder’s behalf, the holder will be required to provide appropriate documentation to such agent. The holder’s agent will then be required to provide certification to us or our paying agent, either directly or through other intermediaries. If you are eligible for a reduced rate of U.S. federal withholding tax under an income tax treaty and you do not timely provide the required certification, you may be able to obtain a refund or credit of any excess amounts withheld by timely filing an appropriate claim for a refund with the IRS.

We generally are not required to withhold tax on dividends paid to a Non-U.S. Holder that are effectively connected with the Non-U.S. Holder’s conduct of a trade or business within the United States (and, if required by an applicable income tax treaty, are attributable to a permanent establishment or fixed place of business that such holder maintains in the United States) if a properly executed IRS Form W-8ECI, stating that the dividends are so connected, is furnished to us (or, if stock is held through a financial institution or other agent, to such agent). In general, such effectively connected dividends will be subject to U.S. federal income tax, on a net income basis at the regular rates applicable to U.S. residents. A corporate Non-U.S. Holder receiving effectively connected dividends may also be subject to an additional “branch profits tax,” which is imposed, under certain circumstances, at a rate of 30% (or such lower rate as may be specified by an applicable treaty) on the corporate Non-U.S. Holder’s effectively connected earnings and profits, subject to certain adjustments. Non-U.S. Holders should consult their tax advisors regarding any applicable income tax treaties that may provide for different rules.

To the extent distributions on our common stock, if any, exceed our current and accumulated earnings and profits, they will first reduce the Non-U.S. Holder’s adjusted basis in our common stock, but not below zero, and then will be treated as gain to the extent of any excess over adjusted basis, and taxed in the same manner as gain realized from a sale or other disposition of common stock as described in the next section. See the discussion below in “Gain on Disposition of Our Common Stock.”

Non-U.S. Holders may be required to periodically update their IRS Forms W-8.

Gain on Disposition of Our Common Stock

Subject to the discussion below regarding backup withholding and FATCA withholding , a Non-U.S. Holder generally will not be subject to U.S. federal income tax with respect to gain realized on a sale or other disposition of our common stock unless (1) the gain is effectively connected with a trade or business of such holder in the United States (and, if required by an applicable income tax treaty, is attributable to a permanent establishment or fixed place of business that such holder maintains in the United States), in which case the Non-U.S. Holder generally will be taxed at the U.S. federal income tax rates applicable to U.S. persons

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(as defined in the Code) and, if the Non-U.S; Holder is a foreign corporation, the branch profits tax described above in “Distributions” may also apply; (2) the Non-U.S. Holder is a nonresident alien individual and is present in the United States for 183 or more days in the taxable year of the disposition and certain other conditions are met, in which case the Non-U.S. Holder will be subject to a 30% tax (or such lower rate as may be specified by an applicable income tax treaty) on the net gain derived from the disposition, which may be offset by U.S.-source capital losses of the Non-U.S. Holder, if the Non-U.S. Holder timely files U.S. tax returns reporting the losses (even though the individual is not considered a resident of the United States); or (3) we are or have been a “United States real property holding corporation” within the meaning of Code Section 897(c)(2) at any time within the shorter of the five-year period preceding such disposition or such holder’s holding period. In general, we would be a U.S. real property holding corporation if interests in U.S. real estate comprised (by fair market value) at least half of our business assets. We believe that we are not, and do not anticipate becoming, a U.S. real property holding corporation. However, because the determination of whether we are a U.S. real property holding corporation depends on the fair market value of our U.S. real property relative to the fair market value of our other business assets, there can be no assurance that we will not become a U.S. real property holding corporation in the future. Even if we are treated as a U.S. real property holding corporation, gain realized by a Non-U.S. Holder on a disposition of our common stock will not be subject to U.S. federal income tax so long as (a) the Non-U.S. Holder owned, directly, indirectly and constructively, no more than 5% of our common stock at all times within the shorter of (i) the five-year period preceding the disposition or (ii) the holder’s holding period and (b) our common stock is regularly traded on an established securities market. There can be no assurance that our common stock will qualify as regularly traded on an established securities market. If any gain on your disposition is taxable because we are a United States real property holding corporation and your ownership of our common stock exceeds 5%, you will be taxed on such disposition generally in the manner applicable to U.S. persons and in addition, a purchaser of your common stock may be required to withhold tax with respect to that obligation.

Information Reporting Requirements and Backup Withholding

Generally, we must report information to the IRS with respect to any distributions we pay on our common stock (even if the payments are not dividends subject to withholding) including the amount of any such dividends, the name and address of the recipient, and the amount, if any, of tax withheld. A similar report is sent to the holder to whom any such dividends are paid. Pursuant to tax treaties or certain other agreements, the IRS may make its reports available to tax authorities in the recipient’s country of residence.

Dividends paid by us (or our paying agents) to a Non-U.S. Holder may also be subject to U.S. backup withholding. U.S. backup withholding generally will not apply to a Non-U.S. Holder who provides a properly executed IRS Form W-8BEN (in the case of individuals) or IRS Form W-8BEN-E (in the case of entities), IRS Form W-8ECI or otherwise establishes an exemption. Notwithstanding the foregoing, backup withholding may apply if the payor has actual knowledge, or reason to know, that the holder is a U.S. person who is not an exempt recipient.

Under current U.S. federal income tax law, U.S. information reporting and backup withholding requirements generally will apply to the proceeds of a disposition of our common stock effected by or through a U.S. office of any broker, U.S. or foreign, except that information reporting and such requirements do not apply if the holder provides a properly executed IRS Form W-8BEN (in the case of individuals) or IRS Form W-8BEN-E (in the case of entities) or otherwise meets documentary evidence requirements for establishing Non- U.S. Holder status or otherwise establishes an exemption. Generally, U.S. information reporting and backup withholding requirements will not apply to a payment of disposition proceeds to a Non-U.S. Holder where the transaction is effected outside the U.S. through a non-U.S. office of a non-U.S. broker. Information reporting and backup withholding requirements may, however, apply to a payment of disposition proceeds if the broker has actual knowledge, or reason to know, that the holder is, in fact, a U.S. person. For information reporting purposes, certain non-U.S. brokers with substantial U.S. ownership or operations will generally be treated in a manner similar to U.S. brokers.

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Backup withholding is not an additional tax. Any amounts of tax withheld under the backup withholding rules may be credited against the tax liability of persons subject to backup withholding, provided that the required information is timely furnished to the IRS.

Non-U.S. Holders should consult with their own tax advisors regarding the application of the information reporting and backup withholding rules to them.

Withholding on Foreign Entities

Sections 1471 through 1474 of the Code (commonly referred to as “FATCA”), impose a U.S. federal withholding tax of 30% on certain payments made to a “foreign financial institution” (as specially defined under these rules) unless such institution enters into an agreement with the U.S. government to withhold on certain payments and to collect and provide to the U.S. tax authorities substantial information regarding certain U.S. account holders of such institution (which includes certain equity and debt holders of such institution, as well as certain account holders that are foreign entities with U.S. owners) or an exemption applies. FATCA also generally will impose a U.S. federal withholding tax of 30% on certain payments made to a non-financial foreign entity unless such entity either certifies that it does not have any “substantial U.S. owners” as defined in the Code or provides the withholding agent a certification identifying certain direct and indirect U.S. owners of the entity or an exemption applies. An intergovernmental agreement between the United States and an applicable foreign country may modify these requirements. Under certain circumstances, a non-U.S. holder might be eligible for refunds or credits of such taxes. FATCA currently applies to dividends paid on our common stock. FATCA would have applied to payments of gross proceeds from the sale or other disposition of stock, but under proposed regulations (the preamble to which specifies that taxpayers are permitted to rely on such proposed regulations pending finalization), no withholding would apply with respect to payments of gross proceeds.

Prospective investors are encouraged to consult with their own tax advisors regarding the possible implications of FATCA on their investment in our common stock.

EACH PROSPECTIVE INVESTOR SHOULD CONSULT ITS OWN TAX ADVISOR REGARDING THE TAX CONSEQUENCES OF PURCHASING, HOLDING AND DISPOSING OF OUR COMMON STOCK, INCLUDING THE CONSEQUENCES OF ANY RECENT OR PROPOSED CHANGE IN APPLICABLE LAW, AS WELL AS TAX CONSEQUENCES ARISING UNDER ANY STATE, LOCAL OR U.S. FEDERAL TAX LAWS.

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UNDERWRITING

Subject to the terms and conditions set forth in the underwriting agreement among us and Piper Sandler & Co., Cowen and Company, LLC and Stifel, Nicolaus & Company, Incorporated, as the representatives of the underwriters named below and the joint book-running managers of this offering, we have agreed to sell to the underwriters, and each of the underwriters has agreed, severally and not jointly, to purchase from us, at the public offering price less the underwriting discounts and commissions set forth on the cover page of this prospectus supplement, the number of shares of common stock listed opposite its name below.

Underwriter	Number of Shares
Piper Sandler & Co.		2,730,000
Cowen and Company, LLC		2,310,000
Stifel, Nicolaus & Company, Incorporated		2,310,000
Craig-Hallum Capital Group LLC		588,000
Lake Street Capital Markets, LLC		462,000
Total		8,400,000

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 shares of common stock if any of them are purchased. If an underwriter defaults, the underwriting agreement provides that the purchase commitments of the nondefaulting underwriters may be increased or the underwriting agreement may be terminated.

The underwriters are offering the shares of common stock subject to their acceptance of the shares of common stock 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. In addition, the underwriters have advised us that they do not intend to confirm sales to any account over which they exercise discretionary authority.

Option to Purchase Additional Shares

We have granted the underwriters an option to purchase up to 1,260,000 additional shares of common stock from us. The underwriters may exercise this option at any time and from time to time during the 30-day period from the date of this prospectus supplement. If any additional shares of common stock are purchased, the underwriters will offer the additional shares on the same terms as those on which the shares are being offered.

Discounts and Commissions

The underwriters have advised us that they propose to offer the shares of common stock directly to the public at the offering price set forth on the cover of this prospectus supplement. The underwriters propose to offer the shares to certain dealers at the same price less a concession of not more than $0.2790 per share of common stock. After the offering, if all of the shares of common stock are not sold at the public offering price, the public offering price and concession may be reduced by the representatives. No such reduction will change the amount of proceeds to be received by us as set forth on the cover of this prospectus supplement.

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The underwriting fee is equal to the public offering price per share of common stock less the amount paid by the underwriters to us per share of common stock. The following table shows the per share and total underwriting discount to be paid by the underwriters in connection with this offering, assuming both no exercise and full exercise of the over-allotment option:

			Total
	Per Share		Without Option		With Option
Public offering price	$	7.750	$	65,100,000	$	74,865,000
Underwriting discounts and commissions	$	0.465	$	3,906,000	$	4,491,900
Proceeds, before expenses, to us	$	7.285	$	61,194,000	$	70,373,100

In addition, we have agreed to reimburse the underwriters for certain out-of-pocket expenses not to exceed $75,000. We estimate that the total fees and expenses payable by us, excluding underwriting discount, will be approximately $450,000, which includes the amounts we have agreed to reimburse the underwriters.

Indemnification of Underwriters

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act, or to contribute to payments that the underwriters may be required to make in respect of those liabilities.

No Sales of Similar Securities

We have agreed not to sell or transfer, without the prior written consent of the representatives, any shares of our common stock or securities convertible into, exchangeable or exercisable for, or that represent the right to receive shares of our common stock, for 90 days after the date of the prospectus used to sell our common stock. Specifically, we and these other persons have agreed, with certain limited exceptions, not to directly or indirectly:

• offer, sell, contract to sell or pledge any shares of our common stock;

• sell any option or contract to purchase any shares of our common stock;

• purchase any option or contract to sell any shares of our common stock;

• grant any option to purchase any shares of our common stock;

• make any short sale or otherwise transfer or dispose of any shares of our common stock;

• file with the Securities and Exchange Commission a registration statement under the Securities Act of 1933 relating to any of our common stock or securities convertible into or exchangeable for, or that represent the right to receive, common stock;

• enter into any swap or other agreement that transfers, in whole or in part, the economic consequences of ownership of any shares of our common stock whether any such swap or transaction is to be settled by delivery of shares or other securities, in cash or otherwise; or

• publicly announce the intention to do any of the foregoing.

The restrictions described in the immediately preceding paragraph do not apply, subject to certain conditions and limitations, to certain transactions, including:

• the issuance of shares of common stock to be sold hereunder;

• the issuance of shares of common stock or options to purchase shares of common stock, or issuance of shares of common stock upon exercise of options or vesting and settlement of restricted stock units,

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pursuant to any stock option, stock bonus or other disclosed stock plan or arrangement, or issuance of shares of common stock upon the conversion or exchange of outstanding convertible or exchangeable securities;

• the filing of one or more registration statements on Form S-8 with respect to any shares of common stock or related securities issued or issuable pursuant to any stock option, stock bonus, or other disclosed stock plan or arrangement;

• the issuance of shares of common stock in connection with the acquisition or license by us of the securities, business, property or other assets of another person or business entity or pursuant to any employee benefit plan assumed by us in connection with any such merger or acquisition;

• the issuance of shares of common stock in connection with any merger, joint venture, commercial relationship or other strategic or collaborative transactions; or

• the issuance of shares of common stock in fulfillment of accrued interest payable on our outstanding convertible debentures.

Our directors, executive officers and an affiliated holder of our outstanding capital stock and other securities have agreed, subject to certain exceptions, that, without the prior written consent of the representatives, they will not, during the period ending 90 days after the date of this prospectus:

• offer, pledge, announce the intention to sell, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, make any short sale or otherwise transfer or dispose of, directly or indirectly, any shares of common stock or any securities convertible into, exercisable or exchangeable for or that represent the right to receive common stock whether now owned or hereafter acquired;

• enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of the common stock or any such other securities;

• make any demand for or exercise any right with respect to the registration of any common stock or any security convertible into or exercisable or exchangeable for common stock; or

• publicly disclose the intention to do any of the foregoing.

The restrictions described in the immediately preceding paragraph contained in the lock-up agreements with our directors, executive officers and affiliated holder do not apply, subject to certain conditions and limitations, to certain transactions, including:

• transfers or dispositions of such securities:

• as a bona fide gift or gifts (including charitable contributions) or for bona fide estate planning);

• to any immediate family member or any trust, partnership, limited liability company or any other entity for the direct or indirect benefit of the undersigned or the immediate family of the locked-up party;

• by testate succession or intestate succession to a legal representative, heir, beneficiary or a member of the immediate family of the locked-up party;

• to another corporation, partnership, limited liability company, trust or other business entity that is a direct or indirect affiliate of the locked-up party;

• to limited partners, limited liability company members or stockholders of the locked-up party;

• pursuant to a bona fide third-party tender offer, merger, consolidation or other similar transaction made to all holders of our capital stock involving a change of control of the Company;

• by operation of law, such as pursuant to a divorce settlement agreement or decree or a qualified domestic relations order;

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• to us in connection with the repurchase of the locked-up party’s shares in connection with the termination of the locked-up party’s employment with us pursuant to contractual agreements with us;

• to us in connection with the repurchase of the locked-up party’s shares in connection with the termination of the locked-up party’s employment with us pursuant to contractual agreements with us;

• transactions relating to shares of common stock acquired by the locked-up party in the offering or in open market transactions subsequent to the offering

• vesting, settlement or exercise of restricted stock units, stock options, warrants or other rights to purchase share of common stock, including vesting, settlement or exercise of restricted stock units, stock options, warrants or other rights to purchase share of common stock;

• the sale or transfer of shares of common stock to satisfy any income, employment or social tax withholding and remittance obligations arising in connection with the exercise, vesting or settlement of restricted stock units or options, as applicable; or

• the establishment of any contract, instruction or plan that satisfies all the requirements of Rule 10b5-1(c)(1)(i)(B) under the Exchange Act.

Piper Sandler & Co., Cowen and Company, LLC and Stifel, Nicolaus & Company, Incorporated, in their sole discretion, may release the common stock and other securities subject to the lock-up agreements described above in whole or in part at any time.

Listing

Our common stock is listed on the Nasdaq Global Market under the symbol “APEN.”

Price Stabilization, Short Positions and Penalty Bids

Until the distribution of the shares is completed, SEC rules may limit underwriters and selling group members from bidding for and purchasing shares of our common stock. However, the underwriters may engage in transactions that stabilize the price of our common stock, such as bids or purchases to peg, fix or maintain that price.

In connection with this offering, the underwriters may purchase and sell shares of our common stock in the open market. These transactions may include short sales, purchases on the open market to cover positions created by short sales and stabilizing transactions. Short sales involve the sale by the underwriters of a greater number of shares than they are required to purchase in this offering. “Covered” short sales are sales made in an amount not greater than the underwriters’ option to purchase additional shares described above. The underwriters may close out any covered short position by either exercising their option or purchasing shares in the open market. In determining the source of shares to close out the covered short position, the underwriters will consider, among other things, the price of shares available for purchase in the open market as compared to the price at which they may purchase shares through the overallotment option. “Naked” short sales are sales in excess of the overallotment option. The underwriters must close out any naked short position by purchasing shares in the open market. A naked short position is more likely to be created if the underwriters are concerned that there may be downward pressure on the price of our common stock in the open market after pricing that could adversely affect investors who purchase in this offering. Stabilizing transactions consist of various bids for or purchases of shares of our common stock made by the underwriters in the open market prior to the closing of this offering.

The underwriters may also impose a penalty bid. This occurs when a particular underwriter repays to the underwriters a portion of the underwriting discount received by it because the representatives have repurchased shares sold by or for the account of such underwriter in stabilizing or short covering transactions.

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Similar to other purchase transactions, the underwriters’ purchases to cover the syndicate short sales may have the effect of raising or maintaining the market price of our common stock or preventing or retarding a decline in the market price of our common stock. As a result, the price of our common stock may be higher than the price that might otherwise exist in the open market. The underwriters may conduct these transactions on the Nasdaq Global Market, in the over-the-counter market or otherwise.

Neither we nor any of 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 our common stock. In addition, neither we nor any of the underwriters make any representation that the representatives will engage in these transactions or that these transactions, once commenced, will not be discontinued without notice.

The underwriters may also engage in passive market making transactions in our common stock on the Nasdaq Global Market in accordance with Rule 103 of Regulation M during a period before the commencement of offers or sales of shares of our common stock in this offering and extending through the completion of distribution. A passive market maker must display its bid at a price not in excess of the highest independent bid of that security. However, if all independent bids are lowered below the passive market maker’s bid, that bid must then be lowered when specified purchase limits are exceeded. If passive market making is commenced, it may be discontinued at any time.

Electronic Distribution

A prospectus in electronic format may be made available by e-mail or on the websites or through online services maintained by one or more of the underwriters or their 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 shares of common stock 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 in electronic format, the information on each underwriter’s or its affiliates’ websites and any information contained in any other website maintained by any of the underwriters or an affiliate is not part of this prospectus, has not been approved and/or endorsed by us or the underwriters and should not be relied upon by investors.

Affiliations

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, investment management, investment research, principal investment, hedging, financing and brokerage activities. 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 will receive customary fees and expenses. In addition, from time to time, certain of the underwriters and their respective affiliates may effect transactions for their own account or the account of customers, and hold on behalf of themselves or their customers, long or short positions in our debt or equity securities or loans, and may do so in the future.

Selling Restrictions

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 supplement 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

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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.

European Economic Area

In relation to each Member State of the European Economic Area, each, a Relevant State, no shares have been offered or will be offered pursuant to the offering to the public in that Relevant State prior to the publication of a prospectus in relation to the shares which has been approved by the competent authority in that Relevant State or, where appropriate, approved in another Relevant State and notified to the competent authority in that Relevant State, all in accordance with the Prospectus Regulation, except that offers of shares may be made to the public in that Relevant State at any time under the following exemptions under the Prospectus Regulation:

(a) to any legal entity which is a qualified investor as defined under the Prospectus Regulation;

(b) to fewer than 150 natural or legal persons (other than qualified investors as defined under the Prospectus Regulation), subject to obtaining the prior consent of the underwriters; or

(c) in any other circumstances falling within Article 1(4) of the Prospectus Regulation,

provided that no such offer of shares shall require us or any underwriter to publish a prospectus pursuant to Article 3 of the Prospectus Regulation or supplement a prospectus pursuant to Article 23 of the Prospectus Regulation and each person who initially acquires any shares 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 Article 2(e) of the Prospectus Regulation. In the case of any shares being offered to a financial intermediary as that term is used in the Prospectus Regulation, each such financial intermediary will be deemed to have represented, acknowledged and agreed that the shares acquired by it in the offer have not been acquired on a nondiscretionary 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 shares to the public other than their offer or resale in a Relevant State to qualified investors as so defined or in circumstances in which the prior consent of the underwriters have been obtained to each such proposed offer or resale.

For the purposes of this provision, the expression an “offer to the public” in relation to shares in any Relevant State means the communication in any form and by any means of sufficient information on the terms of the offer and any shares to be offered so as to enable an investor to decide to purchase or subscribe for any shares, and the expression “Prospectus Regulation” means Regulation (EU) 2017/1129.

We have not authorized and do not authorize the making of any offer of shares through any financial intermediary on their behalf, other than offers made by the underwriters with a view to the final placement of the shares in this document. Accordingly, no purchaser of the shares, other than the underwriters, is authorized to make any further offer of the shares on behalf of us or the underwriters.

United Kingdom

In relation to the United Kingdom, no shares have been offered or will be offered pursuant to this offering to the public in the United Kingdom prior to the publication of a prospectus in relation to the shares that has been approved by the Financial Conduct Authority, except that offers of shares may be made to the public in the United Kingdom at any time under the following exemptions under the UK Prospectus Regulation:

• to any legal entity which is a qualified investor as defined in Article 2 of the UK Prospectus Regulation;

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• to fewer than 150 natural or legal persons (other than qualified investors as defined in Article 2 of the UK Prospectus Regulation), subject to obtaining the prior consent of the underwriters; or

• in any other circumstances falling within section 86 of the Financial Services and Markets Act 2000 (“FSMA”),

provided that no such offer of shares shall require the Issuer or any representative to publish a prospectus pursuant to Article 3 of the UK Prospectus Regulation or supplement a prospectus pursuant to Article 23 of the UK Prospectus Regulation.

For the purposes of this provision, the expression an “offer to the public” in relation to any shares in any relevant state means the communication in any form and by any means of sufficient information on the terms of the offer and any shares to be offered so as to enable an investor to decide to purchase or subscribe for any shares, and the expression “UK Prospectus Regulation” means Regulation (EU) 2017/1129 as it forms part of domestic law by virtue of the European Union (Withdrawal) Act 2018.

We have not authorized and do not authorize the making of any offer of shares through any financial intermediary on their behalf, other than offers made by the underwriters with a view to the final placement of the shares as contemplated in this prospectus. Accordingly, no purchaser of the shares, other than the underwriters, is authorized to make any further offer of the shares on behalf of us or the underwriters.

In addition, in the United Kingdom, this document is being distributed only to, and is directed only at, and any offer subsequently made may only be directed at persons who are “qualified investors” (as defined in Article 2 of the UK Prospectus Regulation) (i) who have professional experience in matters relating to investments 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) who are high net worth companies (or persons to whom it may otherwise be lawfully communicated) falling within Article 49(2)(a) to (d) of the Order (all such persons together being referred to as “relevant persons”) or otherwise in circumstances which have not resulted and will not result in an offer to the public of the shares in the United Kingdom within the meaning of the FSMA.

Any person in the United Kingdom that is not a relevant person should not act or rely on the information included in this document or use it as basis for taking any action. In the United Kingdom, any investment or investment activity that this document relates to may be made or taken exclusively by relevant persons.

Australia

This prospectus:

• does not constitute a disclosure document or a prospectus under Chapter 6D.2 of the Corporations Act 2001 (Cth), or the Corporations Act;

• has not been, and will not be, lodged with the Australian Securities and Investments Commission, or ASIC, as a disclosure document for the purposes of the Corporations Act and does not purport to include the information required of a disclosure document for the purposes of the Corporations Act; and

• may only be provided in Australia to select investors who are able to demonstrate that they fall within one or more of the categories of investors, available under section 708 of the Corporations Act, or Exempt Investors.

The shares may not be directly or indirectly offered for subscription or purchased or sold, and no invitations to subscribe for or buy the shares may be issued, and no draft or definitive offering memorandum, advertisement or other offering material relating to any shares may be distributed in Australia, except where

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disclosure to investors is not required under Chapter 6D of the Corporations Act or is otherwise in compliance with all applicable Australian laws and regulations. By submitting an application for the shares, you represent and warrant to us that you are an Exempt Investor.

As any offer of shares under this prospectus supplement will be made without disclosure in Australia under Chapter 6D.2 of the Corporations Act, the offer of those securities for resale in Australia within 12 months may, under section 707 of the Corporations Act, require disclosure to investors under Chapter 6D.2 if none of the exemptions in section 708 applies to that resale. By applying for the shares you undertake to us that you will not, for a period of 12 months from the date of sale of the shares, offer, transfer, assign or otherwise alienate those shares to investors in Australia except in circumstances where disclosure to investors is not required under Chapter 6D.2 of the Corporations Act or where a compliant disclosure document is prepared and lodged with ASIC.

Canada

The shares of common stock may be sold only to purchasers purchasing as principal that are both “accredited investors” as defined in National Instrument 45-106 Prospectus and Registration Exemptions and “permitted clients” as defined in National Instrument 31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of the common stock must be made in accordance with an exemption from the prospectus requirements and in compliance with the registration requirements of applicable securities laws.

France

This prospectus (including any amendment, supplement or replacement thereto) is not being distributed in the context of a public offering in France within the meaning of Article L. 411-1 of the French Monetary and Financial Code (Code monétaire et financier).

This prospectus has not been and will not be submitted to the French Autorité des marchés financiers (the “AMF”) for approval in France and accordingly may not and will not be distributed to the public in France.

Pursuant to Article 211-3 of the AMF General Regulation, French residents are hereby informed that:

(a) the transaction does not require a prospectus to be submitted for approval to the AMF;

(b) persons or entities referred to in Point 2°, Section II of Article L.411-2 of the Monetary and Financial Code may take part in the transaction solely for their own account, as provided in Articles D. 411-1, D. 734-1, D. 744-1, D. 754-1 and D. 764-1 of the Monetary and Financial Code; and

(c) the financial instruments thus acquired cannot be distributed directly or indirectly to the public otherwise than in accordance with Articles L. 411-1, L. 411-2, L. 412-1 and L. 621-8 to L. 621-8-3 of the Monetary and Financial Code.

This prospectus is not to be further distributed or reproduced (in whole or in part) in France by the recipients of this prospectus. This prospectus has been distributed on the understanding that such recipients will only participate in the issue or sale of our common stock for their own account and undertake not to transfer, directly or indirectly, our common stock to the public in France, other than in compliance with all applicable laws and regulations and in particular with Articles L. 411-1 and L. 411-2 of the French Monetary and Financial Code.

Germany

Each person who is in possession of this prospectus is aware of the fact that no German securities prospectus (wertpapierprospekt) within the meaning of the German Securities Prospectus Act (Wertpapier-prospektgesetz, or the Act) of the Federal Republic of Germany has been or will be published with respect to the

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shares of our common stock. In particular, each underwriter has represented that it has not engaged and has agreed that it will not engage in a public offering in the Federal Republic of Germany within the meaning of the Act with respect to any of the shares of our common stock otherwise than in accordance with the Act and all other applicable legal and regulatory requirements.

Hong Kong

The shares of common stock may not be offered or sold in Hong Kong by means of any document other than (i) in circumstances which do not constitute an offer to the public within the meaning of the Companies Ordinance (Cap. 32, Laws of Hong Kong), or (ii) to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder, or (iii) in other circumstances which do not result in the document being a “prospectus” within the meaning of the Companies Ordinance (Cap. 32, Laws of Hong Kong) and no advertisement, invitation or document relating to the shares 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 in Hong Kong (except if permitted to do so under the laws of Hong Kong) other than with respect to common stock which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder.

Israel

In the State of Israel this prospectus shall not be regarded as an offer to the public to purchase shares of common stock under the Israeli Securities Law, 5728 – 1968, which requires a prospectus to be published and authorized by the Israel Securities Authority, if it complies with certain provisions of Section 15 of the Israeli Securities Law, 5728 – 1968, including, inter alia, if: (i) the offer is made, distributed or directed to not more than 35 investors, subject to certain conditions (the “Addressed Investors”); or (ii) the offer is made, distributed or directed to certain qualified investors defined in the First Addendum of the Israeli Securities Law, 5728 – 1968, subject to certain conditions (the “Qualified Investors”). The Qualified Investors shall not be taken into account in the count of the Addressed Investors and may be offered to purchase securities in addition to the 35 Addressed Investors. The company has not and will not take any action that would require it to publish a prospectus in accordance with and subject to the Israeli Securities Law, 5728 – 1968. We have not and will not distribute this prospectus or make, distribute or direct an offer to subscribe for our common stock to any person within the State of Israel, other than to Qualified Investors and up to 35 Addressed Investors.

Qualified Investors may have to submit written evidence that they meet the definitions set out in of the First Addendum to the Israeli Securities Law, 5728 – 1968. In particular, we may request, as a condition to be offered common stock, that Qualified Investors will each represent, warrant and certify to us and/or to anyone acting on our behalf: (i) that it is an investor falling within one of the categories listed in the First Addendum to the Israeli Securities Law, 5728 – 1968; (ii) which of the categories listed in the First Addendum to the Israeli Securities Law, 5728 – 1968 regarding Qualified Investors is applicable to it; (iii) that it will abide by all provisions set forth in the Israeli Securities Law, 5728 – 1968 and the regulations promulgated thereunder in connection with the offer to be issued common stock; (iv) that the shares of common stock that it will be issued are, subject to exemptions available under the Israeli Securities Law, 5728 – 1968: (a) for its own account; (b) for investment purposes only; and (c) not issued with a view to resale within the State of Israel, other than in accordance with the provisions of the Israeli Securities Law, 5728 – 1968; and (v) that it is willing to provide further evidence of its Qualified Investor status. Addressed Investors may have to submit written evidence in respect of their identity and may have to sign and submit a declaration containing, inter alia, the Addressed Investor’s name, address and passport number or Israeli identification number.

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Singapore

This prospectus has not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the common stock may not be circulated or distributed, nor may the common stock 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 (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, in each case subject to compliance with conditions set forth in the SFA.

Where the shares of common stock 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,

shares, debentures and units of shares and debentures 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 common stock pursuant to an offer made under Section 275 of the SFA except:

(a) to an institutional investor (for corporations, under Section 274 of the SFA) or to a relevant person defined in Section 275(2) of the SFA, or to any person pursuant to an offer that is made on terms that such shares, debentures and units of shares and debentures of that corporation or such rights and interest in that trust are acquired at a consideration of not less than $200,000 (or its equivalent in a foreign currency) for each transaction, whether such amount is to be paid for in cash or by exchange of securities or other assets, and further for corporations, in accordance with the conditions specified in Section 275 of the SFA;

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

(c) where the transfer is by operation of law.

Switzerland

The shares of common stock may not be publicly offered in Switzerland and will not be listed on the SIX Swiss Exchange (the “SIX”) or on any other stock exchange or regulated trading facility in Switzerland. This document 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 document nor any other offering or marketing material relating to the common stock or the offering may be publicly distributed or otherwise made publicly available in Switzerland.

Neither this document nor any other offering or marketing material relating to the offering, or the shares of common stock have been or will be filed with or approved by any Swiss regulatory authority. In particular, this document will not be filed with, and the offer of the shares of common stock will not be supervised by, the Swiss Financial Market Supervisory Authority FINMA, and the offer of shares of common stock has not been and will not be authorized under the Swiss Federal Act on Collective Investment Schemes (“CISA”). Accordingly, no public distribution, offering or advertising, as defined in CISA, its implementing

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ordinances and notices, and no distribution to any non-qualified investor, as defined in CISA, its implementing ordinances and notices, shall be undertaken in or from Switzerland, and the investor protection afforded to acquirers of interests in collective investment schemes under CISA does not extend to acquirers of common stock.

United Arab Emirates

This offering has not been approved or licensed by the Central Bank of the United Arab Emirates (the “UAE”), Securities and Commodities Authority of the UAE and/or any other relevant licensing authority in the UAE including any licensing authority incorporated under the laws and regulations of any of the free zones established and operating in the territory of the UAE, in particular the Dubai Financial Services Authority (“DFSA”), a regulatory authority of the Dubai International Financial Centre (“DIFC”). The offering does not constitute a public offer of securities in the UAE, DIFC and/or any other free zone in accordance with the Commercial Companies Law, Federal Law No 8 of 1984 (as amended), DFSA Offered Securities Rules and NASDAQ Dubai Listing Rules, accordingly, or otherwise. The common stock may not be offered to the public in the UAE and/or any of the free zones.

The shares of common stock may be offered and issued only to a limited number of investors in the UAE or any of its free zones who qualify as sophisticated investors under the relevant laws and regulations of the UAE or the free zone concerned.

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LEGAL MATTERS

Cooley LLP, of Palo Alto, California will pass upon the validity of the shares of common stock offered hereby. The underwriters are being represented by Latham & Watkins LLP, of Costa Mesa, California in connection with the offering. As of the date of this prospectus supplement, GC&H Investments, LLC and GC&H Investments, entities comprised of partners and associates of Cooley LLP, beneficially own an aggregate of 11,763 shares of our common stock.

EXPERTS

Moss Adams LLP, independent registered public accounting firm, has audited our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2020, as set forth in their report, which is incorporated by reference in this prospectus and elsewhere in the registration statement. Our financial statements are incorporated by reference in reliance on Moss Adams LLP’s reports, given on their authority as experts in accounting and auditing.

The consolidated financial statements of Apollo Endosurgery, Inc. and subsidiaries as of December 31, 2019, and for the year then ended, have been incorporated by reference herein and in the registration statement 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. The audit report covering the December 31, 2019 consolidated financial statements contains an explanatory paragraph that states that the company has suffered recurring losses from operations, cash flow deficits and debt covenant violations and has an accumulated deficit that raise substantial doubt about its ability to continue as a going concern. The consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty.

WHERE YOU CAN FIND MORE INFORMATION

This prospectus supplement is part of the registration statement on Form S-3 we filed with the SEC under the Securities Act and does not contain all the information set forth in the registration statement. Whenever a reference is made in this prospectus supplement to any of our contracts, agreements or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference into this prospectus supplement and accompanying prospectus for a copy of such contract, agreement or other document. Because we are subject to the information and reporting requirements of the Exchange Act, we file annual, quarterly and current reports, proxy statements and other information with the SEC. You can read our SEC filings, including the registration statement, over the internet at the SEC’s website at www.sec.gov.

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INCORPORATION BY REFERENCE

The SEC allows us to “incorporate by reference” information from other documents that we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus supplement and accompanying prospectus. Information in this prospectus supplement and accompanying prospectus supersedes information incorporated by reference that we filed with the SEC prior to the date of this prospectus supplement, while information that we file later with the SEC will automatically update and supersede the information in this prospectus supplement and accompanying prospectus. We incorporate by reference into this prospectus supplement and accompanying prospectus and the registration statement of which this prospectus supplement and accompanying prospectus is a part the information or documents listed below that we have filed with the SEC (Commission File No. 001-35706):

• our Annual Report on Form 10-K for the year ended December 31, 2020, which was filed with the SEC on February 25, 2021;

• our Quarterly Report on Form 10-Q for the three months ended March 31, 2021, which was filed with the SEC on May 4, 2021;

• our Quarterly Report on Form 10-Q for the three months ended June 30, 2021, which was filed with the SEC on August 3, 2021;

• the information specifically incorporated by reference into our Annual Report on Form 10-K for the year ended December 31, 2020 from our Definitive Proxy Statement on Schedule  14A relating to our 2021 Annual Meeting of Stockholders, which was filed with the SEC on April 27, 2021 (other than information furnished rather than filed);

• our Current Reports on Form  8-K filed with the SEC on February  8, 2021 (as amended on March  3, 2021), March  25, 2021, May  3, 2021, May  7, 2021, June  17, 2021 (as amended on June  22, 2021), June  24, 2021 and July 16, 2021 (excluding Item 7.01 and Exhibit 99.1); and

• the description of our common stock, which is registered under Section  12 of the Exchange Act, in our registration statement on Form 8-A/A, filed with the SEC on October 31, 2012.

We also incorporate by reference any future filings (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items unless such Form 8-K expressly provides to the contrary) made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, until the termination of the offering of the shares of our common stock made by this prospectus supplement and accompanying prospectus and will become a part of this prospectus supplement and accompanying prospectus from the date that such documents are filed with the SEC. Information in such future filings updates and supplements the information provided in this prospectus supplement and accompanying prospectus. Any statements in any such future filings will automatically be deemed to modify and supersede any information in any document we previously filed with the SEC that is incorporated or deemed to be incorporated herein by reference to the extent that statements in the later filed document modify or replace such earlier statements.

You can request a copy of these filings, at no cost, by writing or telephoning us at the following address or telephone number:

Apollo Endosurgery, Inc.

1120 South Capital of Texas Highway

Building 1, Suite 300

Austin, Texas 78746

Attn: Secretary

(512) 279-5100

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Any information in any of the foregoing documents will automatically be deemed to be modified or superseded to the extent that information in this prospectus modifies or replaces such information.

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PROSPECTUS

$150,000,000

Common Stock

Preferred Stock

Debt Securities

Warrants

From time to time, we may offer and sell up to an aggregate amount of $150,000,000 of any combination of the securities described in this prospectus, either individually or in combination, at prices and on terms described in one or more supplements to this prospectus. We may also offer common stock or preferred stock upon conversion of debt securities, or common stock upon conversion of preferred stock, or common stock, preferred stock or debt securities upon exercise of warrants.

This prospectus describes some of the general terms that may apply to an offering of our securities. We will provide the specific terms of these offerings and securities in one or more supplements to this prospectus. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectus may also add, update or change information contained in this prospectus. You should carefully read this prospectus, the applicable prospectus supplement and any related free writing prospectus, as well as any documents incorporated by reference, before buying any of the securities being offered.

Our common stock is listed on the Nasdaq Global Market under the trading symbol “APEN.” On May 4, 2021, the last reported sale price of our common stock was $5.88 per share. The applicable prospectus supplement will contain information, where applicable, as to other listings, if any, on the Nasdaq Global Market or any securities market or other exchange of the securities covered by the applicable prospectus supplement.

Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the section titled “Risk Factors” on page 5 of this prospectus and any similar section contained in the applicable prospectus supplement and in any free writing prospectuses we have authorized for use in connection with a specific offering, and under similar headings in the documents that are incorporated by reference into this prospectus.

This prospectus may not be used to consummate a sale of securities unless accompanied by a prospectus supplement.

The securities may be sold directly by us to investors, through agents designated from time to time or to or through underwriters or dealers, on a continuous or delayed basis. For additional information on the methods of sale, you should refer to the section titled “Plan of Distribution” in this prospectus. If any agents or underwriters are involved in the sale of any shares of our securities with respect to which this prospectus is being delivered, the names of such agents or underwriters and any applicable fees, commissions, discounts and overallotment options will be set forth in a prospectus supplement. The price to the public of such securities and the net proceeds we expect to receive from such sale will also be set forth in a prospectus supplement.

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 May 19, 2021.

TABLE OF CONTENTS

	Page
ABOUT THIS PROSPECTUS		ii
PROSPECTUS SUMMARY		1
RISK FACTORS		5
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS		6
USE OF PROCEEDS		8
DESCRIPTION OF CAPITAL STOCK		9
DESCRIPTION OF DEBT SECURITIES		17
DESCRIPTION OF WARRANTS		24
LEGAL OWNERSHIP OF SECURITIES		26
PLAN OF DISTRIBUTION		30
LEGAL MATTERS		32
EXPERTS		32
WHERE YOU CAN FIND ADDITIONAL INFORMATION		32
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE		33

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission, or the SEC, using a “shelf” registration process under the Securities Act of 1933, as amended, or the Securities Act. Under this shelf registration statement, we may, from time to time, offer and sell in one or more offerings common stock and preferred stock, various series of debt securities and/or warrants to purchase any of such securities, either individually or in combination with other securities, in one or more offerings, up to a total dollar amount of $150,000,000 of any combination of the securities described in this prospectus. This prospectus provides you with a general description of the securities we may offer.

Each time we sell any type or series of securities under this prospectus, we will provide a prospectus supplement that will contain more specific information about the terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement and any related free writing prospectus that we may authorize to be provided to you may also add, update or change any of the information contained in this prospectus or in the documents that we have incorporated by reference into this prospectus. This prospectus, together with the applicable prospectus supplement, any related free writing prospectus and the documents incorporated by reference into this prospectus and the applicable prospectus supplement, will include all material information relating to the applicable offering. We urge you to read carefully this prospectus, any applicable prospectus supplement and any related free writing prospectuses we have authorized for use in connection with a specific offering, together with the information incorporated herein by reference as described under the heading “Incorporation of Certain Information by Reference,” before buying any of the securities being offered.

This prospectus may not be used to consummate a sale of securities unless it is accompanied by a prospectus supplement.

We have not authorized anyone to provide you with any information other than that contained or incorporated by reference in this prospectus and any applicable prospectus supplement, along with the information contained in any free writing prospectuses we have authorized for use in connection with a specific offering. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. This prospectus is an offer to sell only the securities offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so.

The information appearing in this prospectus, any applicable prospectus supplement or any related free writing prospectus is accurate only as of the date on the front of the document and that any information we have incorporated by reference is accurate only as of the date of the document incorporated by reference, regardless of the time of delivery of this prospectus, any applicable prospectus supplement or any related free writing prospectus, or any sale of securities. Our business, financial condition, results of operations and prospects may have changed since those dates.

This prospectus contains and incorporates by reference market data and industry statistics and forecasts that are based on independent industry publications and other publicly available information. Although we believe that these sources are reliable, we do not guarantee the accuracy or completeness of this information and we have not independently verified this information. Although we are not aware of any misstatements regarding the market and industry data presented in this prospectus and the documents incorporated herein by reference, these estimates involve risks and uncertainties and are subject to change based on various factors, including those discussed under the section titled “Risk Factors” contained in the applicable prospectus supplement and any related free writing prospectus, and under similar headings in the other documents that are incorporated by reference into this prospectus. Accordingly, investors should not place undue reliance on this information.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been

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filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the section titled “Where You Can Find Additional Information.”

Throughout this prospectus, the terms “we,” “us,” “our,” and our “company” refer to Apollo Endosurgery, Inc. and its subsidiaries.

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PROSPECTUS SUMMARY

This summary highlights selected information contained elsewhere in this prospectus or incorporated by reference in this prospectus, and does not contain all of the information that you need to consider in making your investment decision. You should carefully read the entire prospectus, the applicable prospectus supplement and any related free writing prospectus, including the risks of investing in our securities discussed under the sections titled “Risk Factors” contained in this prospectus, the applicable prospectus supplement and any related free writing prospectus, and under similar sections in the other documents that are incorporated by reference into this prospectus. You should also carefully read the other information incorporated by reference into this prospectus, including our financial statements, and the exhibits to the registration statement of which this prospectus is a part.

Apollo Endosurgery, Inc.

Overview

We are a medical technology company primarily focused on the development of next-generation, less invasive medical devices to advance gastrointestinal therapeutic endoscopy.

Our Endoscopy product portfolio consists of the OverStitch^TM Endoscopic Suturing System, the OverStitch Sx^TM Endoscopic Suturing System, X-Tack^TM Endoscopic HeliX Tacking System and Orbera^® Intragastric Balloon.

Our products are used by gastroenterologists and bariatric surgeons in a variety of settings to treat multiple gastrointestinal conditions including closure of acute perforations and chronic fistulas; tissue closure after the removal of abnormal lesions in the esophagus, stomach or colon (also known as endoscopic submucosal dissections, endoscopic mucosal resections and endoscopic full thickness resections); the treatment of swallowing disorders (peroral endoscopic myotomy); esophageal stent fixation and obesity.

Corporate Information

Apollo was founded in 2005 and is incorporated in Delaware with headquarters in Austin, Texas. Our company was founded to develop and commercialize innovations originating from a collaboration of physicians from the Mayo Clinic, Johns Hopkins University, Medical University of South Carolina, the University of Texas Medical Branch and the Chinese University of Hong Kong, who called themselves the Apollo Group. The work of the Apollo Group resulted in a significant portfolio of patents in the field of flexible endoscopy and minimally invasive surgery aimed at minimizing the trauma of surgical access by taking advantage of natural orifices to deliver surgical tools to targeted areas.

In December 2016, we completed a business combination with Lpath, Inc., a publicly traded company. Following the Merger, Lpath, Inc. was renamed “Apollo Endosurgery, Inc.” and our common stock began trading on The Nasdaq Global Market under the symbol “APEN.”

“OverStitch,” “X-Tack,” “Orbera,” the Apollo logo and other trademarks or service marks of Apollo Endosurgery, Inc. appearing in this prospectus and any prospectus supplement are the property of Apollo Endosurgery, Inc. Other trademarks, service marks or trade names appearing in this prospectus are the property of their respective owners. We do not intend our use or display of other companies’ trade names, trademarks or service marks to imply a relationship with, or endorsement or sponsorship of us, by these other companies.

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Today, we have offices in the United Kingdom and Italy that oversee commercial activities outside the United States (“OUS”) and a manufacturing facility in Costa Rica. All other activities are managed and operated from our facilities in Austin, Texas.

Our principal executive offices are located at 1120 S. Capital of Texas Highway, Building 1, Suite 300, Austin, Texas 78746. Our telephone number is (512) 279-5100.

The Securities We May Offer

We may offer shares of our common stock and preferred stock, various series of debt securities and/or warrants to purchase any of such securities, either individually or in combination with other securities, up to a total dollar amount of $150,000,000, from time to time under this prospectus, together with the applicable prospectus supplement and any related free writing prospectus, at prices and on terms to be determined by market conditions at the time of any offering. We may also offer common stock, preferred stock and/or debt securities upon the exercise of warrants. This prospectus provides you with a general description of the securities we may offer. Each time we offer a type or series of securities under this prospectus, we will provide a prospectus supplement that will describe the specific amounts, prices and other important terms of the securities, including, to the extent applicable:

• designation or classification;

• aggregate principal amount or aggregate offering price;

• maturity date, if applicable;

• original issue discount, if any;

• rates and times of payment of interest or dividends, if any;

• redemption, conversion, exercise, exchange or sinking fund terms, if any;

• ranking;

• restrictive covenants, if any;

• voting or other rights, if any;

• conversion or exchange prices or rates, if any, and, if applicable, any provisions for changes to or adjustments in the conversion or exchange prices or rates and in the securities or other property receivable upon conversion or exchange; and

• material or special U.S. federal income tax considerations, if any.

The applicable prospectus supplement and any related free writing prospectus that we may authorize to be provided to you may also add, update or change any of the information contained in this prospectus or in the documents we have incorporated by reference.

THIS PROSPECTUS MAY NOT BE USED TO CONSUMMATE A SALE OF SECURITIES UNLESS IT IS ACCOMPANIED BY A PROSPECTUS SUPPLEMENT.

We may sell the securities directly to investors or to or through agents, underwriters or dealers. We and our agents or underwriters, reserve the right to accept or reject all or part of any proposed purchase of securities. If we do offer securities to or through agents or underwriters, we will include in the applicable prospectus supplement:

• the names of those agents or underwriters;

• applicable fees, discounts and commissions to be paid to them;

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• details regarding overallotment options, if any; and

• the net proceeds to us.

Common Stock

We may issue shares of our common stock from time to time. The holders of our common stock are entitled to one vote for each share held of record on all matters submitted to a vote of stockholders. Subject to preferences that may be applicable to any outstanding shares of preferred stock, the holders of common stock are entitled to receive ratably such dividends as may be declared by our board of directors out of legally available funds. Upon our liquidation, dissolution or winding up, holders of our common stock are entitled to share ratably in all assets remaining after payment of liabilities and the liquidation preferences of any outstanding shares of preferred stock. Holders of common stock have no preemptive rights and no right to convert their common stock into any other securities. There are no redemption or sinking fund provisions applicable to our common stock. In this prospectus, we have summarized certain general features of the common stock under the heading “Description of Capital Stock—Common Stock.” We urge you, however, to read the applicable prospectus supplement (and any related free writing prospectus that we may authorize to be provided to you) related to any common stock being offered.

Preferred Stock

We may issue shares of our preferred stock from time to time, in one or more series. Our board of directors will determine the designations, voting powers, preferences and rights of the preferred stock, as well as the qualifications, limitations or restrictions thereof, including dividend rights, conversion rights, preemptive rights, terms of redemption or repurchase, liquidation preferences, sinking fund terms and the number of shares constituting any series or the designation of any series, or the designation of such series, any or all of which may be greater than the rights of our common stock. Convertible preferred stock will be convertible into our common stock or exchangeable for other securities. Conversion may be mandatory or at your option and would be at prescribed conversion rates.

If we sell any series of preferred stock under this prospectus, we will fix the designations, voting powers, preferences and rights of the preferred stock of each series we issue under this prospectus, as well as the qualifications, limitations or restrictions thereof, in the certificate of designation relating to that series. We will file as an exhibit to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of any certificate of designation that contains the terms of the series of preferred stock we are offering. In this prospectus, we have summarized certain general features of the preferred stock under “Description of Capital Stock—Preferred Stock.” We urge you, however, to read the applicable prospectus supplement (and any related free writing prospectus that we may authorize to be provided to you) related to the series of preferred stock being offered, as well as the complete certificate of designation that contains the terms of the applicable series of preferred stock.

Debt Securities

We may issue debt securities from time to time, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. The senior debt securities will rank equally with any other unsecured and unsubordinated debt. The subordinated debt securities will be subordinate and junior in right of payment, to the extent and in the manner described in the instrument governing the debt, to all of our senior indebtedness. Convertible or exchangeable debt securities will be convertible into or exchangeable for our common stock or our other securities. Conversion or exchange may be mandatory or optional (at our option or the holders’ option) and would be at prescribed conversion or exchange prices.

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The debt securities will be issued under an indenture that we will enter into with a national banking association or other eligible party, as trustee. In this prospectus, we have summarized certain general features of the debt securities under the heading “Description of Debt Securities.” We urge you, however, to read the applicable prospectus supplement (and any related free writing prospectus that we may authorize to be provided to you) related to the series of debt securities being offered, as well as the complete indenture and any supplemental indentures that contain the terms of the debt securities. We have filed the form of indenture as an exhibit to the registration statement of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

Warrants

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 in combination with common stock, preferred stock and/or debt securities offered by any prospectus supplement. In this prospectus, we have summarized certain general features of the warrants under the heading “Description of Warrants.” We urge you, however, to read the applicable prospectus supplement (and any related free writing prospectus that we may authorize to be provided to you) related to the particular series of warrants being offered, as well as the form of warrant and/or the warrant agreement and warrant certificate, as applicable, that contain the terms of the warrants. We have filed the forms of the warrant agreements and forms of warrant certificates containing the terms of the warrants that we may offer as exhibits to the registration statement of which this prospectus is a part. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of warrant and/or the warrant agreement and warrant certificate, as applicable, that contain the terms of the particular series of warrants we are offering, and any supplemental agreements, before the issuance of such warrants.

Warrants may be issued under a warrant agreement that we enter into with a warrant agent. We will indicate the name and address of the warrant agent, if any, in the applicable prospectus supplement relating to a particular series of warrants.

Use of Proceeds

Except as described in any applicable prospectus supplement or in any free writing prospectuses we have authorized for use in connection with a specific offering, we currently intend to use the net proceeds from the sale of the securities offered by us hereunder, if any, for working capital and general corporate purposes. We may also use a portion of the net proceeds to in-license, acquire or invest in complementary businesses or products; however, we have no current commitments or obligations to do so. See “Use of Proceeds” in this prospectus.

Nasdaq Global Market Listing

Our common stock is listed on the Nasdaq Global Market under the symbol “APEN”. The applicable prospectus supplement will contain information, where applicable, as to other listings, if any, on the Nasdaq Global Market or any other securities market or other exchange of the securities covered by the applicable prospectus supplement.

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RISK FACTORS

Investing in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you should consider carefully the risks and uncertainties described under the section titled “Risk Factors” contained in the applicable prospectus supplement and any related free writing prospectus, and discussed under the section titled “Risk Factors” contained in our most recent Annual Report on Form 10-K and in our most recent Quarterly Report on Form 10-Q, as well as any amendments thereto reflected in subsequent filings with the SEC, which are incorporated by reference into this prospectus in their entirety, together with other information in this prospectus, the documents incorporated by reference and any free writing prospectus that we may authorize for use in connection with a specific offering. The risks described in these documents are not the only ones we face, but those that we consider to be material. There may be other unknown or unpredictable economic, business, competitive, regulatory or other factors that could have material adverse effects on our future results. Past financial performance may not be a reliable indicator of future performance, and historical trends should not be used to anticipate results or trends in future periods. If any of these risks actually occur, our business, financial condition, results of operations or cash flow could be harmed. This could cause the trading price of our securities to decline, resulting in a loss of all or part of your investment. Please also read carefully the section below titled “Special Note Regarding Forward-Looking Statements.”

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents we have filed with the SEC that are incorporated 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. These statements relate to future events or to our future operating or financial performance and involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performances or achievements expressed or implied by the forward-looking statements. Forward-looking statements may include, but are not limited to, statements about:

• our ability to become profitable and generate consistent cash flows to remain profitable;

• our plans to develop and commercialize additional products;

• our plans to grow our customer base, both domestically and internationally;

• our ability to attract and retain highly qualified personnel;

• our ability to develop, expand and manage a world-wide sales organization;

• our ability to protect and enhance our products and intellectual property;

• our expectations concerning our relationships and actions with third parties;

• our ability to obtain and maintain approvals to sell existing and future products from domestic and international regulatory bodies;

• future regulatory, judicial and legislative changes in our industry;

• the results of our ongoing or future clinical trials of our devices;

• our ability to maintain and operate our business in light of the COVID-19 pandemic;

• our use of proceeds from offerings of our securities under this prospectus;

• our financial performance; and

• developments and projections relating to our competitors, our industry and the general economy.

These risks are not exhaustive. Other sections of this prospectus may include additional factors that could harm our business and financial performance. Moreover, we operate in a very competitive and rapidly changing environment. New risk factors emerge from time to time, and it is not possible for our management to predict all risk factors nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in, or implied by, any forward-looking statements.

All statements other than statements of historical facts contained in this prospectus, including statements regarding our future financial condition, business strategy and plans, and objectives of management for future operations, are forward-looking statements. In some cases, you can identify forward-looking statements by words such as “anticipate,” “believe,” “continue,” “could,” “design,” “estimate,” “expect,” “intend,” “may,” “plan,” “potentially,” “predict,” “should,” “will” or the negative of these terms or other similar expressions. These statements reflect our current views with respect to future events and are based on assumptions and are subject to risks and uncertainties. Given these uncertainties, you should not place undue reliance on these forward-looking statements. We discuss in greater detail many of these risks under the section titled “Risk Factors” contained in the applicable prospectus supplement, in any free writing prospectuses we may authorize for use in connection with a specific offering, and in our most recent Annual Report on Form 10-K and in our most recent Quarterly Report on Form 10-Q, as well as any amendments thereto reflected in subsequent filings with the SEC, which are incorporated by reference into this prospectus in their entirety. Also, these forward-looking statements represent

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our estimates and assumptions only as of the date of the document containing the applicable statement. Unless required by law, we undertake no obligation to update or revise any forward-looking statements to reflect new information or future events or developments. You should read this prospectus, any applicable prospectus supplement, together with the documents we have filed with the SEC that are incorporated by reference and any free writing prospectus that we may authorize for use in connection with a specific offering completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of the forward-looking statements in the foregoing documents by these cautionary statements.

In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this prospectus, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.

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USE OF PROCEEDS

Except as described in any applicable prospectus supplement or in any free writing prospectuses we have authorized for use in connection with a specific offering, we currently intend to use the net proceeds for working capital and general corporate purposes. We may also use a portion of the net proceeds to in-license, acquire or invest in complementary businesses or products; however, we have no current commitments or obligations to do so.

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DESCRIPTION OF CAPITAL STOCK

The following summary description of our capital stock is based on the provisions of our amended and restated certificate of incorporation and amended and restated bylaws and the applicable provisions of the Delaware General Corporation Law. This information is qualified entirely by reference to the applicable provisions of our amended and restated certificate of incorporation and bylaws. For information on how to obtain copies of our amended and restated certificate of incorporation and bylaws, which are exhibits to the registration statement of which this prospectus is a part, see the sections titled “Where You Can Find More Information” and “Incorporation of Certain Information by Reference” in this prospectus.

General

We have authorized capital stock of up to (i) 100,000,000 shares of common stock, par value $0.001 per share and (ii) 15,000,000 shares of preferred stock. As of March 31, 2021, there were 27,035,842 shares of common stock issued and outstanding, which shares were held by 101 stockholders of record, and no shares of preferred stock outstanding.

The following is a summary of the material provisions of the common stock and preferred stock provided for in our amended and restated certificate of incorporation and amended and restated bylaws.

Common Stock

All outstanding shares of our common stock are fully paid and nonassessable.

Voting Rights

Holders of our common stock are entitled to one vote for each share on all matters submitted to a stockholder vote, except matters that relate only to a series of preferred stock.

In general, stockholder action (except for certain bylaw amendments and certain amendments to our amended and restated certificate of incorporation, which requires the affirmative vote of at least two-thirds of the shares entitled to vote) is based on the affirmative vote of holders of a majority of the shares of common stock represented either in person or by proxy and entitled to vote on such action. Directors are elected by majority vote, unless there is a contested election in which case the bylaws provide for plurality voting.

Dividends

Subject to limitations under Delaware law and preferences that may apply to any then-outstanding shares of preferred stock, holders of our common stock are entitled to share ratably in dividends, if any, as may be declared from time to time by the board of directors in its discretion from funds legally available therefor.

Dividends, if any, will be contingent upon revenues and earnings, if any, and capital requirements and financial conditions. The payment of dividends, if any, will be within the discretion of the board of directors. We presently intend to retain all earnings, if any, and accordingly the board of directors does not anticipate declaring any dividends.

Liquidation

In the event of a liquidation, dissolution or winding up, the holders of common stock are entitled to share pro rata all assets remaining after payment in full of all liabilities and after providing for each class of stock, if any, having preference over the common stock, subject to the liquidation preference of any then outstanding shares of preferred stock.

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Miscellaneous

Holders of common stock have no pre-emptive rights, no conversion rights and there are no redemption provisions applicable to the common stock.

Preferred Stock

Our preferred stock, par value $0.001 per share, may be issued from time to time in one or more series pursuant to a resolution or resolutions providing for such issue duly adopted by the board of directors (authority to do so being hereby expressly vested in our board of directors). The board of directors is further authorized, subject to limitations prescribed by law, to fix by resolution or resolutions the designations, powers, preferences and rights, and the qualifications, limitations or restrictions thereof, of any wholly unissued series of preferred stock, including without limitation authority to fix by resolution or resolutions the dividend rights, dividend rate, conversion rights, voting rights, rights and terms of redemption (including sinking fund provisions), redemption price or prices, and liquidation preferences of any such series, and the number of shares constituting any such series and the designation thereof, or any of the foregoing.

The issuance of preferred stock may delay, deter or prevent a change in control. The description of preferred stock above and the description of the terms of a particular series of preferred stock in any applicable prospectus supplement are not complete. You should refer to any applicable certificate of designation for complete information.

The General Corporate Law of the State of Delaware, or DGCL, the state of our incorporation, provides that the holders of preferred stock will have the right to vote separately as a class on any proposal involving fundamental changes in the rights of holders of that preferred stock. This right is in addition to any voting rights that may be provided for in the applicable certificate of designation.

The board of directors may specify the following characteristics of any our preferred stock:

• the maximum number of shares;

• the designation of the shares;

• the annual dividend rate, if any, whether the dividend rate is fixed or variable, the date or dates on which dividends will accrue, the dividend payment dates and whether dividends will be cumulative;

• the price and the terms and conditions for redemption, if any, including redemption at our option or at the option of the holders, including the time period for redemption, and any accumulated dividends or premiums;

• the liquidation preference, if any, and any accumulated dividends upon the liquidation, dissolution or winding up of our affairs;

• any sinking fund or similar provision, and, if so, the terms and provisions relating to the purpose and operation of the fund;

• the terms and conditions, if any, for conversion or exchange of shares of any other class or classes of our capital stock or any series of any other class or classes, or of any other series of the same class, or any other securities or assets, including the price or the rate of conversion or exchange and the method, if any, of adjustment;

• the voting rights; and

• any or all other preferences and relative, participating, optional or other special rights, privileges or qualifications, limitations or restrictions.

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The issuance of preferred stock will affect, and may adversely affect, the rights of holders of common stock. It is not possible to state the actual effect of the issuance of any shares of preferred stock on the rights of holders of common stock until the board of directors determines the specific rights attached to that preferred stock. The effects of issuing preferred stock could include one or more of the following:

• restricting dividends on the common stock;

• diluting the voting power of the common stock;

• impairing the liquidation rights of the common stock; or

• delaying or preventing changes in control or management of the company.

The board of directors of our company has no present plans to issue any shares of preferred stock nor are any shares of preferred stock presently outstanding. Any shares of our preferred stock issued in the future will be fully paid and nonassessable upon issuance.

Advance Notice Requirement

Our bylaws contain advance notice requirements for business to be brought before an annual or special meeting of stockholders, including nominations of persons for election as directors. As a result, stockholders must satisfy specific timing and information requirements in order to have a proposal considered at or in order to nominate a person for election as a director at an annual or special meeting. Any proposal or nomination that fails to comply with these timing and information requirements may be disqualified.

No Cumulative Voting

Our amended and restated certificate of incorporation does not include a provision for cumulative voting for directors.

Authorized but Unissued Shares

The authorized but unissued shares of our common stock and preferred stock will be available for future issuance without stockholder approval. We may issue additional shares for a variety of purposes, including future public offerings to raise additional capital, to fund acquisitions and as employee compensation. The existence of authorized but unissued shares of common stock and preferred stock could render more difficult or discourage an attempt to obtain control by means of a proxy contest, tender offer, merger or otherwise.

Size of Board and Vacancies

Our amended and restated bylaws provide that the number of directors on the board of directors is fixed exclusively by the board of directors. Newly created directorships resulting from any increase in the authorized number of directors or any vacancies in the board of directors resulting from death, resignation or other cause (including removal from office by a vote of the stockholders) may be filled only by (i) a majority vote of the directors based on the total number of designated directors, though less than a quorum, or by the sole remaining director or (ii) the stockholders holding a majority of the voting power of all of the then outstanding shares of capital stock of our company authorized by law or by the charter to vote on such action at a duly called annual meeting or a duly called special meeting of stockholders (including the special election meeting discussed below). The directors so chosen shall hold office for a term expiring at the next annual meeting of stockholders, and until their respective successors are elected, except in the case of the death, incapacity, resignation or removal of any director.

Amendments of Governance Documents

Our amended and restated certificate of incorporation and amended and restated bylaws provide that the affirmative vote of the holders of at least 66 2/3% of the voting stock then outstanding is required to amend

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certain provisions relating to the number, term, election and removal of its directors, the filling of its board vacancies, stockholder notice procedures, the calling of special meetings of stockholders, stockholders ability to act by written consent, and the indemnification of directors.

Limitations on Liability, Indemnification of Officers and Directors and Insurance

Our amended and restated certificate of incorporation includes provisions that require us to indemnify, to the fullest extent allowable under the DGCL, our directors and officers for monetary damages for actions taken as a director or officer, or for serving at our request as a director or officer or another position at another corporation or enterprise, as the case may be. Our amended and restated certificate of incorporation also provides that we must advance reasonable expenses to directors and officers, subject to receipt of an undertaking from the indemnified party as may be required under the DGCL.

Anti-Takeover Effects of Provisions of Our Charter Documents

Provisions of our amended and restated certificate of incorporation and amended and restated bylaws could have the effect of delaying, deferring or discouraging another party from acquiring control of our company. These provisions, which are summarized below, may have the effect of discouraging takeover bids. These provisions are also designed, in part, to encourage persons seeking to acquire control of the company to first negotiate with the board of directors. The benefits of increased protection of the potential ability to negotiate with an unfriendly or unsolicited acquirer outweigh the disadvantages of discouraging a proposal to acquire the company because negotiation of these proposals could result in an improvement of their terms.

Undesignated Preferred Stock

The authority of our board of directors to issue preferred stock could potentially be used to discourage attempts by third parties to obtain control of our company through a merger, tender offer, proxy contest or otherwise by making it more difficult or more costly to obtain control of the company. The board of directors may issue preferred stock with voting rights or conversion rights that, if exercised, could adversely affect the voting power of the holders of common stock.

Indemnification

We are also expressly authorized by the DGCL to carry directors’ and officers’ insurance to protect the company, its directors, officers and certain employees for some liabilities. The indemnification and advancements provisions in our amended and restated certificate of incorporation and amended and restated bylaws, respectively, may discourage stockholders from bringing a lawsuit against directors for breach of their fiduciary duties. These provisions may also have the effect of reducing the likelihood of derivative litigation against directors and officers, even though such an action, if successful, might otherwise benefit our company and its stockholders. The indemnification provisions will not alter the liability of directors under the federal securities laws. In addition, your investment may be adversely affected to the extent that, in a derivative or direct suit, our company pays the litigation costs of the directors and officers and the costs of settlement and damage awards against directors and officers pursuant to these indemnification and advancements provisions.

We maintain standard policies of insurance that provide coverage (i) to directors and officers against loss arising from claims made by reason of breach of duty or other wrongful act and (ii) to us with respect to indemnification and advancements payments that it may make to such directors and officers.

We have entered into indemnification agreements with each of our officers and directors. These agreements require us to indemnify these individuals to the fullest extent permitted under Delaware law against liabilities that may arise by reason of their service to our company, and to advance expenses incurred as a result of any proceeding against them as to which they could be indemnified. The limitation of liability provision in our amended and restated certificate of incorporation and the indemnification agreements may facilitate our ability to continue to attract and retain qualified individuals to serve as directors and officers.

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Insofar as the above described indemnification provisions permit indemnification of directors, officers or persons controlling our company for liability arising under the Securities Act, in the opinion of the SEC, this indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable.

Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws

Among other things, our amended and restated certificate of incorporation and amended and restated bylaws:

• permit our board of directors to issue up to 15,000,000 shares of preferred stock, with any rights, preferences and privileges as they may designate, including the right to approve an acquisition or other change of control;

• provide that the authorized number of directors may be changed only by resolution of our board of directors;

• provide that our board of directors will be classified into three classes of directors;

• provide that, subject to the rights of any series of preferred stock to elect directors, directors may only be removed for cause, which removal may be effected, subject to any limitation imposed by law, by the holders of at least a majority of the voting power of all of our then-outstanding shares of the capital stock entitled to vote generally at an election of directors;

• provide that all vacancies, including newly created directorships, may, except as otherwise required by law, be filled by the affirmative vote of a majority of directors then in office, even if less than a quorum;

• require that any action to be taken by our stockholders must be effected at a duly called annual or special meeting of stockholders and not be taken by written consent or electronic transmission;

• provide that stockholders seeking to present proposals before a meeting of stockholders or to nominate candidates for election as directors at a meeting of stockholders must provide advance notice in writing, and also specify requirements as to the form and content of a stockholder’s notice;

• provide that special meetings of our stockholders may be called only by the chairman of our board of directors, our chief executive officer or by our board of directors pursuant to a resolution adopted by a majority of the total number of authorized directors; and

• not provide for cumulative voting rights, therefore allowing the holders of a majority of the shares of common stock entitled to vote in any election of directors to elect all of the directors standing for election, if they should so choose.

The amendment of any of these provisions would require approval by the holders of at least 66 ²/₃% of the voting power of all of our then-outstanding common stock entitled to vote generally in the election of directors, voting together as a single class.

The combination of these provisions will make it more difficult for our existing stockholders to replace our board of directors as well as for another party to obtain control of us by replacing our board of directors. Since our board of directors has the power to retain and discharge our officers, these provisions could also make it more difficult for existing stockholders or another party to effect a change in management. In addition, the authorization of undesignated preferred stock makes it possible for our board of directors to issue preferred stock with voting or other rights or preferences that could impede the success of any attempt to change our control.

These provisions are intended to enhance the likelihood of continued stability in the composition of our board of directors and its policies and to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to reduce our vulnerability to hostile takeovers and to discourage certain

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tactics that may be used in proxy fights. However, such provisions could have the effect of discouraging others from making tender offers for our shares and may have the effect of delaying changes in our control or management. As a consequence, these provisions may also inhibit fluctuations in the market price of our stock that could result from actual or rumored takeover attempts. We believe that the benefits of these provisions, including increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure our company, outweigh the disadvantages of discouraging takeover proposals, because negotiation of takeover proposals could result in an improvement of their terms.

Choice of Forum

Our amended and restated certificate of incorporation and amended and restated bylaws each provide that the Court of Chancery of the State of Delaware will, to the fullest extent permitted by applicable law, be the sole and exclusive forum for (i) any derivative action or proceeding brought on behalf of the corporation, (ii) any action asserting a claim of breach of a fiduciary duty owed by any director, officer, or other employee of the corporation to the corporation or the corporation’s stockholders, (iii) any action asserting a claim arising pursuant to any provision of the Delaware General Corporation Law, or (iv) any action asserting a claim that is governed by the internal affairs doctrine. These exclusive-forum provisions will not apply to suits brought to enforce a duty or liability created by the Exchange Act or any other claim for which the U.S. federal courts have exclusive jurisdiction. Our stockholders cannot waive compliance with the federal securities laws and the rules and regulations thereunder.

Our amended and restated bylaws further provide that, unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States of America shall be the exclusive forum for the resolution of any complaint asserting a cause of action arising under the Securities Act, subject to and contingent upon a final adjudication in the State of Delaware of the enforceability of such exclusive forum provision. The Court of Chancery of the State of Delaware recently determined that a provision stating that U.S. federal district courts are the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act is not enforceable. However, this decision may be reviewed and ultimately overturned by the Delaware Supreme Court. Any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock will be deemed to have notice of and consented to the foregoing forum selection provisions. These exclusive-forum provisions 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, employees or agents, which may discourage such lawsuits against us and such persons. However, Section 22 of the Securities Act creates concurrent jurisdiction for federal and state courts over all such Securities Act actions. Accordingly, both state and federal courts have jurisdiction to entertain such claims. Our stockholders cannot waive compliance with the federal securities laws and the rules and regulations thereunder. While the Delaware courts have determined that such choice of forum provisions are facially valid, a stockholder may nevertheless seek to bring a claim in a venue other than those designated in the exclusive forum provisions. In such instance, we would expect to vigorously assert the validity and enforceability of the exclusive forum provisions of our amended and restated certificate of incorporation and/or our amended and restated bylaws. This may require significant additional costs associated with resolving such action in other jurisdictions and there can be no assurance that the provisions will be enforced by a court in those other jurisdictions. For the avoidance of doubt, this provision is intended to benefit and may be enforced by us, our officers and directors, the underwriters to any offering giving rise to such complaint, and any other professional entity whose profession gives authority to a statement made by that person or entity and who has prepared or certified any part of the documents underlying such offering.

Our amended and restated certificate of incorporation does not contain a similar provision providing that the federal district courts of the United States shall be the exclusive forum for the resolution of any complaint asserting a cause of action arising under the Securities Act or the rules and regulations thereunder because the provision is included in our amended and restated bylaws. If any court of competent jurisdiction were to find this exclusive-forum provision in our amended and restated bylaws to be inapplicable or unenforceable, including due to its absence from our amended and restated certificate of incorporation, we may incur additional costs associated with resolving such matters in other jurisdictions.

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Anti-Takeover Effects of Delaware Law

Our company is subject to the provisions of Section 203 of the DGCL regulating corporate takeovers. In general, Section 203 generally prohibits a publicly-held Delaware corporation from engaging in a business combination with an interested stockholder for a period of three years following the date on which the person became an interested stockholder unless:

• prior to the date of the transaction, the board of directors of the corporation approved either the business combination or the transaction which resulted in the stockholder becoming an interested stockholder;

• upon completion of the transaction that 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, but not the outstanding voting stock owned by the interested stockholder, (1) shares owned by persons who are directors and also officers and (2) shares owned by employee stock plans in which employee participants do not have the right to determine confidentially whether shares held subject to the plan will be tendered in a tender or exchange offer; or

• at or subsequent to the date of the transaction, the business combination is approved by the board of directors of the corporation and authorized at an annual or special meeting of stockholders, and not by written consent, by the affirmative vote of at least 66 2/3% of the outstanding voting stock that is not owned by the interested stockholder.

In general, Section 203 defines business combination to include the following:

• any merger or consolidation involving the corporation and the interested stockholder;

• any sale, lease, exchange, mortgage, transfer, pledge or other disposition of 10% or more of either the assets or outstanding stock of the corporation involving the interested stockholder;

• subject to certain exceptions, any transaction that results in the issuance or transfer by the corporation of any stock of the corporation to the interested stockholder;

• 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; or

• the receipt by the interested stockholder of the benefit of any loans, advances, guarantees, pledges or other financial benefits by or through the corporation.

In general, Section 203 defines interested stockholder as an entity or person who, together with affiliates and associates, beneficially owns, or within three years prior to the determination of interested stockholder status did own, 15% or more of the outstanding voting stock of the corporation.

The provisions of Delaware law and our amended and restated certificate of incorporation and amended and restated bylaws could have the effect of discouraging others from attempting hostile takeovers and, as a consequence, they may also inhibit temporary fluctuations in the market price of our common stock that often result from actual or rumored hostile takeover attempts. These provisions may also have the effect of preventing changes in management. It is possible that these provisions may make it more difficult to accomplish transactions that stockholders may otherwise deem to be in their best interests.

Listing on The Nasdaq Global Market

Our common stock is listed on the Nasdaq Global Market under the symbol “APEN”. The applicable prospectus supplement will contain information, where applicable, as to any other listing, if any, on the Nasdaq Global Market or any securities market or other exchange of the preferred stock covered by such prospectus supplement.

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Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Nevada Agency and Transfer Company. Its address is 50 West Liberty Street, Suite 880, Reno, Nevada, 89501, and its telephone number is (775) 322-0626.

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DESCRIPTION OF DEBT SECURITIES

We may issue debt securities from time to time, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. While the terms we have summarized below will apply generally to any debt securities that we may offer under this prospectus, we will describe the particular terms of any debt securities that we may offer in more detail in the applicable prospectus supplement. The terms of any debt securities offered under a prospectus supplement may differ from the terms described below. Unless the context requires otherwise, whenever we refer to the indenture, we also are referring to any supplemental indentures that specify the terms of a particular series of debt securities.

We will issue the debt securities under the indenture that we will enter into with the trustee named in the indenture. The indenture will be qualified under the Trust Indenture Act of 1939, as amended, or the Trust Indenture Act. We have filed the form of indenture as an exhibit to the registration statement of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

The following summary of material provisions of the debt securities and the indenture is subject to, and qualified in its entirety by reference to, all of the provisions of the indenture applicable to a particular series of debt securities. We urge you to read the applicable prospectus supplements and any related free writing prospectuses related to the debt securities that we may offer under this prospectus, as well as the complete indenture that contains the terms of the debt securities.

General

The indenture does not limit the amount of debt securities that we may issue. It provides that we may issue debt securities up to the principal amount that we may authorize and may be in any currency or currency unit that we may designate. Except for the limitations on consolidation, merger and sale of all or substantially all of our assets contained in the indenture, the terms of the indenture do not contain any covenants or other provisions designed to give holders of any debt securities protection against changes in our operations, financial condition or transactions involving us.

We may issue the debt securities issued under the indenture as “discount securities,” which means they may be sold at a discount below their stated principal amount. These debt securities, as well as other debt securities that are not issued at a discount, may be issued with “original issue discount,” or OID, for U.S. federal income tax purposes because of interest payment and other characteristics or terms of the debt securities. Material U.S. federal income tax considerations applicable to debt securities issued with OID will be described in more detail in any applicable prospectus supplement.

We will describe in the applicable prospectus supplement the terms of the series of debt securities being offered, including:

• the title of the series of debt securities;

• any limit upon the aggregate principal amount that may be issued;

• the maturity date or dates;

• the form of the debt securities of the series;

• the applicability of any guarantees;

• whether or not the debt securities will be secured or unsecured, and the terms of any secured debt;

• whether the debt securities rank as senior debt, senior subordinated debt, subordinated debt or any combination thereof, and the terms of any subordination;

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• if the price (expressed as a percentage of the aggregate principal amount thereof) at which such debt securities will be issued is a price 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 another security or the method by which any such portion shall be determined;

• the interest rate or rates, which may be fixed or variable, or the method for determining the rate and the date interest will begin to accrue, the dates interest will be payable and the regular record dates for interest payment dates or the method for determining such dates;

• our right, if any, to defer payment of interest and the maximum length of any such deferral period;

• if applicable, the date or dates after which, or the period or periods during which, and the price or prices at which, we may, at our option, redeem the series of debt securities pursuant to any optional or provisional redemption provisions and the terms of those redemption provisions;

• the date or dates, if any, on which, and the price or prices at which we are obligated, pursuant to any mandatory sinking fund or analogous fund provisions or otherwise, to redeem, or at the holder’s option to purchase, the series of debt securities and the currency or currency unit in which the debt securities are payable;

• the denominations in which we will issue the series of debt securities, if other than denominations of $1,000 and any integral multiple thereof;

• any and all terms, if applicable, relating to any auction or remarketing of the debt securities of that series and any security for our obligations with respect to such debt securities and any other terms which may be advisable in connection with the marketing of debt securities of that series;

• whether the debt securities of the series shall be issued in whole or in part in the form of a global security or securities;

• the terms and conditions, if any, upon which such global security or securities may be exchanged in whole or in part for other individual securities; and the depositary for such global security or securities;

• if applicable, the provisions relating to conversion or exchange of any debt securities of the series and the terms and conditions upon which such debt securities will be so convertible or exchangeable, including the conversion or exchange price, as applicable, or how it will be calculated and may be adjusted, any mandatory or optional (at our option or the holders’ option) conversion or exchange features, the applicable conversion or exchange period and the manner of settlement for any conversion or exchange;

• if other than the full principal amount thereof, the portion of the principal amount of debt securities of the series which shall be payable upon declaration of acceleration of the maturity thereof;

• additions to or changes in the covenants applicable to the particular debt securities being issued, including, among others, the consolidation, merger or sale covenant;

• additions to or changes in the events of default with respect to the securities and any change in the right of the trustee or the holders to declare the principal, premium, if any, and interest, if any, with respect to such securities to be due and payable;

• additions to or changes in or deletions of the provisions relating to covenant defeasance and legal defeasance;

• additions to or changes in the provisions relating to satisfaction and discharge of the indenture;

• additions to or changes in the provisions relating to the modification of the indenture both with and without the consent of holders of debt securities issued under the indenture;

• the currency of payment of debt securities if other than U.S. dollars and the manner of determining the equivalent amount in U.S. dollars;

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• payable in cash or additional debt securities at our or the holders’ option and the terms and conditions upon which the election may be made;

• the terms and conditions, if any, upon which we will pay amounts in addition to the stated interest, premium, if any and principal amounts of the debt securities of the series to any holder that is not a “United States person” for federal tax purposes;

• any restrictions on transfer, sale or assignment of the debt securities of the series; and

• any other specific terms, preferences, rights or limitations of, or restrictions on, the debt securities, any other additions or changes in the provisions of the indenture, and any terms that may be required by us or advisable under applicable laws or regulations.

Conversion or Exchange Rights

We will set forth in the applicable prospectus supplement the terms on which a series of debt securities may be convertible into or exchangeable for our common stock or our other securities. We will include provisions as to settlement upon conversion or exchange and whether conversion or exchange is mandatory, at the option of the holder or at our option. We may include provisions pursuant to which the number of shares of our common stock or our other securities that the holders of the series of debt securities receive would be subject to adjustment.

Consolidation, Merger or Sale

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the indenture will not contain any covenant that restricts our ability to merge or consolidate, or sell, convey, transfer or otherwise dispose of our assets as an entirety or substantially as an entirety. However, any successor to or acquirer of such assets (other than a subsidiary of ours) must assume all of our obligations under the indenture or the debt securities, as appropriate.

Events of Default under the Indenture

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the following are events of default under the indenture with respect to any series of debt securities that we may issue:

• if we fail to pay any installment of interest on any series of debt securities, as and when the same shall become due and payable, and such default continues for a period of 90 days; provided, however, that a valid extension of an interest payment period by us in accordance with the terms of any indenture supplemental thereto shall not constitute a default in the payment of interest for this purpose;

• if we fail to pay the principal of, or premium, if any, on any series of debt securities as and when the same shall become due and payable whether at maturity, upon redemption, by declaration or otherwise, or in any payment required by any sinking or analogous fund established with respect to such series; provided, however, that a valid extension of the maturity of such debt securities in accordance with the terms of any indenture supplemental thereto shall not constitute a default in the payment of principal or premium, if any;

• if we fail to observe or perform any other covenant or agreement contained in the debt securities or the indenture, other than a covenant specifically relating to another series of debt securities, and our failure continues for 90 days after we receive written notice of such failure, requiring the same to be remedied and stating that such is a notice of default thereunder, from the trustee or holders of at least 25% in aggregate principal amount of the outstanding debt securities of the applicable series; and

• if specified events of bankruptcy, insolvency or reorganization occur.

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If an event of default with respect to debt securities of any series occurs and is continuing, other than an event of default specified in the last bullet point above, the trustee or the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series, by notice to us in writing, and to the trustee if notice is given by such holders, may declare the unpaid principal of, premium, if any, and accrued interest, if any, due and payable immediately. If an event of default specified in the last bullet point above occurs with respect to us, the principal amount of and accrued interest, if any, of each issue of debt securities then outstanding shall be due and payable without any notice or other action on the part of the trustee or any holder.

The holders of a majority in principal amount of the outstanding debt securities of an affected series may waive any default or event of default with respect to the series and its consequences, except defaults or events of default regarding payment of principal, premium, if any, or interest, unless we have cured the default or event of default in accordance with the indenture. Any waiver shall cure the default or event of default.

Subject to the terms of the indenture, if an event of default under an indenture shall occur and be continuing, the trustee will be under no obligation to exercise any of its rights or powers under such indenture at the request or direction of any of the holders of the applicable series of debt securities, unless such holders have offered the trustee reasonable indemnity. The holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee, with respect to the debt securities of that series, provided that:

• the direction so given by the holder is not in conflict with any law or the applicable indenture; and

• subject to its duties under the Trust Indenture Act, the trustee need not take any action that might involve it in personal liability or might be unduly prejudicial to the holders not involved in the proceeding.

• A holder of the debt securities of any series will have the right to institute a proceeding under the indenture or to appoint a receiver or trustee, or to seek other remedies only if:

• the holder has given written notice to the trustee of a continuing event of default with respect to that series;

• the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series have made written request,

• such holders have offered to the trustee indemnity satisfactory to it against the costs, expenses and liabilities to be incurred by the trustee in compliance with the request; and

• the trustee does not institute the proceeding, and does not receive from the holders of a majority in aggregate principal amount of the outstanding debt securities of that series other conflicting directions within 90 days after the notice, request and offer.

These limitations do not apply to a suit instituted by a holder of debt securities if we default in the payment of the principal, premium, if any, or interest on, the debt securities.

We will periodically file statements with the trustee regarding our compliance with specified covenants in the indenture.

Modification of Indenture; Waiver

We and the trustee may change an indenture without the consent of any holders with respect to specific matters:

• to cure any ambiguity, defect or inconsistency in the indenture or in the debt securities of any series;

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• to comply with the provisions described above under “Description of Debt Securities—Consolidation, Merger or Sale;”

• to provide for uncertificated debt securities in addition to or in place of certificated debt securities;

• to add to our covenants, restrictions, conditions or provisions such new covenants, restrictions, conditions or provisions for the benefit of the holders of all or any series of debt securities, to make the occurrence, or the occurrence and the continuance, of a default in any such additional covenants, restrictions, conditions or provisions an event of default or to surrender any right or power conferred upon us in the indenture;

• 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, as set forth in the indenture;

• to make any change that does not adversely affect the interests of any holder of debt securities of any series in any material respect;

• to provide for the issuance of and establish the form and terms and conditions of the debt securities of any series as provided above under “Description of Debt Securities—General” to establish the form of any certifications required to be furnished pursuant to the terms of the indenture or any series of debt securities, or to add to the rights of the holders of any series of debt securities;

• to evidence and provide for the acceptance of appointment under any indenture by a successor trustee; or

• to comply with any requirements of the SEC in connection with the qualification of any indenture under the Trust Indenture Act.

In addition, under the indenture, the rights of holders of a series of debt securities may be changed by us and the trustee with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series that is affected. However, unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, we and the trustee may make the following changes only with the consent of each holder of any outstanding debt securities affected:

• extending the fixed maturity of any debt securities of any series;

• reducing the principal amount, reducing the rate of or extending the time of payment of interest, or reducing any premium payable upon the redemption of any series of any debt securities; or

• reducing the percentage of debt securities, the holders of which are required to consent to any amendment, supplement, modification or waiver.

Discharge

Each indenture provides that we can elect to be discharged from our obligations with respect to one or more series of debt securities, except for specified obligations, including obligations to:

• provide for payment;

• register the transfer or exchange of debt securities of the series;

• replace stolen, lost or mutilated debt securities of the series;

• pay principal of and premium and interest on any debt securities of the series;

• maintain paying agencies;

• hold monies for payment in trust;

• recover excess money held by the trustee;

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• compensate and indemnify the trustee; and

• appoint any successor trustee.

In order to exercise our rights to be discharged, we must deposit with the trustee money or government obligations sufficient to pay all the principal of, any premium, if any, and interest on, the debt securities of the series on the dates payments are due.

Form, Exchange and Transfer

We will issue the debt securities of each series only in fully registered form without coupons and, unless we provide otherwise in the applicable prospectus supplement, in denominations of $1,000 and any integral multiple thereof. The indenture provides that we may issue debt securities of a series in temporary or permanent global form and as book-entry securities that will be deposited with, or on behalf of, The Depository Trust Company, or DTC, or another depositary named by us and identified in the applicable prospectus supplement with respect to that series. To the extent the debt securities of a series are issued in global form and as book-entry, a description of terms relating to any book-entry securities will be set forth in the applicable prospectus supplement.

At the option of the holder, subject to the terms of the indenture and the limitations applicable to global securities described in the applicable prospectus supplement, the holder of the debt securities of any series can exchange the debt securities for other debt securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount.

Subject to the terms of the indenture and the limitations applicable to global securities set forth in the applicable prospectus supplement, holders of the debt securities may present the debt securities for exchange or for registration of transfer, duly endorsed or with the form of transfer endorsed thereon duly executed if so required by us or the security registrar, at the office of the security registrar or at the office of any transfer agent designated by us for this purpose. Unless otherwise provided in the debt securities that the holder presents for transfer or exchange, we will impose no service charge for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges.

We will name in the applicable prospectus supplement the security registrar, and any transfer agent in addition to the security registrar, that we initially designate for any debt securities. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

If we elect to redeem the debt securities of any series, we will not be required to:

• issue, register the transfer of, or exchange any debt securities of that series during a period beginning at the opening of business 15 days before the day of mailing of a notice of redemption of any debt securities that may be selected for redemption and ending at the close of business on the day of the mailing; or

• register the transfer of or exchange any debt securities so selected for redemption, in whole or in part, except the unredeemed portion of any debt securities we are redeeming in part.

Information Concerning the Trustee

The trustee, other than during the occurrence and continuance of an event of default under an indenture, undertakes to perform only those duties as are specifically set forth in the applicable indenture. Upon an event of default under an indenture, the trustee must use the same degree of care as a prudent person would exercise or use in the conduct of his or her own affairs. Subject to this provision, the trustee is under no obligation to exercise any of the powers given it by the indenture at the request of any holder of debt securities unless it is offered reasonable security and indemnity against the costs, expenses and liabilities that it might incur.

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Payment and Paying Agents

Unless we otherwise indicate in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities, or one or more predecessor securities, are registered at the close of business on the regular record date for the interest.

We will pay principal of and any premium and interest on the debt securities of a particular series at the office of the paying agents designated by us, except that unless we otherwise indicate in the applicable prospectus supplement, we will make interest payments by check that we will mail to the holder or by wire transfer to certain holders. Unless we otherwise indicate in the applicable prospectus supplement, we will designate the corporate trust office of the trustee as our sole paying agent for payments with respect to debt securities of each series. We will name in the applicable prospectus supplement any other paying agents that we initially designate for the debt securities of a particular series. We will maintain a paying agent in each place of payment for the debt securities of a particular series.

All money we pay to a paying agent or the trustee for the payment of the principal of or any premium or interest on any debt securities that remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us, and the holder of the debt security thereafter may look only to us for payment thereof.

Governing Law

The indenture and the debt securities will be governed by and construed in accordance with the internal laws of the State of New York, except to the extent that the Trust Indenture Act of 1939, as amended, is applicable.

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DESCRIPTION OF WARRANTS

The following description, together with the additional information we may include in any applicable prospectus supplement and free writing prospectus, summarizes the material terms and provisions of the warrants that we may offer under this prospectus, which may consist of warrants to purchase common stock, preferred stock or debt securities and may be issued in one or more series. Warrants may be offered independently or in combination with common stock, preferred stock or debt securities offered by any prospectus supplement. While the terms we have summarized below will apply generally to any warrants that we may offer under this prospectus, we will describe the particular terms of any series of warrants in more detail in the applicable prospectus supplement. The following description of warrants will apply to the warrants offered by this prospectus unless we provide otherwise in the applicable prospectus supplement. The applicable prospectus supplement for a particular series of warrants may specify different or additional terms.

We have filed forms of the warrant agreements and forms of warrant certificates containing the terms of the warrants that may be offered as exhibits to the registration statement of which this prospectus is a part. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of warrant and/or the warrant agreement and warrant certificate, as applicable, that contain the terms of the particular series of warrants we are offering, and any supplemental agreements, before the issuance of such warrants. The following summaries of material terms and provisions of the warrants are subject to, and qualified in their entirety by reference to, all the provisions of the form of warrant and/or the warrant agreement and warrant certificate, as applicable, and any supplemental agreements applicable to a particular series of warrants that we may offer under this prospectus. We urge you to read the applicable prospectus supplement related to the particular series of warrants that we may offer under this prospectus, as well as any related free writing prospectus, and the complete form of warrant and/or the warrant agreement and warrant certificate, as applicable, and any supplemental agreements, that contain the terms of the warrants.

General

We will describe in the applicable prospectus supplement the terms of the series of warrants being offered, 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;

• 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 agreements 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 dates on which the right to exercise the warrants will commence and expire;

• the manner in which the warrant agreements and warrants may be modified;

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• a discussion of any material or special U.S. federal income tax considerations 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.

• Before exercising their warrants, holders of warrants will not have any of the rights of holders of the securities purchasable upon such exercise, including:

• in the case of warrants to purchase debt securities, the right to receive payments of principal of, or premium, if any, or interest on, the debt securities purchasable upon exercise or to enforce covenants in the applicable indenture; or

• in the case of warrants to purchase common stock or preferred stock, the right to receive dividends, if any, or, payments upon our liquidation, dissolution or winding up or to exercise voting rights, if any.

Exercise of Warrants

Each warrant will entitle the holder to purchase the securities that we specify in the applicable prospectus supplement at the exercise price that we describe in the applicable prospectus supplement. The warrants may be exercised as set forth in the prospectus supplement relating to the warrants offered. Unless we otherwise specify in the applicable prospectus supplement, warrants may be exercised at any time up to the close of business on the expiration date set forth in the prospectus supplement relating to the warrants offered thereby. After the close of business on the expiration date, unexercised warrants will become void.

Upon receipt of payment and the warrant or warrant certificate, as applicable, properly completed and duly executed at the corporate trust office of the warrant agent, if any, or any other office, including ours, indicated in the prospectus supplement, we will, as soon as practicable, issue and deliver the securities purchasable upon such exercise. If less than all of the warrants (or the warrants represented by such warrant certificate) are exercised, a new warrant or a new warrant certificate, as applicable, will be issued for the remaining warrants.

Governing Law

Unless we otherwise specify in the applicable prospectus supplement, the warrants and any warrant agreements will be governed by and construed in accordance with the laws of the State of New York.

Enforceability of Rights by Holders of Warrants

Each warrant agent, if any, will act solely as our agent under the applicable warrant agreement and will not assume any obligation or relationship of agency or trust with any holder of any warrant. A single bank or trust company may act as warrant agent for more than one issue of warrants. A warrant agent will have no duty or responsibility in case of any default by us under the applicable warrant agreement or warrant, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a warrant may, without the consent of the related warrant agent or the holder of any other warrant, enforce by appropriate legal action its right to exercise, and receive the securities purchasable upon exercise of, its warrants.

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LEGAL OWNERSHIP OF SECURITIES

We may issue securities in registered form or in the form of one or more global securities. We describe global securities in greater detail below. We refer to those persons who have securities registered in their own names on the books that we or any applicable trustee, depositary or warrant agent maintain for this purpose as the “holders” of those securities. These persons are the legal holders of the securities. We refer to those persons who, indirectly through others, own beneficial interests in securities that are not registered in their own names, as “indirect holders” of those securities. As we discuss below, indirect holders are not legal holders, and investors in securities issued in book-entry form or in street name will be indirect holders.

Book-Entry Holders

We may issue securities in book-entry form only, as we will specify in the applicable prospectus supplement. This means securities may be represented by one or more global securities registered in the name of a financial institution that holds them as depositary on behalf of other financial institutions that participate in the depositary’s book-entry system. These participating institutions, which are referred to as participants, in turn, hold beneficial interests in the securities on behalf of themselves or their customers.

Only the person in whose name a security is registered is recognized as the holder of that security. Securities issued in global form will be registered in the name of the depositary or its participants. Consequently, for securities issued in global form, we will recognize only the depositary as the holder of the securities, and we will make all payments on the securities to the depositary. The depositary passes along the payments it receives to its participants, which in turn pass the payments along to their customers who are the beneficial owners. The depositary and its participants do so under agreements they have made with one another or with their customers; they are not obligated to do so under the terms of the securities.

As a result, investors in a book-entry security will not own securities directly. Instead, they will own beneficial interests in a global security, through a bank, broker or other financial institution that participates in the depositary’s book-entry system or holds an interest through a participant. As long as the securities are issued in global form, investors will be indirect holders, and not holders, of the securities.

Street Name Holders

We may terminate a global security or issue securities in non-global form. In these cases, investors may choose to hold their securities in their own names or in “street name.” Securities held by an investor in street name would be registered in the name of a bank, broker or other financial institution that the investor chooses, and the investor would hold only a beneficial interest in those securities through an account he or she maintains at that institution.

For securities held in street name, we will recognize only the intermediary banks, brokers and other financial institutions in whose names the securities are registered as the holders of those securities, and we will make all payments on those securities to them. These institutions pass along the payments they receive to their customers who are the beneficial owners, but only because they agree to do so in their customer agreements or because they are legally required to do so. Investors who hold securities in street name will be indirect holders, not holders, of those securities.

Legal Holders

Our obligations, as well as the obligations of any applicable trustee and of any third parties employed by us or a trustee, run only to the legal holders of the securities. We do not have obligations to investors who hold beneficial interests in global securities, in street name or by any other indirect means. This will be the case whether an investor chooses to be an indirect holder of a security or has no choice because we are issuing the securities only in global form.

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For example, once we make a payment or give a notice to the holder, we have no further responsibility for the payment or notice even if that holder is required, under agreements with depositary participants or customers or by law, to pass it along to the indirect holders but does not do so. Similarly, we may want to obtain the approval of the holders to amend an indenture, to relieve us of the consequences of a default or of our obligation to comply with a particular provision of the indenture or for other purposes. In such an event, we would seek approval only from the holders, and not the indirect holders, of the securities. Whether and how the holders contact the indirect holders is up to the holders.

Special Considerations for Indirect Holders

If you hold securities through a bank, broker or other financial institution, either in book-entry form or in street name, you should check with your own institution to find out:

• the performance of third-party service providers;

• how it handles securities payments and notices;

• whether it imposes fees or charges;

• how it would handle a request for the holders’ consent, if ever required;

• whether and how you can instruct it to send you securities registered in your own name so you can be a holder, if that is permitted in the future;

• how it would exercise rights under the securities if there were a default or other event triggering the need for holders to act to protect their interests; and

• if the securities are in book-entry form, how the depositary’s rules and procedures will affect these matters.

Global Securities

A global security is a security that represents one or any other number of individual securities held by a depositary. Generally, all securities represented by the same global securities will have the same terms.

Each security issued in book-entry form will be represented by a global security that we deposit with and register in the name of a financial institution or its nominee that we select. The financial institution that we select for this purpose is called the depositary. Unless we specify otherwise in the applicable prospectus supplement, DTC will be the depositary for all securities issued in book-entry form.

A global security may not be transferred to or registered in the name of anyone other than the depositary, its nominee or a successor depositary, unless special termination situations arise. We describe those situations below under the section titled “Special Situations When a Global Security Will Be Terminated” in this prospectus. As a result of these arrangements, the depositary, or its nominee, will be the sole registered owner and holder of all securities represented by a global security, and investors will be permitted to own only beneficial interests in a global security. Beneficial interests must be held by means of an account with a broker, bank or other financial institution that in turn has an account with the depositary or with another institution that does. Thus, an investor whose security is represented by a global security will not be a holder of the security, but only an indirect holder of a beneficial interest in the global security.

If the prospectus supplement for a particular security indicates that the security will be issued in global form only, then the security will be represented by a global security at all times unless and until the global security is terminated. If termination occurs, we may issue the securities through another book-entry clearing system or decide that the securities may no longer be held through any book-entry clearing system.

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Special Considerations for Global Securities

The rights of an indirect holder relating to a global security will be governed by the account rules of the investor’s financial institution and of the depositary, as well as general laws relating to securities transfers. We do not recognize an indirect holder as a holder of securities and instead deal only with the depositary that holds the global security.

If securities are issued only in the form of a global security, an investor should be aware of the following:

• an investor cannot cause the securities to be registered in his or her name, and cannot obtain non-global certificates for his or her interest in the securities, except in the special situations we describe below;

• an investor will be an indirect holder and must look to his or her own bank or broker for payments on the securities and protection of his or her legal rights relating to the securities, as we describe above;

• an investor may not be able to sell interests in the securities to some insurance companies and to other institutions that are required by law to own their securities in non-book-entry form;

• an investor may not be able to pledge his or her interest in a global security in circumstances where certificates representing the securities must be delivered to the lender or other beneficiary of the pledge in order for the pledge to be effective;

• the depositary’s policies, which may change from time to time, will govern payments, transfers, exchanges and other matters relating to an investor’s interest in a global security;

• we and any applicable trustee have no responsibility for any aspect of the depositary’s actions or for its records of ownership interests in a global security, nor do we or any applicable trustee supervise the depositary in any way;

• the depositary may, and we understand that DTC will, require that those who purchase and sell interests in a global security within its book-entry system use immediately available funds, and your broker or bank may require you to do so as well; and

• financial institutions that participate in the depositary’s book-entry system, and through which an investor holds its interest in a global security, may also have their own policies affecting payments, notices and other matters relating to the securities.

There may be more than one financial intermediary in the chain of ownership for an investor. We do not monitor and are not responsible for the actions of any of those intermediaries.

Special Situations When a Global Security Will Be Terminated

In a few special situations described below, the global security will terminate and interests in it will be exchanged for physical certificates representing those interests. After that exchange, the choice of whether to hold securities directly or in street name will be up to the investor. Investors must consult their own banks or brokers to find out how to have their interests in securities transferred to their own name, so that they will be direct holders. We have described the rights of holders and street name investors above.

Unless we provide otherwise in the applicable prospectus supplement, the global security will terminate when the following special situations occur:

• if the depositary notifies us that it is unwilling, unable or no longer qualified to continue as depositary for that global security and we do not appoint another institution to act as depositary within 90 days;

• if we notify any applicable trustee that we wish to terminate that global security; or

• if an event of default has occurred with regard to securities represented by that global security and has not been cured or waived.

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The applicable prospectus supplement may also list additional situations for terminating a global security that would apply only to the particular series of securities covered by the applicable prospectus supplement. When a global security terminates, the depositary, and not we or any applicable trustee, is responsible for deciding the names of the institutions that will be the initial direct holders.

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PLAN OF DISTRIBUTION

We may sell the securities from time to time pursuant to underwritten public offerings, direct sales to the public, “at-the-market” offerings, negotiated transactions, block trades or a combination of these methods. We may sell the securities to or through one or more underwriters or dealers (acting as principal or agent), through agents, or directly to one or more purchasers. We may distribute the securities from time to time in one or more transactions:

• at a fixed price or prices, which may be changed;

• at market prices prevailing at the time of sale;

• at prices related to such prevailing market prices; or

• at negotiated prices.

We will describe the terms of the offering of the securities and the specific plan of distribution in a prospectus supplement or supplements to this prospectus, any related free writing prospectus that we may authorize to be provided to you, an amendment to the registration statement of which this prospectus is a part or other filings we make with the SEC under the Exchange Act that are incorporated by reference. Such description may include, to the extent applicable:

• the name or names of any underwriters, dealers, agents or other purchasers;

• the purchase price of the securities or other consideration therefor, and the proceeds, if any, we will receive from the sale;

• any options to purchase additional shares or other options under which underwriters, dealers, agents or other purchasers may purchase additional securities from us;

• any agency fees or underwriting discounts and other items constituting agents’ or underwriters’ compensation;

• any public offering price;

• any discounts or concessions allowed or reallowed or paid to dealers; and

• any securities exchange or market on which the securities may be listed.

Only underwriters named in the prospectus supplement will be underwriters of the securities offered by the prospectus supplement. Dealers and agents participating in the distribution of the securities may be deemed to be underwriters, and compensation received by them on resale of the securities may be deemed to be underwriting discounts. If such dealers or agents were deemed to be underwriters, they may be subject to statutory liabilities under the Securities Act.

If underwriters are used in the sale, they will acquire the securities for their own account and may resell the securities from time to time in one or more transactions at a fixed public offering price or at varying prices determined at the time of sale. The obligations of the underwriters to purchase the securities will be subject to the conditions set forth in the applicable underwriting agreement. We may offer the securities to the public through underwriting syndicates represented by managing underwriters or by underwriters without a syndicate. Subject to certain conditions, the underwriters will be obligated to purchase all of the securities offered by the prospectus supplement, other than securities covered by any option to purchase additional shares or other option. If a dealer is used in the sale of securities, we, or an underwriter, will sell the securities to the dealer, as principal. The dealer may then resell the securities to the public at varying prices to be determined by the dealer at the time of resale. To the extent required, we will set forth in the prospectus supplement the name of the dealer and the terms of the transaction. Any public offering price and any discounts or concessions allowed or reallowed or paid to dealers may change from time to time. We may use underwriters, dealers or agents with whom we have a material relationship. We will describe in the prospectus supplement, naming the underwriter, dealer or agent, the nature of any such relationship.

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We may sell securities directly or through agents we designate from time to time. We will name any agent involved in the offering and sale of securities and we will describe any commissions payable to the agent in the prospectus supplement. Unless the prospectus supplement states otherwise, the agent will act on a best-efforts basis for the period of its appointment.

We may provide agents, dealers and underwriters with indemnification against civil liabilities, including liabilities under the Securities Act, or contribution with respect to payments that the agents or dealers or underwriters may make with respect to these liabilities. Agents, dealers and underwriters or their affiliates may engage in transactions with, or perform services for us in the ordinary course of business.

All securities we may offer, other than common stock, will be new issues of securities with no established trading market. Any underwriters may make a market in these securities, but will not be obligated to do so and may discontinue any market making at any time without notice. We cannot guarantee the liquidity of the trading markets for any securities.

Any underwriter may be granted an option to purchase additional shares, and engage in stabilizing transactions, short-covering transactions and penalty bids in accordance with Regulation M under the Exchange Act. An underwriter’s option to purchase additional shares involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum price. Syndicate-covering or other short-covering transactions involve purchases of the securities, either through exercise of the option to purchase additional shares or in the open market after the distribution is completed, to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a stabilizing or covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of the activities at any time.

Any underwriters, dealers or agents that are qualified market makers on the Nasdaq Global Market may engage in passive market making transactions in our common stock on the Nasdaq Global Market in accordance with Regulation M under the Exchange Act, during the business day prior to the pricing of the offering, before the commencement of offers or sales of the common stock. Passive market makers must comply with applicable volume and price limitations and must be identified as passive market makers. In general, a passive market maker must display its bid at a price not in excess of the highest independent bid for such security; if all independent bids are lowered below the passive market maker’s bid, however, the passive market maker’s bid must then be lowered when certain purchase limits are exceeded. Passive market making may stabilize the market price of the securities at a level above that which might otherwise prevail in the open market and, if commenced, may be discontinued at any time.

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LEGAL MATTERS

Unless otherwise indicated in the applicable prospectus supplement, Cooley LLP, Palo Alto, California will pass upon the validity of the securities offered by this prospectus and any supplement thereto. As of the date of this prospectus, certain Cooley LLP attorneys and GC&H Investments, LLC and GC&H Investments, entities comprised of partners and associates of Cooley LLP, beneficially own an aggregate of 11,763 shares of our common stock. Additional legal matters may be passed upon for us or any underwriters, dealers or agents, by counsel that we name in the applicable prospectus supplement.

EXPERTS

Moss Adams LLP, independent registered public accounting firm, has audited our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2020, as set forth in their report, which is incorporated by reference in this prospectus and elsewhere in the registration statement. Our financial statements are incorporated by reference in reliance on Moss Adams LLP’s reports, given on their authority as experts in accounting and auditing.

The consolidated financial statements of Apollo Endosurgery, Inc. and subsidiaries as of December 31, 2019, and for the year then ended, 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. The audit report covering the December 31, 2019 consolidated financial statements contains an explanatory paragraph that states that the company has suffered recurring losses from operations, cash flow deficits and debt covenant violations and has an accumulated deficit that raise substantial doubt about its ability to continue as a going concern. The consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty.

WHERE YOU CAN FIND ADDITIONAL INFORMATION

This prospectus is part of the registration statement on Form S-3 we filed with the SEC under the Securities Act and does not contain all the information set forth or incorporated by reference in the registration statement. Whenever a reference is made in this prospectus to any of our contracts, agreements or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference into this prospectus for a copy of such contract, agreement or other document. Because we are subject to the information and reporting requirements of the Exchange Act, we file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. Our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, including any amendments to those reports, and other information that we file with or furnish to the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act can also be accessed free of charge on our website. These filings will be available as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC. Our website address is http://www.apolloendo.com. Information contained on or accessible through our website is not a part of this prospectus and is not incorporated by reference herein, and the inclusion of our website address in this prospectus is an inactive textual reference only.

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INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” information from other documents that we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus. Information in this prospectus supersedes information incorporated by reference that we filed with the SEC prior to the date of this prospectus, while information that we file later with the SEC will automatically update and supersede the information in this prospectus. We incorporate by reference into this prospectus and the registration statement of which this prospectus is a part the information or documents listed below that we have filed with the SEC (Commission File No. 001-35706):

• our Annual Report on Form 10-K for the year ended December 31, 2020, filed with the SEC on February 25, 2021;

• our Quarterly Report on Form 10-Q for the quarter ended March 31, 2021 filed with the SEC on May 4, 2021;

• the information specifically incorporated by reference in our Annual Report on Form 10-K for the year ended December 31, 2020, from our definitive proxy statement relating to our 2021 annual meeting of stockholders, filed with the SEC on April 27, 2021;

• our Current Reports on Form 8-K filed with the SEC on February 8, 2021 (as amended on March  3, 2021), March  25, 2021 and May 3, 2021; and

• the description of our common stock, which is registered under the Exchange Act in the registration statement on Form 8-A/A, filed with the SEC on October 31, 2012.

All filings filed by us pursuant to the Exchange Act after the date of the initial filing of the registration statement of which this prospectus is a part and prior to effectiveness of the registration statement shall be deemed to be incorporated by reference into this prospectus.

We also incorporate by reference any future filings (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items unless such Form 8-K expressly provides to the contrary) made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, including those made after the date of the initial filing of the registration statement of which this prospectus is a part and prior to effectiveness of such registration statement, until we file a post-effective amendment that indicates the termination of the offering of the securities made by this prospectus and will become a part of this prospectus from the date that such documents are filed with the SEC. Information in such future filings updates and supplements the information provided in this prospectus. Any statements in any such future filings will automatically be deemed to modify and supersede any information in any document we previously filed with the SEC that is incorporated or deemed to be incorporated herein by reference to the extent that statements in the later filed document modify or replace such earlier statements.

You can request a copy of these filings, at no cost, by writing or telephoning us at the following address or telephone number:

Apollo Endosurgery, Inc.

1120 S. Capital of Texas Highway

Building 1, Suite #300

Austin, Texas 78746

Attn: Secretary

33

8,400,000 Shares

Common Stock

Preliminary Prospectus Supplement

Joint Book-Running Managers

Piper Sandler Cowen Stifel

Co-Managers

Craig-Hallum Lake Street

October 12, 2021