Scholar Rock Holding 424B5 Prospectus supplement for primary offering

Filed Pursuant to Rule 424(b)(5)
Registration No. 333-254057

Prospectus supplement
(To prospectus dated April 13, 2022)

Scholar Rock Holding Corporation

16,326,530 shares of common stock
Pre-funded warrants to purchase up to 25,510,205 shares of common stock
Common warrants to purchase up to 10,459,181 shares of common stock

We are offering 16,326,530 shares of our common stock, par value $0.001 per share, pre-funded warrants (the “Pre-funded Warrants”) to purchase 25,510,205 shares of common stock and accompanying common warrants to purchase up to 10,459,181 shares of our common stock (the “Common Warrants”) at a combined public offering price of $4.90 per share of common stock and accompanying Common Warrant and $4.8999 per Pre-funded Warrant and accompanying Common Warrant in a registered direct offering directly to investors pursuant to this prospectus supplement and the accompanying prospectus and securities purchase agreements with such investors. The Common Warrants have an exercise price per share equal to 150% of the price per share of the common stock sold in the offering, are exercisable immediately, subject to certain limitations described herein, and will expire on December 31, 2025. We are also offering the shares of our common stock that are issuable from time to time upon exercise of the Common Warrants.

We are offering the Pre-funded Warrants to purchase shares of common stock (and the shares of common stock issuable from time to time upon exercise of the Pre-funded Warrants), in lieu of shares of common stock, to purchasers who so choose. Each Pre-funded Warrant will be exercisable for one share of common stock at an exercise price of $0.0001 per share of common stock. The public offering price per Pre-funded Warrant and accompanying Common Warrant, is equal to the public offering price per share of common stock and accompanying Common Warrant less $0.0001. Each Pre-funded Warrant will be exercisable upon issuance and will expire when exercised in full. The shares of common stock or Pre-funded Warrants, as applicable, and the accompanying Common Warrants, can only be purchased together in this offering but will be issued separately and will be immediately separable upon issuance. There is no established public trading market for the Pre-funded Warrants or the Common Warrants, and we do not expect a market to develop. We do not intend to apply for listing of the Pre-funded Warrants or the Common Warrants on any securities exchange or nationally recognized trading system. Without an active trading market, the liquidity of the Pre-funded Warrants and the Common Warrants will be limited.

We are an “emerging growth company” as defined under U.S. federal securities laws and are subject to reduced public company reporting requirements. Our common stock is listed on The Nasdaq Global Select Market under the symbol “SRRK.” On June 16, 2022, the closing price of our common stock, as reported on The Nasdaq Global Select Market, was $4.86 per share.

We have engaged J.P. Morgan Securities LLC as lead placement agent and Piper Sandler & Co. as co-placement agent (collectively, the “placement agents”), as our exclusive placement agents in connection with this offering. We have agreed to pay the placement agent fees set forth in the table below. See “Plan of Distribution” beginning on page S-36 of this prospectus supplement for more information.

Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties referenced under the heading “Risk Factors” on page S-16 of this prospectus supplement, page 2 of the accompanying prospectus and in the documents that are incorporated herein by reference.

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.

	Per share and accompanying warrant			Per pre-funded warrant and accompanying warrant			Total
Offering price		$	4.90		$	4.8999		$	204,997,450
Placement agent fees(1)		$	0.2205		$	0.2205		$	9,224,885
Proceeds to Scholar Rock Holding Corporation, before expenses		$	4.6795		$	4.6794		$	195,772,565

(1) We have agreed to pay the placement agent a placement agents’ fee equal to 4.5% of the of the gross proceeds received by us from the sale of shares of common stock, Pre-funded Warrants and accompanying Common Warrants in this offering. See “Plan of Distribution” beginning on page S-36 of this prospectus supplement for a description of the compensation payable to the placement agents.

We expect to deliver the securities against payment on or about June 22, 2022.

J.P. Morgan Piper Sandler

June 17, 2022

TABLE OF CONTENTS

Table of contents

Prospectus supplement

Prospectus

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About This Prospectus Supplement

This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this offering of common stock, Pre-funded Warrants and accompanying Common Warrants. The second part is the accompanying prospectus, which provides more general information, some of which may not apply to this offering. The information included or incorporated by reference in this prospectus supplement also adds to, updates and changes information contained or incorporated by reference in the accompanying prospectus. If information included or incorporated by reference in this prospectus supplement is inconsistent with the accompanying prospectus or the information incorporated by reference therein, then this prospectus supplement or the information incorporated by reference in this prospectus supplement will apply and will supersede the information in the accompanying prospectus and the documents incorporated by reference therein.

This prospectus supplement is part of a registration statement that we filed with the Securities and Exchange Commission (“SEC”), using a “shelf” registration process. Under the shelf registration process, we may from time to time offer and sell any combination of the securities described in the accompanying prospectus up to a total dollar amount of $300 million, of which this offering is a part.

You should rely only on the information contained or incorporated by reference in this prospectus supplement, the accompanying prospectus and any free writing prospectus prepared by us or on our behalf. We have not, and the placement agents have not, authorized any other person to provide you with information different from that contained in this prospectus supplement and the accompanying prospectus or incorporated by reference in this prospectus supplement and the accompanying prospectus. If anyone provides you with different or inconsistent information, you should not rely on it. We are not, and the placement agents are not, making an offer to sell or soliciting an offer to buy these securities under any circumstance in any jurisdiction where the offer or solicitation is not permitted. You should assume that the information contained in this prospectus supplement, the accompanying prospectus and any free writing prospectus prepared by us or on our behalf is accurate only as of the date of the respective document in which the information appears, and that any information in documents that 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 supplement or any sale of a security. Our business, financial condition, results of operations and prospects may have changed since those dates.

It is important for you to read and consider all of the information contained in this prospectus supplement and the accompanying prospectus in making your investment decision. We include cross-references in this prospectus supplement and the accompanying prospectus to captions in these materials where you can find additional related discussions. The table of contents in this prospectus supplement provides the pages on which these captions are located. You should read both this prospectus supplement and the accompanying prospectus, together with the additional information described in the sections entitled “Where you can find more information” and “Incorporation of certain information by reference” of this prospectus supplement, before investing in our common stock or Pre-funded Warrants and accompanying Common Warrants.

We are offering to sell, and seeking offers to buy, shares of common stock or Pre-funded Warrants and accompanying Common Warrants only in jurisdictions where offers and sales are permitted. The distribution of this prospectus supplement and the accompanying prospectus and the offering of the common stock, Pre-funded Warrants and accompanying Common Warrants in certain jurisdictions may be restricted by law. Persons outside the United States who come into possession of this prospectus supplement and the accompanying prospectus must inform themselves about, and observe any restrictions relating to, the offering of the common stock, Pre-funded Warrants and accompanying Common Warrants and the distribution of this prospectus supplement and the accompanying prospectus outside the United States. This prospectus supplement and the accompanying prospectus do not constitute, and may not be used in connection with, an offer to sell, or a solicitation of an offer to buy, any securities offered by this prospectus supplement and the accompanying prospectus by any person in any jurisdiction in which it is unlawful for such person to make such an offer or solicitation.

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The information in this prospectus is accurate only as of the date on the front cover of this prospectus and the information in any free writing prospectus that we may provide you in connection with this offering is accurate only as of the date of that free writing prospectus. Our business, financial condition, results of operations and prospects may have changed since those dates. No person is authorized in connection with this prospectus to give any information or to make any representations about us, the securities offered hereby or any matter discussed in this prospectus, other than the information and representations contained in this prospectus. If any other information or representation is given or made, such information or representation may not be relied upon as having been authorized by us.

For investors outside the United States: We have not, and the placement agents have not, taken any action that would permit this offering or possession or distribution of this prospectus in any jurisdiction where action for that purpose is required, other than in the United States. Persons outside the United States who come into possession of this prospectus must inform themselves about, and observe any restrictions relating to, the offering of the securities covered hereby and the distribution of this prospectus outside the United States.

All references in this prospectus supplement and the accompanying prospectus to our consolidated financial statements include the related notes thereto.

Unless the context otherwise indicates, references in this prospectus to “Scholar Rock”, “we”, “our”, “us” and “the Company” refer, collectively, to Scholar Rock Holding Corporation and its subsidiaries.

We own various U.S. federal trademark applications and unregistered trademarks, including “Scholar Rock” and our corporate logo. All other trademarks or trade names referred to in this prospectus are the property of their respective owners. Solely for convenience, the trademarks and trade names in this prospectus are referred to without the symbols ® and ™, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto. We do not intend our use or display of other companies’ trademarks and trade names to imply a relationship with, or endorsement or sponsorship of us by, any other companies.

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Prospectus summary

The following summary of our business highlights some of the information contained elsewhere in, or incorporated by reference into, this prospectus supplement. Because this is only a summary, however, it does not contain all of the information that may be important to you. You should carefully read this prospectus supplement and the accompanying prospectus, including the documents incorporated by reference, which are described under “Incorporation of certain information by reference” in this prospectus supplement. You should also carefully consider the matters discussed in the section of this prospectus supplement entitled “Risk factors” and under similar sections of the accompanying prospectus and other periodic reports incorporated herein and therein by reference.

Company overview

We are a biopharmaceutical company focused on the discovery and development of innovative medicines for the treatment of serious diseases in which signaling by protein growth factors plays a fundamental role. Our novel understanding of the molecular mechanisms of growth factor activation enabled us to develop a proprietary platform for the discovery and development of monoclonal antibodies that locally and selectively target the precursor, or latent, forms of growth factors. By targeting the signaling proteins at the cellular level and acting in the disease microenvironment, we believe we may avoid the historical dose-limiting safety challenges associated with inhibiting growth factors for therapeutic effect. We believe our focus on biologically validated growth factors may facilitate a more efficient development path.

Our first product candidate, apitegromab (formerly SRK-015), is a highly selective, fully human, monoclonal antibody, with a unique mechanism of action that results in inhibition of the activation of the growth factor, myostatin, in skeletal muscle. Apitegromab is being developed as a potential first muscle-directed therapy for the treatment of spinal muscular atrophy (“SMA”). We are conducting SAPPHIRE, a pivotal Phase 3 trial to evaluate the efficacy and safety of apitegromab in patients with non-ambulatory Type 2 and Type 3 SMA (which is estimated to represent the majority of the current prevalent SMA patient population in the United States and Europe). Apitegromab was evaluated in our TOPAZ Phase 2 clinical trial for the treatment of patients with Type 2 and Type 3 SMA. Positive 12-month top-line results were announced in April 2021, and presented at Cure SMA Virtual Conference in June, showing apitegromab’s transformative potential (see “TOPAZ 12-Month Analysis” below). From June 2021 to March 2022, we announced supportive data from additional exploratory analyses from the Phase 2 TOPAZ clinical trial at various medical congresses, including those of the World Muscle Society and the Muscular Dystrophy Association, among others. In June 2022 we announced 24-month efficacy and safety extension data of apitegromab in patients with Type 2 and Type 3 SMA from the TOPAZ Phase 2 clinical trial, and presented at the Cure SMA Research & Clinical Care Meeting (see “TOPAZ 24-Month Analysis” below). The U.S. Food and Drug Association (“FDA”) granted Fast Track Designation, Rare Pediatric Disease designation and Orphan Drug Designation to apitegromab for the treatment of SMA in May 2021, August 2020 and March 2018, respectively. The European Medicines Agency (“EMA”) granted PRIority MEdicines (“PRIME”) designation in March 2021 and the European Commission (“EC”) granted Orphan Medicinal Product designation in December 2018 to apitegromab for the treatment of SMA.

Our second product candidate, SRK-181, is being developed for the treatment of cancers that are resistant to checkpoint inhibitor (“CPI”) therapies, such as anti-PD-1 or anti-PD-L1 antibody therapies. SRK-181 is a highly selective inhibitor of the activation of latent TGFβ1 that is being investigated in our Phase 1 DRAGON proof-of-concept clinical trial in patients with locally advanced or metastatic solid tumors that exhibit primary resistance to anti-PD-(L)1 antibodies. This two-part clinical trial consists of a dose escalation portion (Part A) and a dose expansion portion evaluating SRK-181 in combination with an approved anti-PD-(L)1 antibody therapy (Part B). Part B encompasses five cohorts, including urothelial carcinoma, cutaneous melanoma, non-small cell lung cancer, clear cell renal cell carcinoma and other solid tumors and commenced in 2021. Initial clinical data from Part A were presented in November 2021 at the Society for Immunotherapy of Cancer 36th Annual Meeting.

Our approach and proprietary platform

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molecules between cells and play a fundamental role in regulating a variety of normal cellular processes, including cell growth and differentiation. Current therapeutic approaches to treating diseases in which growth factors play a fundamental role involve directly targeting the active form of the growth factor or its receptor systemically throughout the body. These approaches have suffered from a variety of shortcomings, including lack of pathway selectivity, lack of target selectivity, and non-localized target inhibition.

Our innovative approach is rooted in our structural biology insights into the mechanism by which certain growth factors are activated in close proximity to the cell surface. We integrate these insights with sophisticated protein expression, assay development and monoclonal antibody discovery capabilities. We believe our proprietary platform can address the challenges of treating diseases in which growth factors play a fundamental role by:

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targeting the natural activation mechanism to prevent activation of the growth factor rather than attempting to inhibit the growth factor after activation;

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achieving heightened specificity for the targeted growth factor while minimizing interactions with structurally similar and related growth factors, thereby potentially reducing the risk of unintended systemic adverse events; and

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targeting the disease microenvironment, where we believe we can interfere with the disease process while minimizing the effects on the normal physiological processes mediated by the same growth factors.

Our structural insights and unique antibody discovery capabilities can be applied to other protein classes beyond growth factors, with an aim of generating differentiated candidates targeting cell surface receptors such as immune cell receptors or G-protein coupled receptors, where selectivity remains challenging.

Our programs

Apitegromab in spinal muscular atrophy (SMA)

We are developing apitegromab, a novel, highly selective inhibitor of the activation of the growth factor myostatin, as a potential first muscle-directed therapy for the treatment of SMA. Myostatin, a member of the TGFβ superfamily of growth factors, is expressed primarily in skeletal muscle cells and the absence of its gene is associated with an increase in muscle mass and strength in multiple animal species. We believe that inhibition of the activation of myostatin may promote a clinically meaningful increase in motor function. As a result, we have focused our initial development efforts for apitegromab on the treatment of SMA. SMA is a rare, and often fatal, genetic disorder arising from a deficiency of a protein known as “survival of motor neuron,” or SMN. This disease typically manifests in young children and is characterized by atrophy of the voluntary muscles of the limbs and trunk and dramatically reduced normal neuromuscular function. An estimated 30,000 to 35,000 patients suffer from SMA in the United States and Europe alone, and many more patients are affected worldwide.

In preclinical studies, we have shown that apitegromab selectively avoids interaction with other closely related growth factors that play distinct physiological roles. Using a mouse chimeric analogue of apitegromab, weobserved multi-fold increases in serum latent myostatin levels in mouse models of both early and late SMN restoration and that apitegromab promoted increased strength (as measured by torque generation) in SMN-deficient mice. In a Phase 1 clinical trial designed to evaluate the safety, tolerability, and pharmacokinetic (“PK”)/pharmacodynamic (“PD”) profile of apitegromab in adult healthy volunteers, there were no dose-limiting toxicities and robust and sustained target engagement following administration of apitegromab was observed. Apitegromab was evaluated in the ongoing Phase 2 clinical trial, TOPAZ, evaluating the safety and efficacy of apitegromab dosed intravenously every four weeks (Q4W) over a 12-month treatment period either as monotherapy or with nusinersen, an approved SMN upregulator therapy (i.e., a therapy that upregulates the expression of SMN, such as SMN splicing modulators or gene therapy). The TOPAZ trial enrolled 58 patients with Type 2 and Type 3 SMA in the United States and Europe across three distinct and parallel cohorts. The primary efficacy endpoint for the ambulatory population (Cohort 1) was mean change from baseline in Revised Hammersmith Scale (“RHS”), and mean change from baseline in Hammersmith Functional Motor Scale Expanded (“HFMSE”) for non-ambulatory population (Cohorts 2 and 3). The TOPAZ trial is designed to evaluate patient

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outcomes in multiple extension periods, including 24-month and 36-months. We announced positive 12-month topline results for the TOPAZ Phase 2 clinical trial in April 2021 and 24-month extension results in June 2022 showing support for sustained and continued improvement with apitegromab for non-ambulatory patients with Types 2 and 3 SMA receiving an SMN therapy. See “ TOPAZ 12-Month Analysis” and “TOPAZ 24-Month Analysis” below. We are currently conducting SAPPHIRE, a pivotal Phase 3 clinical trial to evaluate the efficacy and safety of apitegromab in patients with non-ambulatory Type 2 and Type 3 SMA receiving background SMN upregulator therapy. We believe that apitegromab has the potential to be the first muscle-directed therapy, which is aimed at improving motor function in patients with SMA and could be used both as a monotherapy or in conjunction with SMN upregulator therapies.

Apitegromab in other myostatin-related disorders

We see potential for apitegromab broadly across all forms of SMA (i.e., including Type 1 SMA and ambulatory SMA) and our intention is to further investigate this potential. We also believe that the role of apitegromab as a muscle-directed therapy has broad potential beyond SMA, spanning a number of muscle disorders in which fast-twitch fibers may play an important role in motor function. In some settings, we believe that disease-stabilizing therapy may be necessary to address the underlying defect, which can then be complemented by the potential motor function-building benefit of apitegromab. In settings in which the defect may be less severe and/or the disease may have a slower rate of progression, apitegromab may have the potential to serve as a monotherapy.

There is also increasing recognition of the important role of skeletal muscle in modulating metabolic physiology, highlighting a potential therapeutic opportunity for myostatin blockade. Emerging data support the hypothesis that blockade of the myostatin pathway has the potential to reduce the mass of visceral fat, a significant driver of cardiometabolic pathophysiology. Excessive fat mass and metabolic abnormalities have been observed in many muscle atrophy states, such as SMA and spinal cord injury. More broadly, reducing visceral fat mass, or improving body compositions (e.g., enhanced muscle-to-fat ratios), may be a potential therapeutic strategy to address a wide range of disorders, such as non-alcoholic steatohepatitis (“NASH”), diabetes, and obesity.

Based on this evidence, we believe a wide range of potential therapeutic applications may be envisioned for apitegromab. We are considering the investigation of apitegromab in multiple indications beyond SMA and have efforts underway to evaluate these opportunities (including preclinical and translational research, clinical development and regulatory path assessments, and commercial assessments).

SRK-181 in cancer immunotherapy

Our second antibody product candidate, SRK-181, a highly selective inhibitor of the activation of latent TGFβ1, is in clinical development for the treatment of locally advanced or metastatic solid tumors that are resistant to anti-PD-(L)1 therapies. We estimate at least 750,000 cancer patients in the US are eligible for treatment with checkpoint inhibitor therapies every year, of which the majority do not respond to treatment. Increased signaling by TGFβ1 is a key driver of a number of disease-relevant processes, including immune system evasion by cancer cells, bone marrow fibrosis associated with hematological disorders, and tissue and organ fibrosis. Historically, selectively targeting TGFβ1 signaling has been challenging due to the inability of either small molecule inhibitors or antibodies to avoid off-target inhibition of other, closely related growth factors, TGFβ2 and TGFβ3. Treatment of animals with these non-selective TGFβ inhibitors has been associated with a range of toxicities, most notably cardiac toxicity. Furthermore, since each of these growth factors signals through the same TGFβ receptor, ALK5, inhibitors of the TGFβ receptor kinase suffer from similar dose-limiting toxicities. In preclinical studies of our antibodies, we have observed selective inhibition of TGFβ1 activation in vitro and immunomodulatory and antifibrotic activity in multiple disease models in vivo. A 28-day pilot nonclinical toxicology study in rats of our leading antibody did not observe any drug-related toxicity up to the highest dose (100 mg/kg weekly) tested in the study. In the same study, we tested non-selective TGFβ inhibitors and observed the published toxicities, including cardiac toxicity as well as death. We have also completed four-week GLP toxicology studies in rats and non-human primates and no SRK-181 related adverse effects were observed up to the highest evaluated dose of 200 mg/kg per week and 300 mg/kg per week, respectively.

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In many human cancers, TGFβ signaling is associated with lack of response to PD-(L)1 blockade, particularly in patients with tumors harboring an immune excluded phenotype (i.e., CD8+ T cells present in nearby stroma but excluded from the tumor parenchyma). We have observed multiple mouse models that recapitulate the immune-excluded phenotype and are resistant to PD-1 blockade become responsive to the combination of SRK-181-mIgG1, the murine analog of SRK-181, and an anti-PD-1 antibody. These models, including the MBT-2 bladder cancer model, the Cloudman S91 melanoma model and the EMT6 breast cancer model, were poorly responsive or unresponsive to single agent treatment with either anti-PD-1 or SRK-181-mIgG1, with little or no effect on tumor growth. However, in representative experiments, the combination of SRK-181-mIgG1 and anti-PD-1 resulted in tumor regressions of 72%, 57% and 70% in these three mouse models, respectively. Furthermore, this combination treatment led to statistically significant survival benefit in all three models.

Our DRAGON Phase 1 clinical trial of SRK-181 is intended to initially evaluate our therapeutic hypothesis that SRK-181 in combination with anti-PD-(L)1 therapy may overcome primary resistance to anti-PD-(L)1 therapy and lead to anti-tumor responses. This clinical trial in patients with locally advanced or metatstatic solid tumors is ongoing and investigates the safety, PK and efficacy of SRK-181. The DRAGON trial consists of two parts: Part A (dose escalation of SRK-181 as a single-agent or in combination with an approved anti-PD-(L)1 therapy) and Part B (dose expansion evaluating SRK-181 in combination with an approved anti-PD-(L)1 antibody therapy). Based on the observed safety and pharmacokinetic data from Part A, we determined the recommended dose for the Part B dose expansion phase and has initiated Part B. Part B encompasses five cohorts, including urothelial carcinoma, cutaneous melanoma, non-small cell lung cancer, clear cell renal cell carcinoma and other solid tumors and commenced in 2021. Initial clinical data from Part A, primarily focused on safety and PK, was presented in November 2021 at the Society for Immunotherapy of Cancer 36th Annual Meeting.

SRK-181 in other oncology settings

We believe SRK-181 has potential for use in additional oncology settings, such as in immunotherapy-naive patients, in combination with therapies beyond checkpoint inhibitors, and in myelofibrosis.

TGFβ in fibrotic diseases

In December 2018, we entered into a three-year collaboration with Gilead Sciences Inc. (“Gilead”) to discover and develop therapeutics that target TGFβ-driven signaling, a central regulator of fibrosis. Under the collaboration, Gilead had exclusive options to license worldwide rights to antibodies from certain TGFβ programs being developed by us. We received $80.0 million in proceeds upon signing the agreement and an additional $25.0 million for a preclinical milestone achieved in December 2019 for the successful demonstration of efficacy in preclinical in vivo proof-of-concept studies. The collaboration period concluded on December 19, 2021 and on January 6, 2022, Gilead agreed that its option exercise period for all programs terminated which returned rights to us to a suite of antibodies with novel pharmacological profiles that were discovered over the course of the collaboration with Gilead.

Of particular note, we have discovered antibodies that selectively inhibit the activation of latent TGFβ1 in the context of fibrotic extracellular matrix and that avoid perturbing TGFβ1 presented by cells of immune system. Such antibodies demonstrated significant antifibrotic activity in a variety of preclinical rodent models and safety at all doses tested in a non-GLP mouse safety study.

Discovery and preclinical programs

Utilizing our proprietary platform, we have multiple early stage and preclinical programs directed against targets that are known to be important in serious diseases. We are discovering and generating highly selective and differentiated monoclonal antibodies against difficult targets by 1) applying our structural insights and antibody discovery expertise, 2) prioritizing human biology, and 3) embedding translational thinking early in the research and development process.

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Additional therapeutic areas and targets that we could potentially apply our scientific platform and expertise to include:

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Advancing active discovery programs for context-dependent inhibitors of TGFβ1.

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Advancing programs which selectively inhibit other TGFβ superfamily pathways such as those involving bone morphogenetic proteins (BMPs) via the targeting of BMP co-receptors as controllers of iron regulation. This approach could provide the potential for tissue specific modulation of BMP signaling and iron regulation.

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Exploring opportunities in modulating metabolic physiology including understanding the important role of skeletal muscle in modulating metabolism. This is highlighted by potential therapeutic opportunity for myostatin blockade. For example, evidence is emerging that blockade of the myostatin pathway can reduce the mass of visceral fat, a significant driver of cardiometabolic pathophysiology. We have efforts underway to evaluate these opportunities, including preclinical and translational research, development path assessments, and commercial evaluations.

We continue to enhance our internal biologics discovery capabilities including the use of single-domain antibody libraries. This added capability allows us to more efficiently discover antibodies and furthers our commitment to building a differentiated portfolio of product candidates.

Our pipeline

Using our innovative approach and proprietary platform, we are creating a differentiated pipeline of novel product candidates that selectively inhibit the activation of latent growth factors believed to be important drivers in a variety of diseases, including neuromuscular disorders, cancer and fibrosis. Our proprietary platform includes (i) our know-how enabling expression and purification of latent protein growth factor complexes in quantity and quality sufficient to enable antibody discovery; (ii) strategies to identify rare antibodies that selectively bind targeted latent protein growth factor complexes using our own proprietary antibody libraries; and (iii) assays developed by us in which to test the highly selective antibodies’ ability to modulate the activation of specific latent growth factors. We have worldwide rights to our proprietary platform and all of our product candidates, with the exception of certain early-stage antibodies that specifically inhibit the activation of TGFβ1 in the context of regulatory T cells, which we previously licensed to Janssen Biotech, Inc. (“Janssen”). Such worldwide rights previously licensed to Janssen will return to us as of July 19, 2022, the effective date of termination of our license agreement with Janssen.

The following summarizes our pipeline of programs as of the date of this prospectus:

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COVID-19 pandemic

In March 2020, the World Health Organization declared the outbreak of a novel coronavirus as a pandemic (the “COVID-19 pandemic”), which continues to spread throughout the United States and worldwide. We have been and

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could continue to be materially and adversely affected by the risks, or the public perception of the risks, related to an epidemic, pandemic, outbreak, or other public health crisis, such as the COVID-19 pandemic. The ultimate extent of the impact of any epidemic, pandemic, outbreak, or other public health crisis on our business, financial condition and results of operations will depend on future developments, which are highly uncertain and cannot be predicted, including new information that may emerge concerning the severity of such epidemic, pandemic, outbreak, or other public health crisis and actions taken to contain or prevent the further spread, including the development and deployment of any vaccine program. Accordingly, we cannot predict the extent to which our business, including our clinical trials, financial condition and results of operations will be affected. As a result of the COVID-19 pandemic, we have experienced disruptions that have impacted our business, preclinical studies and clinical trials, including disruptions or restrictions on our ability to access and monitor certain clinical trial sites, restrictions on clinical trial participants’ ability to access our clinical trial sites and delays in enrollment. Some clinical trial participants have missed or experienced delays in receiving doses of study drug and completing their clinical trial assessments. For example, four patients (one in Cohort 2 and three in Cohort 3) of the TOPAZ clinical trial each missed three doses of apitegromab over the course of the 12-month treatment period due to COVID-19-related site access restrictions. This has affected our clinical trials and could result in further impacts, including delays in or adverse impacts to data readouts from our clinical trials and delays in our ability to identify and enroll patients in current or future clinical trials and decision by enrolled patients to discontinue from our clinical trials due to COVID-19 related concerns. While our laboratory operations have resumed to near-normal capacity, we may continue to experience challenges in procuring materials and supplies, as well as research services from our vendors in a consistently timely manner due to COVID-19 related supply chain issues. Some of our third-party manufacturers have diverted resources or manufacturing capacity to accommodate the development or manufacture of COVID-19 vaccines. Although this has not yet had an impact on our ability to produce sufficient quantities of apitegromab or SRK-181 for our clinical trials, we continue to work closely with our third-party manufacturers to mitigate potential impacts to our clinical supply chain. In addition, delays in the development of COVID-19 vaccines or the deployment of vaccines which are approved or otherwise authorized for emergency use, a recurrence or “subsequent waves” of COVID-19 cases, or the discovery of vaccine-resistant COVID-19 variants could cause other widespread or more severe impacts. We continue to monitor developments as we adjust to the disruptions and uncertainties relating to the COVID-19 pandemic.

Recent developments

SAPPHIRE phase 3 pivotal trial design

SAPPHIRE is a randomized, double-blind, placebo-controlled, Phase 3 clinical trial. Approximately 156 patients aged 2-12 years old with non-ambulatory Type 2 or Type 3 SMA are anticipated to be enrolled in the main efficacy population. Patients will be randomized 1:1:1 to receive for 12 months either apitegromab 10 mg/kg, apitegromab 20 mg/kg, or placebo by intravenous (“IV”) infusion every 4 weeks in addition to background SMN therapy. Patients receiving the background SMN therapy of nusinersen as well as patients receiving background SMN therapy of risdiplam will both be eligible for enrollment.

Additional key elements of the study design include the following:

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At baseline, all patients will be required to be in the chronic maintenance phase of SMN therapy, corresponding to either at least 6 months of prior treatment in the case of risdiplam or at least 10 months of prior treatment in the case of nusinersen.

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Randomization of patients will be stratified by both the background SMN therapy (nusinersen vs. risdiplam) as well as the age at which SMN therapy had been initiated (< 5 years vs. ≥ 5 years).

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The primary efficacy endpoint will evaluate the mean change from baseline in the HFMSE total score after 12 months of treatment.

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Additional endpoints will evaluate safety, proportion of patients with ≥ 3-point HFMSE increase, Revised Upper Limb Module (“RULM”), World Health Organization (“WHO”) motor developmental milestones, pharmacokinetics, pharmacodynamics, anti-drug antibody, and other outcome measures.

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In addition, this clinical trial provides the opportunity for an interim analysis when at least 50% of patients in the main efficacy population (age 2-12 years) have completed 12 months of treatment. Separately from the main efficacy population, an exploratory population of 48 patients aged 13-21 years old with non-ambulatory Type 2 or Type 3 SMA will be evaluated. These patients will be randomized 2:1 to receive either apitegromab 20 mg/kg or placebo added to background SMN therapy with nusinersen or risdiplam. In this subpopulation of older individuals with SMA, the safety and tolerability of apitegromab will be characterized, and efficacy will also be evaluated in an exploratory, nonpowered manner.

TOPAZ phase 2 clinical trial

We completed enrollment of 58 patients in our TOPAZ Phase 2 clinical trial of apitegromab in SMA in January 2020. One patient discontinued from the 12-month treatment period for reasons that were determined to be unrelated to apitegromab treatment. All remaining 57 patients completed the 12-month treatment period and opted into the extension period. 55 of 57 of patients completed the 24-month treatment period and 54 of those patients opted into the third year extension period. As of June 1, 2022, 54 of the patients remain enrolled.

The clinical trial consisted of three distinct cohorts of patients with Type 2 or Type 3 SMA and evaluated the safety and efficacy of apitegromab over a 12-month treatment period. All patients in the clinical trial received apitegromab dosed every four weeks (Q4W) either as a monotherapy or in conjunction with an approved SMN upregulator therapy.

In our view, this approach of having evaluated multiple distinct cohorts offers a greater number of opportunities to discern the effects of apitegromab on clinically meaningful motor function measures across multiple patient subpopulations. It is estimated that patients with Type 2 or Type 3 SMA represent over 85% of the overall patient population. We view each of the cohorts evaluated in the TOPAZ trial as representing a significant proportion of patients suffering from SMA.

The primary efficacy objectives evaluated in the TOPAZ trial, HFMSE and RHS, are clinically meaningful outcome measures validated for SMA. These endpoints assess motor tasks involving short-term bursts of strength and thus involve fast-twitch fiber function. As the hypothesized effect of myostatin blockade under investigation is to drive increases in fast-twitch fiber function, we believe these endpoints are of direct relevance in assessing the clinical effect of apitegromab.

Our overall approach to the efficacy analysis is informed by SMA disease biology, the anticipated mechanism of action of apitegromab, the effects of SMN upregulators, and available clinical data on SMA. The primary effect of SMN upregulator therapy appears to be to address the SMN deficiency and to modify the disease course; thus, the key in preventing significant motor functional deterioration is intervening at a very young age. For most patients with SMA, however, this window for early intervention is no longer available. As a result, these individuals have already suffered considerable atrophy and motor function impairment. Natural history data indicate that most patients with Type 2 or 3 SMA, other than very young individuals, generally have a stable functional baseline over a 12-month period as evidenced by their HFMSE scores. A one-point improvement on the Hammersmith scale may be considered meaningful on an individual level and a spontaneous improvement of 3 or more points from one’s baseline would be a notable divergence from the otherwise expected course of disease for most patients.

TOPAZ 12-month analysis

On April 6, 2021, we announced positive top-line data for the 12-month treatment period of our TOPAZ Phase 2 clinical trial, which enrolled 58 patients with Type 2 and Type 3 SMA across 16 study sites in the United States and Europe. The clinical trial evaluated the safety and efficacy of intravenous apitegromab dosed every four weeks (Q4W) over a 12-month treatment period. Four patients (one in Cohort 2 and three in Cohort 3) each missed three consecutive doses of apitegromab over the course of the 12-month treatment period due to COVID-19-related site access restrictions and were excluded from the prespecified intent-to-treat primary analysis.

Cohort 1: This open-label, single-arm cohort enrolled 23 patients with ambulatory Type 3 SMA. Patients were treated with 20 mg/kg of apitegromab either as a monotherapy or in conjunction with an approved SMN upregulator

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therapy (nusinersen). The primary objectives of Cohort 1 were to assess safety and the mean change from baseline in RHS following 12 months of treatment.

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Cohort 2: This open-label, single-arm cohort enrolled 15 patients with Type 2 or non-ambulatory Type 3 SMA and who were already receiving treatment with an approved SMN upregulator therapy (nusinersen) initiated at age five years or older. One patient missed three consecutive doses of apitegromab due to COVID-19-related site access restrictions and was excluded from the prespecified intent-to-treat primary analysis. The primary objectives of the cohort were to assess safety and the mean change from baseline in HFMSE following 12 months of treatment.

One patient in Cohort 2 was identified as having received concomitant treatment with an acetylcholinesterase inhibitor before and during the study, which was not permitted by the trial protocol. This patient experienced a 7-point decline in HFMSE score at the 12-month timepoint. In the per protocol analysis conducted in accordance with the prespecified approach, which excludes this patient as well as the patient who missed three consecutive doses due to COVID-19-related site access restrictions, the mean change from baseline in HFMSE score for Cohort 2 was a 1.2-point improvement.

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Cohort 3: This randomized, double-blind, parallel arm portion of the clinical trial enrolled patients with Type 2 SMA who had initiated treatment with an approved SMN upregulator therapy (nusinersen) before five years of age. Twenty patients were randomized in a 1:1 ratio to receive the low dose (apitegromab 2 mg /kg Q4W) or high dose (apitegromab 20 mg/kg Q4W); both treatment arms were in conjunction with an approved SMN upregulator therapy (nusinersen). Three patients (two in high-dose arm and one in low-dose arm) each missed three consecutive doses of apitegromab due to COVID-19-related site access restrictions and were excluded from the prespecified intent-to-treat primary analysis. The primary objectives of the cohort were to assess safety and the mean change from baseline in HFMSE following 12 months of treatment.

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Dose response was observed; the 20 mg/kg dose achieved numerically greater mean improvements from baseline in HFMSE scores than the 2 mg/kg dose across all assessed timepoints in the 12-month treatment period. The clinically observed dose response was consistent with the pharmacodynamic (target engagement) results. Both the 20 mg/kg and 2 mg/kg doses yielded high levels of target engagement (>100-fold increase from baseline), but the 20 mg/kg dose led to a relatively higher absolute level of target engagement.

TOPAZ 24-month analysis

On June 17, 2022, we announced new data from the Phase 2 TOPAZ trial extension period evaluating patient outcomes after 24-months of treatment, which support sustained and continued improvement with apitegromab for non-ambulatory patients with Types 2 and 3 SMA receiving an SMN therapy.

TOPAZ evaluated apitegromab across a broad age range (2-21 years) of patients with Types 2 and 3 SMA. All 35 non-ambulatory patients (Cohorts 2 and 3) and 12 of 23 ambulatory patients (Cohort 1) were receiving nusinersen maintenance therapy. The primary efficacy endpoint for the non-ambulatory population was mean change from baseline in HFMSE. Additional endpoints included mean change from baseline in RULM, an assessment specifically designed for upper limb function in patients with SMA. The HFMSE is a validated measure for the assessment of gross motor function in SMA, while the RULM is validated to evaluate upper limb motor performance by evaluating tasks which correspond to the ability to perform various everyday activities with their hands and arms.

For this 24-month evaluation, an observed case analysis was conducted, which pooled all the non-ambulatory patients (Cohorts 2 and 3) and was based upon the available data for given timepoints. This analysis population included patients receiving either low dose (2 mg/kg) or high dose (20 mg/kg) apitegromab (inclusive of patients in Cohort 3 who switched from 2 mg/kg to 20 mg/kg in Year 2) and did not exclude any patients who had missed apitegromab doses due to study site access restrictions from COVID-19.

Non-ambulatory patients (age range of 2 to 21 years old) with valid HFMSE assessments had sizable, sustained gains in HFMSE scores at 24 months from baseline (prior to first dose of apitegromab), while RULM scores continued to increase at 24 months. The mean change from baseline results for non-ambulatory patients showed:

	12-Month data	24-Month data pooled non- ambulatory pts	24-Month data *excluding pts w/scoliosis surgery
Mean Change from Baseline in HFMSE (95% CI)	3.6 points (95% CI: 1.2, 6.0) N=32	4.0 points (95% CI: 1.5, 6.5) N=29	4.4 points (95% CI: 2.0, 6.9) N=28
Mean Change from Baseline in RULM (95% CI)	1.3 points (95% CI: 0.2, 2.3) N=31	1.9 points (95% CI: 0.8, 3.0) N=33	2.3 points (95% CI: 1.2, 3.4) N=30

* Three patients in the non-ambulatory group underwent scoliosis surgery in year 2, which has been reported to negatively impact HFMSE scores for a considerable period afterwards. This analysis excluded post-surgery data of these patients.

Dose response continued to be observed across the 24 months of apitegromab administration based upon HFMSE scores and pharmacodynamic data (target engagement as measured by serum latent myostatin concentrations), with signs that that there may be further HFMSE increases as non-ambulatory patients originally receiving the low dose switched to the high dose treatment.

Data at 24-months for ambulatory patients with Type 3 SMA (Cohort 1) suggest stability of Revised Hammersmith Scale (RHS) scores in patients receiving 20 mg/kg of apitegromab and nusinersen. The mean RHS change from baseline at 24-months was -0.7 points (95% CI: -3.1, 1.7) for the apitegromab and nusinersen subgroup (n=10) and -2.8 points (95% CI: -8.4, 2.8) for the apitegromab monotherapy subgroup (n=11). A subset of individuals in Cohort 1(n=21) had RHS improvements, as reflected by 42.9% (9/21) and 23.8% (5/21) of patients having ≥1-point and ≥3-point RHS increases from baseline at 24 months respectively.

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Of the 55 patients who completed the 24-month TOPAZ extension period, 54 have opted to continue treatment in the 36-month extension period.

Consistent with the 12-month safety data, no serious safety risks were identified as part of the analysis of the cumulative 24-month data. The incidence and severity of adverse events were consistent with the underlying patient population and background therapy. The five most common treatment-emergent adverse events (TEAEs) were headache, pyrexia, upper respiratory tract infection, cough, and nasopharyngitis. No deaths or serious adverse reactions have been observed with apitegromab. A total of 14 serious TEAEs have been reported over the 24-month treatment period, all assessed by the respective trial investigator as unrelated to apitegromab.

Overall safety and tolerability profile over 24 months of apitegromab treatment:

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The incidence and types of treatment-emergent adverse events (AEs) were consistent with the underlying disease or nusinersen therapy

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The five most common treatment-emergent AEs were headache, pyrexia, upper respiratory tract infection, cough, and nasopharyngitis

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No deaths or suspected unexpected serious adverse reactions (SUSARs) reported

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Adverse events continue to be reported as mostly mild to moderate in severity, as observed in the 12-month analysis

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No serious safety risks identified to date

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Fourteen patients experienced a serious TEAE, all assessed by the respective trial investigator as unrelated to apitegromab:

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One patient treated with 2 mg/kg dose (Cohort 3) was hospitalized due to adenoidal hypertrophy and tonsillar hypertrophy to perform scheduled adenotonsillectomy (Grade 2). Events resolved without sequelae.

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Two patients treated with 20 mg/kg dose (both Cohort 1) presented with gait inability considered a significant disability (both Grade 3). Events remain ongoing.

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One patient treated with 20 mg/kg dose (Cohort 1) was hospitalized with post lumbar puncture syndrome (Grade 2). Event resolved without sequelae.

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One patient treated with 20 mg/kg dose (Cohort 1) was hospitalized due to viral upper respiratory tract infection (Grade 2). Event resolved without sequelae.

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Five patients treated with 20 mg/kg dose (one from Cohort 1, three from Cohort 2, and one from Cohort 3) were hospitalized for spinal fusion surgery/ scoliosis/ scoliosis surgery (all Grade 3). All events resolved without sequelae.

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One patient treated with 20 mg/kg dose (Cohort 1) was hospitalized due to bilateral developmental hip dysplasia and left hip dislocation (both Grade 3). Events resolved without sequelae.

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One patient treated with 2 mg/kg dose (Cohort 3) was hospitalized due to hip dislocation (Grade 3). Event resolved with sequelae (anxiety and post-operative pain).

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One patient treated with 20 mg/kg dose (Cohort 3) was hospitalized due to respiratory syncytial virus infection (Grade 2). Events resolved without sequelae.

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One patient treated with 2 mg/kg dose (Cohort 3) was hospitalized due to vomiting and pneumonia (Grade 3). Events resolved without sequelae.

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Four patients presented with non-serious Grade 3 events, all assessed by the respective trial investigator as unrelated to apitegromab:

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One patient treated with 20 mg/kg dose (Cohort 1) presented with post lumbar puncture syndrome. Event resolved without sequelae.

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One patient treated with 20 mg/kg dose (Cohort 2) presented with worsening of scoliosis. Event resolved (with surgery, reported as serious, above) without sequelae.

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One patient treated with 20 mg/kg dose (Cohort 2) presented with osteopenia. Events remains ongoing.

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One patient treated with 2 mg/kg (Cohort 3) presented with two instances of hypoglycemia and one instance of metabolic acidosis. All events resolved without sequelae.

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One patient (Cohort 1) discontinued from the trial due to Grade 2 muscle fatigue that started prior to initiation of dosing with study drug; assessed by the trial investigator as unrelated to apitegromab.

Company information

We were incorporated in 2017 under the laws of the State of Delaware as the holding company for Scholar Rock, Inc. Scholar Rock, Inc. is a wholly owned subsidiary of Scholar Rock Holding Corporation. On December 22, 2017, we completed a series of transactions pursuant to which Scholar Rock Merger Sub, LLC, a wholly owned subsidiary of Scholar Rock Holding Corporation, was merged with and into Scholar Rock, LLC (the “Reorganization”). The purpose of the Reorganization was to reorganize our corporate structure so that we would continue as a corporation and so that our investors prior to the Reorganization would own our capital stock after the Reorganization rather than equity interests in a limited liability company. All of our convertible preferred stock converted into shares of common stock upon the completion of our initial public offering at the then effective conversion ratio. Our operations to date have been limited to organizing and staffing our company, business planning, raising capital, developing our technology, identifying potential product candidates, producing drug substance and drug product material for use in preclinical studies and clinical trials, conducting preclinical studies of our product candidates and conducting clinical trials for our product candidates, apitegromab and SRK-181. We do not have any products approved for sale and have not generated any product revenue to date.

Our principal executive offices are located at 301 Binney Street, Cambridge, MA 02142, and our phone number is (857) 259-3860. Our website address is http://www.scholarrock.com. The information contained on our website or social media accounts, or that can be accessed through our website or social media accounts, is not a part of this prospectus and is not incorporated by reference into this prospectus. You should not rely on any such information in deciding whether to purchase our common stock.

Implications of being an emerging growth company

As a company with less than $1.07 billion in revenue during our most recently completed fiscal year, we qualify as an “emerging growth company” and “smaller reporting company” as defined in Section 2(a) of the Securities Act of 1933, as amended (the “Securities Act”), as modified by the Jumpstart Our Business Startups Act of 2012. As an emerging growth company, we may take advantage of specified reduced disclosure and other requirements that are otherwise applicable, in general, to public companies that are not emerging growth companies. These provisions include:

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reduced disclosure about our executive compensation arrangements;

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exemption from the non-binding stockholder advisory votes on executive compensation or golden parachute arrangements;

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exemption from the auditor attestation requirement in the assessment of our internal control over financial reporting; and

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reduced disclosure of financial information in this prospectus supplement, the accompanying prospectus and the information incorporated herein and therein, such as being permitted to include only two years of audited financial information and two years of selected financial information in addition to any required unaudited interim financial statements, with correspondingly reduced “Management’s Discussion and Analysis of Financial Condition and Results of Operations” disclosure.

We may take advantage of these exemptions until we are no longer an emerging growth company. We would cease to be an emerging growth company on the last day of 2023, or sooner if we have more than $1.07 billion

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in annual revenues as of the end of a fiscal year, have more than $700 million in market value of our capital stock held by non-affiliates as of any June 30 before that time or if we issue more than $1.0 billion of non-convertible debt over a three-year-period. We may choose to take advantage of some, but not all, of the available exemptions. We are also a “smaller reporting company” as defined in the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and have elected to take advantage of certain of the scaled disclosures available to smaller reporting companies.

The JOBS Act permits an emerging growth company to take advantage of an extended transition period to comply with new or revised accounting standards applicable to public companies. We have irrevocably elected not to avail ourselves of this extended transition period and, as a result, we will adopt new or revised accounting standards on the relevant dates on which adoption of such standards is required for non-emerging growth companies.

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The Offering

Common stock offered by us

16,326,530 shares of our common stock.

Pre-funded Warrants offered by us

Pre-funded warrants to purchase up to 25,510,205 shares of common stock. We are also offering to each purchaser the opportunity to purchase, if the purchaser so chooses, Pre-funded Warrants, in lieu of shares of common stock. Each Pre-funded Warrant will be exercisable for one share of our common stock. The purchase price of each Pre-funded Warrant will equal the price per share at which the shares of common stock are being sold to the public in this offering, minus $0.0001, and the exercise price of each Pre-funded Warrant will be $0.0001 per share. This offering also relates to the shares of common stock issuable upon exercise of any Pre-funded Warrants sold in this offering. The exercise price and number of shares of common stock issuable upon exercise will be subject to certain further adjustments as described herein. See “Description of Securities Offered” on page S-26 of this prospectus supplement.

Each Pre-Funded Warrant is exercisable for one share of our common stock (subject to adjustment as provided therein) at any time at the option of the holder, provided that the holder will be prohibited from exercising its Pre-Funded Warrant for shares of our common stock if, as a result of such exercise, the holder, together with its affiliates, would own more than 9.99% (or, at the election of the purchaser, 4.99%, 14.99% or 19.99%) of the total number of shares of our common stock then issued and outstanding. However, any holder may increase or decrease such percentage to any other percentage not in excess of 19.99%, provided that any increase or decrease in such percentage shall not be effective until the sixty-first (61st) day after such notice to us.

Common Warrants offered by us

Common Warrants to purchase an aggregate of up to 10,459,181 shares of our common stock. Each share of our common stock and each Pre-funded Warrant to purchase one share of our common stock is being sold together with a Common Warrant to purchase one quarter of one share of our common stock. Each Common Warrant has an exercise price per share equal to 150% of the price per share of the common stock sold in the offering, is immediately exercisable and will expire December 31, 2025. The shares of common stock or the Pre-funded Warrants, as the case may be, and the accompanying Common Warrants, can only be purchased together in this offering but will be issued separately and will be immediately separable upon issuance. This offering also relates to the offering of the shares of common stock issuable upon exercise of the Common Warrants. See “Description of Securities Offered” on page S-26 of this prospectus supplement.

Each Common Warrant is exercisable for one quarter of one share of our common stock (subject to adjustment as provided

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therein) at any time at the option of the holder, provided that the holder will be prohibited from exercising its Common Warrant for shares of our common stock if, as a result of such exercise, the holder, together with its affiliates, would own more than 4.99% (or, at the election of the purchaser, 9.99%, 14.99% or 19.99%) of the total number of shares of our common stock then issued and outstanding. However, any holder may increase such percentage to any other percentage not in excess of 9.99%, 14.99% or 19.99%, provided that any increase in such percentage shall not be effective until 61 days after such notice to us.

Common stock to be outstanding immediately after this offering

51,627,353 shares.

Use of proceeds

We estimate that our net proceeds from this offering will be approximately $195.4 million, after deducting estimated offering expenses payable by us.

We intend to use the net proceeds we receive from this offering, together with our existing cash, cash equivalents and investments, to advance our ongoing and future clinical programs, to further develop our technology platform and to continue to advance our preclinical pipeline. Any remaining proceeds will be used for other ongoing research and development activities and general corporate purposes. See “Use of Proceeds” for additional information.

Risk factors

See “Risk factors” beginning on page S-16 of this prospectus supplement and other information included and incorporated by reference in this prospectus supplement and the accompanying prospectus for a discussion of factors that you should carefully consider before deciding to invest in our securities.

Market symbol and trading

Our common stock is listed on The Nasdaq Global Select Market under the symbol “SRRK”. There is no established trading market for the Common Warrants or the Pre-Funded Warrants and we do not expect a market to develop. In addition, we do not intend to apply for the listing of the Common Warrants or Pre-Funded Warrants on any national securities exchange or other trading market. Without an active trading market, the liquidity of the Common Warrants and Pre-Funded Warrants will be limited.

The number of shares of our common stock that will be outstanding immediately after this offering as shown above is based on 35,300,823 shares outstanding as of March 31, 2022. The number of shares outstanding as of March 31, 2022 as used throughout this prospectus, unless otherwise indicated, excludes:

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2,179,487 pre-funded warrants to purchase shares of common stock outstanding as of March 31, 2022 with an exercise price of $0.0001 per share;

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337,783 shares of common stock issuable upon the exercise of stock options outstanding as of March 31, 2022 under our 2017 Stock Option and Incentive Plan at a weighted-average exercise price of $6.04 per share

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4,229,323 shares of common stock issuable upon the exercise of stock options outstanding as of March 31, 2022 under our 2018 Stock Option and Incentive Plan at a weighted-average exercise price of $25.60 per share;

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1,045,487 shares of common stock issuable upon the vesting and settlement of restricted stock units as of March 31, 2022 issued under our 2018 Stock Option and Incentive Plan;

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2,156,438 shares of common stock reserved for the future issuance under our 2018 Stock Option and Incentive Plan as of March 31, 2022; and

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1,489,463 shares of our common stock available for future issuance under our 2018 Employee Stock Purchase Plan as of March 31, 2022.

Unless otherwise indicated, all information in this prospectus supplement assumes no exercise of outstanding stock options or settlement of unvested restricted stock units issued from the 2018 Employee Stock Purchase Plan after March 31, 2022, and no exercise of the Pre-funded Warrants or the Common Warrants offered and sold in this offering.

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Risk factors

Investing in our securities involves a high degree of risk. You should carefully consider the risks and uncertainties described below and in the documents incorporated by reference in this prospectus supplement, as well as other information we include or incorporate by reference into this prospectus supplement, before making an investment decision. Our business, financial condition and results of operations could be materially adversely affected by the materialization of any of these risks. The trading price of our securities could decline due to the materialization of any of these risks, and you may lose all or part of your investment. This prospectus supplement and the documents incorporated herein by reference also contain forward-looking statements that involve risks and uncertainties. Actual results could differ materially from those anticipated in these forward-looking statements as a result of certain factors, including the risks described in the documents incorporated herein by reference, including our Quarterly Report on Form 10-Q for the quarter ended March 31, 2022, which is on file with the SEC and is incorporated herein by reference, and other reports and documents that are incorporated by reference into this prospectus supplement and other documents we file with the SEC that are deemed incorporated by reference into this prospectus supplement.

Risks related to this offering

You will experience substantial dilution.

Based on an estimated public offering price of $4.90 per share, and a net tangible book value of $171.3 million, or approximately $4.85 per share of common stock, as of March 31, 2022, if you purchase securities in this offering, you will experience an increase of $2.20 per share in the net tangible book value of the common stock you purchase representing the difference between our as adjusted net tangible book value per share after giving effect to this offering and the public offering price per share of common stock. The exercise of outstanding stock options and warrants, including those sold in this offering, will, however, result in dilution of your investment. See the section titled “Dilution” below for a more detailed illustration of the dilution you would incur if you participate in this offering.

We have broad discretion in the use of our existing cash, cash equivalents and marketable securities and the net proceeds from this offering and may not use them effectively.

Our management will have broad discretion in the application of our existing cash, cash equivalents and marketable securities and the net proceeds from this offering, including for any of the purposes described in the section titled “Use of Proceeds,” and you will not have the opportunity as part of your investment decision to assess whether such proceeds are being used appropriately. Because of the number and variability of factors that will determine our use of our existing cash and cash equivalents and the net proceeds from this offering, their ultimate use may vary substantially from their currently intended use. Our management might not apply our existing cash and cash equivalents and the net proceeds from this offering in ways that ultimately increase the value of your investment. The failure by our management to apply these funds effectively could harm our business. Pending their use, we may invest the net proceeds from this offering in short-term, investment-grade, interest-bearing securities. These investments may not yield a favorable return to our stockholders. If we do not invest or apply the net proceeds from this offering in ways that enhance stockholder value, we may fail to achieve expected financial results, which could cause our stock price to decline.

You may experience future dilution as a result of future equity offerings.

In order to raise additional capital, we may in the future offer additional shares of our common stock or other securities convertible into or exchangeable for our common stock at prices that may not be the same as the price per share in this offering. We may sell shares or other securities in any other offering at a price per share that is less than the price per share paid by investors in this offering, and investors purchasing shares or other securities in the future could have rights superior to those of existing stockholders. The price per share at which we sell additional shares of our common stock, or securities convertible or exchangeable into common stock, in future transactions may be higher or lower than the price per share paid by investors in this offering.

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Sales of a substantial number of shares of our common stock in the public market after this offering could cause our stock price to fall.

Sales of a substantial number of shares of our common stock in the public market or the perception that these sales might occur could depress the market price of our common stock and could impair our ability to raise capital through the sale of additional equity securities. We are unable to predict the effect that sales may have on the prevailing market price of our common stock. In addition, the sale of substantial amounts of our common stock could adversely impact the price of our common stock. As of March 31, 2022, 35,300,823 shares of our common stock were outstanding. The sale, or the availability for sale, of a large number of shares of our common stock in the public market could cause the price of our common stock to decline.

The trading price of the shares of our common stock could be highly volatile, and purchasers of our common stock could incur substantial losses.

Since our common stock began trading on The Nasdaq Global Select Market on May 29, 2018, our stock has traded at prices as low as $4.33 per share and as high as $70.00 per share through June 16, 2022. This volatility may affect the price at which you could sell the shares of our common stock, and the sale of substantial amounts of our common stock could adversely affect the price of our common stock. Our stock price is likely to continue to be volatile and subject to significant price and volume fluctuations in response to market and other factors, including those described in the sections captioned “Risk factors” in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein.

As a result, you may not be able to sell your shares of common stock at or above the price at which you purchase them. In addition, the stock market in general, and The Nasdaq Global Select Market and the stock of biotechnology and emerging pharmaceutical companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies. Broad market and industry factors may negatively affect the market price of our common stock, regardless of our actual operating performance.

We do not intend to pay dividends on our common stock so any returns will be limited to the value of our stock.

We currently anticipate that we will retain future earnings for the development, operation and expansion of our business and do not anticipate declaring or paying any cash dividends for the foreseeable future. Any return to stockholders will therefore be limited to the appreciation of their stock.

The sale of our common stock in this offering, including any shares issuable upon exercise of any Pre-funded Warrants or Common Warrants, and any future sales of our common stock, or the perception that such sales could occur, may depress our stock price and our ability to raise funds in new stock offerings.

We may from time to time issue additional shares of common stock at a discount from the current trading price of our common stock. As a result, our stockholders would experience immediate dilution upon the purchase of any shares of our common stock sold at such discount. In addition, as opportunities present themselves, we may enter into financing or similar arrangements in the future, including the issuance of debt securities, preferred stock or common stock. Sales of shares of our common stock in this offering, including any shares issuable upon exercise of any Pre-funded Warrants or Common Warrants issued in this offering and in the public market following this offering, or the perception that such sales could occur, may lower the market price of our common stock and may make it more difficult for us to sell equity securities or equity-related securities in the future at a time and price that our management deems acceptable, or at all.

There is no public market for the Pre-funded Warrants or Common Warrants being offered in this offering.

There is no established public trading market for the Pre-funded Warrants or Common Warrants being offered in this offering, and we do not expect a market to develop. In addition, we do not intend to apply to list the Pre-funded Warrants or Common Warrants on any securities exchange or nationally recognized trading system, including Nasdaq. Without an active market, the liquidity of the Pre-funded Warrants and the Common Warrants will be limited.

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We may not receive any additional funds upon the exercise of the Pre-Funded Warrants or Common Warrants.

Each Pre-Funded Warrant may be exercised by way of a cashless exercise, meaning that the holder may not pay a cash purchase price upon exercise, but instead would receive upon such exercise the net number of shares of our common stock determined according to the formula set forth in the Pre-Funded Warrants. Accordingly, we may not receive any additional funds upon the exercise of the Pre-Funded Warrants.

Each Common Warrant may be exercised by way of a cashless exercise if at the time of exercise hereof there is no effective registration statement registering, or the prospectus contained therein is not available for the issuance of the Warrant Shares to the holder.

Significant holders or beneficial holders of our common stock may not be permitted to exercise Pre-Funded Warrants that they hold.

A holder of a pre-funded warrant will not be entitled to exercise any portion of any Pre-Funded Warrants which, upon giving effect to such exercise, would cause (i) the aggregate number of shares of our common stock beneficially owned by the holder (together with its affiliates) to exceed 9.99% (or, at the election of the purchaser, 4.99%, 14.99% or 19.99%) of the number of shares of our common stock outstanding immediately after giving effect to the exercise, or (ii) the combined voting power of our securities beneficially owned by the holder (together with its affiliates) to exceed 9.99% of the combined voting power of all of our securities then outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the pre-funded warrants. Such percentage may be increased or decreased by written notice by the holder of the Pre-Funded Warrants to any other percentage not in excess of 19.99%. Such increase or decrease will not be effective until the sixty-first (61st) day after such notice is delivered to us. As a result, you may not be able to exercise your Pre-Funded Warrants for shares of our common stock at a time when it would be financially beneficial for you to do so. In such circumstance you could seek to sell your Pre-Funded Warrants to realize value, but you may be unable to do so in the absence of an established trading market for the Pre-Funded Warrants.

The Common Warrants being offered may not have value.

The Common Warrants being offered by us in this offering have an exercise price of $7.35 per share, subject to certain adjustments, and expire on December 31, 2025, upon which date such warrants will expire and have no further value. In the event that the market price of our common stock does not exceed the exercise price of the Common Warrants during the period when they are exercisable, the Common Warrants may not have any value.

Holders of Pre-funded Warrants and Common Warrants purchased in this offering will have no rights as common stockholders until such holders exercise their Pre-funded Warrants or Common Warrants and acquire our common stock.

Until holders of Pre-funded Warrants or Common Warrants acquire shares of our common stock upon exercise of such warrants, holders of Pre-funded Warrants and Common Warrants will have no rights with respect to the shares of our common stock underlying such Pre-funded Warrants and Common Warrants. Upon exercise of the Pre-funded Warrants and Common Warrants, the holders will be entitled to exercise the rights of a common stockholder only as to matters for which the record date occurs after the exercise date.

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Cautionary statement regarding forward-looking statements

This prospectus supplement and the accompanying prospectus, including the documents that we incorporate by reference herein and therein, contain forward-looking statements within the meaning of Section 27A of the Securities Act, and Section 21E of the Exchange Act. Any statements about our expectations, beliefs, plans, objectives, assumptions or future events or performance are not historical facts and may be forward-looking. These statements are often, but are not always, made through the use of words or phrases such as “anticipate,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “seek,” “should,” “target,” “will,” “would,” and similar expressions, or the negative of these terms, or similar expressions. Accordingly, these statements involve estimates, assumptions and uncertainties which could cause actual results to differ materially from those expressed in them. Any forward-looking statements are qualified in their entirety by reference to the factors discussed throughout this prospectus supplement and the accompanying prospectus, and in particular those factors referenced in the section “Risk factors.”

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

•

the success, cost and timing of preclinical studies and clinical trials for apitegromab, including, but not limited to, progress and completion of clinical trials for apitegromab, and the results, and the timing of results, from these trials;

•

the success, cost and timing of clinical trials for SRK-181, including the results, progress and completion of our DRAGON Phase 1 clinical trial for SRK-181, any preclinical studies and any future clinical trials for SRK-181, and the results, and the timing of results, from these trials;

•

the success, cost and timing of our other product development activities, preclinical studies and clinical trials, and the results, and timing of results, from these studies and trials;

•

our success in identifying and executing a development program for additional indications for apitegromab, SRK-181 and in identifying product candidates from our other programs;

•

the clinical utility of our product candidates and their potential advantages over other therapeutic options;

•

our ability to obtain, generally or on terms acceptable to us, funding for our operations, including funding necessary to complete further development and, upon successful development, if approved, commercialization of apitegromab, SRK-181 or any of our future product candidates;

•

risks associated with the COVID-19 pandemic, which may adversely impact our workforce, global supply chain, business, preclinical studies, clinical trials and financial results;

•

the potential for our identified research priorities to advance our proprietary platform, development programs or product candidates;

•

the timing, scope or likelihood of our ability to obtain and maintain regulatory approval from the

FDA the EC and other regulatory authorities for apitegromab, SRK-181 and any future product candidates, and any related restrictions, limitations or warnings in the label of any approved product candidate;

•

our ability to continue to grow our organization, including our personnel, systems and relationships with third parties;

•

our ability to retain our executives and highly skilled technical and managerial personnel, which could be affected due to any transition in management, or if we fail to recruit additional highly skilled personnel;

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•

our expectations regarding our ability to obtain and maintain intellectual property protection for our product candidates and the duration of such protection;

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our ability and the potential to successfully manufacture our product candidates for clinical trials and for commercial use, if approved;

•

our ability to establish or maintain collaborations or strategic relationships, including our collaboration with Gilead;

•

our expectations relating to the potential of our proprietary platform technology;

•

our ability to obtain additional funding when necessary;

•

the size and growth potential of the markets for our product candidates, and our ability to serve those markets, either alone or in combination with others;

•

our expectations related to the use of our cash reserves;

•

the impact of new laws and regulations or amendments to existing laws and regulations;

•

developments and projections relating to our competitors and our industry;

•

our expected use of proceeds from this offering;

•

our estimates and expectations regarding cash and expense levels, future revenues, capital requirements and needs for additional financing, including our expected use of proceeds from our public offerings, and liquidity sources; and

•

our expectations regarding the period during which we qualify as an emerging growth company under the Jumpstart Our Business Startups Act of 2012.

We have included important factors in the cautionary statements included in this prospectus supplement and the accompanying prospectus and the documents we incorporate by reference herein and therein, particularly in the “Risk factors” sections of these documents, that we believe could cause actual results or events to differ materially from the forward-looking statements that we make. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments we may make. No forward-looking statement is a guarantee of future performance.

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

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Use of proceeds

We estimate that the net proceeds from this offering will be approximately $195.4 million, based on an aggregate of 16,326,530 shares of our common stock and Pre-funded Warrants to purchase 25,510,205 shares of our common stock being sold at a public offering price of $4.90 per share and accompanying Common Warrant and 4.899 per Pre-funded Warrant and accompanying Common Warrant after deducting estimated placement agent fees and estimated offering expenses payable by us. These estimates exclude the proceeds, if any, from the exercise of Common Warrants and Pre-funded Warrants sold in this offering.

We intend to use the net proceeds we receive from this offering, together with our existing cash, cash equivalents and investments, to advance our ongoing and future clinical programs (including the development of apitegromab in SMA through the anticipated Phase 3 SAPPHIRE topline data readout and SRK-181 in immuno-oncology), to further develop our technology platform and to continue to advance our preclinical pipeline. Any remaining proceeds will be used for other ongoing research and development activities and general corporate purposes. We may temporarily invest the net proceeds in a variety of capital preservation instruments, including investment grade, interest bearing instruments and U.S. government securities, until they are used for their stated purpose. We have not determined the amount of net proceeds to be used specifically for such purposes. As a result, management will retain broad discretion over the allocation of net proceeds.

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Dividend policy

We have never declared or paid any dividends on our capital stock. We currently intend to retain all available funds and any future earnings, if any, to fund the development and expansion of our business and we do not anticipate paying any cash dividends in the foreseeable future. In addition, pursuant to our loan and security agreement with Oxford Finance LLC and Silicon Valley Bank, we are prohibited from paying cash dividends without the prior written consent of Oxford Finance LLC and Silicon Valley Bank. Moreover, any future indebtedness that we may incur could preclude us from paying dividends. Investors should not purchase our common stock with the expectation of receiving cash dividends.

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Capitalization

The following table sets forth our cash, cash equivalents and marketable securities and our capitalization as of March 31, 2022:

•

on an actual basis; and

•

on an as adjusted basis to reflect the sale by us of (i) 16,326,530 shares of common stock in this offering at a public offering price of $4.90 per share and accompanying Common Warrant, and (ii) receipt of the estimated net proceeds of $195.4 million from the sale of the common stock, Common Warrants and Pre-funded Warrants; and assuming no exercise of the Pre-funded Warrants issued in this offering and no exercise of the Common Warrants (and excluding shares of our common stock issued and any proceeds received upon exercise of the Pre-funded Warrants or any resulting accounting associated with the Pre-funded Warrants), after deducting placement agent fees and estimated offering expenses payable by us.

You should read the data set forth in the table below in conjunction with our financial statements, including the related notes, and “Management’s discussion and analysis of financial condition and results of operations” from our Quarterly Report on Form 10-Q for the quarter ended March 31, 2022, which is incorporated by reference into this prospectus supplement.

	As of March 31, 2022
(in thousands, except share data)	Actual			As adjusted
Cash, cash equivalents and marketable securities		$	210,211		$	405,655
Total long-term liabilities			61,288			61,288
Preferred stock, $0.001 par value; 10,000,000 shares authorized, actual and as adjusted, no shares issued and outstanding, actual and as adjusted			0			0
Common stock, $0.001 par value; 150,000,000 shares authorized, actual and as adjusted, 35,300,823 shares issued and outstanding, actual; 51,627,353shares issued and outstanding, as adjusted			35			51
Additional paid-in capital			555,513			750,941
Accumulated other comprehensive income (loss)			(152)			(152)
Accumulated deficit			(384,080)			(384,080)
Total stockholders’ equity			171,316			366,760
Total capitalization		$	232,604		$	428,048

The number of shares of our common stock that will be outstanding immediately after this offering as shown above is based on 35,300,823 shares outstanding as of March 31, 2022. The number of shares outstanding as of March 31, 2022, as used throughout this prospectus, unless otherwise indicated, excludes:

•

2,179,487 pre-funded warrants to purchase shares of common stock outstanding as of March 31, 2022 with an exercise price of $0.0001 per share;

•

1,045,487 shares of common stock issuable upon the vesting and settlement of restricted stock units outstanding as of March 31, 2022 issued under our 2018 Stock Option and Incentive Plan;

•

2,156,438 shares of common stock reserved for the future issuance under our 2018 Stock Option and Incentive Plan as of March 31, 2022; and

•

1,489,463 shares of our common stock available for future issuance under our 2018 Employee Stock Purchase Plan as of March 31, 2022.

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Dilution

Our net tangible book value as of March 31, 2022 was approximately $171.3 million, or approximately $4.85 per share of common stock. Net tangible book value per share represents the amount of total tangible assets (total assets less intangible assets) less total liabilities, divided by the number of shares of our common stock outstanding as of March 31, 2022.

Net tangible book value dilution per share to investors participating in this offering represents the difference between the effective public offering price per share paid by purchasers of securities in this offering and the pro forma as adjusted net tangible book value per share of our common stock immediately after this offering. After giving effect to the sale of (i) shares of our common stock and accompanying Common Warrants to purchase shares of our common stock in this offering at a public offering price of $4.90 per share, and (ii) Pre-funded Warrants to purchase shares of our common stock and accompanying Common Warrants to purchase shares of our common stock in this offering at a public offering price of $4.8999 per Pre-funded Warrant and accompanying Common Warrant, and after deducting estimated placement agent fees and commissions and offering expenses payable by us, our pro forma as adjusted net tangible book value as of March 31, 2022 would have been approximately $366.8 million, or $7.10 per share. This represents an immediate increase in net tangible book value of $2.25 per share to existing stockholders and immediate increase of $2.20 per share to investors purchasing our common stock in this offering at the public offering price. The following table illustrates this dilution on a per share basis:

Public offering price per share and accompanying Common Warrant			$	4.90
Historical net tangible book value per share as of March 31, 2022	$	4.85
Increase in pro forma net tangible book value per share attributable to this offering	$	2.25
Pro forma as adjusted net tangible book value per share after giving effect to this offering			$	7.10
Increase in net tangible book value per share to investors participating in this offering			$	2.20

The discussion and table above assumes no exercise of Common Warrants or Pre-funded Warrants sold in this offering.

The information above and in the foregoing table is based upon 35,300,823 shares of our common stock outstanding as of March 31, 2022. The information above and in the foregoing table excludes as of March 31, 2022:

•

2,179,487 pre-funded warrants to purchase shares of common stock outstanding as of March 31, 2022 with an exercise price of $0.0001 per share;

•

1,045,487 shares of common stock issuable upon the vesting and settlement of restricted stock units outstanding as of March 31, 2022 issued under our 2018 Stock Option and Incentive Plan;

•

2,156,438 shares of common stock reserved for the future issuance under our 2018 Stock Option and Incentive Plan as of March 31, 2022; and

•

1,489,463 shares of our common stock available for future issuance under our 2018 Employee Stock Purchase Plan as of March 31, 2022.

After giving effect to the sale of (i) 16,326,530 shares of our common stock and accompanying Common Warrants to purchase an additional 4,081,631 shares of our common stock in this public offering at the combined public offering price of $4.90 per share and (ii) Pre-funded Warrants to purchase 25,510,205 shares of our common stock and accompanying Common Warrants to purchase an additional 6,377,550 shares of our common

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stock in this public offering at the combined public offering price of $4.90 minus $0.0001 (including, in each case, the shares of common stock to be issued and the proceeds received, if any, from exercises of the Pre-funded Warrants and the Common Warrants, as applicable), and after deducting the placement agent fees and commissions and estimated offering expenses payable by us, our as adjusted net tangible book value per share as of March 31, 2022 would have been approximately $5.06, representing an immediate increase in as adjusted net tangible book value per share of $0.21 to existing stockholders and immediate increase in as adjusted net tangible book value per share of $0.16 to investors purchasing common stock in this offering.

To the extent that outstanding options as of March 31, 2022 have been or may be exercised, unvested restricted stock units have settled or other shares issued, investors purchasing our securities in this offering may experience dilution. To the extent that Pre-funded Warrants and/or Common Warrants purchased in this offering may be exercised, investors purchasing our securities in this offering may experience dilution. In addition, 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. To the extent that additional capital is raised through the sale of equity or convertible debt securities, the issuance of these securities could result in further dilution to our stockholders.

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DESCRIPTION OF SECURITIES OFFERED

We are offering 16,326,530 shares of our common stock, Pre-funded Warrants to purchase 25,510,205 shares of our common stock and Common Warrants to purchase 10,459,181 shares of our common stock. We are also registering the shares of common stock issuable from time to time upon exercise of the Pre-funded Warrants and Common Warrants offered hereby.

Common stock

The material terms and provisions of our common stock and each other class of our securities which qualifies or limits our common stock are described in the section entitled “Description of Capital Stock” beginning on page 9 of the accompanying prospectus and the Description of Capital Stock included as Exhibit 4.4 to our Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on March 7, 2022.

Pre-funded warrants

The following summary of certain terms and provisions of Pre-funded Warrants that are being offered hereby is not complete and is subject to, and qualified in its entirety by, the provisions of the Pre-funded Warrant, the form of which will be filed as an exhibit to a Current Report on Form 8-K in connection with this offering and incorporated by reference into the registration statement of which this prospectus supplement forms a part. Prospective investors should carefully review the terms and provisions of the form of Pre-funded Warrant for a complete description of the terms and conditions of the Pre-funded Warrants.

Pre-funded warrants will be issued in certificated form only.

Duration and exercise price

Each Pre-funded Warrant offered hereby will have an initial exercise price per share equal to $0.0001. The exercise price and number of shares of common stock issuable upon exercise is subject to appropriate adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting our common stock and the exercise price.

Exercisability

The Pre-funded Warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our common stock purchased upon such exercise (except in the case of a cashless exercise as discussed below). A holder (together with its affiliates) may not exercise any portion of such holder’s Pre-funded Warrant to the extent that the holder would own more than 9.99% (or, at the election of the purchaser, 4.99%, 14.99% or 19.99%) of the outstanding shares of common stock immediately after exercise, except that upon at least 61 days’ written prior notice from the holder to us, the holder may increase or decrease the amount of ownership of outstanding shares of common stock after exercising the holder’s Pre-funded Warrants up to 19.99% of the number of shares of common stock outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the Pre-funded Warrants. No fractional shares of common stock will be issued in connection with the exercise of a Pre-funded Warrant. In lieu of fractional shares, we will either pay the holder an amount in cash equal to the fractional amount multiplied by the exercise price or round up to the next whole share.

Cashless exercise

In lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of common stock determined according to a formula set forth in the Pre-funded Warrants.

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Fundamental transactions

In the event of any fundamental transaction, as described in the Pre-funded Warrants and generally including any merger with or into another entity, sale of all or substantially all of our assets, tender offer or exchange offer, or reclassification of our shares of common stock, then upon any subsequent exercise of a Pre-funded Warrant, the holder will have the right to receive as alternative consideration, for each share of common stock that would have been issuable upon such exercise immediately prior to the occurrence of such fundamental transaction, the number of shares of common stock of the successor or acquiring corporation or of our company, if it is the surviving corporation, and any additional consideration receivable upon or as a result of such transaction by a holder of the number of shares of common stock for which the Pre-funded Warrant is exercisable immediately prior to such event.

Transferability

Subject to applicable laws, the pre-funded warrants may be offered for sale, sold, transferred or assigned without our consent. The Pre-funded Warrants will be held in definitive form by the warrant agent. The ownership of the Pre-funded Warrants and any transfers of the Pre-funded Warrants will be registered in a warrant register maintained by the warrant agent. We will initially act as warrant agent.

Exchange listing

There is no established trading market for the Pre-funded Warrants. We do not intend to list the Pre-funded Warrants on any securities exchange or nationally recognized trading system.

Right as a stockholder

Except as otherwise provided in the Pre-funded Warrants or by virtue of such holder’s ownership of shares of our common stock, the holders of the Pre-funded Warrants do not have the rights or privileges of holders of our common stock, including any voting rights, until such Pre-funded Warrant holders exercise their Pre-funded Warrants.

Common warrants

The following summary of certain terms and provisions of the Common Warrants that are being offered hereby is not complete and is subject to, and qualified in its entirety by, the provisions of the Common Warrant, the form of which will be filed as an exhibit to a Current Report on Form 8-K in connection with this offering and incorporated by reference into the registration statement of which this prospectus supplement forms a part. Prospective investors should carefully review the terms and provisions of the form of Common Warrant for a complete description of the terms and conditions of the Common Warrants.

Common Warrants will be issued in certificated form only.

Duration and exercise price

Each Common Warrant offered hereby has an initial exercise price per share equal to $7.35 The Common Warrants are immediately exercisable and will expire upon December 31, 2025. The exercise price and number of shares of common stock issuable upon exercise is subject to appropriate adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting our common stock and the exercise price.

Exercisability

The Common Warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our common stock purchased upon such exercise (except in the case of a cashless exercise as discussed below). A holder (together with its affiliates) may not exercise any portion of such holder’s Common Warrant to the extent that the holder would own more than 4.99% (or, at the election of the purchaser, 9.99%, 14.99% or 19.99%) of the

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outstanding shares of common stock immediately after exercise, except that upon at least 61 days’ prior notice from the holder to us, the holder may increase the amount of ownership of outstanding shares of common stock after exercising the holder’s Common Warrants up to 9.99%, 14.99% or 19.99% of the number of shares of common stock outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the Common Warrants. No fractional shares of common stock will be issued in connection with the exercise of a Common Warrant. In lieu of fractional shares, we will either pay the holder an amount in cash equal to the fractional amount multiplied by the exercise price or round up to the next whole share.

Cashless exercise

If at the time of exercise hereof there is no effective registration statement registering, or the prospectus contained therein is not available for the issuance of the shares of common stock issuable upon exercise of the Common Warrants, then in lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of common stock determined according to a formula set forth in the Common Warrants.

Fundamental transactions

In the event of any fundamental transaction, as described in the Common Warrants and generally including any merger with or into another entity, sale of all or substantially all of our assets, tender offer or exchange offer, or reclassification of our shares of common stock, then upon any subsequent exercise of a Common Warrant, the holder will have the right to receive as alternative consideration, for each share of common stock that would have been issuable upon such exercise immediately prior to the occurrence of such fundamental transaction, the number of shares of common stock of the successor or acquiring corporation or of our company, if it is the surviving corporation, and any additional consideration receivable upon or as a result of such transaction by a holder of the number of shares of common stock for which the Common Warrant is exercisable immediately prior to such event.

Transferability

Subject to applicable laws, a Common Warrant or the rights thereunder may not be transferred or assigned, in whole or in part unless such transfer is to the Common Warrant holder’s successors and Affiliates (as defined in the Common Warrant). The ownership of the Common Warrants and any transfers of the Common Warrants will be registered in a warrant register maintained by the warrant agent. We will initially act as warrant agent.

Exchange listing

There is no trading market available for the Common Warrants on any securities exchange or nationally recognized trading system. We do not intend to list the Common Warrants on any securities exchange or nationally recognized trading system.

Right as a stockholder

Except as otherwise provided in the Common Warrants or by virtue of such holder’s ownership of shares of our common stock, the holders of the Common Warrants do not have the rights or privileges of holders of our common stock, including any voting rights, until they exercise their Common Warrants.

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CERTAIN UNITED STATES FEDERAL INCOME TAX CONSIDERATIONS

Subject to the limitations, assumptions and qualifications described herein, the following is a summary of certain U.S. federal income tax considerations of the purchase, ownership and disposition of shares of Scholar Rock’s common stock issued pursuant to this offering (the “Shares”), the purchase, exercise, disposition and lapse of Pre-funded Warrants and Common Warrants to purchase shares of Scholar Rock’s common stock issued pursuant to this offering, and the purchase, ownership and disposition of shares of Scholar Rock’s common stock issuable upon exercise of the Pre-funded Warrants and Common Warrants (the “Warrant Shares”). The Shares, the Pre-funded Warrants, the Common Warrants and the Warrant Shares are collectively referred to herein as the “Offered Securities.” All prospective holders of the Offered Securities should consult their tax advisors with respect to the U.S. federal, state, local and non-U.S. tax consequences of the purchase, ownership and disposition of the Offered Securities.

This discussion is based on current provisions of the U.S. Internal Revenue Code of 1986, as amended (the “Code”), existing U.S. Treasury regulations promulgated thereunder, published administrative pronouncements and rulings of the U.S. Internal Revenue Service (the “IRS”), and judicial decisions, all as in effect as of the date of this prospectus supplement. These authorities are subject to change and to differing interpretation, possibly with retroactive effect. Any change or differing interpretation could alter the tax consequences to holders described in this discussion. There can be no assurance that a court or the IRS will not challenge one or more of the tax consequences described herein, and Scholar Rock has not obtained, nor does it intend to obtain, a ruling with respect to the U.S. federal income tax consequences to a holder of the purchase, ownership or disposition of the Offered Securities.

This discussion addresses only Offered Securities that are held as capital assets within the meaning of Section 1221 of the Code (generally, property held for investment). This discussion does not address all the U.S. federal income tax consequences that may be relevant to particular holders in light of their individual circumstances, nor does it address any alternative minimum, Medicare contribution, estate or gift tax consequences, or any aspects of U.S. state, local or non-U.S. taxes). It does not address holders that are subject to special rules, such as:

•

banks, insurance companies or other financial institutions;

•

tax-exempt organizations or governmental organizations;

•

brokers or dealers in securities;

•

traders in securities that elect to use a mark-to-market method of accounting for their securities holdings;

•

persons who hold any of the Offered Securities as a position in a hedging transaction, “straddle,” “conversion transaction,” or other risk reduction transaction;

•

persons deemed to sell any of the Offered Securities under the constructive sale provisions of the Code;

•

entities or arrangements classified as partnerships for U.S. federal income tax purposes or other pass-through entities such as subchapter S corporations (or investors in such entities or arrangements);

•

regulated investment companies or real estate investment trusts;

•

controlled foreign corporations, passive foreign investment companies or corporations that accumulate earnings to avoid U.S. federal income tax;

•

U.S. Holders (as defined below) whose functional currency is not the U.S. dollar;

•

“qualified foreign pension funds” as defined in Section 897(l)(2) of the Code and entities all of the interests of which are held by qualified foreign pension funds;

•

U.S. expatriates and former citizens or former long-term residents of the United States; or

•

holders that acquire the Offered Securities through the exercise of an employee stock option or otherwise as compensation or through a tax-qualified retirement plan.

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If a holder is a partnership or other pass-through entity (including an entity or arrangement treated as a partnership or other type of pass-through entity for U.S. federal income tax purposes), the U.S. federal income tax treatment of a partner or beneficial owner will generally depend on the status of such partner or beneficial owner and the entity’s activities. Partnerships, partners and beneficial owners in partnerships or other pass-through entities that own the Offered Securities should consult their tax advisors as to the particular U.S. federal income tax considerations applicable to the acquisition, ownership and disposition of the Offered Securities.

For purposes of this discussion, a “U.S. Holder” is a beneficial owner of the Offered Securities, that, for U.S. federal income tax purposes, is:

•

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

•

a corporation, or an entity treated as a corporation, created or organized in or under the laws of the United States, any state thereof or the District of Columbia;

•

a trust that (1) is subject to (A) the primary supervision of a court within the United States and (B) the authority of one or more “United States persons” (within the meaning of Section 7701(a)(30) of the Code) to control all substantial decisions of the trust or (2) has a valid election in effect under applicable Treasury Regulations to be treated as a United States person; or

•

an estate that is subject to U.S. federal income tax on its income regardless of its source.

As used herein, the term “Non-U.S. Holder” means a beneficial owner, other than an entity treated as a partnership for U.S. federal income tax purposes, of the Offered Securities that is for U.S. federal income tax purposes not a U.S. Holder.

PROSPECTIVE INVESTORS ARE URGED TO CONSULT THEIR TAX ADVISORS REGARDING THE PARTICULAR FEDERAL, STATE, LOCAL AND NON-U.S. TAX CONSEQUENCES TO THEM OF THE PURCHASE, OWNERSHIP AND DISPOSITION OF THE OFFERED SECURITIES.

General treatment of Pre-funded warrants

Although it is not entirely free from doubt, a Pre-funded Warrant should be treated as a share of common stock of Scholar Rock for U.S. federal income tax purposes and a holder of Pre-funded Warrants should generally be taxed in the same manner as a holder of common stock as described below. Accordingly, upon exercise, the holding period of a Pre-funded Warrant should carry over to the Warrant Share received. Similarly, the tax basis of the Pre-funded Warrant should carry over to the Warrant Share received upon exercise increased by the exercise price of $0.0001. Holders should consult their tax advisors regarding the risks associated with the acquisition of an investment unit pursuant to this offering (including potential alternative characterizations). The balance of this discussion generally assumes that the characterization described above is respected for U.S. federal income tax purposes.

Allocation of purchase price

Each Share or Pre-funded Warrant and Common Warrant is expected to be treated for U.S. federal income tax purposes as an investment unit consisting of one Share or one Pre-funded Warrant and one Common Warrant. In determining the tax basis of each Share or Pre-funded Warrant and Common Warrant constituting a unit, holders should allocate their purchase price for the unit between the Share or Pre-funded Warrant and Common Warrant on the basis of their relative fair market values at the time of issuance. Scholar Rock does not intend to advise holders of the Offered Securities with respect to this determination. A holder’s allocation of the purchase price between the Shares or Pre-funded Warrant and Common Warrants is not binding on the IRS or the courts, and no assurance can be given that the IRS or the courts will agree with a holder’s allocation. All holders are advised to consult their tax and financial advisors with respect to the relative fair market values of the Shares or Pre-funded Warrants and Common Warrants for U.S. federal income tax purposes.

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Tax considerations applicable to U.S. holders

Distributions on shares, warrant shares and Pre-funded warrants

Scholar Rock does not anticipate declaring or paying any cash dividends to holders of Scholar Rock’s common stock in the foreseeable future. If Scholar Rock makes distributions of cash or other property on the Shares, Warrant Shares or Pre-funded Warrants (other than certain distributions of stock), such distributions will constitute dividends to the extent paid out of Scholar Rock’s current or accumulated earnings and profits, as determined for U.S. federal income tax purposes. Dividends received by a corporate U.S. Holder may be eligible for a dividends received deduction, subject to applicable limitations. Dividends received by certain non-corporate U.S. Holders, including individuals, are generally taxed at the lower applicable capital gains rate provided certain holding period and other requirements are satisfied. Distributions in excess of Scholar Rock’s current and accumulated earnings and profits will constitute a return of capital and first be applied against and reduce a U.S. Holder’s adjusted tax basis in its Shares, Warrant Shares or Pre-funded Warrants, as applicable, but not below zero. Any excess will be treated as capital gain and will be treated as described below under “—Sale or Other Taxable Disposition of the Shares, Warrant Shares and Pre-funded Warrants.”

Sale or other taxable disposition of the shares, warrant shares and Pre-funded warrants

Upon the sale, exchange or other taxable disposition of the Shares, Warrant Shares or Pre-funded Warrants, a U.S. Holder will generally recognize capital gain or loss equal to the difference between the amount of cash and the fair market value of any property received upon the sale, exchange or other taxable disposition and such U.S. Holder’s adjusted tax basis in the Shares, Warrant Shares or Pre-funded Warrants. This capital gain or loss will be long term capital gain or loss if the U.S. Holder’s holding period in such Shares, Warrant Shares or Pre-funded Warrants is more than one year at the time of the sale, exchange or other taxable disposition. Long-term capital gains recognized by certain non-corporate U.S. Holders, including individuals, generally will be subject to reduced rates of U.S. federal income tax. The deductibility of capital losses is subject to certain limitations.

Sale or other disposition or exercise of common warrants

Upon the sale, exchange or other disposition of a Common Warrant (other than by exercise), a U.S. Holder will generally recognize capital gain or loss equal to the difference between the amount realized on the sale, exchange or other disposition and the U.S. Holder’s tax basis in the Common Warrant. This capital gain or loss will be long-term capital gain or loss if the U.S. Holder’s holding period in such Common Warrant is more than one year at the time of the sale, exchange or other disposition. The deductibility of capital losses is subject to certain limitations.

In general, a U.S. Holder will not be required to recognize income, gain or loss upon exercise of a Common Warrant for its exercise price. A U.S. Holder’s tax basis in Warrant Shares received upon exercise of Common Warrants will be equal to the sum of (i) the U.S. Holder’s tax basis in the Common Warrants exchanged therefor and (ii) the exercise price of such Common Warrants. A U.S. Holder’s holding period in the Warrant Shares received upon exercise will commence on the day after such U.S. Holder exercises the Common Warrants. Although there is no direct legal authority as to the U.S. federal income tax treatment of an exercise of a warrant on a cashless basis, Scholar Rock intends to take the position that such exercise will not be taxable, either because the exercise is not a gain realization event or because it qualifies as a tax-free recapitalization. In the former case, the holding period of Warrant Shares received upon exercise of Common Warrants should commence on the day after the Common Warrants are exercised. In the latter case, the holding period of the Warrant Shares received upon exercise of Common Warrants would include the holding period of the exercised Common Warrants. However, Scholar Rock’s position is not binding on the IRS and the IRS may treat a cashless exercise of a warrant as a taxable exchange. U.S. Holders are urged to consult their tax advisors as to the consequences of an exercise of a Common Warrant on a cashless basis, including with respect to their holding period and tax basis in the Warrant Shares received.

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Lapse of common warrants

If a Common Warrant expires without being exercised, a U.S. Holder will recognize a capital loss in an amount equal to such U.S. Holder’s tax basis in the warrant. Such loss will be long-term capital loss if, at the time of the expiration, the U.S. Holder’s holding period in such warrant is more than one year. The deductibility of capital losses is subject to certain limitations.

Certain adjustments to and distributions on Pre-funded warrants and common warrants

Under Section 305 of the Code, an adjustment to the number of Warrant Shares that will be issued on the exercise of the Pre-funded Warrants and Common Warrants, or an adjustment to the exercise price of the Pre-funded Warrants and Common Warrants (or in certain circumstances, a failure to make adjustments), may be treated as a constructive distribution to a U.S. Holder of the Pre-funded Warrants and Common Warrants if, and to the extent that, such adjustment has the effect of increasing such U.S. Holder’s proportionate interest in Scholar Rock’s earnings and profits as determined under U.S. federal income tax principles or Scholar Rock’s assets, depending on the circumstances of such adjustment (for example, if such adjustment is to compensate for a distribution of cash or other property to Scholar Rock’s shareholders). Such distributions will constitute dividends to the extent deemed paid out of Scholar Rock’s current or accumulated earnings and profits, as discussed above under “Distributions on Shares, Warrant Shares and Pre-funded Warrants.” U.S. Holders should consult their tax advisors regarding the proper treatment of any adjustments to the number of Warrant Shares that will be issued on the exercise of the Pre-funded Warrants or Common Warrants or the exercise price of the Pre-funded Warrants or Common Warrants.

In addition, if Scholar Rock were to make a distribution in cash or other property with respect to its common stock after the issuance of the Common Warrants, then Scholar Rock may, in certain circumstances, make a corresponding distribution to holders of Common Warrants. The taxation of a distribution received with respect to a Common Warrant is unclear. It is possible such a distribution would be treated as a distribution (or constructive distribution), although other treatments are possible. U.S. Holders should consult their tax advisors regarding the proper treatment of distributions received with respect to Common Warrants.

Backup withholding and information reporting

In general, backup withholding and information reporting requirements may apply to payments on the Offered Securities and to the receipt of proceeds on the sale, exchange or other taxable disposition of the Offered Securities. Backup withholding (currently at a rate of 24 percent) may apply if a U.S. Holder fails to furnish its taxpayer identification number, a U.S. Holder fails to certify under penalties of perjury that such taxpayer identification number is correct and that such U.S. Holder is not subject to backup withholding (generally on a properly completed and duly executed IRS Form W-9), the applicable withholding agent is notified by the IRS that the holder previously failed to properly report payments of interest or dividends, or such U.S. Holder otherwise fails to comply with the applicable requirements of the backup withholding rules.

Certain U.S. Holders generally are not subject to backup withholding and information reporting requirements, provided that their exemptions from backup withholding and information reporting are properly established. Backup withholding is not an additional tax. Any amounts withheld from a payment to a U.S. Holder under the backup withholding rules generally will be allowed as a credit against such U.S. Holder’s U.S. federal income tax liability and may entitle such U.S. Holder to a refund, provided the required information is furnished to the IRS in a timely manner. U.S. Holders should consult their tax advisors regarding the application of backup withholding, the availability of an exemption from backup withholding, and the procedure for obtaining such an exemption, if available.

Tax considerations applicable to non-U.S. holders

Distributions on shares, warrant shares and Pre-funded warrants

As mentioned above, Scholar Rock does not anticipate declaring or paying any cash dividends to holders of Scholar Rock’s common stock in the foreseeable future. However, distributions of cash or other property (other

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than certain distributions of stock) on the Shares, Warrant Shares or Pre-funded Warrants will constitute dividends to the extent paid out of Scholar Rock’s current or accumulated earnings and profits, as determined for U.S. federal income tax purposes. Distributions in excess of Scholar Rock’s current and accumulated earnings and profits will constitute a return of capital and first be applied against and reduce a Non-U.S. Holder’s adjusted tax basis in its common stock, but not below zero. Any excess will be subject to the treatment as described below under “—Gain on Sale or Other Taxable Disposition of the Offered Securities”.

Dividends paid to a Non-U.S. Holder that are not effectively connected with the Non-U.S. Holder’s conduct of a trade or business in the United States generally will be subject to withholding tax at a 30-percent rate or a reduced rate specified by an applicable income tax treaty. In order to obtain a reduced rate of withholding, the Non-U.S. Holder will be required to provide Scholar Rock or Scholar Rock’s paying agent with a properly executed applicable IRS Form W-8BEN or IRS Form W-8BEN-E (or appropriate successor form), as applicable, certifying under penalties of perjury that the Non-U.S. Holder is not a United States person and is eligible for the benefits under the applicable tax treaty. These forms may need to be periodically updated. If a Non-U.S. Holder holds the Offered Securities through a financial institution or other intermediary, the Non-U.S. Holder generally will be required to provide the appropriate documentation to the financial institution or other intermediary. A Non-U.S. Holder eligible for a reduced rate of U.S. withholding tax pursuant to an income tax treaty who fails to timely provide an IRS Form W-8BEN or W-8BEN-E, as applicable, may obtain a refund of any excess amounts withheld by timely filing an appropriate claim with the IRS.

If dividends paid to a Non-U.S. Holder are effectively connected with the Non-U.S. Holder’s conduct of a trade or business in the United States (and, if required by an applicable income tax treaty, are attributable to a permanent establishment or fixed base maintained by the Non-U.S. Holder in the United States), the Non-U.S. Holder will generally be taxed on the dividends in the same manner as a U.S. Holder. In this case, the Non-U.S. Holder will be exempt from the withholding tax discussed in the preceding paragraph, although the Non-U.S. Holder will be required to provide a properly executed IRS Form W-8ECI (or appropriate successor form) in order to claim an exemption from withholding. Such effectively connected dividends, although not subject to U.S. federal withholding tax, are subject to U.S. federal income tax on a net income basis at the regular U.S. federal income tax rates generally applicable to Non-U.S. Holders. Dividends received by a corporate Non-U.S. Holder that are effectively connected with such Non-U.S. Holder’s conduct of a trade or business in the United States (and, if required by an applicable income tax treaty, attributable to a permanent establishment or fixed base maintained by the Non-U.S. Holder in the United States) may be subject to an additional branch profits tax at a 30-percent rate (or such lower rate as may be specified by an applicable income tax treaty). Non-U.S. Holders should consult their tax advisors with respect to other U.S. tax consequences of the acquisition, ownership and disposition of the Offered Securities, including the possible imposition of the branch profits tax.

Exercise of common warrants

A Non-U.S. Holder generally will not recognize gain or loss on the exercise of a Common Warrant and the related receipt of Warrant Shares. However, if a cashless exercise of Common Warrants results in a taxable exchange, as described above under “—Tax Considerations Applicable to U.S. Holders—Sale or Other Disposition or Exercise of Common Warrants,” the rules described below under “Gain on Sale or Other Taxable Disposition of the Offered Securities” would apply.

Lapse of common warrants

If a non-U.S. holder allows a common warrant to expire unexercised, such non-U.S. holder will recognize a capital loss for U.S. federal income tax purposes in an amount equal to such holder’s tax basis in the common warrant. See “—Tax Considerations Applicable to U.S. Holders”—Lapse of Warrants” above.

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Gain on sale or other taxable disposition of the offered securities

Subject to the discussions below under “—Information Reporting and Backup Withholding” and “—FATCA,” a Non-U.S. Holder generally will not be subject to U.S. federal income or withholding tax on gain realized on a sale, exchange or other taxable disposition of the Offered Securities unless:

•

the gain is effectively connected with the Non-U.S. Holder’s conduct of a trade or business in the United States (and, if required by an applicable income tax treaty, is attributable to a permanent establishment or fixed base maintained by the Non-U.S. Holder in the United States),

•

the Non-U.S. Holder is a nonresident alien individual present in the United States for 183 days or more during the taxable year of the disposition and certain other requirements are met; or

•

Scholar Rock is or has been a “United States real property holding corporation,” as defined in the Code, at any time within the five-year period ending on the date of disposition or the Non-U.S. Holder’s holding period, whichever period is shorter, and the Non-U.S. Holder is not eligible for an exemption under an applicable income tax treaty.

Scholar Rock believes that it is not, and does not anticipate becoming, a United States real property holding corporation. Even if Scholar Rock is or has been a United States real property holding corporation during the specified testing period, as long as Scholar Rock’s common stock is regularly traded on an established securities market (such as the Nasdaq Global Market) at any time during the calendar year in which the disposition occurs, a Non-U.S. Holder will not be subject to U.S. federal income tax on the disposition of Shares or Warrant Shares if the Non-U.S. Holder does not own or has not owned (actually or constructively) more than 5 percent of Scholar Rock’s common stock at any time during the shorter of the two periods mentioned above. Special rules may apply to the determination of the 5-percent threshold in the case of a Non-U.S. Holder of a Pre-funded Warrants and/or Common Warrants. Non-U.S. Holders are urged to consult their tax advisors regarding the effect of holding Pre-funded Warrants or Common Warrants on the calculation of such 5-percent threshold. Non-U.S. Holders should consult their tax advisors regarding the application of this regularly traded exception.

If a Non-U.S. Holder recognizes gain on a sale, exchange or other disposition of the Offered Securities that is effectively connected with the Non-U.S. Holder’s conduct of a trade or business in the United States (and if required by an applicable income tax treaty, is attributable to a permanent establishment or fixed base maintained by the Non-U.S. Holder in the United States), the Non-U.S. Holder will generally be subject to U.S. federal income tax at the regular U.S. federal income tax rates generally applicable to a United States person. If the Non-U.S. Holder is a corporation, the Non-U.S. Holder may also be subject to the branch profits tax at a 30-percent rate or such lower rate as may be specified by an applicable income tax treaty. Non-U.S. Holders should consult their tax advisors with respect to other U.S. tax consequences of the acquisition, ownership and disposition of the Offered Securities, including the possible imposition of the branch profits tax.

Certain adjustments to and distributions on Pre-funded warrants and common warrants

As discussed above under “—Tax Considerations Applicable to U.S. Holders—Certain Adjustments to and Distributions on Pre-funded Warrants and Common Warrants,” certain adjustments to the number of Warrant Shares on the exercise of the Pre-funded Warrants or Common Warrants, or an adjustment to the exercise price of the Pre-funded Warrants or Common Warrants (or certain failures to make adjustments), may be deemed to be the payment of a distribution with respect to the Pre-funded Warrants or Common Warrants. Such a deemed distribution could be deemed to be the payment of a dividend to a Non-U.S. Holder to the extent of Scholar Rock’s earnings and profits, notwithstanding the fact that such Holder will not receive a cash payment. In the event of such a deemed dividend, Scholar Rock may be required to withhold tax from subsequent distributions of cash or property to Non-U.S. Holders. Non-U.S. Holders should consult their tax advisors regarding the proper treatment of any adjustments to the Pre-funded Warrants and Common Warrants.

In addition, as discussed above under “—Tax Considerations Applicable to U.S. Holders—Certain Adjustments to and Distributions on Pre-funded Warrants and Common Warrants,” the taxation of a distribution received with respect to a Common Warrant is unclear. It is possible such a distribution would be treated as a distribution (or

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constructive distribution), although other treatments are possible. Non-U.S. Holders should consult their tax advisors regarding the U.S. withholding tax and other U.S. tax consequences of distributions received with respect to Common Warrants.

Information reporting and backup withholding

Information returns will be filed with the IRS in connection with payments of dividends on the Offered Securities. Copies of the information returns reporting those dividends and withholding may also be made available to the tax authorities in the country in which a Non-U.S. Holder is a resident under the provisions of an applicable income tax treaty or agreement. Unless a Non-U.S. Holder complies with certification procedures to establish that the Non-U.S. Holder is not a United States person, information returns may also be filed with the IRS in connection with the proceeds from a sale, exchange or other disposition of the Offered Securities to or through the U.S. office (and, in certain cases, the foreign office) of a broker.

A Non-U.S. Holder may be subject to backup withholding (currently at a rate of 24 percent) on payments on the Offered Securities or on the proceeds from a sale, exchange or other disposition of the Offered Securities unless the Non-U.S. Holder complies with certification procedures to establish that the Non-U.S. Holder is not a United States person or otherwise establishes an exemption. Compliance with the certification procedures required to claim a reduced rate of withholding under a treaty (including properly certifying non-U.S. status on an IRS Form W-8BEN, IRS Form W-8BEN-E or other appropriate version of IRS Form W-8 (or appropriate successor form)) generally will satisfy the certification requirements necessary to avoid backup withholding as well. Notwithstanding the foregoing, U.S. federal backup withholding may apply if the payor has actual knowledge, or reason to know, that a holder is a United States person.

Backup withholding is not an additional tax. Any amounts withheld from a payment to a Non-U.S. Holder under the backup withholding rules generally will be allowed as a credit against such Non-U.S. Holder’s U.S. federal income tax liability and may entitle such Non-U.S. Holder to a refund, provided the required information is furnished to the IRS in a timely manner. Non-U.S. Holders are urged to consult their tax advisors regarding the application of backup withholding and the availability of and procedure for obtaining an exemption from backup withholding in their particular circumstances.

FATCA

Provisions of the Code commonly referred to as “FATCA” require withholding of 30 percent on payments of dividends on the Offered Securities, as well as payments of gross proceeds of dispositions of the Offered Securities, to a “foreign financial institution” (which is broadly defined for this purpose and in general includes investment vehicles) and certain other non-U.S. entities unless various U.S. information reporting and due diligence requirements (generally relating to ownership by United States persons of interests in or accounts with those entities) have been satisfied or an exemption applies. However, the IRS has issued proposed Treasury regulations that eliminate FATCA withholding on payments of gross proceeds (but not on payments of dividends). Pursuant to the preamble to the proposed Treasury regulations, any applicable withholding agent may (but is not required to) rely on this proposed change to FATCA withholding until final Treasury regulations are issued or the proposed Treasury regulations are withdrawn. An intergovernmental agreement between the United States and an applicable foreign country may modify these requirements. If FATCA withholding is imposed, a beneficial owner that is not a foreign financial institution generally may obtain a refund of any amounts withheld by filing a U.S. federal income tax return (which may entail significant administrative burden). Non-U.S. Holders should consult their tax advisors regarding the effects of FATCA on their investments in the Offered Securities.

Scholar Rock will not pay any additional amounts to Non-U.S. Holders with respect to any amounts withheld, including pursuant to FATCA.

THE PRECEDING DISCUSSION OF U.S. FEDERAL TAX CONSIDERATIONS IS FOR GENERAL INFORMATION ONLY. IT IS NOT TAX ADVICE. PROSPECTIVE INVESTORS SHOULD CONSULT THEIR TAX ADVISORS REGARDING THE PARTICULAR U.S. FEDERAL, STATE AND LOCAL AND NON-U.S. TAX CONSEQUENCES OF PURCHASING, HOLDING AND DISPOSING OF THE OFFERED SECURITIES, INCLUDING THE CONSEQUENCES OF ANY PROPOSED CHANGE IN APPLICABLE LAWS.

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PLAN OF DISTRIBUTION

J.P. Morgan Securities LLC as lead placement agent and Piper Sandler as co-placement agent, referred to as the placement agents, have entered into a placement agency agreement with us in which they have agreed to act as placement agents in connection with the offering. Subject to the terms and conditions contained in the placement agency agreement, the placement agents are acting on a reasonable best efforts basis, in connection with the issuance and sale by us of shares of common stock, Pre-funded Warrants and accompanying Common Warrants to the investors. The placement agents have no obligation to buy any of the shares of common stock, Pre-funded Warrants or the accompanying Common Warrants from us nor are the placement agents required to arrange the purchase or sale of any specific number or dollar amount of the shares of common stock, Pre-funded Warrants and accompanying Common Warrants.

We have agreed to indemnify the placement agents and certain other persons against certain liabilities under the Securities Act. The placement agents have informed us that they will not engage in overallotment, stabilizing transactions or syndicate covering transactions in connection with this offering.

We have agreed to pay the placement agents a fee equal to 4.5% of the gross proceeds received by us from the sale of shares of common stock, Pre-funded Warrants and accompanying Common Warrants in this offering.

The following table shows the per share of common stock or Pre-Funded Warrant and accompanying Common Warrant and total fees we will pay to the placement agent assuming the sale of all of the shares of common stock, Pre-funded Warrants and accompanying Common Warrants offered pursuant to this prospectus supplement:

	PER SHARE AND ACCOMPANYING WARRANT			PER PRE-FUNDED WARRANT AND ACCOMPANYING WARRANT			TOTAL
Offering price		$	4.90		$	4.8999		$	204,997,450
Placement agent fees		$	0.2205		$	0.2205		$	9,224,885
Proceeds before expenses, to us		$	4.6795		$	4.6794		$	195,772,565

We have entered into a securities purchase agreement directly with the investors in connection with this offering, and will only sell to investors who have entered into such securities purchase agreement. Our obligations to issue and sell the shares of common stock, Pre-funded Warrants and accompanying Common Warrants to the investors will be subject to the conditions set forth in the securities purchase agreement and warrants, which may be waived by us at our discretion. The investors’ obligations to purchase shares of common stock, Pre-funded Warrants and accompanying Common Warrants will be subject to the conditions set forth in the securities purchase agreement and warrants as well, which may also be waived.

We are also offering to certain purchasers whose purchase of shares of common stock in this offering could result in the purchaser, together with its affiliates and certain related parties, beneficially owning more than 9.99% (or, at the election of the holder, 4.99%, 14.99% or 19.99%) of our outstanding common stock following the consummation of this offering, the opportunity to purchase, in lieu of the shares of our common stock that would result in ownership in excess of 9.99% (or, at the election of the holder, 4.99%, 14.99% or 19.99%), Pre-funded Warrants to purchase such excess shares of our common stock. Each Pre-funded Warrant will have an exercise price of $0.0001. The purchase price for each such Pre-funded Warrant would equal the per share public offering price for the common stock in this offering less the $0.0001 per share exercise price of each such Pre-funded Warrant.

We and our officers and directors have agreed to a 60-day “lock-up” with respect to the common stock and other of our securities that they beneficially own. This means that, subject to certain exceptions, for a period of 60 days following the date of this prospectus supplement, we and such persons may not offer, sell, pledge or otherwise dispose of these securities without the prior written consent of the placement agents.

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This is a brief summary of certain provisions of the placement agency agreement that we have entered into and does not purport to be a complete statement of its terms and conditions. A copy of the placement agency agreement will be filed with the SEC and incorporated by reference into the registration statement of which this prospectus supplement forms a part. See “Where You Can Find More Information” on page S-38.

The placement agents and certain of their affiliates have provided in the past, and may provide from time to time in the future, certain commercial banking, financial advisory, investment banking and other services for us and our affiliates in the ordinary course of their business, for which they have received and may continue to receive customary fees and commissions. In addition, from time to time, the placement agents and certain of their 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.

The transfer agent for our common stock to be issued in this offering is Computershare Trust Company, N.A. Our common stock is traded on The Nasdaq Global Select Market under the symbol “SRRK.” We do not intend to apply for listing of the warrants on any securities exchange or other nationally recognized trading system. We currently anticipate that the closing of the securities will take place on or about June 22, 2022. At the closing, Computershare Trust Company, N.A. will credit the shares of common stock to the respective accounts of the investors.

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LEGAL MATTERS

Certain legal matters, including the legality of the securities offered, will be passed upon for us by Goodwin Procter LLP, Boston, Massachusetts. The placement agents are being represented in this offering by Cooley LLP, New York, New York.

EXPERTS

Ernst & Young 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, 2021, as set forth in their report, which is incorporated by reference in this prospectus supplement and elsewhere in the registration statement. Our financial statements are incorporated by reference in reliance on Ernst & Young LLP’s report, given on their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

This prospectus supplement is part of a registration statement that we have filed with the SEC. Certain information in the registration statement has been omitted from this prospectus supplement in accordance with the rules of the SEC. We are subject to the information requirements of the Exchange Act and, in accordance therewith, file annual, quarterly and special reports, proxy statements and other information with the SEC. These documents also may be accessed through the SEC’s electronic data gathering, analysis and retrieval system, via electronic means, including the SEC’s home page on the Internet (www.sec.gov). You may also inspect the registration statement, this prospectus supplement and the accompanying prospectus on this website.

We have the authority to designate and issue more than one class or series of stock having various preferences, conversion and other rights, voting powers, restrictions, limitations as to dividends, qualifications, and terms and conditions of redemption. We will furnish a full statement of the relative rights and preferences of each class or series of our stock which has been so designated and any restrictions on the ownership or transfer of our stock to any shareholder upon request and without charge. Written requests for such copies should be directed Investor Relations, Scholar Rock Holding Corporation, 301 Binney Street, Cambridge, MA 02142. Our website is located at http://www.scholarrock.com. Information contained on our website is not incorporated by reference into this prospectus supplement, and, except for the documents incorporated by reference as noted below, you should not consider any information on, or that can be accessed from, our website as part of this prospectus supplement or the accompanying prospectus.

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to incorporate by reference the information and reports we file with it, which means that we can disclose important information to you by referring you to these documents. The information incorporated by reference is an important part of this prospectus supplement, and information that we file after the date hereof with the SEC will automatically update and supersede the information already incorporated by reference. We are incorporating by reference the documents listed below, which we have already filed with the SEC, and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, except as to any portion of any future report or document that is not deemed filed under such provisions, after the date of this prospectus supplement and prior to the termination of this offering:

•

our Annual Report on Form 10-K for the year ended December 31, 2021, filed with the SEC on March 7, 2022;

•

our Definitive Proxy Statement on Schedule 14A (other than information furnished rather than filed), filed with the SEC on April 13, 2022;

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our Quarterly Report on Form 10-Q for the quarter ended March 31, 2022 filed with the SEC on May 16, 2022;

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our Current Reports on Form 8-K (other than information furnished rather than filed) filed with the SEC on May 27, 2022 and June 17, 2022; and

•

the description of our common stock contained in our registration statement on Form 8-A filed with the SEC on May 21, 2018, including any amendments or reports filed for the purposes of updating this description.

Pursuant to Rule 412 under the Securities Act, any statement contained in a document incorporated or deemed to be incorporated by reference into this prospectus supplement will be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement or any other subsequently filed document that is deemed to be incorporated by reference into this prospectus supplement modifies or supersedes the statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement.

Upon request, we will provide, without charge, to each person, including any beneficial owner, to whom a copy of this prospectus supplement is delivered, a copy of the documents incorporated by reference into this prospectus supplement but not delivered with the prospectus. You may request a copy of these filings, and any exhibits we have specifically incorporated by reference as an exhibit in this prospectus supplement, at no cost by writing us at the following address: Investor Relations, Scholar Rock Holding Corporation, 301 Binney Street, Cambridge, MA 02142. Our website is located at http://www.scholarrock.com. The reference to our website is intended to be an inactive textual reference and, except for the documents incorporated by reference as noted above, the information on, or accessible through, our website is not intended to be part of this prospectus supplement.

You should rely only on the information incorporated by reference or provided in this prospectus supplement and the accompanying prospectus. We have not authorized anyone else to provide you with different information. You should not assume that the information in this prospectus supplement or in the documents incorporated by reference is accurate as of any date other than the date on the front of this prospectus supplement or those documents.

We advise that there have been no material changes in our affairs that have occurred since the end of the latest fiscal period for which audited financial statements were included in the latest Form 10-K and that have not been described in a Form 10-Q or Form 8-K filed under the Exchange Act.

This prospectus supplement is part of a registration statement we filed with the SEC. We have incorporated exhibits into the registration statement. You should read the exhibits carefully for provisions that may be important to you.

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PROSPECTUS

$300,000,000

Common Stock
Preferred Stock
Debt Securities
Warrants
Units

We may from time to time offer and sell up to $300,000,000 in aggregate principal amount of, in one or more series or classes, our common stock, preferred stock, debt securities, warrants and/or units. We may offer these securities separately or together in units. We will specify in the accompanying prospectus supplement the terms of the securities being offered. We may sell these securities to or through underwriters and also to other purchasers or through agents. We will set forth the names of any underwriters or agents, and any fees, conversions, or discount arrangements, in the accompanying prospectus supplement. We may not sell any securities under this prospectus without delivery of the applicable prospectus supplement.

You should read this document and any prospectus supplement or amendment carefully before you invest in our securities.

Our common stock is listed on The Nasdaq Global Select Market under the symbol “SRRK.” On March 1, 2022, the closing price for our common stock, as reported on The Nasdaq Global Select Market, was $16.92 per share. Our principal executive offices are located at 301 Binney Street, Cambridge, MA 02142.

We are an “emerging growth company” as defined by the Jumpstart Our Business Startups Act of 2012 and, as such, we are subject to reduced public company reporting requirements.

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

The date of this Prospectus is April 13, 2022.

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ABOUT THIS PROSPECTUS

This prospectus is part of an automatic registration statement that we filed with the Securities and Exchange Commission, or the SEC, Securities Act of 1933, as amended, using a “shelf” registration process. Under this shelf registration process, we may from time to time sell any combination of the securities described in this prospectus in one or more offerings.

This prospectus provides you with a general description of the securities we may offer in one or more offerings for an aggregate offering amount of up to $300,000,000. Each time we sell securities, we will provide one or more prospectus supplements that will contain specific information about the terms of the offering. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and the accompanying prospectus supplement together with the additional information described under the heading “Where You Can Find More Information”.

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

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RISK FACTORS

Investing in our securities involves a high degree of risk. You should carefully consider the risks described in the documents incorporated by reference in this prospectus and any prospectus supplement, as well as other information we include or incorporate by reference into this prospectus and any applicable prospectus supplement, before making an investment decision. Our business, financial condition or results of operations could be materially adversely affected by the materialization of any of these risks. The trading price of our securities could decline due to the materialization of any of these risks, and you may lose all or part of your investment. This prospectus and the documents incorporated herein by reference also contain forward-looking statements that involve risks and uncertainties. Actual results could differ materially from those anticipated in these forward-looking statements as a result of certain factors, including the risks described below and in the documents incorporated herein by reference, including our Annual Report on Form 10-K for the fiscal year ended December 31, 2021, which is on file with the SEC and is incorporated herein by reference, and other documents we file with the SEC that are deemed incorporated by reference into this prospectus. See “Where You Can Find More Information” for information about how to obtain a copy of these documents.

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CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

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

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

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the success, cost and timing of clinical trials for apitegromab, including the progress and completion of clinical trials for apitegromab, and the results, and the timing of results, from these trials;

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the success, cost and timing of preclinical studies and clinical trials for SRK-181, including, but not limited to, the results, progress and completion of our DRAGON Phase 1 clinical trial for SRK-181, any future preclinical studies and future clinical trials for SRK-181, and the results, and the timing of results, from these trials;

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the success, cost and timing of our other product development activities, preclinical studies and clinical trials, and the results, and timing of results, from these studies and trials;

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our success in identifying and executing a development program for additional indications for apitegromab, SRK-181 and in identifying product candidates from our other programs;

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the clinical utility of our product candidates and their potential advantages over other therapeutic options;

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risks associated with the COVID-19 pandemic, which may adversely impact our workforce, global supply chain, business, preclinical studies, clinical trials and financial results;

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the potential for our identified research priorities to advance our proprietary platform, development programs or product candidates;

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the timing, scope or likelihood of our ability to obtain and maintain regulatory approval from the U.S. Food and Drug Administration, or FDA, the European Commission and other regulatory authorities for apitegromab, SRK-181 and any future product candidates, and any related restrictions, limitations or warnings in the label of any approved product candidate;

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our ability to continue to grow our organization, including our personnel, systems and relationships with third parties;

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our expectations regarding our ability to obtain and maintain intellectual property protection for our product candidates and the duration of such protection;

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our ability and the potential to successfully manufacture our product candidates for clinical trials and for commercial use, if approved;

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our ability to establish or maintain collaborations or strategic relationships;

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our expectations relating to the potential of our proprietary platform technology;

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our ability to obtain additional funding when necessary;

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the size and growth potential of the markets for our product candidates, and our ability to serve those markets, either alone or in combination with others;

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our expectations related to the use of our cash reserves;

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the impact of new laws and regulations or amendments to existing laws and regulations;

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developments and projections relating to our competitors and our industry;

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our expected use of proceeds from this offering;

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our expectations regarding the period during which we qualify as an emerging growth company, or EGC, under the Jumpstart Our Business Startups Act.

We have included important factors in the cautionary statements included in this prospectus and the documents we incorporate by reference herein, particularly in the “Risk Factors” sections of these documents, that we believe could cause actual results or events to differ materially from the forward-looking statements that we make. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments we may make. No forward-looking statement is a guarantee of future performance.

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

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THE COMPANY

The following highlights information about the Registrant and our business contained elsewhere or incorporated by reference in this prospectus. It is not complete and does not contain all of the information that you should consider before investing in any of our securities. You should carefully read this prospectus together with the more detailed information incorporated by reference in this prospectus.

We have a productive scientific platform and are building our portfolio of novel product candidates with the aim of transforming the lives of patients suffering from a wide range of serious diseases, including neuromuscular disorders, cancer, and fibrosis. We have discovered and progressed the development of:

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Apitegromab, an inhibitor of the activation of latent myostatin, for the treatment of spinal muscular atrophy (“SMA”). We also believe apitegromab could have potential in the treatment of other myostatin-related disorders.

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SRK-181, an inhibitor of the activation of latent transforming growth factor beta-1 (“TGFβ1”), for the treatment of cancers that are resistant to anti-PD-(L)1 antibody therapies.

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Potent and selective inhibitors of the activation of transforming growth factor beta (“TGFβ”) for the treatment of fibrotic diseases. We are advancing multiple antibody profiles toward product candidate selection including antibodies that selectively inhibit the activation of latent TGFβ1 in the context of fibrotic extracellular matrix and that avoid perturbing TGFβ1 presented by cells of the immune system.

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Additional discovery and early preclinical programs related to the selective modulation of growth factor signaling including BMP6 and other growth factors.

Our second product candidate, SRK-181, is being developed for the treatment of cancers that are resistant to checkpoint inhibitor therapies (“CPI therapies”), such as anti-PD-1 or anti-PD-L1 antibody therapies. SRK-181 is a highly selective inhibitor of the activation of latent TGFβ1 that is being investigated in our DRAGON Phase 1 proof-of-concept clinical trial in patients with locally advanced or metastatic solid tumors that exhibit primary resistance to anti-PD-(L)1 antibodies. This two-part clinical trial consists of a dose escalation portion (Part A) and a dose expansion portion evaluating SRK-181 in combination with an approved anti-PD-(L)1 antibody therapy (Part B). Part B encompasses five cohorts, including urothelial carcinoma, cutaneous melanoma, non-small cell lung cancer, clear cell renal cell carcinoma and other solid

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tumors and commenced in 2021. Initial clinical data from Part A were presented in November 2021 at the Society for Immunotherapy of Cancer (“SITC”) 36th Annual Meeting.

Our approach and proprietary platform

Beyond these programs, we continue to discover and develop highly specific monoclonal antibodies to selectively modulate growth factor signaling. Growth factors are naturally occurring proteins that typically act as signaling molecules between cells and play a fundamental role in regulating a variety of normal cellular processes, including cell growth and differentiation. Current therapeutic approaches to treating diseases in which growth factors play a fundamental role involve directly targeting the active form of the growth factor or its receptor systemically throughout the body. These approaches have suffered from a variety of shortcomings, including lack of pathway selectivity, lack of target selectivity, and non-localized target inhibition.

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targeting the natural activation mechanism to prevent activation of the growth factor rather than attempting to inhibit the growth factor after activation;

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Company information

We were incorporated in 2017 under the laws of the State of Delaware as the holding company for Scholar Rock, Inc. Scholar Rock, Inc. is a wholly owned subsidiary of Scholar Rock Holding Corporation. On December 22, 2017, we completed a series of transactions pursuant to which Scholar Rock Merger Sub, LLC, a wholly owned subsidiary of Scholar Rock Holding Corporation, was merged with and into Scholar Rock, LLC, or the Reorganization. The purpose of the Reorganization was to reorganize our corporate structure so that we would continue as a corporation and so that our investors prior to the Reorganization would own our capital stock after the Reorganization rather than equity interests in a limited liability company. All of our convertible preferred stock converted into shares of common stock upon the completion of our initial public offering at the then effective conversion ratio. Our operations to date have been limited to organizing and staffing our company, business planning, raising capital, developing our technology, identifying potential product candidates, producing drug substance and drug product material for use in preclinical studies and clinical trials, conducting preclinical studies of our product candidates and conducting clinical trials for our product candidates, apitegromab (formerly SRK-015) and SRK-181. We do not have any products approved for sale and have not generated any product revenue to date.

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USE OF PROCEEDS

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

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SECURITIES WE MAY OFFER

This prospectus contains summary descriptions of the securities we may offer from time to time. These summary descriptions are not meant to be complete descriptions of each security. The particular terms of any security will be described in the applicable prospectus supplement.

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DESCRIPTION OF CAPITAL STOCK

The following description of our common stock and preferred stock, together with the additional information we include in any applicable prospectus supplements, summarizes the material terms and provisions of the common stock and preferred stock that we may offer under this prospectus. The following description of our capital stock does not purport to be complete and is subject to, and qualified in its entirety by, our Amended and Restated Certificate of Incorporation, as amended to date, and our Amended and Restated Bylaws, which are exhibits to the registration statement of which this prospectus forms a part, and by applicable law. We refer in this section to our Amended and Restated Certificate of Incorporation, as amended to date, as our “certificate of incorporation,” and we refer to our Amended and Restated Bylaws as our “bylaws.” The terms of our common stock and preferred stock may also be affected by Delaware law.

Authorized Capital Stock

Our authorized capital stock consists of 150,000,000 shares of common stock, par value $0.001 per share, and 10,000,000 shares of preferred stock, par value $0.001 per share, all of which shares of preferred stock are undesignated.

As of December 31, 2021, 35,209,099 shares of our common stock were outstanding and held by approximately 10 stockholders of record. In addition, as of December 31, 2021, we had outstanding options to purchase 3,743,400 shares of our common stock, at a weighted-average exercise price of $25.55 per share, 1,544,062 of which were exercisable and 314,901 shares of unvested restricted stock units.

Common Stock

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

In the event of our liquidation, dissolution or winding up, holders of our common stock will be entitled to share ratably in all assets remaining after payment of all debts and other liabilities and any liquidation preference of any outstanding preferred stock. The shares to be issued by us will be, when issued and paid for, validly issued, fully paid and non-assessable.

Listing

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A.

Prefunded Warrants for Common Stock

In November 2020, the Company sold pre-funded warrants to purchase 2,179,487 shares of common stock.

Form. The pre-funded warrants are issued as individual warrant agreements to each individual purchaser of a pre-funded warrant.

Term. The pre-funded warrants do not expire.

Exercisability. The pre-funded warrants are exercisable at any time after their original issuance. The pre-funded warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a

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duly executed exercise notice and by payment in full of the exercise price in immediately available funds for the number of shares of our common stock purchased upon such exercise. As an alternative to payment of the exercise price in immediately available funds, the holder may elect to exercise the pre-funded warrant through a cashless exercise, in which case the holder would receive upon such exercise the net number of shares of our common stock determined according to the formula set forth in the pre-funded warrants. No fractional shares of our common stock will be issued in connection with the exercise of a pre-funded warrant. In lieu of fractional shares, we will pay the holder an amount in cash equal to the fractional amount multiplied by the last closing trading price of our common stock on the exercise date.

Exercise limitations. Under the pre-funded warrants, we may not effect the exercise of any pre-funded warrant, and a holder will not be entitled to exercise any portion of any pre-funded warrant, which, upon giving effect to such exercise, would cause (i) the aggregate number of shares of our common stock beneficially owned by the holder (together with its affiliates) to exceed 9.99% of the number of shares of our common stock outstanding immediately after giving effect to the exercise, or (ii) the combined voting power of our securities beneficially owned by the holder (together with its affiliates) to exceed 9.99% of the combined voting power of all of our securities then outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the pre-funded warrants. However, any holder may increase or decrease such percentage to any other percentage not in excess of 19.99% upon at least 61 days’ prior notice from the holder to us.

Exercise price. The exercise price per whole share of our common stock purchasable upon the exercise of the pre-funded warrants is $0.0001 per share of our common stock. The exercise price of the prefunded warrants and the number of shares of our common stock issuable upon exercise of the pre-funded warrants are subject to appropriate adjustment in the event of certain stock dividends and distributions, stock splits, stock combinations, reclassifications or similar events affecting our common stock and also upon any distributions of assets, including cash, stock or other property to our stockholders. The exercise price will not be adjusted below the par value of our common stock.

Transferability. Subject to applicable laws, the pre-funded warrants may be offered for sale, sold, transferred or assigned without our consent. The pre-funded warrants will be held in definitive form by the warrant agent. The ownership of the pre-funded warrants and any transfers of the pre-funded warrants will be registered in a warrant register maintained by the warrant agent. We will initially act as warrant agent.

Preferred Stock

Undesignated Preferred Stock

Our board of directors or any authorized committee thereof has the authority, without further action by our stockholders, to issue up to 10,000,000 shares of preferred stock in one or more series and to fix the rights, preferences, privileges, and restrictions thereof. No shares of preferred stock are outstanding, and we have no present plans to issue any shares of preferred stock.

The purpose of authorizing our board of directors to issue preferred stock in one or more series and determine the number of shares in the series and its rights and preferences is to eliminate delays associated with a shareholder vote on specific issuances. Examples of rights and preferences that the board of directors may fix are:

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dividend rights;

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dividend rates;

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conversion rights;

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voting rights;

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terms of redemption; and

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liquidation preferences.

The existence of authorized but unissued shares of preferred stock may enable our board of directors to render more difficult or to discourage an attempt to obtain control of us by means of a merger, tender

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offer, proxy contest or otherwise. For example, if in the due exercise of its fiduciary obligations, our board of directors were to determine that a takeover proposal is not in the best interests of us or our stockholders, our board of directors could cause shares of preferred stock to be issued without stockholder approval in one or more private offerings or other transactions that might dilute the voting or other rights of the proposed acquirer, stockholder or stockholder group. The rights of holders of our common stock described above will be subject to, and may be adversely affected by, the rights of any preferred stock that we may designate and issue in the future. The issuance of shares of preferred stock could decrease the amount of earnings and assets available for distribution to holders of shares of common stock. The issuance may also adversely affect the rights and powers, including voting rights, of these holders and may have the effect of delaying, deterring or preventing a change in control of us.

Additional Series of Preferred Stock

We will incorporate by reference as an exhibit to the registration statement, which includes this prospectus, the form of any certificate of designation that describes the terms of the series of preferred stock we are offering. This description and the applicable prospectus supplement will include:

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the title and stated value;

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the number of shares authorized;

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the liquidation preference per share;

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the purchase price;

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the dividend rate, period and payment date, and method of calculation for dividends;

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whether dividends will be cumulative or non-cumulative and, if cumulative, the date from which dividends will accumulate;

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the procedures for any auction and remarketing, if any;

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the provisions for a sinking fund, if any;

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the provisions for redemption or repurchase, if applicable, and any restrictions on our ability to exercise those redemption and repurchase rights;

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any listing of the preferred stock on any securities exchange or market;

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whether the preferred stock will be convertible into our common stock, and, if applicable, the conversion price, or how it will be calculated, and the conversion period;

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whether the preferred stock will be exchangeable into debt securities, and, if applicable, the exchange price, or how it will be calculated, and the exchange period;

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voting rights, if any, of the preferred stock;

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preemptive rights, if any;

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restrictions on transfer, sale or other assignment, if any;

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whether interests in the preferred stock will be represented by depositary shares;

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a discussion of any material United States federal income tax considerations applicable to the preferred stock;

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the relative ranking and preferences of the preferred stock as to dividend rights and rights if we liquidate, dissolve or wind up our affairs;

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any limitations on issuance of any class or series of preferred stock ranking senior to or on a parity with the series of preferred stock as to dividend rights and rights if we liquidate, dissolve or wind up our affairs; and

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any other specific terms, preferences, rights or limitations of, or restrictions on, the preferred stock.

When we issue shares of preferred stock under this prospectus, the shares will fully be paid and nonassessable and will not have, or be subject to, any preemptive or similar rights.

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Registration Rights

Gilead Sciences, Inc., or Gilead,, is entitled to rights with respect to the registration of certain shares under the Securities Act pursuant to a registration rights agreement, or Registration Rights Agreement, and include demand registration rights, short-form and shelf registration rights and piggyback registration rights. All fees, costs and expenses of underwritten registrations, subject to certain restrictions, will be borne by us and all selling expenses, including underwriting discounts and selling commissions, will be borne by Gilead.

Demand Registration Rights

Under the terms of the Registration Rights Agreement with Gilead, beginning on December 19, 2020, we are required, upon the written request of the stockholder to register securities with an aggregate value of at least $10.0 million based on then-current value of the securities, to use reasonable best efforts to effect the registration of such shares on Form S-1, subject to certain exceptions. Under the terms of the Registration Rights Agreement, we are required to effect up to two registrations pursuant to this provision, and the short-form and shelf registration rights provisions of the Registration Rights Agreement, except that the number of shelf takedowns that are not underwritten offerings are not limited.

An aggregate of up to 980,392 shares of common stock are entitled to the demand registration rights under the Registration Rights Agreement.

Short-Form and Shelf Registration Rights

Under the terms of the Registration Rights Agreement, beginning on December 19, 2020, if we are eligible to file a registration statement on Form S-3, upon the written request of the stockholder to register securities with an aggregate value of at least $3.0 million based on then-current value of the securities, we will use reasonable best efforts to cause registration of the securities on Form S-3. In addition, under the terms of the Registration Rights Agreement, upon the written request of the stockholder, we will be required to file a shelf registration statement on Form S-3 to register the securities pursuant to Securities Act Rule 415 and use our reasonable best efforts to cause such shelf registration statement to become effective, subject to certain exceptions.

The right to have such shares registered on Form S-3 is further subject to other specified conditions and limitations in each case.

An aggregate of up to 980,392 shares of common stock are entitled to the Form S-3 registration rights under the Registration Rights Agreement.

Piggyback Registration Rights

If we propose to register any of our securities, either for our own account or for the account of other security holders, under the Registration Rights Agreement, we will use reasonable best efforts to include the stockholder’s shares in the registration.

Under the Registration Rights Agreement, subject to certain exceptions, the underwriters may limit the number of shares included in the underwritten offering to the number of shares which the underwriters determine in their sole discretion will not jeopardize the success of the offering, including, specifically, where the underwriter has determined that in their opinion there is a risk that the price of the securities will be reduced or the number of securities intended to be included on our behalf will be reduced.

An aggregate of up to 980,392 shares of common stock are entitled to these piggyback registration rights under the Registration Rights Agreement.

Indemnification

The Registration Rights Agreement contains customary cross- indemnification provisions, under which we are obligated to indemnify the stockholder in the event of material misstatements or omissions in the

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registration statement attributable to us, and the stockholder is obligated to indemnify us for material misstatements or omissions attributable to it.

Expiration of Registration Rights

The registration rights granted under the Registration Rights Agreement will terminate, with respect to 50% of the Registrable Securities held by the stockholder, on December 19, 2023 and with respect to 50% of the Registrable Securities held by the stockholder, on December 19, 2024.

Anti-Takeover Effects of Our Certificate of Incorporation and Our Bylaws

Our certificate of incorporation and bylaws contain certain provisions that are intended to enhance the likelihood of continuity and stability in the composition of the board of directors and which may have the effect of delaying, deferring or preventing a future takeover or change in control of the company unless such takeover or change in control is approved by the board of directors.

These provisions include:

Classified Board. Our certificate of incorporation provides that our board of directors is divided into three classes of directors, with the classes as nearly equal in number as possible. As a result, approximately one-third of our board of directors will be elected each year. The classification of directors has the effect of making it more difficult for stockholders to change the composition of our board. Our certificate of incorporation provides that, subject to any rights of holders of preferred stock to elect additional directors under specified circumstances, the number of directors will be fixed exclusively pursuant to a resolution adopted by our board of directors. Our board of directors has eight members. Our certificate of incorporation provides that the affirmative vote of at least two-thirds of the outstanding shares of capital stock entitled to vote, and the affirmative vote of at least two-thirds of the outstanding shares of each class entitled to vote as a class, is required to amend or repeal the foregoing provision. This requirement of a supermajority vote to amend or repeal that provision of our bylaws could enable a minority of our stockholders to prevent a declassification of our Board.

Action by Written Consent; Special Meetings of Stockholders. Our certificate of incorporation provides that stockholder action can be taken only at an annual or special meeting of stockholders and cannot be taken by written consent in lieu of a meeting. This limit may lengthen the amount of time required to take stockholder actions and would prevent the amendment of our bylaws or removal of directors by our stockholders without holding a meeting of stockholders. Our certificate of incorporation provides that the affirmative vote of at least two-thirds of the outstanding shares of capital stock entitled to vote, and the affirmative vote of at least two-thirds of the outstanding shares of each class entitled to vote as a class, is required to amend or repeal the foregoing provision. Our certificate of incorporation and bylaws provide that, except as otherwise required by law, special meetings of the stockholders can be called only by or at the direction of the board of directors pursuant to a resolution adopted by a majority of the total number of directors, and only those matters set forth in the notice of the special meeting may be considered or acted upon at a special meeting of stockholders. Our bylaws limit the business that may be conducted at an annual meeting of stockholders to those matters properly brought before the meeting. Stockholders are not permitted to call a special meeting or to require the board of directors to call a special meeting. Our bylaws provide that the affirmative vote of at least two thirds of the outstanding shares entitled to vote, and of each class entitled to vote, respectively, is required to amend the or repeal the provision in our bylaws that provides that special meetings of the stockholders can be called only by or at the direction of the board of directors pursuant to a resolution adopted by a majority of the total number of directors, unless the Board first recommends such amendment or repeal to stockholders. This requirement of a supermajority vote to amend or repeal that provision of our bylaws could enable a minority of our stockholders to prevent a change to such provision and has the effect of making it more difficult for stockholders to call a special meeting of stockholders.

Removal of Directors. Our certificate of incorporation provides that our directors may be removed only for cause and then only by the affirmative vote of the holders of two-thirds or more of the shares then entitled to vote at an election of directors, at a meeting of the stockholders called for that purpose. Furthermore, any vacancy on our board of directors, however occurring, including a vacancy resulting

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from an increase in the size of our board, may only be filled by the affirmative vote of a majority of our directors then in office even if less than a quorum. This requirement of a supermajority vote to remove directors could enable a minority of our stockholders to prevent a change in the composition of our board, and the treatment of vacancies also has the effect of making it more difficult for stockholders to change the composition of our board.

Advance Notice Procedures. Our bylaws establish an advance notice procedure for stockholder proposals to be brought before an annual meeting of our stockholders, including proposed nominations of persons for election to the board of directors. These procedures provide that notice of stockholder proposals must be timely given in writing to our corporate secretary prior to the meeting at which the action is to be taken. Generally, to be timely, notice must be received at our principal executive offices not less than 90 days nor more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. Our bylaws specify the requirements as to form and content of all stockholders’ notices. Stockholders at an annual meeting will only be able to consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the direction of the board of directors or by a stockholder who was a stockholder of record on the record date for the meeting, who is entitled to vote at the meeting and who has given our secretary timely written notice, in proper form, of the stockholder’s intention to bring that business before the meeting. Although the bylaws do not give the board of directors the power to approve or disapprove stockholder nominations of candidates or proposals regarding other business to be conducted at a special or annual meeting, the bylaws may have the effect of precluding the conduct of certain business at a meeting if the proper procedures are not followed or may discourage or deter a potential acquirer from conducting a solicitation of proxies to elect its own slate of directors or otherwise attempting to obtain control of the company.

Super Majority Approval Requirements and Amendment to Certificate of Incorporation and Bylaws. Any amendment of our certificate of incorporation must first be approved by a majority of our board of directors, and if required by law or our certificate of incorporation, must thereafter be approved by a majority of the outstanding shares entitled to vote on the amendment and a majority of the outstanding shares of each class entitled to vote thereon as a class, except that the amendment of the provisions relating to stockholder action, board composition, limitation of liability and the amendment of our bylaws and certificate of incorporation must be approved by not less than two-thirds of the outstanding shares entitled to vote on the amendment, and not less than two-thirds of the outstanding shares of each class entitled to vote thereon as a class. Our bylaws may be amended by the affirmative vote of a majority of the directors then in office, subject to any limitations set forth in the bylaws, and may also be amended by the affirmative vote of at least two-thirds of the outstanding shares entitled to vote on the amendment, or, if our board of directors recommends that the stockholders approve the amendment, by the affirmative vote of the majority of the outstanding shares entitled to vote on the amendment, in each case voting together as a single class.

Authorized but Unissued Shares. Our authorized but unissued shares of common stock and preferred stock are available for future issuance without stockholder approval. These additional shares may be utilized for a variety of corporate purposes, including future public offerings to raise additional capital and corporate acquisitions. The existence of authorized but unissued shares of common stock and preferred stock could render more difficult or discourage an attempt to obtain control of a majority of our common stock by means of a proxy contest, tender offer, merger or otherwise. For example, if in the due exercise of its fiduciary obligations, our board of directors were to determine that a takeover proposal is not in the best interests of our stockholders, our board of directors could cause shares of convertible preferred stock to be issued without stockholder approval in one or more private offerings or other transactions that might dilute the voting or other rights of the proposed acquirer or insurgent stockholder or stockholder group. In this regard, our certificate of incorporation grants our board of directors broad power to establish the rights and preferences of authorized and unissued shares of convertible preferred stock. The issuance of shares of convertible preferred stock could decrease the amount of earnings and assets available for distribution to holders of shares of common stock. The issuance may also adversely affect the rights and powers, including voting rights, of these holders and may have the effect of delaying, deterring or preventing a change in control of us.

Choice of Forum. Our bylaws provide that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware will be the sole and exclusive forum for:

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(1) any derivative action or proceeding brought on our behalf; (2) any action asserting a claim of breach of a fiduciary duty or other wrongdoing by any of our directors, officers, employees or agents to us or our stockholders; (3) any action asserting a claim against us arising pursuant to any provision of the General Corporation Law of the State of Delaware or our certificate of incorporation or bylaws; (4) any action to interpret, apply, enforce or determine the validity of our certificate of incorporation or bylaws; or (5) any action asserting a claim governed by the internal affairs doctrine.

In addition, our bylaws contain a provision by virtue of which, unless we consent in writing to the selection of an alternative forum, the United States District Court for the District of Massachusetts will be the exclusive forum for any complaint asserting a cause of action arising under the Securities Act. In addition, our bylaws provide that any person or entity purchasing or otherwise acquiring any interest in shares of our common stock is deemed to have notice of and consented to the foregoing provisions.

We have chosen the United States District Court for the District of Massachusetts as the exclusive forum for such causes of action because our principal executive offices are located in Cambridge, Massachusetts. Some companies that have adopted similar federal district court forum selection provisions are currently subject to a suit in the Court of Chancery of the State of Delaware brought by stockholders who assert that the federal district court forum selection provision is not enforceable. While the Delaware Supreme Court ruled in March 2020 that federal forum selection provisions purporting to require claims under the Securities Act be brought in federal court are “facially valid” under Delaware law, there is uncertainty as to whether other courts will enforce our federal forum selection provision, and we may incur additional costs of litigation should such enforceability be challenged.

Section 203 of the Delaware General Corporation Law

We are subject to the provisions of Section 203 of the Delaware General Corporation Law, or Section 203. In general, Section 203 prohibits a publicly-held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a three-year period following the time that this stockholder becomes an interested stockholder, unless the business combination is approved in a prescribed manner. A “business combination” includes, among other things, a merger, asset or stock sale or other transaction resulting in a financial benefit to the interested stockholder. An “interested stockholder” is a person who, together with affiliates and associates, owns, or did own within three years prior to the determination of interested stockholder status, 15% or more of the corporation’s voting stock.

Under Section 203, a business combination between a corporation and an interested stockholder is prohibited unless it satisfies one of the following conditions: before the stockholder became interested, the board of directors approved either the business combination or the transaction which resulted in the stockholder becoming an interested stockholder; upon consummation of the transaction which resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction commenced, excluding for purposes of determining the voting stock outstanding, shares owned by persons who are directors and also officers, and employee stock plans, in some instances; or at or after the time the stockholder became interested, the business combination was approved by the board of directors of the corporation and authorized at an annual or special meeting of the stockholders by the affirmative vote of at least two-thirds of the outstanding voting stock which is not owned by the interested stockholder.

A Delaware corporation may “opt out” of these provisions with an express provision in its original certificate of incorporation or an express provision in its certificate of incorporation or bylaws resulting from a stockholders’ amendment approved by at least a majority of the outstanding voting shares. We have not opted out of these provisions. As a result, mergers or other takeover or change in control attempts of us may be discouraged or prevented.

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DESCRIPTION OF DEBT SECURITIES

The paragraphs below describe the general terms and provisions of the debt securities we may issue. When we offer to sell a particular series of debt securities, we will describe the specific terms of the securities in a supplement to this prospectus, including any additional covenants or changes to existing covenants relating to such series. The prospectus supplement also will indicate whether the general terms and provisions described in this prospectus apply to a particular series of debt securities. You should read the actual indenture if you do not fully understand a term or the way we use it in this prospectus.

We may offer senior or subordinated debt securities. Each series of debt securities may have different terms. The senior debt securities will be issued under one or more senior indentures, dated as of a date prior to such issuance, between us and the trustee identified in the applicable prospectus supplement, as amended or supplemented from time to time. We will refer to any such indenture throughout this prospectus as the “senior indenture.” Any subordinated debt securities will be issued under one or more separate indentures, dated as of a date prior to such issuance, between us and the trustee identified in the applicable prospectus supplement, as amended or supplemented from time to time. We will refer to any such indenture throughout this prospectus as the “subordinated indenture” and to the trustee under the senior or subordinated indenture as the “trustee.” The senior indenture and the subordinated indenture are sometimes collectively referred to in this prospectus as the “indentures.” The indentures will be subject to and governed by the Trust Indenture Act of 1939, as amended. We included copies of the forms of the indentures as exhibits to our registration statement and they are incorporated into this prospectus by reference.

If we issue debt securities at a discount from their principal amount, then, for purposes of calculating the aggregate initial offering price of the offered securities issued under this prospectus, we will include only the initial offering price of the debt securities and not the principal amount of the debt securities.

We have summarized below the material provisions of the indentures and the debt securities, or indicated which material provisions will be described in the related prospectus supplement. The prospectus supplement relating to any particular securities offered will describe the specific terms of the securities, which may be in addition to or different from the general terms summarized in this prospectus. Because the summary in this prospectus and in any prospectus supplement does not contain all of the information that you may find useful, you should read the documents relating to the securities that are described in this prospectus or in any applicable prospectus supplement. Please read “Where You Can Find More Information” to find out how you can obtain a copy of those documents. Except as otherwise indicated, the terms of the indentures are identical. As used under this caption, the term “debt securities” includes the debt securities being offered by this prospectus and all other debt securities issued by us under the indentures.

General

The indentures:

•

do not limit the amount of debt securities that we may issue;

•

allow us to issue debt securities in one or more series;

•

do not require us to issue all of the debt securities of a series at the same time;

•

allow us to reopen a series to issue additional debt securities without the consent of the holders of the debt securities of such series; and

•

provide that the debt securities will be unsecured, except as may be set forth in the applicable prospectus supplement.

Unless we give you different information in the applicable prospectus supplement, the senior debt securities will be unsubordinated obligations and will rank equally with all of our other senior unsecured and unsubordinated indebtedness. Payments on the subordinated debt securities will be subordinated to the prior payment in full of all of our senior indebtedness, as described under “Description of Debt Securities — Subordination” and in the applicable prospectus supplement.

Each indenture provides that we may, but need not, designate more than one trustee under an indenture. Any trustee under an indenture may resign or be removed and a successor trustee may be appointed to act

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with respect to the series of debt securities administered by the resigning or removed trustee. If two or more persons are acting as trustee with respect to different series of debt securities, each trustee shall be a trustee of a trust under the applicable indenture separate and apart from the trust administered by any other trustee. Except as otherwise indicated in this prospectus, any action described in this prospectus to be taken by each trustee may be taken by each trustee with respect to, and only with respect to, the one or more series of debt securities for which it is trustee under the applicable indenture.

The prospectus supplement for each offering will provide the following terms, where applicable:

•

the title of the debt securities and whether they are senior or subordinated;

•

the aggregate principal amount of the debt securities being offered, the aggregate principal amount of the debt securities outstanding as of the most recent practicable date and any limit on their aggregate principal amount, including the aggregate principal amount of debt securities authorized;

•

the price at which the debt securities will be issued, expressed as a percentage of the principal and, if other than the principal amount thereof, the portion of the principal amount thereof payable upon declaration of acceleration of the maturity thereof or, if applicable, the portion of the principal amount of such debt securities that is convertible into common stock or other securities of ours or the method by which any such portion shall be determined;

•

if convertible, the terms on which such debt securities are convertible, including the initial conversion price or rate and the conversion period and any applicable limitations on the ownership or transferability of common stock or other securities of ours received on conversion;

•

the date or dates, or the method for determining the date or dates, on which the principal of the debt securities will be payable;

•

the fixed or variable interest rate or rates of the debt securities, or the method by which the interest rate or rates is determined;

•

the date or dates, or the method for determining the date or dates, from which interest will accrue;

•

the dates on which interest will be payable;

•

the record dates for interest payment dates, or the method by which such dates will be determined;

•

the persons to whom interest will be payable;

•

the basis upon which interest will be calculated if other than that of a 360-day year of twelve 30- day months;

•

any make-whole amount, which is the amount in addition to principal and interest that is required to be paid to the holder of a debt security as a result of any optional redemption or accelerated payment of such debt security, or the method for determining the make-whole amount;

•

the place or places where the principal of, and any premium or make-whole amount, and interest on, the debt securities will be payable;

•

where the debt securities may be surrendered for registration of transfer or conversion or exchange;

•

where notices or demands to or upon us in respect of the debt securities and the applicable indenture may be served;

•

the times, prices and other terms and conditions upon which we may redeem the debt securities; any obligation we have to redeem, repay or purchase the debt securities pursuant to any sinking fund or analogous provision or at the option of holders of the debt securities, and the times and prices at which we must redeem, repay or purchase the debt securities as a result of such obligation;

•

the currency or currencies in which the debt securities are denominated and payable if other than United States dollars, which may be a foreign currency or units of two or more foreign currencies or a composite currency or currencies and the terms and conditions relating thereto, and the manner of determining the equivalent of such foreign currency in United States dollars;

•

whether the principal of, and any premium or make-whole amount, or interest on, the debt securities of the series are to be payable, at our election or at the election of a holder, in a currency or currencies

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other than that in which the debt securities are denominated or stated to be payable, and other related terms and conditions;

•

whether the amount of payments of principal of, and any premium or make-whole amount, or interest on, the debt securities may be determined according to an index, formula or other method and how such amounts will be determined;

•

whether the debt securities will be in registered form, bearer form, or both, and (i) if in registered form, the person to whom any interest shall be payable, if other than the person in whose name the security is registered at the close of business on the regular record date for such interest, or (ii) if in bearer form, the manner in which, or the person to whom, any interest on the security shall be payable if otherwise than upon presentation and surrender upon maturity;

•

any restrictions applicable to the offer, sale or delivery of securities in bearer form and the terms upon which securities in bearer form of the series may be exchanged for securities in registered form of the series and vice versa, if permitted by applicable laws and regulations;

•

whether any debt securities of the series are to be issuable initially in temporary global form and whether any debt securities of the series are to be issuable in permanent global form with or without coupons and, if so, whether beneficial owners of interests in any such permanent global security may, or shall be required to, exchange their interests for other debt securities of the series, and the manner in which interest shall be paid;

•

the identity of the depositary for securities in registered form, if such series are to be issuable as a global security;

•

the date as of which any debt securities in bearer form or in temporary global form shall be dated if other than the original issuance date of the first security of the series to be issued;

•

the applicability, if any, of the defeasance and covenant defeasance provisions described in this prospectus or in the applicable indenture;

•

whether and under what circumstances we will pay any additional amounts on the debt securities in respect of any tax, assessment or governmental charge and, if so, whether we will have the option to redeem the debt securities in lieu of making such a payment;

•

whether and under what circumstances the debt securities being offered are convertible into common stock or other securities of ours, as the case may be, including the conversion price or rate and the manner or calculation thereof;

•

the circumstances, if any, specified in the applicable prospectus supplement, under which beneficial owners of interests in the global security may obtain definitive debt securities and the manner in which payments on a permanent global debt security will be made if any debt securities are issuable in temporary or permanent global form;

•

any provisions granting special rights to holders of securities upon the occurrence of such events as specified in the applicable prospectus supplement;

•

if the debt securities of such series are to be issuable in definitive form only upon receipt of certain certificates or other documents or satisfaction of other conditions, then the form and/or terms of such certificates, documents or conditions;

•

the name of the applicable trustee and the nature of any material relationship with us or any of our affiliates, and the percentage of debt securities of the class necessary to require the trustee to take action;

•

any deletions from, modifications of or additions to our events of default or covenants with regard to such debt securities and any change in the right of any trustee or any of the holders to declare the principal amount of any of such debt securities due and payable;

•

applicable CUSIP numbers; and

•

any other terms of such debt securities not inconsistent with the provisions of the applicable indenture.

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We may issue debt securities that provide for less than the entire principal amount thereof to be payable upon declaration of acceleration of the maturity of the debt securities. We refer to any such debt securities throughout this prospectus as “original issue discount securities.” The applicable prospectus supplement will describe the United States federal income tax consequences and other relevant considerations applicable to original issue discount securities.

We also may issue indexed debt securities. Payments of principal of, and premium and interest on, indexed debt securities are determined with reference to the rate of exchange between the currency or currency unit in which the debt security is denominated and any other currency or currency unit specified by us, to the relationship between two or more currencies or currency units or by other similar methods or formulas specified in the prospectus supplement.

Except as described under “— Merger, Consolidation or Sale of Assets” or as may be set forth in any prospectus supplement, the debt securities will not contain any provisions that (i) would limit our ability to incur indebtedness or (ii) would afford holders of debt securities protection in the event of (a) a highly leveraged or similar transaction involving us, or (b) a change of control or reorganization, restructuring, merger or similar transaction involving us that may adversely affect the holders of the debt securities. In the future, we may enter into transactions, such as the sale of all or substantially all of our assets or a merger or consolidation, that may have an adverse effect on our ability to service our indebtedness, including the debt securities, by, among other things, substantially reducing or eliminating our assets.

Our governing instruments do not define the term “substantially all” as it relates to the sale of assets. Additionally, Delaware cases interpreting the term “substantially all” rely upon the facts and circumstances of each particular case. Consequently, to determine whether a sale of “substantially all” of our assets has occurred, a holder of debt securities must review the financial and other information that we have disclosed to the public.

We will provide you with more information in the applicable prospectus supplement regarding any deletions, modifications, or additions to the events of default or covenants that are described below, including any addition of a covenant or other provision providing event risk or similar protection.

Payment

Unless we give you different information in the applicable prospectus supplement, the principal of, and any premium or make-whole amount, and interest on, any series of the debt securities will be payable at the corporate trust office of the trustee. We will provide you with the address of the trustee in the applicable prospectus supplement. We may also pay interest by mailing a check to the address of the person entitled to it as it appears in the applicable register for the debt securities or by wire transfer of funds to that person at an account maintained within the United States.

All monies that we pay to a paying agent or a trustee for the payment of the principal of, and any premium or make-whole amount, or interest on, any debt security will be repaid to us if unclaimed at the end of two years after the obligation underlying payment becomes due and payable. After funds have been returned to us, the holder of the debt security may look only to us for payment, without payment of interest for the period which we hold the funds.

Denomination, Interest, Registration and Transfer

Unless otherwise described in the applicable prospectus supplement, the debt securities of any series will be issuable in denominations of $1,000 and integral multiples of $1,000.

Subject to the limitations imposed upon debt securities that are evidenced by a computerized entry in the records of a depository company rather than by physical delivery of a note, a holder of debt securities of any series may:

•

exchange them for any authorized denomination of other debt securities of the same series and of a like aggregate principal amount and kind upon surrender of such debt securities at the corporate trust office of the applicable trustee or at the office of any transfer agent that we designate for such purpose; and

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•

surrender them for registration of transfer or exchange at the corporate trust office of the applicable trustee or at the office of any transfer agent that we designate for such purpose.

Every debt security surrendered for registration of transfer or exchange must be duly endorsed or accompanied by a written instrument of transfer satisfactory to the applicable trustee or transfer agent. Payment of a service charge will not be required for any registration of transfer or exchange of any debt securities, but we or the trustee may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith. If in addition to the applicable trustee, the applicable prospectus supplement refers to any transfer agent initially designated by us for any series of debt securities, we may at any time rescind the designation of any such transfer agent or approve a change in the location through which any such transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for such series. We may at any time designate additional transfer agents for any series of debt securities.

Neither we, nor any trustee, will be required to:

•

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

•

register the transfer of or exchange any debt security, or portion thereof, so selected for redemption, in whole or in part, except the unredeemed portion of any debt security being redeemed in part; and

•

issue, register the transfer of or exchange any debt security that has been surrendered for repayment at the option of the holder, except the portion, if any, of such debt security not to be so repaid.

Merger, Consolidation or Sale of Assets

The indentures provide that we may, without the consent of the holders of any outstanding debt securities, (i) consolidate with, (ii) sell, lease or convey all or substantially all of our assets to, or (iii) merge with or into, any other entity provided that:

•

either we are the continuing entity, or the successor entity, if other than us, assumes the obligations (a) to pay the principal of, and any premium or make-whole amount, and interest on, all of the debt securities and (b) to duly perform and observe all of the covenants and conditions contained in each indenture;

•

after giving effect to the transaction, there is no event of default under the indentures and no event which, after notice or the lapse of time, or both, would become such an event of default, occurs and continues; and

•

an officers’ certificate and legal opinion covering such conditions are delivered to each applicable trustee.

Covenants

Existence. Except as described under “— Merger, Consolidation or Sale of Assets,” the indentures require us to do or cause to be done all things necessary to preserve and keep in full force and effect our existence, rights and franchises. However, the indentures do not require us to preserve any right or franchise if we determine that any right or franchise is no longer desirable in the conduct of our business.

Payment of taxes and other claims. The indentures require us to pay, discharge or cause to be paid or discharged, before they become delinquent (i) all taxes, assessments and governmental charges levied or imposed on us, and (ii) all lawful claims for labor, materials and supplies which, if unpaid, might by law become a lien upon our property. However, we will not be required to pay, discharge or cause to be paid or discharged any such tax, assessment, charge or claim whose amount, applicability or validity is being contested in good faith by appropriate proceedings.

Provision of financial information. The indentures require us to (i) within 15 days of each of the respective dates by which we are required to file our annual reports, quarterly reports and other documents

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with the SEC, file with the trustee copies of the annual report, quarterly report and other documents that we file with the SEC under Section 13 or 15(d) of the Exchange Act, (ii) file with the trustee and the SEC any additional information, documents and reports regarding compliance by us with the conditions and covenants of the indentures, as required, (iii) within 30 days after the filing with the trustee, mail to all holders of debt securities, as their names and addresses appear in the applicable register for such debt securities, without cost to such holders, summaries of any documents and reports required to be filed by us pursuant to (i) and (ii) above, and (iv) supply, promptly upon written request and payment of the reasonable cost of duplication and delivery, copies of such documents to any prospective holder.

Additional covenants. The applicable prospectus supplement will set forth any of our additional covenants relating to any series of debt securities.

Events of Default, Notice and Waiver

Unless the applicable prospectus supplement states otherwise, when we refer to “events of default” as defined in the indentures with respect to any series of debt securities, we mean:

•

default in the payment of any installment of interest on any debt security of such series continuing for 30 days;

•

default in the payment of principal of, or any premium or make-whole amount on, any debt security of such series for five business days at its stated maturity;

•

default in making any sinking fund payment as required for any debt security of such series for five business days;

•

default in the performance or breach of any covenant or warranty in the debt securities or in the indenture by us continuing for 60 days after written notice as provided in the applicable indenture, but not of a covenant added to the indenture solely for the benefit of a series of debt securities issued thereunder other than such series;

•

a default under any bond, debenture, note, mortgage, indenture or instrument:

(i)

having an aggregate principal amount of at least $30,000,000; or

(ii)

under which there may be issued, secured or evidenced any existing or later created indebtedness for money borrowed by us, if we are directly responsible or liable as obligor or guarantor,

if the default results in the indebtedness becoming or being declared due and payable prior to the date it otherwise would have, without such indebtedness having been discharged, or such acceleration having been rescinded or annulled, within 30 days after notice to the issuing company specifying such default. Such notice shall be given to us by the trustee, or to us and the trustee by the holders of at least 10% in principal amount of the outstanding debt securities of that series. The written notice shall specify such default and require us to cause such indebtedness to be discharged or cause such acceleration to be rescinded or annulled and shall state that such notice is a “Notice of Default” under such indenture;

•

bankruptcy, insolvency or reorganization, or court appointment of a receiver, liquidator or trustee of us; and

•

any other event of default provided with respect to a particular series of debt securities.

If an event of default occurs and is continuing with respect to debt securities of any series outstanding, then the applicable trustee or the holders of 25% or more in principal amount of the debt securities of that series will have the right to declare the principal amount of all the debt securities of that series to be due and payable. If the debt securities of that series are original issue discount securities or indexed securities, then the applicable trustee or the holders of 25% or more in principal amount of the debt securities of that series will have the right to declare the portion of the principal amount as may be specified in the terms thereof to be due and payable. However, at any time after such a declaration of acceleration has been made, but before a judgment or decree for payment of the money due has been obtained by the applicable trustee, the holders

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of at least a majority in principal amount of outstanding debt securities of such series or of all debt securities then outstanding under the applicable indenture may rescind and annul such declaration and its consequences if:

•

we have deposited with the applicable trustee all required payments of the principal, any premium or make-whole amount, interest and, to the extent permitted by law, interest on overdue installment of interest, plus applicable fees, expenses, disbursements and advances of the applicable trustee; and

•

all events of default, other than the non-payment of accelerated principal, or a specified portion thereof, and any premium or make-whole amount, have been cured or waived.

The indentures also provide that the holders of at least a majority in principal amount of the outstanding debt securities of any series or of all debt securities then outstanding under the applicable indenture may, on behalf of all holders, waive any past default with respect to such series and its consequences, except a default:

•

in the payment of the principal, any premium or make-whole amount, or interest;

•

in respect of a covenant or provision contained in the applicable indenture that cannot be modified or amended without the consent of the holders of the outstanding debt security that is affected by the default; or

•

in respect of a covenant or provision for the benefit or protection of the trustee, without its express written consent.

The indentures require each trustee to give notice to the holders of debt securities within 90 days of a default unless such default has been cured or waived. However, the trustee may withhold notice if specified persons of such trustee consider such withholding to be in the interest of the holders of debt securities. The trustee may not withhold notice of a default in the payment of principal, any premium or interest on any debt security of such series or in the payment of any sinking fund installment in respect of any debt security of such series.

The indentures provide that holders of debt securities of any series may not institute any proceedings, judicial or otherwise, with respect to such indenture or for any remedy under the indenture, unless the trustee fails to act for a period of 60 days after the trustee has received a written request to institute proceedings in respect of an event of default from the holders of 25% or more in principal amount of the outstanding debt securities of such series, as well as an offer of indemnity reasonably satisfactory to the trustee. However, this provision will not prevent any holder of debt securities from instituting suit for the enforcement of payment of the principal of, and any premium or make-whole amount, and interest on, such debt securities at the respective due dates thereof.

The indentures provide that, subject to provisions in each indenture relating to its duties in the case of a default, a trustee has no obligation to exercise any of its rights or powers at the request or direction of any holders of any series of debt securities then outstanding under the indenture, unless the holders have offered to the trustee reasonable security or indemnity. The holders of at least a majority in principal amount of the outstanding debt securities of any series or of all debt securities then outstanding under an indenture shall have the right to direct the time, method and place of conducting any proceeding for any remedy available to the applicable trustee, or of exercising any trust or power conferred upon such trustee. However, a trustee may refuse to follow any direction which:

•

is in conflict with any law or the applicable indenture;

•

may involve the trustee in personal liability; or

•

may be unduly prejudicial to the holders of debt securities of the series not joining the proceeding.

Within 120 days after the close of each fiscal year, we will be required to deliver to each trustee a certificate, signed by one of our several specified officers, stating whether or not that officer has knowledge of any default under the applicable indenture. If the officer has knowledge of any default, the notice must specify the nature and status of the default.

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Modification of the Indentures

The indentures provide that modifications and amendments may be made only with the consent of the affected holders of a majority in principal amount of all outstanding debt securities issued under that indenture. However, no such modification or amendment may, without the consent of the holders of the debt securities affected by the modification or amendment:

•

change the stated maturity of the principal of, or any premium or make-whole amount on, or any installment of principal of or interest on, any such debt security;

•

reduce the principal amount of, the rate or amount of interest on, or any premium or make-whole amount payable on redemption of, any such debt security;

•

reduce the amount of principal of an original issue discount security that would be due and payable upon declaration of acceleration of the maturity thereof or would be provable in bankruptcy, or adversely affect any right of repayment of the holder of any such debt security;

•

change the place of payment or the coin or currency for payment of principal of, or any premium or make-whole amount, or interest on, any such debt security;

•

impair the right to institute suit for the enforcement of any payment on or with respect to any such debt security;

•

reduce the percentage in principal amount of any outstanding debt securities necessary to modify or amend the applicable indenture with respect to such debt securities, to waive compliance with particular provisions thereof or defaults and consequences thereunder or to reduce the quorum or voting requirements set forth in the applicable indenture; and

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modify any of the foregoing provisions or any of the provisions relating to the waiver of particular past defaults or covenants, except to increase the required percentage to effect such action or to provide that some of the other provisions may not be modified or waived without the consent of the holder of such debt security.

The holders of a majority in aggregate principal amount of the outstanding debt securities of each series may, on behalf of all holders of debt securities of that series, waive, insofar as that series is concerned, our compliance with material restrictive covenants of the applicable indenture.

We and our respective trustee may make modifications and amendments of an indenture without the consent of any holder of debt securities for any of the following purposes:

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to evidence the succession of another person to us as obligor under such indenture;

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to add to our covenants for the benefit of the holders of all or any series of debt securities or to surrender any right or power conferred upon us in such indenture;

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to add events of default for the benefit of the holders of all or any series of debt securities;

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to add or change any provisions of an indenture (i) to change or eliminate restrictions on the payment of principal of, or premium or make-whole amount, or interest on, debt securities in bearer form, or (ii) to permit or facilitate the issuance of debt securities in uncertificated form, provided that such action shall not adversely affect the interests of the holders of the debt securities of any series in any material respect;

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to change or eliminate any provisions of an indenture, provided that any such change or elimination shall become effective only when there are no debt securities outstanding of any series created prior thereto which are entitled to the benefit of such provision;

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to secure the debt securities;

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to establish the form or terms of debt securities of any series;

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to provide for the acceptance of appointment by a successor trustee or facilitate the administration of the trusts under an indenture by more than one trustee;

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to cure any ambiguity, defect or inconsistency in an indenture, provided that such action shall not adversely affect the interests of holders of debt securities of any series issued under such indenture; and

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to supplement any of the provisions of an indenture to the extent necessary to permit or facilitate defeasance and discharge of any series of such debt securities, provided that such action shall not adversely affect the interests of the holders of the outstanding debt securities of any series.

Voting

The indentures provide that in determining whether the holders of the requisite principal amount of outstanding debt securities of a series have given any request, demand, authorization, direction, notice, consent or waiver under the indentures or whether a quorum is present at a meeting of holders of debt securities:

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the principal amount of an original issue discount security that shall be deemed to be outstanding shall be the amount of the principal thereof that would be due and payable as of the date of such determination upon declaration of acceleration of the maturity thereof;

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the principal amount of any debt security denominated in a foreign currency that shall be deemed outstanding shall be the United States dollar equivalent, determined on the issue date for such debt security, of the principal amount or, in the case of an original issue discount security, the United States dollar equivalent on the issue date of such debt security of the amount determined as provided in the preceding bullet point;

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the principal amount of an indexed security that shall be deemed outstanding shall be the principal face amount of such indexed security at original issuance, unless otherwise provided for such indexed security under such indenture; and

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debt securities owned by us or any other obligor upon the debt securities or by any affiliate of ours or of such other obligor shall be disregarded.

The indentures contain provisions for convening meetings of the holders of debt securities of a series. A meeting will be permitted to be called at any time by the applicable trustee, and also, upon request, by us or the holders of at least 25% in principal amount of the outstanding debt securities of such series, in any such case upon notice given as provided in such indenture. Except for any consent that must be given by the holder of each debt security affected by the modifications and amendments of an indenture described above, any resolution presented at a meeting or adjourned meeting duly reconvened at which a quorum is present may be adopted by the affirmative vote of the holders of a majority of the aggregate principal amount of the outstanding debt securities of that series represented at such meeting.

Notwithstanding the preceding paragraph, except as referred to above, any resolution relating to a request, demand, authorization, direction, notice, consent, waiver or other action that may be made, given or taken by the holders of a specified percentage, which is less than a majority of the aggregate principal amount of the outstanding debt securities of a series, may be adopted at a meeting or adjourned meeting duly reconvened at which a quorum is present by the affirmative vote of such specified percentage.

Any resolution passed or decision taken at any properly held meeting of holders of debt securities of any series will be binding on all holders of such series. The quorum at any meeting called to adopt a resolution, and at any reconvened meeting, will be persons holding or representing a majority in principal amount of the outstanding debt securities of a series. However, if any action is to be taken relating to a consent or waiver which may be given by the holders of at least a specified percentage in principal amount of the outstanding debt securities of a series, the persons holding such percentage will constitute a quorum.

Notwithstanding the foregoing provisions, the indentures provide that if any action is to be taken at a meeting with respect to any request, demand, authorization, direction, notice, consent, waiver or other action that such indenture expressly provides may be made, given or taken by the holders of a specified percentage in principal amount of all outstanding debt securities affected by such action, or of the holders of such series and one or more additional series:

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there shall be no minimum quorum requirement for such meeting; and

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the principal amount of the outstanding debt securities of such series that vote in favor of such request, demand, authorization, direction, notice, consent, waiver or other action shall be taken account in determining whether such request, demand, authorization, direction, notice, consent, waiver or other action has been made, given or taken under such indenture.

Subordination

Unless otherwise provided in the applicable prospectus supplement, subordinated debt securities will be subject to the following subordination provisions.

Upon any distribution to our creditors in a liquidation, dissolution or reorganization, the payment of the principal of and interest on any subordinated debt securities will be subordinated to the extent provided in the applicable indenture in right of payment to the prior payment in full of all senior debt. However, our obligation to make payments of the principal of and interest on such subordinated debt securities otherwise will not be affected. No payment of principal or interest will be permitted to be made on subordinated debt securities at any time if a default on senior debt exists that permits the holders of such senior debt to accelerate its maturity and the default is the subject of judicial proceedings or we receive notice of the default. After all senior debt is paid in full and until the subordinated debt securities are paid in full, holders of subordinated debt securities will be subrogated to the rights of holders of senior debt to the extent that distributions otherwise payable to holders of subordinated debt securities have been applied to the payment of senior debt. The subordinated indenture will not restrict the amount of senior debt or other indebtedness of ours. As a result of these subordination provisions, in the event of a distribution of assets upon insolvency, holders of subordinated debt securities may recover less, ratably, than our general creditors.

The term “senior debt” will be defined in the applicable indenture as the principal of and interest on, or substantially similar payments to be made by us in respect of, other outstanding indebtedness, whether outstanding at the date of execution of the applicable indenture or subsequently incurred, created or assumed. The prospectus supplement may include a description of additional terms implementing the subordination feature.

No restrictions will be included in any indenture relating to subordinated debt securities upon the creation of additional senior debt.

If this prospectus is being delivered in connection with the offering of a series of subordinated debt securities, the accompanying prospectus supplement or the information incorporated in this prospectus by reference will set forth the approximate amount of senior debt outstanding as of the end of our most recent fiscal quarter.

Discharge, Defeasance and Covenant Defeasance

Unless otherwise indicated in the applicable prospectus supplement, the indentures allow us to discharge our obligations to holders of any series of debt securities issued under any indenture when:

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either (i) all securities of such series have already been delivered to the applicable trustee for cancellation; or (ii) all securities of such series have not already been delivered to the applicable trustee for cancellation but (a) have become due and payable, (b) will become due and payable within one year, or (c) if redeemable at our option, are to be redeemed within one year, and we have irrevocably deposited with the applicable trustee, in trust, funds in such currency or currencies, currency unit or units or composite currency or currencies in which such debt securities are payable, an amount sufficient to pay the entire indebtedness on such debt securities in respect of principal and any premium or make-whole amount, and interest to the date of such deposit if such debt securities have become due and payable or, if they have not, to the stated maturity or redemption date;

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we have paid or caused to be paid all other sums payable; and

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an officers’ certificate and an opinion of counsel stating the conditions to discharging the debt securities have been satisfied has been delivered to the trustee.

Unless otherwise indicated in the applicable prospectus supplement, the indentures provide that, upon our irrevocable deposit with the applicable trustee, in trust, of an amount, in such currency or currencies,

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currency unit or units or composite currency or currencies in which such debt securities are payable at stated maturity, or government obligations, or both, applicable to such debt securities, which through the scheduled payment of principal and interest in accordance with their terms will provide money in an amount sufficient to pay the principal of, and any premium or make-whole amount, and interest on, such debt securities, and any mandatory sinking fund or analogous payments thereon, on the scheduled due dates therefor, the issuing company may elect either:

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to defease and be discharged from any and all obligations with respect to such debt securities; or

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to be released from its obligations with respect to such debt securities under the applicable indenture or, if provided in the applicable prospectus supplement, its obligations with respect to any other covenant, and any omission to comply with such obligations shall not constitute an event of default with respect to such debt securities.

Notwithstanding the above, we may not elect to defease and be discharged from the obligation to pay any additional amounts upon the occurrence of particular events of tax, assessment or governmental charge with respect to payments on such debt securities and the obligations to register the transfer or exchange of such debt securities, to replace temporary or mutilated, destroyed, lost or stolen debt securities, to maintain an office or agency in respect of such debt securities, or to hold monies for payment in trust.

The indentures only permit us to establish the trust described in the paragraph above if, among other things, we have delivered to the applicable trustee an opinion of counsel to the effect that the holders of such debt securities will not recognize income, gain or loss for United States federal income tax purposes as a result of such defeasance or covenant defeasance and will be subject to United States federal income tax on the same amounts, in the same manner and at the same times as would have been the case if such defeasance or covenant defeasance had not occurred. Such opinion of counsel, in the case of defeasance, will be required to refer to and be based upon a ruling received from or published by the Internal Revenue Service or a change in applicable United States federal income tax law occurring after the date of the indenture. In the event of such defeasance, the holders of such debt securities would be able to look only to such trust fund for payment of principal, any premium or make-whole amount, and interest.

When we use the term “government obligations,” we mean securities that are:

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direct obligations of the United States or the government that issued the foreign currency in which the debt securities of a particular series are payable, for the payment of which its full faith and credit is pledged; or

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obligations of a person controlled or supervised by and acting as an agency or instrumentality of the United States or other government that issued the foreign currency in which the debt securities of such series are payable, the payment of which is unconditionally guaranteed as a full faith and credit obligation by the United States or such other government, which are not callable or redeemable at the option of the issuer thereof and shall also include a depository receipt issued by a bank or trust company as custodian with respect to any such government obligation or a specific payment of interest on or principal of any such government obligation held by such custodian for the account of the holder of a depository receipt. However, except as required by law, such custodian is not authorized to make any deduction from the amount payable to the holder of such depository receipt from any amount received by the custodian in respect of the government obligation or the specific payment of interest on or principal of the government obligation evidenced by such depository receipt.

Unless otherwise provided in the applicable prospectus supplement, if after we have deposited funds and/or government obligations to effect defeasance or covenant defeasance with respect to debt securities of any series, (i) the holder of a debt security of such series is entitled to, and does, elect under the terms of the applicable indenture or the terms of such debt security to receive payment in a currency, currency unit or composite currency other than that in which such deposit has been made in respect of such debt security, or (ii) a conversion event occurs in respect of the currency, currency unit or composite currency in which such deposit has been made, the indebtedness represented by such debt security will be deemed to have been, and will be, fully discharged and satisfied through the payment of the principal of, and premium or make-whole amount, and interest on, such debt security as they become due out of the proceeds yielded by converting the amount so deposited in respect of such debt security into the currency, currency unit or

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composite currency in which such debt security becomes payable as a result of such election or such cessation of usage based on the applicable market exchange rate.

When we use the term “conversion event,” we mean the cessation of use of:

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a currency, currency unit or composite currency both by the government of the country that issued such currency and for the settlement of transactions by a central bank or other public institutions of or within the international banking community;

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the European Currency Unit both within the European Monetary System and for the settlement of transactions by public institutions of or within the European Communities; or

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any currency unit or composite currency other than the European Currency Unit for the purposes for which it was established.

Unless otherwise provided in the applicable prospectus supplement, all payments of principal of, and any premium or make-whole amount, and interest on, any debt security that is payable in a foreign currency that ceases to be used by its government of issuance shall be made in United States dollars.

In the event that (i) we effect covenant defeasance with respect to any debt securities and (ii) those debt securities are declared due and payable because of the occurrence of any event of default, the amount in the currency, currency unit or composite currency in which such debt securities are payable, and government obligations on deposit with the applicable trustee, will be sufficient to pay amounts due on such debt securities at the time of their stated maturity but may not be sufficient to pay amounts due on such debt securities at the time of the acceleration resulting from such event of default. However, the issuing company would remain liable to make payments of any amounts due at the time of acceleration.

The applicable prospectus supplement may further describe the provisions, if any, permitting such defeasance or covenant defeasance, including any modifications to the provisions described above, with respect to the debt securities of or within a particular series.

Conversion Rights

The terms and conditions, if any, upon which the debt securities are convertible into common stock or other securities of ours will be set forth in the applicable prospectus supplement. The terms will include whether the debt securities are convertible into shares of common stock or other securities of ours, the conversion price, or manner of calculation thereof, the conversion period, provisions as to whether conversion will be at the issuing company’s option or the option of the holders, the events requiring an adjustment of the conversion price and provisions affecting conversion in the event of the redemption of the debt securities and any restrictions on conversion.

Global Securities

The debt securities of a series may be issued in whole or in part in the form of one or more global securities that will be deposited with, or on behalf of, a depository identified in the applicable prospectus supplement relating to such series. Global securities, if any, issued in the United States are expected to be deposited with The Depository Trust Company, or DTC, as depository. We may issue global securities in either registered or bearer form and in either temporary or permanent form. We will describe the specific terms of the depository arrangement with respect to a series of debt securities in the applicable prospectus supplement relating to such series. We expect that unless the applicable prospectus supplement provides otherwise, the following provisions will apply to depository arrangements.

Once a global security is issued, the depository for such global security or its nominee will credit on its book-entry registration and transfer system the respective principal amounts of the individual debt securities represented by such global security to the accounts of participants that have accounts with such depository. Such accounts shall be designated by the underwriters, dealers or agents with respect to such debt securities or by us if we offer such debt securities directly. Ownership of beneficial interests in such global security will be limited to participants with the depository or persons that may hold interests through those participants.

We expect that, under procedures established by DTC, ownership of beneficial interests in any global security for which DTC is the depository will be shown on, and the transfer of that ownership will be effected

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only through, records maintained by DTC or its nominee, with respect to beneficial interests of participants with the depository, and records of participants, with respect to beneficial interests of persons who hold through participants with the depository. Neither we nor the trustee will have any responsibility or liability for any aspect of the records of DTC or for maintaining, supervising or reviewing any records of DTC or any of its participants relating to beneficial ownership interests in the debt securities. The laws of some states require that certain purchasers of securities take physical delivery of such securities in definitive form. Such limits and laws may impair the ability to own, pledge or transfer beneficial interest in a global security.

So long as the depository for a global security or its nominee is the registered owner of such global security, such depository or such nominee, as the case may be, will be considered the sole owner or holder of the debt securities represented by the global security for all purposes under the applicable indenture. Except as described below or in the applicable prospectus supplement, owners of beneficial interest in a global security will not be entitled to have any of the individual debt securities represented by such global security registered in their names, will not receive or be entitled to receive physical delivery of any such debt securities in definitive form and will not be considered the owners or holders thereof under the applicable indenture. Beneficial owners of debt securities evidenced by a global security will not be considered the owners or holders thereof under the applicable indenture for any purpose, including with respect to the giving of any direction, instructions or approvals to the trustee under the indenture. Accordingly, each person owning a beneficial interest in a global security with respect to which DTC is the depository must rely on the procedures of DTC and, if such person is not a participant with the depository, on the procedures of the participant through which such person owns its interests, to exercise any rights of a holder under the applicable indenture. We understand that, under existing industry practice, if DTC requests any action of holders or if an owner of a beneficial interest in a global security desires to give or take any action which a holder is entitled to give or take under the applicable indenture, DTC would authorize the participants holding the relevant beneficial interest to give or take such action, and such participants would authorize beneficial owners through such participants to give or take such actions or would otherwise act upon the instructions of beneficial owners holding through them.

Payments of principal of, and any premium or make-whole amount, and interest on, individual debt securities represented by a global security registered in the name of a depository or its nominee will be made to or at the direction of the depository or its nominee, as the case may be, as the registered owner of the global security under the applicable indenture. Under the terms of the applicable indenture, we and the trustee may treat the persons in whose name debt securities, including a global security, are registered as the owners thereof for the purpose of receiving such payments. Consequently, neither we nor the trustee have or will have any responsibility or liability for the payment of such amounts to beneficial owners of debt securities including principal, any premium or make-whole amount, or interest. We believe, however, that it is currently the policy of DTC to immediately credit the accounts of relevant participants with such payments, in amounts proportionate to their respective holdings of beneficial interests in the relevant global security as shown on the records of DTC or its nominee. We also expect that payments by participants to owners of beneficial interests in such global security held through such participants will be governed by standing instructions and customary practices, as is the case with securities held for the account of customers in bearer form or registered in street name, and will be the responsibility of such participants. Redemption notices with respect to any debt securities represented by a global security will be sent to the depository or its nominee. If less than all of the debt securities of any series are to be redeemed, we expect the depository to determine the amount of the interest of each participant in such debt securities to be redeemed to be determined by lot. Neither we, the trustee, any paying agent nor the security registrar for such debt securities will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in the global security for such debt securities or for maintaining any records with respect thereto.

Neither we nor the trustee will be liable for any delay by the holders of a global security or the depository in identifying the beneficial owners of debt securities, and we and the trustee may conclusively rely on, and will be protected in relying on, instructions from the holder of a global security or the depository for all purposes. The rules applicable to DTC and its participants are on file with the SEC.

If a depository for any debt securities is at any time unwilling, unable or ineligible to continue as depository and we do not appoint a successor depository within 90 days, we will issue individual debt

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securities in exchange for the global security representing such debt securities. In addition, we may at any time and at our sole discretion, subject to any limitations described in the applicable prospectus supplement relating to such debt securities, determine not to have any of such debt securities represented by one or more global securities and in such event will issue individual debt securities in exchange for the global security or securities representing such debt securities. Individual debt securities so issued will be issued in denominations of $1,000 and integral multiples of $1,000.

The debt securities of a series may also be issued in whole or in part in the form of one or more bearer global securities that will be deposited with a depository, or with a nominee for such depository, identified in the applicable prospectus supplement. Any such bearer global securities may be issued in temporary or permanent form. The specific terms and procedures, including the specific terms of the depositary arrangement, with respect to any portion of a series of debt securities to be represented by one or more bearer global securities will be described in the applicable prospectus supplement.

No Recourse

There is no recourse under any obligation, covenant or agreement in the applicable indenture or with respect to any security against any of our or our successor’s past, present or future shareholders, employees, officers or directors.

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DESCRIPTION OF WARRANTS

The following description, together with the additional information we may include in any applicable prospectus supplements, summarizes the material terms and provisions of the warrants that we may offer under this prospectus and the related warrant agreements and warrant certificates. While the terms summarized below will apply generally to any warrants that we may offer, we will describe the particular terms of any series of warrants in more detail in the applicable prospectus supplement. If we indicate in the prospectus supplement, the terms of any warrants offered under that prospectus supplement may differ from the terms described below. Specific warrant agreements will contain additional important terms and provisions and will be incorporated by reference as an exhibit to the registration statement, which includes this prospectus.

General

We may issue warrants for the purchase of common stock, preferred stock and/or debt securities in one or more series. We may issue warrants independently or together with common stock, preferred stock and/or debt securities, and the warrants may be attached to or separate from these securities.

We will evidence each series of warrants by warrant certificates that we will issue under a separate warrant agreement. We will enter into the warrant agreement with a warrant agent. We will indicate the name and address of the warrant agent in the applicable prospectus supplement relating to a particular series of warrants.

We will describe in the applicable prospectus supplement the terms of the series of warrants, including:

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the offering price and aggregate number of warrants offered;

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the currency for which the warrants may be purchased;

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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;

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if applicable, the date on and after which the warrants and the related securities will be separately transferable;

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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;

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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;

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the effect of any merger, consolidation, sale or other disposition of our business on the warrant agreement and the warrants;

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the terms of any rights to redeem or call the warrants;

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any provisions for changes to or adjustments in the exercise price or number of securities issuable upon exercise of the warrants;

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the periods during which, and places at which, the warrants are exercisable;

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the manner of exercise;

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

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the manner in which the warrant agreement and warrants may be modified;

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federal income tax consequences of holding or exercising the warrants;

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the terms of the securities issuable upon exercise of the warrants; and

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any other specific terms, preferences, rights or limitations of or restrictions on the warrants.

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DESCRIPTION OF UNITS

We may issue units comprised of shares of common stock, shares of preferred stock, debt securities and warrants in any combination. We may issue units in such amounts and in as many distinct series as we wish. This section outlines certain provisions of the units that we may issue. If we issue units, they will be issued under one or more unit agreements to be entered into between us and a bank or other financial institution, as unit agent. The information described in this section may not be complete in all respects and is qualified entirely by reference to the unit agreement with respect to the units of any particular series. The specific terms of any series of units offered will be described in the applicable prospectus supplement. If so described in a particular supplement, the specific terms of any series of units may differ from the general description of terms presented below. We urge you to read any prospectus supplement related to any series of units we may offer, as well as the complete unit agreement and unit certificate that contain the terms of the units. If we issue units, forms of unit agreements and unit certificates relating to such units will be incorporated by reference as exhibits to the registration statement, which includes this prospectus.

Each unit that we may issue will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security. The unit agreement under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately, at any time or at any time before a specified date. The applicable prospectus supplement may describe:

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the designation and terms of the units and of the securities comprising the units, including whether and under what circumstances those securities may be held or transferred separately;

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any provisions of the governing unit agreement;

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the price or prices at which such units will be issued;

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the applicable United States federal income tax considerations relating to the units;

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any provisions for the issuance, payment, settlement, transfer or exchange of the units or of the securities comprising the units; and

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any other terms of the units and of the securities comprising the units.

The provisions described in this section, as well as those described under “Description of Capital Stock,” “Description of Debt Securities” and “Description of Warrants” will apply to the securities included in each unit, to the extent relevant and as may be updated in any prospectus supplements.

Issuance in Series

We may issue units in such amounts and in as many distinct series as we wish. This section summarizes terms of the units that apply generally to all series. Most of the financial and other specific terms of your series will be described in the applicable prospectus supplement.

Unit Agreements

We will issue the units under one or more unit agreements to be entered into between us and a bank or other financial institution, as unit agent. We may add, replace or terminate unit agents from time to time. We will identify the unit agreement under which each series of units will be issued and the unit agent under that agreement in the applicable prospectus supplement.

The following provisions will generally apply to all unit agreements unless otherwise stated in the applicable prospectus supplement:

Modification without Consent

We and the applicable unit agent may amend any unit or unit agreement without the consent of any holder:

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to cure any ambiguity, including modifying any provisions of the governing unit agreement that differ from those described below;

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to correct or supplement any defective or inconsistent provision; or

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to make any other change that we believe is necessary or desirable and will not adversely affect the interests of the affected holders in any material respect.

We do not need any approval to make changes that affect only units to be issued after the changes take effect. We may also make changes that do not adversely affect a particular unit in any material respect, even if they adversely affect other units in a material respect. In those cases, we do not need to obtain the approval of the holder of the unaffected unit; we need only obtain any required approvals from the holders of the affected units.

Modification with Consent

We may not amend any particular unit or a unit agreement with respect to any particular unit unless we obtain the consent of the holder of that unit, if the amendment would:

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impair any right of the holder to exercise or enforce any right under a security included in the unit if the terms of that security require the consent of the holder to any changes that would impair the exercise or enforcement of that right; or

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reduce the percentage of outstanding units or any series or class the consent of whose holders is required to amend that series or class, or the applicable unit agreement with respect to that series or class, as described below.

Any other change to a particular unit agreement and the units issued under that agreement would require the following approval:

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If the change affects only the units of a particular series issued under that agreement, the change must be approved by the holders of a majority of the outstanding units of that series; or

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If the change affects the units of more than one series issued under that agreement, it must be approved by the holders of a majority of all outstanding units of all series affected by the change, with the units of all the affected series voting together as one class for this purpose.

These provisions regarding changes with majority approval also apply to changes affecting any securities issued under a unit agreement, as the governing document.

In each case, the required approval must be given by written consent.

Unit Agreements Will Not Be Qualified under Trust Indenture Act

No unit agreement will be qualified as an indenture, and no unit agent will be required to qualify as a trustee, under the Trust Indenture Act. Therefore, holders of units issued under unit agreements will not have the protections of the Trust Indenture Act with respect to their units.

Mergers and Similar Transactions Permitted; No Restrictive Covenants or Events of Default

The unit agreements will not restrict our ability to merge or consolidate with, or sell our assets to, another corporation or other entity or to engage in any other transactions. If at any time we merge or consolidate with, or sell our assets substantially as an entirety to, another corporation or other entity, the successor entity will succeed to and assume our obligations under the unit agreements. We will then be relieved of any further obligation under these agreements.

The unit agreements will not include any restrictions on our ability to put liens on our assets, nor will they restrict our ability to sell our assets. The unit agreements also will not provide for any events of default or remedies upon the occurrence of any events of default.

Governing Law

The unit agreements and the units will be governed by Delaware law.

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Form, Exchange and Transfer

Unless the accompanying prospectus supplement states otherwise, we will issue each unit in global — i.e., book-entry — form only. Units in book-entry form will be represented by a global security registered in the name of a depositary, which will be the holder of all the units represented by the global security. Those who own beneficial interests in a unit will do so through participants in the depositary’s system, and the rights of these indirect owners will be governed solely by the applicable procedures of the depositary and its participants. We will describe book-entry securities, and other terms regarding the issuance and registration of the units in the applicable prospectus supplement.

Unless the accompanying prospectus supplement states otherwise, each unit and all securities comprising the unit will be issued in the same form.

If we issue any units in registered, non-global form, the following will apply to them.

The units will be issued in the denominations stated in the applicable prospectus supplement. Holders may exchange their units for units of smaller denominations or combined into fewer units of larger denominations, as long as the total amount is not changed.

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Holders may exchange or transfer their units at the office of the unit agent. Holders may also replace lost, stolen, destroyed or mutilated units at that office. We may appoint another entity to perform these functions or perform them ourselves.

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Holders will not be required to pay a service charge to transfer or exchange their units, but they may be required to pay for any tax or other governmental charge associated with the transfer or exchange. The transfer or exchange, and any replacement, will be made only if our transfer agent is satisfied with the holder’s proof of legal ownership. The transfer agent may also require an indemnity before replacing any units.

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If we have the right to redeem, accelerate or settle any units before their maturity, and we exercise our right as to less than all those units or other securities, we may block the exchange or transfer of those units during the period beginning 15 days before the day we mail the notice of exercise and ending on the day of that mailing, in order to freeze the list of holders to prepare the mailing. We may also refuse to register transfers of or exchange any unit selected for early settlement, except that we will continue to permit transfers and exchanges of the unsettled portion of any unit being partially settled. We may also block the transfer or exchange of any unit in this manner if the unit includes securities that are or may be selected for early settlement.

Only the depositary will be entitled to transfer or exchange a unit in global form, since it will be the sole holder of the unit.

Payments and Notices

In making payments and giving notices with respect to our units, we will follow the procedures as described in the applicable prospectus supplement.

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PLAN OF DISTRIBUTION

We may sell securities:

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through underwriters;

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through dealers;

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through agents;

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directly to purchasers; or

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through a combination of any of these methods or any other method permitted by law.

In addition, we may issue the securities as a dividend or distribution or in a subscription rights offering to our existing security holders.

We may directly solicit offers to purchase securities, or agents may be designated to solicit such offers. In the prospectus supplement relating to such offering, we will name any agent that could be viewed as an underwriter under the Securities Act and describe any commissions that we must pay to any such agent. Any such agent will be acting on a best efforts basis for the period of its appointment or, if indicated in the applicable prospectus supplement, on a firm commitment basis. This prospectus may be used in connection with any offering of our securities through any of these methods or other methods described in the applicable prospectus supplement.

The distribution of the securities may be effected from time to time in one or more transactions:

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at a fixed price, or prices, which may be changed from time to time;

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at market prices prevailing at the time of sale;

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at prices related to such prevailing market prices; or

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at negotiated prices.

Each prospectus supplement will describe the method of distribution of the securities and any applicable restrictions.

The prospectus supplement with respect to the securities of a particular series will describe the terms of the offering of the securities, including the following:

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the name of the agent or any underwriters;

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the public offering or purchase price;

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any discounts and commissions to be allowed or paid to the agent or underwriters;

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all other items constituting underwriting compensation;

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any discounts and commissions to be allowed or paid to dealers; and

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any exchanges on which the securities will be listed.

If any underwriters or agents are used in the sale of the securities in respect of which this prospectus is delivered, we will enter into an underwriting agreement, sales agreement or other agreement with them at the time of sale to them, and we will set forth in the prospectus supplement relating to such offering the names of the underwriters or agents and the terms of the related agreement with them.

In connection with the offering of securities, we may grant to the underwriters an option to purchase additional securities with an additional underwriting commission, as may be set forth in the accompanying prospectus supplement. If we grant any such option, the terms of such option will be set forth in the prospectus supplement for such securities.

If a dealer is used in the sale of the securities in respect of which the prospectus is delivered, we will sell such securities to the dealer, as principal. The dealer, who may be deemed to be an “underwriter” as that term

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is defined in the Securities Act, may then resell such securities to the public at varying prices to be determined by such dealer at the time of resale.

If we offer securities in a subscription rights offering to our existing security holders, we may enter into a standby underwriting agreement with dealers, acting as standby underwriters. We may pay the standby underwriters a commitment fee for the securities they commit to purchase on a standby basis. If we do not enter into a standby underwriting arrangement, we may retain a dealer-manager to manage a subscription rights offering for us.

Agents, underwriters, dealers and other persons may be entitled under agreements which they may enter into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, and may be customers of, engage in transactions with or perform services for us in the ordinary course of business.

If so indicated in the applicable prospectus supplement, we will authorize underwriters or other persons acting as our agents to solicit offers by certain institutions to purchase securities from us pursuant to delayed delivery contracts providing for payment and delivery on the date stated in the prospectus supplement. Each contract will be for an amount not less than, and the aggregate amount of securities sold pursuant to such contracts shall not be less nor more than, the respective amounts stated in the prospectus supplement. Institutions with whom the contracts, when authorized, may be made include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and other institutions, but shall in all cases be subject to our approval. Delayed delivery contracts will not be subject to any conditions except that:

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the purchase by an institution of the securities covered under that contract shall not at the time of delivery be prohibited under the laws of the jurisdiction to which that institution is subject; and

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if the securities are also being sold to underwriters acting as principals for their own account, the underwriters shall have purchased such securities not sold for delayed delivery. The underwriters and other persons acting as our agents will not have any responsibility in respect of the validity or performance of delayed delivery contracts.

Offered securities may also be offered and sold, if so indicated in the prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more remarketing firms, acting as principals for their own accounts or as agents for us. Any remarketing firm will be identified and the terms of its agreement, if any, with us and its compensation will be described in the applicable prospectus supplement. Remarketing firms may be deemed to be underwriters in connection with their remarketing of offered securities.

Certain agents, underwriters and dealers, and their associates and affiliates, may be customers of, have borrowing relationships with, engage in other transactions with, or perform services, including investment banking services, for us or one or more of our respective affiliates in the ordinary course of business.

In order to facilitate the offering of the securities, any underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the securities or any other securities the prices of which may be used to determine payments on such securities. Specifically, any underwriters may overallot in connection with the offering, creating a short position for their own accounts. In addition, to cover overallotments or to stabilize the price of the securities or of any such other securities, the underwriters may bid for, and purchase, the securities or any such other securities in the open market. Finally, in any offering of the securities through a syndicate of underwriters, the underwriting syndicate may reclaim selling concessions allowed to an underwriter or a dealer for distributing the securities in the offering if the syndicate repurchases previously distributed securities in transactions to cover syndicate short positions, in stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the securities above independent market levels. Any such underwriters are not required to engage in these activities and may end any of these activities at any time.

We may engage in at the market offerings into an existing trading market in accordance with Rule 415 (a)(4) under the Securities Act. In addition, we may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions.

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If the applicable prospectus supplement so indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities pledged by us or borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in such sale transactions will be an underwriter and, if not identified in this prospectus, will be named in the applicable prospectus supplement (or a post-effective amendment). In addition, we may otherwise loan or pledge securities to a financial institution or other third party that in turn may sell the securities short using this prospectus and an applicable prospectus supplement. Such financial institution or other third party may transfer its economic short position to investors in our securities or in connection with a concurrent offering of other securities.

Under Rule 15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in two business days, unless the parties to any such trade expressly agree otherwise. The applicable prospectus supplement may provide that the original issue date for your securities may be more than two scheduled business days after the trade date for your securities. Accordingly, in such a case, if you wish to trade securities on any date prior to the second business day before the original issue date for your securities, you will be required, by virtue of the fact that your securities initially are expected to settle in more than two scheduled business days after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

The securities may be new issues of securities and may have no established trading market. The securities may or may not be listed on a national securities exchange. We can make no assurance as to the liquidity of or the existence of trading markets for any of the securities.

The specific terms of any lock-up provisions in respect of any given offering will be described in the applicable prospectus supplement.

The underwriters, dealers and agents may engage in transactions with us, or perform services for us, in the ordinary course of business for which they receive compensation.

The anticipated date of delivery of offered securities will be set forth in the applicable prospectus supplement relating to each offer.

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LEGAL MATTERS

Certain legal matters in connection with this offering will be passed upon for us by Goodwin Procter LLP, Boston, Massachusetts. Any underwriters will also be advised about the validity of the securities and other legal matters by their own counsel, which will be named in the prospectus supplement.

EXPERTS

Ernst & Young 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, 2021, 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 Ernst & Young LLP’s report, given on their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We are subject to the information requirements of the Exchange Act and, in accordance therewith, file annual, quarterly and special reports, proxy statements and other information with the SEC. These documents also may be accessed through the SEC’s electronic data gathering, analysis and retrieval system, or EDGAR, via electronic means, including the SEC’s home page on the Internet (www.sec.gov).

We have the authority to designate and issue more than one class or series of stock having various preferences, conversion and other rights, voting powers, restrictions, limitations as to dividends, qualifications, and terms and conditions of redemption. See “Description of Capital Stock.” We will furnish a full statement of the relative rights and preferences of each class or series of our stock which has been so designated and any restrictions on the ownership or transfer of our stock to any shareholder upon request and without charge. Written requests for such copies should be directed to Investor Relations, Scholar Rock Holding Corporation, 301 Binney Street, Cambridge, MA 02142. Our website is located at http://www.scholarrock.com. Information contained on our website is not incorporated by reference into this prospectus and, therefore, is not part of this prospectus or any accompanying prospectus supplement.

INCORPORATION BY REFERENCE

The SEC allows us to incorporate by reference the information and reports we file with it, which means that we can disclose important information to you by referring you to these documents. The information incorporated by reference is an important part of this prospectus, and information that we file later with the SEC will automatically update and supersede the information already incorporated by reference. We are incorporating by reference the documents listed below, which we have already filed with the SEC, and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, including all filings made after the date of the filing of this registration statement and prior to the effectiveness of this registration statement, except as to any portion of any future report or document that is not deemed filed under such provisions, until we sell all of the securities:

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our Annual Report on Form 10-K for the year ended December 31, 2021 filed with the SEC on March 7, 2022;

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our Definitive Proxy Statement on Schedule 14A (other than information furnished rather than filed), filed with the SEC on April 23, 2020; and

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Upon request, we will provide, without charge, to each person, including any beneficial owner, to whom a copy of this prospectus is delivered, a copy of the documents incorporated by reference into this prospectus but not delivered with the prospectus. You may request a copy of these filings, and any exhibits we have specifically incorporated by reference as an exhibit in this prospectus, at no cost by writing us at the following address: Investor Relations, Scholar Rock Holding Corporation, 301 Binney Street, Cambridge, MA 02142.

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This prospectus is part of a registration statement we filed with the SEC. We have incorporated exhibits into this registration statement. You should read the exhibits carefully for provisions that may be important to you.

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

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16,326,530 shares of common stock
Pre-funded warrants to purchase up to 25,510,205 shares of common stock
Common warrants to purchase up to 10,459,181 shares of common stock

PROSPECTUS

J.P. Morgan

Piper Sandler

June 17, 2022

Scholar Rock Holding (SRRK) 424B5Prospectus supplement for primary offering