10-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended DECEMBER 31, 2025

Commission File Number 001-40602

ERASCA, INC.

(Exact name of Registrant as specified in its Charter)

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code: (858) 465-6511

Securities registered pursuant to Section 12(b) of the Act:

Title of each class TradingSymbol(s) Name of each exchange on which registered

Common Stock, $0.0001 par value per share ERAS Nasdaq Global Select Market

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☐No ☒

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. YES ☐ No ☒

Indicate by check mark whether the Registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes☒ NO ☐

Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files). Yes☒NO ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer ☐ Accelerated filer ☐

Non-accelerated filer ☒ Smaller reporting company ☒

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).☐

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). YES ☐ NO ☒

The aggregate market value of the Registrant's common stock held by non-affiliates of the Registrant was approximately $316.4 million based on the closing price of the Registrant's common stock as reported on the Nasdaq Global Select Market of $1.27 per share on June 30, 2025, the last business day of the Registrant's most recently completed second quarter. Shares of common stock held by each executive officer and director and by each other person who may be deemed to be an affiliate of the Registrant have been excluded from this computation. The determination of affiliate status for this purpose is not necessarily a conclusive determination for other purposes.

The number of shares of Registrant’s Common Stock outstanding as of March 5, 2026 was 310,799,547.

DOCUMENTS INCORPORATED BY REFERENCE

Certain sections of the Registrant’s definitive proxy statement for the 2026 annual meeting of stockholders to be filed with the Securities and Exchange Commission pursuant to Regulation 14A not later than 120 days after the end of the fiscal year covered by this Form 10-K are incorporated by reference into Part III of this Form 10-K.

Table of Contents

Page

PART I

Item 1. Business 3

Item 1A. Risk Factors 45

Item 1B. Unresolved Staff Comments 98

Item 1C. Cybersecurity 99

Item 2. Properties 100

Item 3. Legal Proceedings 100

Item 4. Mine Safety Disclosures 100

PART II

Item 6. [Reserved] 101

Item 7A. Quantitative and Qualitative Disclosures About Market Risk 114

Item 8. Financial Statements and Supplementary Data 114

Item 9A. Controls and Procedures 115

Item 9B. Other Information 115

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections 115

PART III

Item 10. Directors, Executive Officers and Corporate Governance 116

Item 11. Executive Compensation 116

Item 14. Principal Accountant Fees and Services 116

PART IV

Item 15. Exhibits, Financial Statement Schedules 117

PART I

Forward-Looking Statements and Market Data

This Annual Report on Form 10-K contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended (the Exchange Act), and Section 27A of the Securities Act of 1933, as amended (the Securities Act). All statements other than statements of historical facts contained in this Annual Report on Form 10-K, including statements regarding our future results of operations and financial position, business strategy, research and development plans, the anticipated timing, costs, design and conduct of our ongoing and planned preclinical studies and planned clinical trials for our product candidates, the timing and likelihood of regulatory filings and approvals for our product candidates, our ability to commercialize our product candidates, if approved, the pricing and reimbursement of our product candidates, if approved, the impact of global geopolitical and economic events and war on our business, the potential to develop future product candidates, the potential benefits of current and future licenses, acquisitions, and strategic arrangements with third parties, and our intent to enter into any future strategic arrangements, the timing and likelihood of success, plans and objectives of management for future operations, and future results of anticipated product development efforts, are forward-looking statements. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. This Annual Report on Form 10-K also contains estimates and other statistical data made by independent parties and by us relating to market size and growth and other data about our industry. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions and estimates of our future performance and the future performance of the markets in which we operate are necessarily subject to a high degree of uncertainty and risk.

In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “contemplate,” “believe,” “estimate,” “predict,” “potential” or “continue” or the negative of these terms or other similar expressions. The forward-looking statements in this Annual Report on Form 10-K are only predictions. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. These forward-looking statements speak only as of the date of this Annual Report on Form 10-K and are subject to a number of risks, uncertainties and assumptions, including those described in Part I, Item 1A, “Risk Factors.” The events and circumstances reflected in our forward-looking statements may not be achieved or occur, and actual results could differ materially from those projected in the forward-looking statements. Moreover, we operate in an evolving environment. New risk factors and uncertainties may emerge from time to time, and it is not possible for management to predict all risk factors and uncertainties. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

This Annual Report on Form 10-K includes our trademarks as well as trademarks, tradenames and service marks that are the property of other organizations. Solely for convenience, trademarks and tradenames referred to in this Annual Report on Form 10-K appear without the ® and TM symbols, but those references are not intended to indicate, in any way, that we will not assert, to the fullest extent under applicable law, our rights, or that the applicable owner will not assert its rights, to these trademarks and tradenames.

We maintain a website at www.erasca.com, to which we regularly post copies of our press releases as well as additional

information about us. Our filings with the Securities and Exchange Commission (SEC) are available free of charge through our website as soon as reasonably practicable after being electronically filed with or furnished to the SEC. Information contained in our website does not constitute a part of this report or our other filings with the SEC.

Risk Factor Summary

Below is a summary of the principal factors that make an investment in our common stock speculative or risky. This summary does not address all of the risks that we face. Additional discussion of the risks summarized in this risk factor summary, and other risks that we face, can be found below under the heading “Risk Factors” in Item 1A of Part I of this Annual Report on Form 10-K, and should be carefully considered, together with other information in this Annual Report on Form 10-K and our other filings with the SEC before making investment decisions regarding our common stock.

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We have a limited operating history, have incurred significant operating losses since our inception and expect to incur significant losses for the foreseeable future. We may never generate any revenue or become profitable or, if we achieve profitability, we may not be able to sustain it.

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We will require substantial additional capital to finance our operations, and a failure to obtain this necessary capital when needed on acceptable terms, or at all, could force us to delay, limit, reduce or terminate our development programs, commercialization efforts or other operations.

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If we are unable to successfully develop and commercialize our product candidates or experience significant delays in doing so, our business will be materially harmed.

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Our approach to the discovery and development of product candidates is unproven, and we do not know whether we will be able to develop any products of commercial value, or if competing approaches will limit the commercial value of our product candidates.

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Clinical and preclinical development involves a lengthy and expensive process with an uncertain outcome, and the results of preclinical studies and early clinical trials are not necessarily predictive of future results. Our product candidates may not have favorable results in clinical trials, if any, or receive regulatory approval on a timely basis, or at all.

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Any difficulties or delays in the commencement or completion, or termination or suspension, of our current or future clinical trials could result in increased costs to us, delay or limit our ability to generate revenue and adversely affect our commercial prospects.

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Use of our product candidates could be associated with side effects, adverse events or other properties or safety risks, which could delay or preclude approval, cause us to suspend or discontinue clinical trials, abandon a product candidate, limit the commercial profile of an approved label or result in other significant negative consequences that could severely harm our business, prospects, operating results and financial condition.

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We rely on third parties to conduct many of our preclinical studies and clinical trials and to manufacture our product candidates, and these third parties may not perform satisfactorily.

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We face significant competition from entities that have developed or may develop product candidates for cancer, including companies developing novel treatments and technology platforms. If our competitors develop technologies or product candidates more rapidly than we do or their technologies are more effective, our business and our ability to develop and successfully commercialize products may be adversely affected.

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Our success depends on our ability to protect our intellectual property and our proprietary technologies.

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The trading price of the shares of our common stock has been, and is likely to continue to be highly volatile, and purchasers of our common stock could incur substantial losses.

Item 1. Business.

Overview

At Erasca, our name is our mission: to erase cancer.

We are a clinical-stage precision oncology company singularly focused on discovering, developing, and commercializing therapies for patients with RAS/MAPK pathway-driven cancers. Molecular alterations in RAS, the most frequently mutated oncogene, and the MAPK pathway, one of the most frequently altered signaling pathways in cancer, account for more than five million new patients diagnosed with cancer globally each year. Our company was co-founded by leading pioneers in precision oncology and RAS targeting to create novel therapies and combination regimens designed to comprehensively shut down the RAS/MAPK pathway for the treatment of patients with cancer. Our focused RAS/MAPK pathway pipeline comprises modality-agnostic programs aligned with our three therapeutic strategies of: (1) targeting key upstream and downstream signaling nodes in the RAS/MAPK pathway; (2) targeting RAS directly; and (3) targeting escape routes that emerge in response to treatment. Our pipeline enables us to pursue a systematic, data-driven, portfolio-wide clinical development effort to identify therapeutic approaches with the goal of prolonging survival in numerous patient populations with high unmet medical needs.

Our modality-agnostic approach aims to allow us to selectively and potently target critical signaling nodes with the most appropriate modality, including small and large molecule therapeutics. Our purpose-built pipeline includes two clinical-stage programs (ERAS-0015, a pan-RAS molecular glue; and ERAS-4001, a pan-KRAS inhibitor), and ERAS-12, a discovery-stage program (an EGFR D2/D3 biparatopic antibody), for which we have identified a lead candidate. We believe our world-class team’s capabilities and experience, further guided by our scientific advisory board (SAB), which includes the world’s leading experts in the RAS/MAPK pathway, uniquely position us to achieve our bold mission of erasing cancer.

Of the more than five million new patients diagnosed globally per year with cancers driven by RAS/MAPK pathway molecular alterations, most have limited or no targeted therapy treatment options. While the RAS/MAPK pathway has been well characterized and validated based on multiple compounds approved or in development targeting discrete signaling nodes in the cascade, most of these compounds face resistance and tolerability challenges, highlighting the need for new approaches to target this pathway. We believe that to effectively shut down a pathway that signals as promiscuously as RAS/MAPK, a holistic approach must be taken to target not just individual nodes, but multiple nodes and cooperative mechanisms in parallel. As depicted in the following figure and described below, we are pursuing three therapeutic strategies that may be used in combination with the goal of comprehensively, and perhaps synergistically, shutting down the RAS/MAPK pathway.

Target upstream and downstream MAPK pathway nodes with single agents and combinations intended to clamp these oncogenic drivers. We are evaluating drug combinations targeting upstream and downstreamnodes to shut down, or “clamp,” the signaling of various oncogenic drivers, such as receptor tyrosine kinases (RTKs), NF1, RAS, RAF, and MEK alterations, trapped between the inhibited nodes. For example, we are exploring ERAS-0015 in combination with an anti-EGFR monoclonal antibody for the treatment of patients with metastatic colorectal cancer.

Target RAS, the midstream MAPK pathway node, directly with single agents and combinations. Our RAS-targeting franchise, ERAS-0015 and ERAS-4001, consists of molecules that are designed to potently and selectively bind to oncogenic RAS alterations (e.g., G12X, G13X +/- Q61X) and to block activation of wildtype RAS isoforms that mediate tumor resistance. These molecules are designed to prevent RAS-mediated signaling either by preventing RAS from binding to downstream effector proteins by forming a RAS-Cyclophilin A protein complex (as in the case of ERAS-0015) or by locking KRAS in the inactive GDP-bound state (as in the case of ERAS-4001).

Target escape routes enabled by other proteins or pathways to further disrupt RAS/MAPK pathway signaling. RAS-drivencancers utilize escape routes, namely cooperative mechanisms, to develop resistance to targeted therapies. By shutting down these potential escape routes, we aim to provide more robust inhibition of oncogenic signaling.

To pursue these therapeutic strategies, we have assembled and are developing a pipeline targeting multiple signaling nodes to shut down the RAS/MAPK pathway. We intend to study these agents either alone or in rational combinations across multiple relevant tumor types. The following table summarizes our current modality-agnostic pipeline to eradicate RAS/MAPK pathway-driven cancers.

We in-licensed our RAS-targeting franchise in May 2024. The RAS targeting landscape can be divided into pan-RAS, pan-KRAS, and mutant-selective approaches. We believe pan-RAS and pan-KRAS targeting molecules can address a broad population of patients with G12X, G13X, and possibly Q61X mutations, and also have the potential to address or prevent resistance by blocking wildtype RAS activation.

ERAS-0015 is a potential best-in-class pan-RAS molecular glue in development for the treatment of patients with RAS-mutated solid tumors. In vitro, ERAS-0015 has shown approximately 8-21 times higher binding affinity to cyclophilin A versus the most advanced pan-RAS molecular glue in development. We believe this higher binding affinity results in approximately 5 times more potent RAS inhibition in cell-based assays versus the comparator. ERAS-0015 also has favorable absorption, distribution, metabolism and excretion (ADME) and pharmacokinetics (PK) properties in multiple animal species. As a result of these favorable in vitro potency and ADME/PK attributes, ERAS-0015 has demonstrated comparable to greater in vivo antitumor activity at doses which are approximately one-tenth to one-eighth of the dose of the most advanced pan-RAS molecular glue. In combination with an anti-PD-1 antibody, ERAS-0015 was able to achieve complete disappearance of tumors in mice on day 31. The combination of ERAS-0015 plus the anti-EGFR antibody cetuximab induced significant tumor growth inhibition and demonstrated the potential combination benefit of blocking both oncogenic drivers. Our initial clinical trial for ERAS-0015 is called AURORAS-1. The investigational new drug application (IND) for AURORAS-1 was cleared by the US Food and Drug Administration (FDA) in May 2025. ERAS-0015, which we license from Guangzhou Joyo Pharmatech Co., Ltd. (Joyo), is also being evaluated in the JYP0015M101 clinical trial in China, which is assessing ERAS-0015 in adult patients with advanced solid tumors harboring specific RAS mutations. The JYP0015M101 clinical trial is sponsored by Joyo.

On January 12, 2026, we provided an update regarding the initial clinical progress of ERAS-0015. The update consisted of the following, as of a data cutoff of January 7, 2026:

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Dose escalation in the ongoing AURORAS-1 Phase 1 trial was advancing faster than anticipated, underscoring significant unmet medical need and high investigator and patient enthusiasm

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Ongoing confirmed and unconfirmed responses were observed in multiple patients with differing tumor types and RAS mutations

Ongoing responses (two confirmed partial responses (PRs) and one unconfirmed PR) were observed in patients with different tumor types and RAS mutations achieved at a low dose of 8 mg once daily (QD)

Additional ongoing unconfirmed responses were observed in patients at doses above 8 mg QD

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Favorable safety and tolerability results, with no dose-limiting toxicities and predominantly low-grade adverse events observed at all dose levels evaluated

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Well-behaved, linear PK across all dose levels evaluated to date with no observed evidence of exposure plateau

On January 20, 2026, we announced that subsequent to the cut-off date, we have dosed patients at 40 mg QD.

We anticipate a Phase 1 monotherapy data readout from the AURORAS-1 and JYP0015M101 trials in the first half of 2026. In addition, we anticipate the initiation of monotherapy expansion cohorts and combination dose escalation cohorts as part of the AURORAS-1 trial in the second half of 2026, with associated data readouts planned for 2027.

ERAS-4001 is a potential first-in-class pan-KRAS inhibitor in development for the treatment of patients with KRAS-mutated solid tumors. The preclinical in vitro potency of ERAS-4001 showed good activity against KRAS G12X mutations, as well as KRAS wildtype amplifications, with no activity observed against HRAS or NRAS wildtype proteins. We believe sparing wildtype HRAS and NRAS has the potential to provide a wider therapeutic window in the clinic versus the most advanced pan-RAS molecular glue in development. ERAS-4001 demonstrated activity against both GDP-bound (“inactive state”) and GTP-bound (“active state”) KRAS G12D with single digit nanomolar IC50 (a measure of the drug concentration needed to achieve half-maximal inhibition) values in a biochemical RAS – RAF1 RBD (RAS Binding Domain) assay. In vivo, ERAS-4001 showed tumor regression in multiple models when administered as a monotherapy. In combination with an anti-PD-1 antibody, ERAS-4001 was able to achieve complete disappearance of tumors in mice on day 31. The combination of ERAS-4001 plus the anti-EGFR antibody cetuximab induced significant tumor growth inhibition and demonstrated the potential combination benefit of blocking both oncogenic drivers. The initial clinical trial for ERAS-4001 is called BOREALIS-1. The IND for BOREALIS-1 was cleared by the FDA in May 2025. We anticipate a Phase 1 monotherapy data readout from the BOREALIS-1 trial in the second half of 2026. In addition, we anticipate the initiation of monotherapy expansion cohorts and combination dose escalation cohorts in 2027.

We believe ERAS-0015 has the potential to address unmet medical needs in approximately 2.7 million patients who are diagnosed annually worldwide with RAS-mutant tumors, including the more than 2.2 million patients with KRAS-mutant tumors whom ERAS-4001 could also address.

Our next program is ERAS-12, our investigational EGFR D2/D3 biparatopic antibody (bpAb). ERAS-12 is a potential best-in-class biologic, for which we have identified a lead candidate, that is designed to inhibit EGFR through multiple proposed mechanisms of action. In tumors where EGFR signaling is thought to be a primary driver of tumor growth, an antibody-based approach has been shown to be an effective way to target the receptor. However, all approved anti-EGFR antibodies target domain III (D3) only, which is the main site for ligand binding, and no approved antibodies target domain II (D2), which is responsible for dimerization of EGFR upon ligand binding. Binding of D2 prevents both EGFRhomodimerization as well as heterodimerization. We believe the combined binding of D2 and D3 could result in differentiated andimproved inhibition of downstream EGFR signaling. ERAS-12 also aims to exploit the innate immune system to induce tumor cell apoptosis. The Fragment crystallizable (Fc) region of IgG1 antibodies contain binding spots for both immune effector cells (e.g., NK cells) and the classical complement component C1q. By combining novel cell signal inhibition with enhancements to the Fc, we aim to create a potent multi-modal BIC anti-EGFR biologic which we believe could function as a targeted therapy with immunomodulatory activity.

In May 2025, in connection with our expectation that ERAS-0015 and ERAS-4001 would both become clinical stage programs, we conducted a strategic pipeline review. Following this review, in order to prioritize organizational focus and resources to advance our differentiated RAS-targeting franchise, we decided to evaluate strategic alternatives for our naporafenib program, which we in-licensed from Novartis Pharma AG (Novartis). After evaluating the clinical progress of our RAS franchise, we made a strategic decision to stop development of naporafenib. In March 2026, we sent a notice to Novartis to terminate our exclusive license agreement with Novartis (as amended, the Novartis Agreement) pursuant to which we acquired exclusive rights to develop naporafenib. The effective date of the termination of the Novartis Agreement is June 3, 2026. In connection with such termination, we and Novartis have agreed that we shall continue to ensure that the patients currently enrolled in the SEACRAFT-1 and SEACRAFT-2 trials will be permitted to continue to participate in such trials for the foreseeable future.

Our core values, team, and social mission

We are a team of experienced drug discoverers, developers, and company builders who are united by our mission to erase cancer and passionate about creating potentially life-saving precision oncology medicines singularly focused on targeting the RAS/MAPK pathway. Our leadership team has broad and deep experience in oncology, including advancing therapeutic candidates from discovery research to clinical development, regulatory approval, and commercialization. Our core values are embodied by our quest for the CURE:

Dr. Jonathan Lim, our Chairman, CEO, and Co-Founder, has helped pioneer transformative advancements in precision oncology and drug delivery, including leading Ignyta’s trailblazing pursuit of a global tissue agnostic label for ROZLYTREK, which became the first drug in biopharmaceutical history to achieve the unprecedented triple crown of breakthrough designations with BTD (FDA), PRIME (EMA) and Sakigake (PMDA). He has served as Chairman and/or CEO and founding investor of six biotechnology companies that have collectively achieved global regulatory approval and launch of seven therapeutic products in oncology, immunology, and drug delivery, benefitting thousands of patients worldwide.

Dr. Michael Varney, our Chair of R&D, SAB member, and a member of our board of directors, is a pioneer drug discoverer and biotech leader. His leadership at Agouron resulted in the discovery of multiple currently marketed anti-cancer agents, including XALKORI and INLYTA. As Executive Vice President and Head of Genentech’s Research and Early Development (gRED) and a member of the Roche Corporate Executive Committee, he was responsible for all aspects of gRED innovation, drug discovery and development, and built a team-based organization that today contributes to more than 40% of Genentech’s development portfolio, including the marketed anti-cancer agents ERIVEDGE and COTELLIC. Under his leadership, gRED teams discovered and developed successful medicines that include VENCLEXTA with AbbVie, the first BCL-2 inhibitor, and POLIVY, an antibody drug conjugate for the treatment of diffuse large B-cell lymphoma.

Dr. Shannon Morris, our Chief Medical Officer, initially joined us as Senior Vice President of Clinical Development and was promoted to Chief Medical Officer in April 2023. She has more than 20 years of experience in the life sciences industry with a focus in oncology drug development, including contributions in both early and late phase development, as well as in both targeted and immune-based therapies. Prior to joining Erasca, she was responsible for the clinical development of lerapolturev, a novel poliovirus-based therapeutic targeting GBM, at Istari Oncology. Prior to Istari, she was the clinical lead for the approval of COSELA. During her time at GSK and MedImmune, she held positions of increasing responsibility and was involved in the development of a number of molecules, including the early development of MEKINIST, and supported the successful biologics license application for IMFINZIin bladder cancer.

Dr. David Chacko, our Chief Financial Officer and Chief Business Officer, joined us from Versant Ventures, where he was a Principal with both investing and operating responsibilities. He helped lead investment opportunities across multiple therapeutic areas and advanced several Versant portfolio companies operationally through company formation, fundraising, corporate and business development, and clinical and regulatory activities. His prior roles at Alcon/Novartis, McKinsey, SR One, and Morgan Stanley bring to Erasca deep experience in strategy, finance, fundraising, business development, and operations.

Many members of our leadership team have worked together previously at Ignyta or Roche/Genentech, or have joined us from other leading companies in the biopharmaceutical and life science tools sectors such as Illumina, Lilly, Medivation, Merck, Myovant, Neurocrine, Pfizer, and Turning Point, and have worked on numerous oncology drugs that have been approved and launched for the benefit of patients.

Dr. Lim founded Erasca with Dr. Kevan Shokat (Professor and Chair of the Department of Cellular and Molecular Pharmacology at UCSF; Professor of Chemistry at the University of California, Berkeley; and an investigator at the Howard Hughes Medical Institute). In addition to Dr. Shokat, our SAB includes the following RAS/MAPK pathway experts:

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Dr. Rene Bernards is a leader in the field of molecular carcinogenesis. His research at the Netherlands Cancer Institute uses functional genomic approaches to find vulnerabilities of cancers that can be exploited therapeutically. He studied medical biology at the University of Amsterdam and obtained his Ph.D. from Leiden University. After a post-doctoral fellowship, he became an assistant professor at Harvard University. In 1992, he joined the Netherlands Cancer Institute, where he continues to work at present.

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Dr. Stephen Blacklow is a world expert in SHP2 who helped pioneer development of the first SHP2 inhibitor with Novartis, and is the Gustavus Adolphus Pfeiffer Professor of Biological Chemistry and Molecular Pharmacology, Biological Chemistry and Molecular Pharmacology at Harvard Medical School; a Professor of Pathology at the Brigham And Women’s Hospital; a Professor of Cancer Biology at the Dana-Farber Cancer Institute; and the Chair of the Department of Biological Chemistry and Molecular Pharmacology at Harvard Medical School.

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Dr. Karen Cichowski is a world expert in RAS/MAPK pathway signaling, including elucidating how deregulated cell signaling drives tumorigenesis in nervous system, lung, prostate, and breast cancers, combining translational mouse modeling techniques with basic biochemical and cell biological studies, and in identifying novel combination therapies to shut down aberrant RAS/MAPK pathway signaling. She is Professor of Medicine at Harvard Medical School and Professor of Medicine/Genetics at Brigham and Women’s Hospital.

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Dr. Ryan Corcoran is a gastrointestinal oncologist with a primary interest in translational oncology research who focuses on targeted therapies directed against mutations commonly found in human cancers, such as BRAF and KRAS mutations. He is also a world expert in ERK, having studied nearly every ERK inhibitor that has been or is being developed in the field. He is also the Director of the Gastrointestinal Cancer Center Program; the Scientific Director of the Termeer Center for Targeted Therapy at Massachusetts General Hospital Cancer Center; and an Associate Professor of Medicine at Harvard Medical School.

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Dr. George Demetri is a world expert in targeted oncology therapies who pioneered the development of GLEEVEC that helped launch the revolution in precision oncology. He is the Director of the Center for Sarcoma and Bone Oncology at the Dana-Farber Cancer Institute; the Director of the Ludwig Center at the Dana-Farber/Harvard Cancer Center; and Executive Director for Clinical and Translational Research at the Ludwig Institute for Cancer Research.

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Dr. Piro Lito is a world expert in KRAS-driven cancers. His research focuses on proteins that drive cancer cell growth aiming to uncover the fundamental processes that govern tumor biology and to identify novel therapies that prolong survival and improve the quality of life in patients with cancer. More specifically, his research has made several key contributions in the effort to better understand KRAS-driven cancers and to develop therapeutics that directly target mutant KRAS. He is an associate member and attending physician at Memorial Sloan Kettering Cancer Center.

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Dr. Pablo Rodriguez-Viciana is a world expert in the RAS/MAPK pathway whose major focus is the function of the SHOC2 phosphatase complex as a unique regulatory node required for efficient RAS/MAPK pathway activation in the context of diseases such as cancer and RASopathies. He has served as the group leader at the UCL Cancer Institute since 2008 and is a former postdoctoral researcher in Dr. Frank McCormick’s lab at the University of California, San Francisco.

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Dr. Michael Varney is a pioneer drug discoverer and biotech leader and the former Executive Vice President and Head of Genentech’s gRED and a former member of the Roche Corporate Executive Committee.

Erasca Foundation

At Erasca, while our mission to erase cancer inspires us, we know we can do more to make an even broader contribution to society. In May 2021, we established the Erasca Foundation, a nonprofit California public benefit corporation, which was funded by the donation of 1,093,557 shares of our common stock (which at the time represented 1% of our capital stock), in conjunction with our initial public offering (IPO). In 2025, the Erasca Foundation provided funding for initiatives to positively impact society, including providing funding to Family Health Centers of San Diego; Cancer Angels of San Diego; the Emilio Nares Foundation; and Life Science Cares.

Our corporate strategies to erase cancer

Our mission is to erase cancer by eradicating RAS/MAPK pathway-driven cancers. Our corporate strategies to achieve our mission include:

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Relentlessly focus on patients and society in our mission to erase cancer. There are more than five million new patientsdiagnosed globally per year with cancers driven by RAS/MAPK pathway alterations, most of whom have limited or no targeted therapy treatment options. We are a team of experienced drug discoverers, developers, and company builders who are united by our mission to erase cancer and passionate about creating potentially life-saving precision oncology medicines.

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Develop novel single agent and combination regimens to comprehensively shut down the RAS/MAPK pathway for the treatment of patients with cancer. We are pursuing three therapeutic strategies that may be used in combination to comprehensively, and perhapssynergistically, shut down the RAS/MAPK pathway: (1) target upstream and downstream MAPK pathway nodes with single agents and combinations intended to clamp these oncogenic drivers; (2) target RAS directly with single agents and combinations; and (3) target escape routes enabled by other proteins or pathways to further disrupt RAS/MAPK pathway signaling. Our strategic focus on the RAS/MAPK pathway allows us to comprehensively target critical nodes in the pathway that could drive cancer signaling.

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Advance our modality-agnostic RAS/MAPK pathway-focused pipeline. OurRAS/MAPK pathway-focused pipeline comprises several targeted therapy programs. Our modality-agnostic approach aims to selectively and potently target critical RAS/MAPK signaling nodes with the appropriate modality, including small and large molecule therapeutics. ERAS-0015 (our pan-RAS molecular glue) and ERAS-4001 (our pan-KRAS inhibitor) are currently being studied in clinical trials. Given the high unmet medical need of the patients we seek to treat, we will continually evaluate the potential for expedited development and review pathways.

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Internally develop and externally source, on a global basis, potentially disruptive programs targeting RAS/MAPK pathway alterations. We use computational biology and computational chemistry to accelerate our development activities. We have standardized how we characterize our compounds across in vitro/vivo activity, drug distribution, metabolism, and PK, structural, and secondary pharmacology assays, and centralized the storage of these data for automated analyses. We also believe that innovation is a collective, global endeavor and a single platform is unlikely to discover all the best ideas and approaches. We therefore plan to continue to opportunistically evaluate synergistic, in-pathway opportunities, regardless of origin, that meet our high scientific bar. Our extensive network and relationships provide us preferential—and at times exclusive—access to certain assets of interest.

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Lead the next revolution in precision oncology. The first wave of precision oncology included tyrosine kinase inhibitors such asROZLYTREK, approved for select tumors that harbor ROS1 or NTRK fusions. While these initial development efforts focused on specific disease-causing alterations in areas of high unmet medical need, these patient populations were modest in size. We believe that to effectively shut down a pathway that signals as promiscuously as RAS/MAPK and encompasses a range of alterations, a holistic approach must be taken to target not just specific individual mutations, but multiple alterations and cooperative mechanisms in parallel. We are pursuing tissue agnostic and tissue specific indications using flexible trial designs intended to efficiently transition molecules through each phase of development with the goal of identifying early efficacy signals warranting additional resource allocation for both monotherapy and combination approaches.

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Evaluate opportunities to accelerate development timelines and enhance the commercial potential of our programs in collaboration with third parties. We own or control worldwide development and commercialization rights to our entire pipeline oftargeted therapy programs. This provides us with the flexibility to explore combinations of our agents with each other, other investigational agents, and/or standard of care therapies. We intend to continue evaluating opportunities to work with partners that meaningfully enhance our capabilities with respect to the development and commercialization of our product candidates. In addition, we intend to commercialize our product candidates in the United States. We intend to explore partnerships in selected geographies to maximize the worldwide commercial potential of our programs.

Our singular focus on the RAS/MAPK pathway

Background

The RAS/MAPK pathway is one of the most frequently altered signaling pathways in cancer. Molecular alterations in key signaling nodes within the RAS/MAPK pathway have been shown to drive cell proliferation across a wide range of tumor types. As described further below, our pipeline targets all of the key signaling nodes colored in purple, either directly or indirectly as single agents and in combination in order to prolong survival in a wide range of patient populations.

EGFR

RTKs like EGFR are proteins that are embedded in the cell membrane and relay growth signals from the outside environment to the cell’s internal machinery. At rest, these proteins reside on the cell membrane as inactive monomers. Growth factors secreted by nearby cells bind to specific RTKs, such as epidermal growth factor (EGF) binding to EGFR, and cause these RTKs to dimerize. Dimerized RTKs activate one another through transphosphorylation of their intracellular regions. Intracellular proteins, such as adapter proteins, bind to these phosphorylated regions and propagate the pro-growth signals within the cell via one or more signaling pathways. Cells express a variety of RTKs so that environmental cues can be relayed to specific cell populations in specific contexts. EGFR mediates pro-growth signaling in skin and in the ducts and outer surfaces of many organs.

Overactive RTK signaling can result in uncontrolled cell growth and survival that transforms normal cells into cancer cells.

RAS

RAS proteins are ubiquitously expressed GTPase proteins. The RAS protein family consists of KRAS, NRAS, and HRAS proteins and acts as the entry node in the RAS/MAPK signaling pathway. KRAS is the most abundantly expressed RAS protein followed by NRAS and then HRAS. RAS proteins act as signaling transducers since they are recruited to activated RTK complexes where they are converted into an active conformation (RAS-GTP) that enables them to activate downstream effector proteins, such as RAF proteins. The activation state of a RAS protein is dictated by the phosphorylation state of the bound guanosine; RAS adopts an inactive RAS-GDP conformation when bound to GDP and an active RAS-GTP conformation when bound to GTP. Conversion of RAS into an active conformation is mediated by binding to co-factor proteins, e.g., SOS1, and these co-factor proteins enable the exchange of the RAS-bound nucleotide from GDP to GTP. In the active state, RAS-GTP proteins interact with multiple effector proteins to propagate cell signaling through multiple pathways. For example, activated RAS-GTP proteins interact with RAF proteins to activate MAPK signaling, and PI3K proteins to activate PI3K pathway signaling. RAS can transition from the active state into the inactive state by hydrolyzing its bound nucleotide from GTP to GDP either intrinsically or catalyzed through interactions with co-factor proteins, such as NF1. RAS proteins are the most frequently mutated oncoproteins in cancer. These mutations occur at hotspots, such as amino acid residues 12, 13, and 61, and these hotspot mutations impair RAS’s ability to hydrolyze GTP to GDP. As a result, mutant RAS-GTP remains in the active state for prolonged periods of time resulting in hyperactive stimulation of the RAS/MAPK and other pathways.

RAF

RAF proteins are ubiquitously expressed serine-threonine kinases that are a part of the RAS/MAPK pathway and whose activity is regulated by RAS proteins. The RAF protein family consists of ARAF, BRAF, and CRAF (RAF1). In the absence of activated RAS-GTP, RAF proteins assume an autoinhibited conformation in complex with downstream effector proteins, MEK1 and MEK2. RAF proteins can homodimerize (e.g., BRAF-BRAF dimers) or heterodimerize (e.g., CRAF-BRAF dimers). When RAF proteins bind to activated RAS-GTP, they adopt an active conformation that results in activation of their kinase domains. The activated kinase domains then phosphorylate complexed MEK proteins, activating those proteins and releasing them from the RAF-MEK complex. Activated MEK then signals further down the RAS/MAPK pathway. Mutations in RAF proteins, especially in BRAF, have been observed in many cancers, such as melanoma, CRC, NSCLC, and thyroid cancer. For example, the BRAF V600E mutation (a class I BRAF mutation) is frequently observed in melanoma and this mutation enables BRAF to constitutively activate MEK as a monomer. Approved BRAF inhibitors for class I mutations include vemurafenib, dabrafenib, and encorafenib. Class II BRAF mutations enable BRAF to constitutively dimerize and activate MEK. Class III BRAF mutations impair the ability of the mutant BRAF protein to phosphorylate MEK, but class III mutant BRAF proteins can aberrantly dimerize with wildtype RAF proteins and enable their dimerized wildtype RAF partners to activate MEK. To our knowledge, there are no approved inhibitors of BRAF Class II or Class III mutations. A number of inhibitors targeting BRAF Class II and Class III mutations, as well as pan-RAF inhibitors designed to disrupt wildtype RAF signaling, are in development; however, to our knowledge, none have received regulatory approval.

MEK

MEK1 and MEK2 proteins are ubiquitously expressed serine-threonine kinases that are activated by RAF-mediated phosphorylation and signal downstream by activating ERK proteins. MEK1 and MEK2 proteins form complexes with RAF proteins in the inactive state and are recruited as a unit to activated RAS-GTP. RAS-GTP then activates the RAF-MEK complex by binding to RAF, which then activates MEK via phosphorylation and releases from the RAF-MEK complex. Activated MEK then selectively phosphorylates ERK1 and ERK2 proteins, which are the terminal nodes of the RAS/MAPK pathway. Currently approved MEK inhibitors, such as trametinib, binimetinib, cobimetinib, and selumetinib, allosterically bind MEK proteins and inhibit MEK activation, either as free proteins alone or in complex with RAF. The inhibition of RAS/MAPK signaling by MEK inhibitors can result in an upregulation of signaling upstream of MEK due to negative feedback loops within the RAS/MAPK pathway. This increased signaling pressure can overwhelm MEK inhibitors and result in reactivation of MAPK signaling. Most MEK inhibitors are approved in combination with a BRAF inhibitor partially due to their vulnerability of being overwhelmed by the reactivation of MAPK signaling. In this combination, BRAF inhibitors attenuate upstream signaling pressure on MEK inhibitors, and MEK inhibitors further limit downstream MAPK signaling not inhibited by the BRAF inhibitor.

Our therapeutic strategies for shutting down the RAS/MAPK pathway

We believe that to effectively shut down a pathway that signals as promiscuously as RAS/MAPK, a holistic approach must be taken to target not just single nodes, but multiple nodes and cooperative mechanisms in parallel. Our internally and externally sourced RAS/MAPK pathway-focused pipeline comprises several targeted therapy programs. Our pipeline enables us to pursue a systematic, data-driven, portfolio-wide clinical development effort to identify therapeutic approaches that aim to prolong survival in numerous patient populations with high unmet medical needs. We are pursuing three therapeutic strategies that may be used in combination with the goal of comprehensively, and perhaps synergistically, shutting down the RAS/MAPK pathway:

Target upstream and downstream MAPK pathway nodes with single agents and combinations intended to clamp these oncogenic drivers. We are evaluating drug combinations targeting upstream anddownstream nodes to shut down, or "clamp," the signaling of various oncogenic drivers such as RTKs, NF1, RAS, RAF, and MEK alterations, trapped between the inhibited nodes. For example, we are exploring ERAS-0015 in combination with an anti-EGFR monoclonal antibody for the treatment of patients with metastatic colorectal cancer.

Target escape routes enabled by other proteins or pathways to further disrupt RAS/MAPK pathway signaling. RAS-driven cancers utilize escape routes, namely cooperative mechanisms, to develop resistance to targeted therapies. By shutting down these potential escape routes, we aim to provide more robust inhibition of oncogenic signaling.

Our strategic focus on the RAS/MAPK pathway allows us to comprehensively target critical nodes in the pathway that could drive signaling. As shown in the figure below, our pipeline targets, either directly or indirectly, each of the signaling nodes colored in purple.

Our innovation model

Due to the magnitude of the challenge of erasing cancer, we are combining our robust internal development capabilities with a global in-licensing and acquisition strategy to assemble a modality-agnostic RAS/MAPK pathway-focused pipeline. We believe these complementary approaches to innovation provide us with important optionality, both therapeutically and strategically, as we endeavor to bring forth the next generation of potentially differentiated targeted therapies for RAS/MAPK pathway-driven cancers.

Internal development

We use computational biology and computational chemistry to accelerate our development activities. We have standardized how we characterize our compounds across in vitro/vivo activity, drug distribution, metabolism, and PK, structural, and secondary pharmacology assays, and centralized the storage of these data for automated analyses. These data are continuously reviewed by our scientific teams, and promising trends, including unpredicted ones that arise serendipitously, are prioritized for future exploration.

Based on our previous collective experiences at Ignyta, Roche/Genentech, Pfizer, and elsewhere, our team has extensive precision oncology expertise with dynamic clinical trial designs such as adaptive trials, biomarker-based basket and umbrella studies, and master protocols. We will continue to leverage this experience, in collaboration with industry and academic partners, in order to quickly demonstrate clinical proof-of-concept in a variety of tumor types for both single agent and combination approaches.

External sources of innovation

We believe innovation in cancer therapy is a collective, global endeavor unlikely to emerge from a single company or a single platform. There are exciting product candidates, technologies, and approaches in development worldwide, and our innovation model gives us the flexibility to supplement our internal efforts with externally sourced assets through collaboration, in-license, or acquisition. We also established Erasca Ventures, our wholly-owned subsidiary, in March 2021 to make equity investments in early-stage biotechnology companies that are aligned with our mission and strategy. To date, we have in-licensed or acquired novel therapies from multiple geographic regions, including ERAS-0015, which we in-licensed from Joyo, ERAS-4001, which we in-licensed from Medshine Discovery Inc. (Medshine), and our ERAS-12 program, which we acquired from Emerge Life Sciences, Pte. Ltd. (ELS).

We leverage our extensive network of preferred relationships with our Scientific Advisory Board and our Research, Development, and Commercial Advisory Board, as well as leading institutional investors, investment banks, academic institutions, and biopharmaceutical companies that keep us apprised of assets of strategic interest. We pursue the best science in the world, regardless of its origin, and will continue to opportunistically evaluate additional opportunities to strengthen and diversify our pipeline through academic and biopharmaceutical collaborations, in-licenses, acquisitions, and strategic investments that meet our high scientific bar and can help us advance our mission to erase cancer.

Modality-agnostic pipeline

Cancer is a complex, heterogeneous disease that is unlikely to succumb to a one-size-fits-all approach. We believe shutting down the RAS/MAPK pathway in cancer requires a systematic, data-driven approach to development, part of which involves choosing the most appropriate technology for the target of interest, or what we call a modality-agnostic approach. We therefore seek to understand the biology of the target of interest first, and then choose the therapeutic modality best suited to optimally inhibit that target. We are currently utilizing several modalities to target the RAS/MAPK pathway, including small and large molecule therapeutics.

For example, we are developing proprietary bispecific antibodies that are designed to bind EGFR in both the active and inactive conformations, potentially leading to deeper inhibition of EGFR-mediated RAS/MAPK pathway signaling. In addition to inhibiting EGFR signaling, our bispecific antibodies are designed to induce higher orders of EGFR receptor clustering on the cell surface, which may induce antitumor activity mediated by the immune system, such as antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, and/or complement-dependent cytotoxicity. We believe these design attributes can potentially enable our proprietary bispecific anti-EGFR antibodies to achieve meaningfully improved activity relative to currently approved anti-EGFR antibodies, such as cetuximab, panitumumab, and amivantamab, since those antibodies preferentially bind EGFR only in the inactive state and may not as strongly elicit antitumor immunological responses.

Our pipeline

We have assembled a RAS/MAPK pathway-focused pipeline, consisting of modality-agnostic programs aligned with our three therapeutic strategies of: (1) targeting key upstream and downstream signaling nodes in the RAS/MAPK pathway; (2) targeting RAS directly; and (3) targeting escape routes that emerge in response to treatment. The table below summarizes our current pipeline. We have exclusive worldwide development and commercial rights for all of our programs.

RAS Franchise: ERAS-0015 pan-RAS molecular glue and ERAS-4001 pan-KRAS small molecule inhibitor

Our RAS franchise consists of two clinical-stage programs: ERAS-0015, a pan-RAS molecular glue and ERAS-4001, a pan-KRAS small molecule inhibitor, for which both INDs were cleared by the FDA in May 2025. Phase 1 monotherapy data readouts are expected for ERAS-0015 (AURORAS-1 and JYP0015M101) in the first half of 2026, and ERAS-4001 (BOREALIS-1) in the second half of 2026. For both data readouts, the data are expected to include safety, PK, and efficacy results at relevant dose(s) in relevant population(s) of interest.

Both molecules exceed our target product profile across three key attributes: potency, favorable ADME/PK properties including oral bioavailability, and strong IP position. We are pursuing a clinical development strategy that we believe could enable us to address RAS mutant tumor types where there is the highest unmet medical need, including CRC, PDAC, and NSCLC. We plan to move swiftly into strategic combinations while, in parallel, characterizing the monotherapy activity and combination potential of each molecule. We also plan on capitalizing on our unique portfolio which has complementary proposed mechanisms of action and target profiles to develop novel combinations.

ERAS-0015: our pan-RAS molecular glue

ERAS-0015's improved potency and oral bioavailability may enable dosing at a lower dose, which could translate into linear PK across biologically relevant doses, better GI tolerability profile given the lower drug load in the GI tract, and an improved therapeutic window.

Biophysical characterization of ERAS-0015

ERAS-0015 is a pan-RAS molecular glue that we believe has the potential to treat patients with RAS mutant solid tumors. The molecule forms a tripartite complex with Cyclophilin A (CypA) and the active form of RAS to inhibit RAS-dependent signaling. In surface plasmon residence (SPR) and isothermal titration calorimetry (ITC) binding assays, ERAS-0015 has demonstrated 8-21-fold higher binding affinity to cyclophilin A relative to RMC-6236 (the leading pan-RAS molecular glue in development), which we believe may enable more potent inhibition of RAS signaling.

We performed a tumor PK distribution assessment in TGI studies of ERAS-0015 versus RMC-6236 in PK-59 and PSN-1 CDX models. PK concentrations of paired tumor and blood samples were measured at 4 and 24 hours after the last dose of the TGI studies.

In the PK-59 CDX study, the dose normalized ERAS-0015 (across 3 ERAS-0015 dose levels: 0.1, 0.3, and 1 milligrams per kilograms (mpk)) tumor PK exposures relative to the corresponding blood concentrations at 4 and 24 hours post-dose were much higher compared to the same measure for RMC-6236 (dose normalized for 2 RMC-6236 dose levels: 1 and 3 mpk), indicating preferential tumor distribution for ERAS-0015. In addition, the decrease in ERAS-0015 tumor concentrations from 4 to 24 hours post-dose was much smaller compared to that of RMC-6236, suggesting longer tumor residence time for ERAS-0015.

Similar findings were also observed in the PSN-1 CDX study as shown in the figure below. (In the PSN-1 model, ERAS-0015 exposures were dose normalized across 0.3 and 1 mpk; RMC-6236 exposures were dose normalized across 3 and 10 mpk).

Taken together, these data demonstrated that ERAS-0015 showed preferential tumor distribution and longer residence time relative to RMC-6236, which we believe may help drive greater antitumor activity. We believe that the preferential tumor distribution and longer residence time could be related to the higher CypA binding affinity.

Preclinical potency of ERAS-0015

In multiple in vitro cell lines containing representative mutations in KRAS G12X, Q61R, and G13D as well as KRAS wildtype, ERAS-0015 showed superior in vitro potency when compared to RMC-6236 with an average of 5 times greater potency. The moleculeshowed subnanomolar to nanomolar potency against KRAS G12X, G13D, and KRAS wildtype and was also active against HRAS and NRAS. ERAS-0015 showed no activity in the BRAF V600E A375 cell line, demonstrating selective inhibition of RAS.

Preclinical efficacy of ERAS-0015

In vivo, ERAS-0015 achieved tumor regression in multiple CDX models across PDAC, CRC, and NSCLC tumor types at doses as low as 0.3 to 0.5 mpk. Potentially due to its greater binding affinity to CypA than RMC-6236, ERAS-0015 demonstrated comparable to greater in vivo antitumor activity at doses which were approximately one-tenth to one-eighth of the dose of RMC-6236.

For example, in the PK-59 KRAS G12D PDAC model, tumor regression observed with RMC-6236 at 3 mpk was comparable to the regression observed with ERAS-0015 at 0.3 mpk. This difference in in vivo antitumor activity was observed across multiple CDX models including KRAS G12R PDAC CDX PSN-1 and KRAS G12V CRC CDX SW620. This difference in in vivo antitumor activity was also observed in the NCI-H727 KRAS G12V NSCLC CDX model. ERAS-0015 was able to achieve tumor regression at 1 mpk relative to RMC-6236 at 10 mpk.

Activity was also observed with the combination of ERAS-0015 and anti-PD-1 therapy in a KPC KRAS G12D CDX model where tumor regression was maintained even after treatment with both molecules was stopped on Day 31. Furthermore, tumors did not form after rechallenge, which involved injecting tumor cells in the contralateral side of the animal without administering any drug therapy. These rechallenge data suggest that the combination of ERAS-0015 and anti-PD-1 can stimulate immunologic antitumor memory in the rechallenged mouse. Doses administered were tolerable as measured by body weight change.

Pharmacokinetics and ADME of ERAS-0015

ERAS-0015 has shown encouraging PK results in multiple species, including mouse, rat, dog, and monkey. In a head-to-head comparison of ERAS-0015 and RMC-6236, ERAS-0015 outperformed RMC-6236 on three key metrics (specifically, lower clearance, longer half-life, and higher bioavailability demonstrated across all species tested) that we believe may provide ERAS-0015 a clinical advantage in the clinic over RMC-6236.

ERAS-0015 has shown favorable overall ADME properties in vitro and encouraging PK characteristics in in vivo animal studies that we believe support development in the clinic. Based on the differentiated potency and PK/ADME results, we predict that ERAS-0015 will be efficacious at lower doses than the leading pan-RAS molecular glue in development, which may lower the risk of solubility-limited absorption issues and enable linear PK exposure relative to the leading pan-RAS molecular glue in development. In addition, the GLP hERG IC50 was 6.0 micromolar which suggests potentially low concern for cardiovascular risk.

Initial clinical development strategy for ERAS-0015

Our initial clinical trial for ERAS-0015 is called AURORAS-1. The AURORAS-1 trial is assessing ERAS-0015 as a monotherapy and in combination with approved and unapproved therapies for the treatment of patients with RASm solid tumors. ERAS-0015 is also being evaluated in JYP0015M101, a clinical trial in China sponsored by Joyo that is assessing ERAS-0015 in adult patients with advanced solid tumors harboring specific RAS mutations. We anticipate a Phase 1 monotherapy data readout from the AURORAS-1 and JYP0015M101 trials in the first half of 2026. In addition, we anticipate the initiation of monotherapy expansion cohorts and combination dose escalation cohorts as part of the AURORAS-1 trial in the second half of 2026, with associated data readouts planned for 2027.

In addition, we have entered into a clinical trial collaboration and supply agreement (CTCSA) with Tango Therapeutics, Inc. (Tango) to enable the evaluation of ERAS-0015 with Tango's PRMT5 inhibitor, vopimetostat, in a Phase 1 clinical trial sponsored by Tango. Pursuant to the CTCSA, Erasca will supply ERAS-0015 to Tango free of charge and Tango will be responsible for sponsoring the trial and the costs related to the trial.

Early clinical progress of ERAS-0015

On January 12, 2026, we provided an update regarding the initial clinical progress of ERAS-0015. The update consisted of the following, as of a data cutoff of January 7, 2026:

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Dose escalation in the ongoing AURORAS-1 Phase 1 trial was advancing faster than anticipated, underscoring significant unmet medical need and high investigator and patient enthusiasm

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Ongoing confirmed and unconfirmed responses were observed in multiple patients with differing tumor types and RAS mutations

Ongoing responses (two confirmed partial responses (PRs) and one unconfirmed PR) were observed in patients with different tumor types and RAS mutations achieved at a low dose of 8 mg QD

Additional ongoing unconfirmed responses were observed in patients at doses above 8 mg QD

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Favorable safety and tolerability results, with no dose-limiting toxicities and predominantly low-grade adverse events observed at all dose levels evaluated

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Well-behaved, linear PK across all dose levels evaluated to date with no observed evidence of exposure plateau

On January 20, 2026, we announced that subsequent to the cut-off date, we have dosed patients at 40 mg QD.

ERAS-4001: our pan-KRAS small molecule inhibitor

Biophysical characterization and preclinical potency of ERAS-4001

ERAS-4001 is a pan-KRAS small molecule inhibitor that demonstrated high affinity and long target residence time in vitro against multiple KRAS G12X mutations as well as KRAS wildtype, and selectivity for KRAS wildtype over HRAS wildtype and NRAS wildtype.

ERAS-4001 potently and selectively inhibited multiple cell lines that represent KRAS G12X, G13D, and wildtype with single digit nanomolar potency. Demonstrating selective inhibition of KRAS, ERAS-4001 showed no activity in two KRAS independent cell lines, which are shown at the bottom.

In biochemical assays, ERAS-4001 potently inhibited KRAS in both the GTP- and GDP-bound states with single digit nanomolar IC50s. ERAS-4001’s potent disruption of binding between KRAS G12D and the RAS-binding domain peptide is intended to model ERAS-4001’s potential to block KRAS from signaling downstream via the RAS/MAPK pathway. ERAS-4001 showed the potential to inhibit KRAS mutants where KRAS spends more time in the activated GTP-bound state, such as G12D and G12V mutations.

Preclinical activity of ERAS-4001

ERAS-4001 showed encouraging in vivo activity in multiple CDX models. ERAS-4001 achieved tumor stasis and regression in three sensitive KRAS G12D models and one sensitive KRAS G12V model. In addition, ERAS-4001 showed promising activity in the pan-KRAS inhibitor insensitive model, the KRAS G12V mutant CDX NCI-H727.

ERAS-4001 has also demonstrated antitumor activity in combination with an anti-PD-1 in a KPC KRAS G12D CDX model where tumor regression was maintained even after treatment with both molecules was stopped on Day 38. Furthermore, no tumors formed in the rechallenge study, suggesting the combination of ERAS-4001 and anti-PD-1 can stimulate immunologic antitumor memory in the rechallenged mouse.

Pharmacokinetics and ADME of ERAS-4001

ERAS-4001 showed encouraging PK results, including oral bioavailability in mouse, rat, and dog.

ERAS-4001 demonstrated favorable ADME results in vitro. The GLP cardiovascular telemetry study in dogs showed no QTc prolongation.

Initial clinical development strategy for ERAS-4001

The initial clinical trial for ERAS-4001 is called BOREALIS-1. The BOREALIS-1 trial is assessing ERAS-4001 as a monotherapy and in combination with approved and unapproved therapies for the treatment of patients with KRASm solid tumors. We anticipate a Phase 1 monotherapy data readout in the second half of 2026. In addition, we anticipate the initiation of monotherapy expansion cohorts and combination dose escalation cohorts in 2027.

ERAS-12: our EGFR D2/D3 biparatopic antibody program

Inhibition of activated EGFR signaling mediated by overexpression of EGFR has shown promise in treating various tumors, including CRC and head and neck squamous cell carcinoma. In tumors where overexpression of wildtype EGFR is thought to be a primary driver of EGFR signaling, an antibody-based approach is an effective way to target the receptor, and approved antibodies have demonstrated good tolerability as well as activity by inhibiting EGFR activation and mediating antibody-dependent cellular cytotoxicity, a process by which the antibody alerts the immune system to attack the bound tumor cell. However, all approved anti-EGFR antibodies target D3 only, which is the main site for ligand binding, and no approved antibodies target D2, which is responsible for dimerization of EGFR upon ligand binding. Binding of D2 prevents both EGFRhomodimerization as well as heterodimerization. Overexpression of EGFR activates EGFR signaling by facilitating both homo- and heterodimerization. Consequently, an antibody that targets D2, the receptor domain responsible for dimerization upon ligand binding, would be predicted to be particularly efficacious.

Biparatopic antibodies are a subset of bispecific antibodies that have specificity for unique, non-overlapping epitopes found on the same molecular target. We have identified a lead biparatopic antibody that targets these two distinct domains on the EGFR receptor, which allows the antibody to inhibit both the ligand binding and dimerization functionality of the receptor.

Diagram (A) visualizes the EGFR antibody ER-2a binding to the extracellular domain II of EGFR wildtype (purple), which is accessible when EGFR is in the active state. EGFR assumes an active state conformation when its ligand is bound (the bound ligand is shown in blue). Diagram (B) visualizes the EGFR antibody ER-3a binding to the extracellular domain III of EGFR wildtype (purple), which is accessible when EGFR is in the inactive state. In the rectangle, the portion of ER-2b that recognizes domain II of EGFR and the portion of ER-3b that recognizes domain III of EGFR are combined into a bispecific antibody that binds EGFR in both states.

This dual inhibition can potentially achieve differentiated and potentially more effective EGFR inhibition than currently approved EGFR antibodies. Overall, we anticipate this strategy will result in better control of tumor growth and delay the emergence of resistance mechanisms.

Our lead ERAS-12 antibody is also designed with enhanced Fc-effector functions, including complement dependent cytotoxicity, antibody dependent cellular cytotoxicity, and antibody dependent cellular phagocytosis. The Fc region of IgG1 contains several binding sites for immune effector cells (i.e., Fcγ) and the classical complement protein C1q. As noted, our lead antibody is biparatopic, binding to both D2 and D3 of EGFR. This potentially can produce oligomerized EGFR-antibody structures on the cell surface. Complexes of this type can amplify Fc-effector functions creating multiple mechanisms to induce tumor cell death and encourage durable immune activity.

The biparatopic antibody ER-3a/ER-2a and EGFR active state-binding antibody ER-2a inhibited cell growth in FaDu, an HNSCC cell line, and HCT-8, a CRC cell line, and the NSCLC cell line H1975. FaDu and HCT-8 expressed wildtype EGFR and H1975 expressed EGFR with two kinase domain mutations, L858R and T790M. EGFR’s ligand, EGF, was added to these cells to further stimulate EGFR activity and model environments where EGF is expressed. As expected, only the two antibodies that recognized the active state of EGFR, ER-3a/ER-2a, inhibited the proliferation of all three cell lines, as indicated by a reduced confluency percentage.

Our acquisition and license agreements

Guangzhou Joyo

In May 2024, we entered into an exclusive license agreement (the Joyo License Agreement) with Joyo under which we were granted an exclusive, worldwide (except mainland China, Hong Kong and Macau), royalty-bearing license to certain patent and other intellectual property rights owned or controlled by Joyo to develop, manufacture, and commercialize certain pan-RAS inhibitors in all fields of use. Pursuant to the Joyo License Agreement, we had an option to expand the territory of the license to include mainland China, Hong Kong and Macau by making a $50.0 million payment to Joyo on or prior to the first dosing of the first patient in a Phase 2 clinical trial by either us or Joyo, or a payment of $150.0 million after the first dosing of the first patient in a Phase 2 clinical trial by either us or Joyo, and before filing a new drug application (or the foreign equivalent) by either us or Joyo. In March 2026, we sent Joyo notice that we were exercising our option to expand our territory under the Joyo License Agreement to include mainland China, Hong Kong and Macau, and based upon feedback from Joyo that it had dosed the first patient in a Phase 2 clinical trial, we made the corresponding $150.0 million payment (less applicable withholding amounts). We have the right to sublicense (through multiple tiers) our rights under the Joyo License Agreement, subject to certain limitations and conditions, and are required to use commercially reasonable efforts to commercialize licensed products in the United States.

Under the Joyo License Agreement, we made an upfront cash payment to Joyo of $12.5 million. In addition, we are obligated to make development and regulatory milestone payments of up to $51.5 million (with such amount increasing to $57.5 million following our exercise of the option to expand our territory to include mainland China, Hong Kong, and Macau) and commercial milestone payments of up to $125.0 million upon the achievement of the corresponding milestones. We are also obligated to pay tiered royalties on net sales of all licensed products, in the low- to mid-single digit percentages, subject to certain reductions.

The Joyo License Agreement will expire upon the last to expire royalty term, which is determined on a licensed product-by-licensed product and country-by-country basis, and is the later of: (i) ten years from the date of first commercial sale for the licensed product in such country, (ii) the last to expire valid claim within the licensed patent rights covering such licensed product, or (iii) the expiration of all regulatory exclusivity for the licensed product in such country. Upon expiration of the Joyo License Agreement, on a licensed product-by-licensed product and country-by-country basis, the license granted to us with respect to such product in such countries shall be deemed to be fully paid-up, royalty-free, non-terminable, irrevocable and perpetual.

The Joyo License Agreement may be terminated in its entirety by either party in the event of an uncured material breach by the other party or in the event the other party becomes subject to specified bankruptcy, insolvency, or similar circumstances. Joyo may terminate the Joyo License Agreement in the event that we or our affiliates or any of our or their sublicensees institutes, prosecutes or otherwise participates in any challenge to the licensed patents. We may terminate the Joyo License Agreement in its entirety at any time upon the provision of prior written notice to Joyo.

Upon termination of the Joyo License Agreement for any reason, all rights and licenses granted to us will terminate; and Joyo has an option to negotiate a license under any patent rights, know-how, or other intellectual property rights relating to the licensed products that are owned or controlled by us for the purpose of developing, manufacturing and commercializing the licensed products in our territory on terms to be negotiated between the parties.

Medshine

In May 2024, we entered into an exclusive license agreement (the Medshine License Agreement) with Medshine under which we were granted an exclusive, worldwide, royalty-bearing license to certain patent and other intellectual property rights owned or controlled by Medshine to develop, manufacture and commercialize certain pan-KRAS inhibitors in all fields of use. We have the right to sublicense (through multiple tiers) our rights under the Medshine License Agreement, subject to certain limitations and conditions, and are required to use commercially reasonable efforts to commercialize licensed products in certain geographical markets.

Under the Medshine License Agreement, we made an upfront cash payment to Medshine of $10.0 million. In addition, we are obligated to make development and regulatory milestone payments of up to $30.0 million and commercial milestone payments of up to $130.0 million upon the achievement of the corresponding milestones. We are also obligated to pay a low-single digit percentage royalty on net sales of all licensed products, subject to certain reductions.

The Medshine License Agreement will expire upon the last to expire royalty term, which is determined on a licensed product-by-licensed product and country-by-country basis, and is the later of: (i) ten years from the date of first commercial sale for the licensed product in such country, (ii) the last to expire valid claim within the licensed patent rights covering such licensed product, or (iii) the expiration of all regulatory exclusivity for the licensed product in such country. Upon expiration of the Medshine License Agreement, on a licensed product-by-licensed product and country-by-country basis, the license granted to us with respect to such product in such countries shall be deemed to be fully paid-up, royalty-free, non-terminable, irrevocable and perpetual.

The Medshine License Agreement may be terminated in its entirety by either party in the event of an uncured material breach by the other party or in the event the other party becomes subject to specified bankruptcy, insolvency, or similar circumstances. Medshine may terminate the Medshine License Agreement in the event that we or our affiliates or any of our or their sublicensees commences or actively and voluntarily participates in any challenge to the licensed patents. We may terminate the Medshine License Agreement in its entirety at any time upon the provision of prior written notice to Medshine.

Upon termination of the Medshine License Agreement for any reason, all rights and licenses granted to us will terminate. In addition, upon termination of the Medshine License Agreement by Medshine for cause, Medshine has an option to negotiate a license under any patent rights, know-how, or other intellectual property rights relating to the licensed products that are owned or controlled by us for the purpose of developing, manufacturing and commercializing the licensed products on terms to be negotiated between the parties.

Emerge Life Sciences

In March 2021, we entered into an asset purchase agreement (the ELS Purchase Agreement) with Emerge Life Sciences, Pte. Ltd. (ELS) wherein we purchased all rights, title, and interest (including all patent and other intellectual property rights) to ELS’s EGFR antibodies directed against the EGFR domain II (EGFR-D2) and domain III (EGFR-D3) as well as a bispecific antibody where one arm is directed against EGFR-D2 and the other is directed against EGFR-D3. Under the ELS Purchase Agreement, we issued 500,000 shares of our common stock to ELS and made an upfront payment of $2.0 million, which represent all of the consideration payable to ELS under the ELS Purchase Agreement.

Novartis

In December 2022, we entered into the Novartis Agreement with Novartis under which we were granted an exclusive, worldwide, royalty-bearing license to certain patent and other intellectual property rights owned or controlled by Novartis to develop, manufacture, use, and commercialize naporafenib in all fields of use. In May 2025, in connection with our expectation that ERAS-0015 and ERAS-4001 would both become clinical stage programs, we conducted a strategic pipeline review. Following this review, in order to prioritize organizational focus and resources to advance our differentiated RAS-targeting franchise, we decided to evaluate strategic alternatives for our naporafenib program. After evaluating the clinical progress of our RAS franchise, we made a strategic decision to stop development of naporafenib. In March 2026, we sent a notice to Novartis to terminate the Novartis Agreement. The effective date of the termination of the Novartis Agreement is June 3, 2026. In connection with such termination, we and Novartis have agreed that we shall continue to ensure that the patients currently enrolled in the SEACRAFT-1 and SEACRAFT-2 trials will be permitted to continue to participate in such trials for the foreseeable future.

Asana BioSciences

In November 2020, we entered into the Asana Merger Agreement with Asana BioSciences, LLC (Asana), pursuant to which ASN Product Development, Inc. (ASN) became our wholly-owned subsidiary. Asana and ASN had previously entered into a license agreement, which was amended and restated prior to the closing of the merger transaction (the Asana License Agreement), pursuant to which ASN acquired an exclusive, worldwide license to certain intellectual property rights relating to inhibitors of ERK1 and ERK2 owned or controlled by Asana to develop and commercialize ERAS-007 and certain other related compounds for all applications. In May 2024, we announced a strategic reprioritization that included deprioritizing the final trial in the HERKULES series of clinical trials that was evaluating ERAS-007. In September 2025, we sent a notice to Asana to terminate the Asana License Agreement, with an effective termination date of November 8, 2025. In connection with such termination, we and Asana have agreed that we shall continue to ensure that the patients currently enrolled in the HERKULES series of trials will be permitted to continue to participate in such trials for the foreseeable future.

NiKang Therapeutics, Inc.

In February 2020, we entered into a license agreement (the NiKang License Agreement) with NiKang Therapeutics, Inc. (NiKang) under which we were granted an exclusive, worldwide license to certain intellectual property rights owned or controlled by NiKang related to certain SHP2 inhibitors to develop and commercialize ERAS-601 and certain other related compounds for all applications. In November 2023, the Company announced a strategic reprioritization that included deprioritizing the FLAGSHP-1 clinical trial that was evaluating ERAS-601. In September 2025, the Company sent a notice to NiKang to terminate the NiKang License Agreement, with an effective termination date of October 9, 2025. In connection with such termination, we and NiKang have agreed that we shall continue to ensure that the patients currently enrolled in the FLAGSHP-1 trial and an investigator-initiated trial of ERAS-601 will be permitted to continue to participate in such trials for the foreseeable future.

Katmai Pharmaceuticals

In March 2020, we entered into a license agreement (the Katmai License Agreement) with Katmai Pharmaceuticals, Inc. (Katmai) under which we were granted an exclusive, worldwide, royalty-bearing license to certain patent rights and know-how controlled by Katmai related to the development of small molecule therapeutic and diagnostic products that modulate EGFR and enable the identification, diagnosis, selection, treatment, and/or monitoring of patients for neuro-oncological applications to develop, manufacture, use, and commercialize ERAS-801 and certain other related compounds in all fields of use. In May 2024, we announced a strategic reprioritization which included deprioritizing our THUNDERBBOLT-1 clinical trial evaluating ERAS-801 in patients with recurrent glioblastoma. In April 2025, we entered into a termination agreement (the Katmai Termination Agreement) with Katmai. The Katmai Termination Agreement terminated the Katmai License Agreement as of April 1, 2025. Under the Katmai Termination Agreement, we assigned to Katmai certain know-how, intellectual property rights, third-party vendor agreements, regulatory filings, and materials that we developed in connection with the development of ERAS-801 under the Katmai License Agreement, and Katmai is obligated to make payments to us upon the occurrence of specific events related to Katmai’s future development and commercialization of ERAS-801. In addition, we provided certain transition services to Katmai for a 90-day period, for which Katmai reimbursed us for our internal costs related to such services.

Commercialization

We intend to maintain exclusive worldwide development and commercialization rights to our product candidates, and, if marketing approval is obtained, to commence commercialization activities by building a focused sales and marketing organization to sell our products on our own in the United States and potentially other regions such as Europe. We will likely seek commercialization partnerships for our product candidates in other regions beyond the United States and Europe. We currently have no sales, marketing, or commercial product distribution capabilities. We intend to build the necessary infrastructure and capabilities over time for commercialization in the United States and potentially other regions, following further advancement of our product candidates. Clinical data, the size of the addressable patient population, the size of the commercial infrastructure and manufacturing needs, and the status of our pipeline, may all influence or alter our commercialization plans.

Competition + Cooperation (“Coopetition”)

Although the biotechnology and pharmaceutical industries, and the oncology sector, are characterized by rapid evolution of technologies, fierce competition, and strong defense of intellectual property rights, we believe the most fearsome competitor of all is cancer itself. As such, we view other companies in this sector more as potential allies and collaborators than as competitors, as we all have a common cause: to defeat cancer. Many of the companies that are developing or marketing treatments for cancer, including major pharmaceutical and biotechnology companies that are working on therapies targeting the RAS/MAPK pathway, are companies with whom we endeavor to collaborate in our mission to erase cancer.

Collaborating with these companies alleviates some of the traditional challenges that emerging companies face with respect to financial resources, established presence in the market, expertise in research and development, manufacturing, preclinical and clinical testing, obtaining regulatory approvals and reimbursement, and marketing approved products. Similarly, recruiting and retaining qualified scientific and management personnel, establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, programs are challenges for all companies developing or marketing treatments for cancer.

That said, our commercial potential could be reduced or eliminated if other companies develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than products that we may develop. Other companies also may obtain FDA or other regulatory approval for their products more rapidly than we may obtain approval for ours, which could result in these companies establishing a strong market position before we are able to enter the market or make our development more complicated.

There are numerous companies developing or marketing treatments for cancer, including many major pharmaceutical and biotechnology companies. These treatments consist of small molecule drug products, biologics, cell-based therapies, and traditional chemotherapy. There are also a number of pharmaceutical companies with product candidates in development that target the nodes involving the RAS/MAPK pathway. These include, among others, Adlai Nortye, Amgen, Boehringer Ingelheim, BridgeBio Oncology Therapeutics, Bristol Myers Squibb, Eli Lilly, GenFleet Therapeutics, Jacobio Pharmaceuticals, Merck, Pfizer, Revolution Medicines, and Roche/Genentech.

Intellectual property

We strive to protect the proprietary technology, inventions, and improvements that are commercially or strategically important to our business, including seeking, maintaining, and defending patent rights, whether developed internally or in-licensed/acquired from third parties. We also rely on trade secrets and know-how relating to our proprietary technology and product candidates and continuing innovation to develop, strengthen and maintain our proprietary position. We also plan to rely on data exclusivity, market exclusivity and patent term adjustments or extensions when available. Our commercial success will depend in part on our ability to obtain and maintain patent and other intellectual property protection for our proprietary technology, inventions and improvements; to preserve the confidentiality of our trade secrets; to defend and enforce our proprietary rights, including any patents or trademarks that we may own in the future; and to operate without infringing on the valid and enforceable patents and other proprietary rights of third parties. Intellectual property rights may not address all potential threats to our competitive advantage.

We continually assess and refine our intellectual property strategy as we develop new product candidates. To that end, we are prepared to file additional patent applications in any appropriate fields if our intellectual property strategy includes such filings, or where we seek to adapt to competition or seize business opportunities. Further, we are prepared to file patent applications, as we consider appropriate under the circumstances, relating to the new technologies that we develop.

We cannot be sure that patents will be granted with respect to any of our pending patent applications or with respect to any patent applications we may own or license in the future, nor can we be sure that any of our existing patents or any patents we may own or license in the future will be useful in protecting our technology.

As of December 31, 2025, our patent estate for the programs listed below, which consists of owned and in-licensed patent families, includes one issued US patent, four pending US provisional applications, six pending US non-provisional patent applications, one issued foreign patent, eleven pending international patent applications filed under the Patent Cooperation Treaty (PCT application), and thirty-nine foreign patent applications in various markets outside of the United States. In particular, we have patents and/or patent applications pending for each of our product candidates.

ERAS-0015

As of December 31, 2025, we have in-licensed one patent family from Joyo. The patent family relates to compositions of RAS molecular glues, their preparation and methods of use, and includes one issued US patent, one pending US non-provisional patent application, one issued foreign patent, and thirteen pending foreign patent applications. Any patents that issue from applications for the in-licensed family are expected to expire in 2043, absent any patent term adjustments or extensions. As of December 31, 2025, we have in-licensed one additional patent family from Joyo. The patent family relates to methods of using RAS molecular glues, and includes one pending PCT patent application and one pending foreign patent application. Any patents that issue from applications for this in-licensed family are expected to expire in 2045, absent any patent term adjustments or extensions.

As of December 31, 2025, we own or co-own seven patent families relating to compositions of RAS molecular glues, their preparation and methods of use and include four pending US provisional applications, four pending PCT patent applications, and three pending foreign patent applications. Any patents issued from these applications are expected to expire between 2045 and 2046, absent any patent term adjustments or extensions.

ERAS-4001

As of December 31, 2025, we have in-licensed one patent family from Medshine relating to RAS inhibitors, their preparation, and methods of use. The patent family includes two pending US non-provisional patent applications and seventeen pending foreign patent applications. Any patents that issue from applications for the in-licensed family are expected to expire in 2043,absent any patent term adjustments or extensions.

As of December 31, 2025, we own six patent families relating to RAS inhibitors, their preparation, and methods of use. The patent families include one pending US non-provisional patent application, four pending foreign patent applications, and six pending PCT patent applications. Any patents issued from these applications are expected to expire between 2044 and 2045, absent any patent term adjustments or extensions.

ERAS-12

As of December 31, 2025, we own two patent families relating to EGFR antibodies, their preparation, and methods of use. The patent families include two pending US non-provisional patent applications and one pending foreign patent application. Any patents issued from these applications are expected to expire between 2042 and 2043, absent any patent term adjustments or extensions.

Other IP programs or patents

With respect to our product candidates and processes we intend to develop and commercialize in the normal course of business, we intend to pursue patent protection covering, when possible, compositions, methods of use, dosing and formulations. We may also pursue patent protection with respect to manufacturing and drug development processes and technologies. Obtaining and maintaining patent protection depends on compliance with various procedural, document submission, fee payment, and other requirements imposed by governmental patent agencies. We may not be able to obtain patent protections for our compositions, methods of use, dosing and formulations, manufacturing and drug development processes and technologies throughout the world. Issued patents can provide protection for varying periods of time, depending upon the date of filing of the patent application, the date of patent issuance and the legal term of patents in the countries in which they are obtained. In general, patents issued for applications filed in the United States can provide exclusionary rights for 20 years from the earliest effective filing date. In addition, in certain instances, the term of an issued US patent that covers or claims an FDA-approved product can be extended to recapture a portion of the term effectively lost as a result of the FDA regulatory review period, which is called patent term extension. The restoration period cannot be longer than five years and the total patent term, including the restoration period, must not exceed 14 years following FDA approval. The US Patent and Trademark Office (USPTO) may also adjust the term of a US patent to accommodate for delays caused by the USPTO during the prosecution of a US patent application. Congress has defined the conditions upon which an applicant can receive an adjustment to the term and such requirements are established in 35 USC 154(b). Similar provisions are available in Europe and other jurisdictions to extend the term of a patent that covers an approved drug. The term of patents outside of the United States varies in accordance with the laws of the foreign jurisdiction, but typically is also 20 years from the earliest effective filing date. However, the actual protection afforded by a patent varies on a product-by-product basis, from country-to-country, and depends upon many factors, including the type of patent, the scope of its coverage, the availability of regulatory-related extensions, the availability of legal remedies in a particular country, and the

validity and enforceability of the patent. Patent terms may be inadequate to protect our competitive position on our products for an adequate amount of time. In the future, if and when our therapeutic candidates receive FDA approval, we expect to apply for patent term extensions on patents covering those therapeutic candidates. We intend to seek patent term extensions in any jurisdiction where these are available and where we also have a patent that may be eligible; however, there is no guarantee that the applicable authorities, including the USPTO and FDA, will agree with our assessment of whether such extensions should be granted, and even if granted, the length of such extensions.

The patent positions of companies like ours are generally uncertain and involve complex legal and factual questions. No consistent policy regarding the scope of claims allowable in patents in the field of biopharmaceuticals has emerged in the United States. The relevant patent laws and their interpretation outside of the United States is also uncertain. Changes in either the patent laws or their interpretation in the United States and other countries may diminish our ability to protect our technology or product candidates and could affect the value of such intellectual property. In particular, our ability to stop third parties from making, using, selling, offering to sell or importing products that infringe our intellectual property will depend in part on our success in obtaining and enforcing patent claims that cover our technology, inventions and improvements. We cannot guarantee that patents will be granted with respect to any of our pending patent applications or with respect to any patent applications we may file in the future, nor can we be sure that any patents that may be granted to us in the future will be commercially useful in protecting our products, the methods of use or manufacture of those products. Moreover, even our issued patents do not guarantee us the right to practice our technology in relation to the commercialization of our products. Patent and other intellectual property rights in the pharmaceutical and biotechnology space are evolving and involve many risks and uncertainties. For example, third parties may have blocking patents that could be used to prevent us from commercializing our product candidates and practicing our proprietary technology, and our issued patents may be challenged, invalidated or circumvented, which could limit our ability to stop competitors from marketing related products or could limit the term of patent protection that otherwise may exist for our product candidates. In addition, the scope of the rights granted under any issued patents may not provide us with protection or competitive advantages against competitors with similar technology. Furthermore, our competitors may independently develop similar technologies that are outside the scope of the rights granted under any issued patents. For these reasons, we may face competition with respect to our product candidates. Moreover, because of the extensive time required for development, testing and regulatory review of a potential product, it is possible that, before any particular product candidate can be commercialized, any patent protection for such product may expire or remain in force for only a short period following commercialization, thereby reducing the commercial advantage the patent provides.

We also rely on trade secrets to protect aspects of our technology and business not amenable to, or that we do not consider appropriate for, patent protection. We seek to protect this intellectual property, in part, by requiring our employees, consultants, outside scientific collaborators, sponsored researchers and other service providers and advisors to execute confidentiality agreements upon the commencement of employment or other relationship with us. In general, these agreements provide that confidential information concerning our business or financial affairs developed or made known to the individual during the course of the individual’s relationship with us is to be kept confidential and not disclosed to third parties except in specific circumstances. In the case of employees, the agreements further provide that inventions and discoveries conceived or reduced to practice by the individual that are related to our business, or actual, or demonstrably anticipated, research or development, or made during normal working hours, on our premises or using our equipment, supplies, or proprietary information, are our exclusive property. In many cases our agreements with consultants, outside scientific collaborators, sponsored researchers and other service providers and advisors require them to assign, or grant us licenses to, inventions resulting from the work or services they render under such agreements or grant us an option to negotiate a license to use such inventions.

We seek trademark protection in the United States and in certain other jurisdictions where available and when we deem appropriate. We currently have an issued United States trademark for our “ERASCA” mark and have registrations for such mark pending in foreign jurisdictions, including the European Union. We have also filed a trademark application in the United States as well as foreign jurisdictions, including the European Union, for registration of our “MAPKLAMP” mark.

Manufacturing

We do not own or operate, and currently have no plans to establish, any manufacturing facilities. We rely, and expect to continue to rely, on third parties for the manufacture of our product candidates for preclinical and clinical testing, as well as for commercial manufacture if any of our product candidates obtain marketing approval. We are working with our current manufacturers to ensure that we will be able to scale up our manufacturing capabilities to support our clinical plans. We are also in the process of locating and qualifying additional manufacturers to build redundancies into our supply chain. In addition, we rely on third parties to package, label, store, and distribute our product candidates, and we intend to continue to rely on third parties with respect to our commercial products if marketing approval is obtained. We believe that this strategy allows us to maintain a more efficient infrastructure by eliminating the need for us to invest in our own manufacturing facilities, equipment, and personnel while also enabling us to focus our expertise and resources on the design and development of our product candidates.

Government Regulation

The FDA and comparable regulatory authorities in state and local jurisdictions and in other countries impose substantial and burdensome requirements upon companies involved in the clinical development, manufacture, marketing and distribution of drugs and biologics such as those we are developing. These entities regulate, among other things, the research and development, testing, manufacture, quality control, safety, effectiveness, labeling, storage, record keeping, approval, advertising and promotion, distribution, post-approval monitoring and reporting, sampling and export and import of our product candidates.

US regulation of drugs and biologics

In the United States, the FDA regulates drugs under the Federal Food, Drug, and Cosmetic Act (FDCA), and its implementing regulations, and biologics under the FDCA and the Public Health Service Act and their implementing regulations. FDA approval of an NDA or biologics license application (BLA) or supplement is required before any new unapproved drug, biologic or dosage form, including a new use of a previously approved drug or biologic, can be marketed in the United States.

The process required by the FDA before such product candidates may be marketed in the United States generally involves the following:

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completion of extensive preclinical laboratory tests and preclinical animal studies, certain of which must be performed in accordance with applicable Good Laboratory Practice (GLP) regulations;

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submission to the FDA of an investigational new drug application (IND) which must become effective before human clinical trials may be initiated and must be updated annually;

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approval by an independent institutional review board (IRB) or ethics committee representing each clinical site before each clinical trial can be initiated;

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performance of adequate and well-controlled human clinical trials in accordance with Good Clinical Practice (GCP) requirements to establish the safety and efficacy, or with respect to biologics, the safety, purity and potency of the product candidate for each proposed indication;

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preparation of and submission to the FDA of an NDA or BLA, after completion of all pivotal clinical trials;

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potential review of the product application by an FDA advisory committee, where appropriate and if applicable;

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a determination by the FDA within 60 days of its receipt of an NDA or BLA to file the application for review;

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satisfactory completion of an FDA pre-approval inspection of the manufacturing facilities where the proposed product drug substance is produced to assess compliance with current Good Manufacturing Practice requirements (cGMPs) and audits of selected clinical trial sites to ensure compliance with GCP; and

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FDA review and approval of an NDA or BLA prior to any commercial marketing or sale of the drug in the United States.

Preclinical studies include laboratory evaluation of product chemistry, toxicity and formulation, as well as in vitro and animal studies to assess potential safety and efficacy. The conduct of preclinical studies is subject to federal regulations and requirements, including GLP regulations applicable to certain safety/toxicology studies.

An IND is a request for allowance from the FDA to administer an investigational drug product to humans. The central focus of an IND submission is on the general investigational plan and the protocol or protocols for preclinical studies and clinical trials. The IND also includes results of animal and in vitro studies assessing the toxicology, pharmacokinetics, pharmacology and pharmacodynamic characteristics of the product, chemistry, manufacturing and controls (CMC) information, and any available human data or literature to support the use of the investigational product. An IND must become effective before human clinical trials may be initiated. The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA, within the 30-day period, raises safety concerns or questions about the proposed clinical trial. In such a case, the IND may be placed on clinical hold and the IND sponsor and the FDA must resolve any outstanding concerns or questions before the clinical trial can be initiated. Submission of an IND therefore may or may not result in FDA allowance to initiate a clinical trial.

Clinical trials involve the administration of the investigational product to human subjects under the supervision of qualified investigators in accordance with GCP, which, among other things, includes the requirement that all research subjects, or their legal representative, provide their informed consent for their participation in any clinical trial. Clinical trials are conducted under protocols detailing, among other things, the inclusion and exclusion criteria, the objectives of the trial, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated. A separate submission to the existing IND must be made for each successive clinical trial conducted during product development and for any subsequent protocol amendments. While the IND is active, progress reports summarizing the results of the clinical trials and nonclinical studies performed since the last progress report, among other things, must be submitted at least annually to the FDA, and written IND safety reports must be submitted to the FDA and investigators for serious and unexpected suspected adverse events, findings from other studies suggesting a significant risk to humans exposed to the same or similar drugs or biologics, findings from animal or in vitro testing suggesting a significant risk to humans, and any clinically important increased incidence of a serious suspected adverse reaction compared to that listed in the protocol or investigator brochure.

Furthermore, an independent IRB for each site proposing to conduct the clinical trial must review and approve the plan for any clinical trial and its informed consent form before the clinical trial initiates at that site, and must monitor the trial until completed. An IRB is charged with protecting the welfare and rights of trial participants and considers such items as whether the risks to individuals participating in the clinical trials are minimized and are reasonable in relation to anticipated benefits. Regulatory authorities, the IRB or the sponsor may suspend a clinical trial at any time on various grounds, including a finding that the subjects are being exposed to an unacceptable health risk or that the trial is unlikely to meet its stated objectives. Some trials also include oversight by an independent group of qualified experts organized by the clinical trial sponsor, known as a data safety monitoring board or committee, which provides authorization for whether or not a trial may move forward at designated check points based on access to certain data from the trial and may recommend that the clinical trial be halted if it determines that there is an unacceptable safety risk for subjects or other grounds, such as no demonstration of efficacy. There are also requirements governing the reporting of clinical trials and clinical trial results to public registries.

The clinical investigation of a drug is generally divided into three phases. Although the phases are usually conducted sequentially, they may overlap or be combined.

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Phase 1: The investigational product is initially introduced into healthy human subjects or patients with the target disease or condition.These trials are designed to test the safety, dosage tolerance, absorption, metabolism and distribution of the investigational product in humans, the side effects associated with increasing doses, and, if possible, to gain early evidence on effectiveness.

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Phase 2: The investigational product is administered to a limited patient population with a specified disease or condition to evaluate thepreliminary efficacy, optimal dosages and dosing schedule and to identify possible adverse side effects and safety risks. Multiple Phase 2 clinical trials may be conducted to obtain information prior to beginning larger and more expensive Phase 3 clinical trials.

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Phase 3: The investigational product is administered to an expanded patient population to further evaluate dosage, to provide statisticallysignificant evidence of clinical efficacy and to further test for safety, generally at multiple geographically dispersed clinical trial sites. These clinical trials are intended to establish the overall risk/benefit ratio of the investigational product and to provide an adequate basis for labeling.

Post-marketing trials, sometimes referred to as Phase 4 clinical trials, may be conducted after initial marketing approval. These clinical trials are used to gain additional experience from the treatment of patients in the intended therapeutic indication. In certain instances, such as with accelerated approval drugs, the FDA may mandate the performance of Phase 4 clinical trials as a condition of approval.

Concurrent with clinical trials, companies may complete additional animal studies and develop additional information about the biological characteristics of the product candidate, and must finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other things, must develop methods for testing the identity, strength, quality and purity of the final product, or for biologics, the safety, purity and potency.

In addition, during the development of a new drug or biologic, sponsors are given opportunities to meet with the FDA at certain points. These points may be prior to submission of an IND, at the end of Phase 2, and before an NDA or BLA is submitted. Meetings at other times may be requested. These meetings can provide an opportunity for the sponsor to share information about the data gathered to date, for the FDA to provide advice, and for the sponsor and the FDA to reach agreement on the next phase of development.

NDA and BLA review process

Assuming successful completion of all required testing in accordance with all applicable regulatory requirements, the results of product development, including results from nonclinical studies and clinical trials are submitted to the FDA as part of an NDA or BLA requesting approval to market the product for one or more indications. The submission of an NDA or BLA requires payment of a substantial application user fee to the FDA, unless a waiver or exemption applies.

The NDA or BLA must include all relevant data available from pertinent preclinical studies and clinical trials, including negative or ambiguous results as well as positive findings, together with detailed information relating to the product’s CMC and proposed labeling, among other things. Data can come from company-sponsored clinical trials intended to test the safety and effectiveness of the product, or from a number of alternative sources, including trials initiated and sponsored by investigators.

In addition, under the Pediatric Research Equity Act (PREA), an NDA or BLA or supplement to an NDA or BLA must contain data to assess the safety and effectiveness of the drug or biological product candidate for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective, or a deferral or waiver for such data, as described in an agreed initial Pediatric Study Plan (iPSP). The Food and Drug Administration Safety and Innovation Act requires that a sponsor who is planning to submit a marketing application for a drug or biological product that includes a new active ingredient, new indication, new dosage form, new dosing regimen or new route of administration submit an iPSP within sixty days after an end-of-Phase 2 meeting, if no such meeting occurs, then before the start of the pivotal study or as may be agreed between the sponsor and FDA. Unless otherwise required by regulation, such as a molecular target relevant to pediatric cancers, PREA does not apply to any drug or biological product for an indication for which orphan designation has been granted.

Within 60 days following submission of the application, the FDA reviews the submitted BLA or NDA to determine if the application is substantially complete before the agency accepts it for filing. The FDA may refuse to file any NDA or BLA that it deems incomplete or not properly reviewable at the time of submission and may request additional information. In this event, the NDA or BLA must be resubmitted with the additional information. Once an NDA or BLA has been accepted for filing, the FDA’s goal is to review standard applications within ten months after the filing date, or, if the application qualifies for priority review, six months after the FDA accepts the application for filing. In both standard and priority reviews, the review process may also be extended for a three-month period by the FDA to review additional information deemed a major amendment to the application. Once accepted for filing, the FDA reviews an NDA to determine, among other things, whether a product is safe and effective for its intended use and whether its manufacturing is sufficient to assure and preserve the product’s identity, strength, quality and purity. The FDA reviews a BLA to determine, among other things, whether a product is safe, pure and potent and the facility in which it is manufactured, processed, packed or held meets standards designed to assure the product’s continued safety, purity and potency. When reviewing an NDA or BLA, the FDA may convene an advisory committee to provide clinical insight on application review questions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions.

Before approving an NDA or BLA, the FDA will typically inspect the facility or facilities where the product is manufactured. The FDA will not approve an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Additionally, before approving an NDA or BLA, the FDA may inspect one or more clinical sites to assure compliance with GCP.

After the FDA evaluates the NDA or BLA and conducts inspections of manufacturing facilities where the investigational product and/or its drug substance will be produced, the FDA may issue an approval letter or a Complete Response Letter (CRL). An approval letter authorizes commercial marketing of the product with specific prescribing information for specific indications. A CRL signals that the review cycle is complete and the application cannot be approved in its present form. The CRL will generally describe all of the deficiencies that the FDA has identified in the NDA or BLA, except that where the FDA determines that the data supporting the application are inadequate to support approval, the FDA may issue the CRL without first conducting any required inspections, testing submitted product lots and/or reviewing proposed labeling. In issuing the CRL, the FDA may recommend actions that the applicant might take to place a resubmitted NDA or BLA in condition for approval, including requests for additional data, information or clarification. The FDA may delay or refuse approval of an NDA or BLA if applicable regulatory criteria are not satisfied, require additional testing or information and/or require post-marketing testing and surveillance to monitor safety or efficacy of a product.

If regulatory approval of a product is granted, such approval will be granted for particular indications and may entail limitations on the indicated uses for which such product may be marketed. For example, the FDA may approve the NDA or BLA with a Risk Evaluation and Mitigation Strategy (REMS) to ensure the benefits of the product outweigh its risks. A REMS is a safety strategy to manage a known or potential serious risk associated with a product and to enable patients to have continued access to such medicines by managing their safe use, and could include medication guides, physician communication plans, or elements to assure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. The FDA also may condition approval on, among other things, changes to proposed labeling or the development of adequate controls and specifications. The FDA may also require one or more Phase 4 post-market trials and additional surveillance to further assess and monitor the product’s safety and effectiveness after commercialization, and may limit further marketing of the product based on the results of these post-marketing trials.

Expedited development and review programs

The FDA offers a number of expedited development and review programs for qualifying product candidates. For example, the fast track designation (FTD) program is intended to expedite or facilitate the process for reviewing product candidates that meet certain criteria. Specifically, product candidates are eligible for FTD if they are intended to treat a serious or life-threatening disease or condition and demonstrate the potential to address unmet medical needs for the disease or condition. FTD applies to the combination of the product candidate and the specific indication for which it is being studied. The sponsor of a fast track product candidate has opportunities for more frequent interactions with the review team during product development and, once an NDA or BLA is submitted, the application may be eligible for priority review, if the relevant criteria are met. An NDA or BLA for a fast track product candidate may also be eligible for rolling review, where the FDA may consider for review sections of the NDA or BLA on a rolling basis before the complete application is submitted, if the sponsor provides a schedule for the submission of the sections of the NDA or BLA, the FDA agrees to accept sections of the NDA or BLA and determines that the schedule is acceptable, and the sponsor pays any required user fees upon submission of the first section of the NDA or BLA.

A product candidate intended to treat a serious or life-threatening disease or condition may also be eligible for breakthrough therapy designation (BTD) to expedite its development and review. A product candidate can receive BTD if preliminary clinical evidence indicates that the product candidate, alone or in combination with one or more other drugs or biologics, may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. The designation includes all of the fast track program features, as well as more intensive FDA interaction and guidance beginning as early as Phase 1 and an organizational commitment to expedite the development and review of the product candidate, including involvement of senior managers.

Any marketing application for a drug or biologic submitted to the FDA for approval, including a product candidate with a FTD and/or BTD, may be eligible for other types of FDA programs intended to expedite the FDA review and approval process, such as priority review. An NDA or BLA is eligible for priority review if the product candidate has the potential to provide a significant improvement in the treatment, diagnosis or prevention of a serious disease or condition. For new molecular entity NDAs and original BLAs, priority review designation means the FDA’s goal is to take action on the marketing application within six months of the 60-day filing date (as compared to 10 months under standard review).

Additionally, depending on the design of the applicable clinical trials, product candidates studied for their safety and effectiveness in treating serious or life-threatening diseases or conditions may receive accelerated approval upon a determination that the product candidate has an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity,

rarity, or prevalence of the condition and the availability or lack of alternative treatments. As a condition of accelerated approval, the FDA will generally require the sponsor to perform adequate and well-controlled confirmatory clinical trials to verify and describe the anticipated effect on irreversible morbidity or mortality or other clinical benefit, and may require that such confirmatory trials are underway prior to granting any accelerated approval. Products receiving accelerated approval may be subject to expedited withdrawal procedures if the sponsor fails to conduct the required confirmatory trials in a timely manner or if such trials fail to verify the predicted clinical benefit. In addition, the FDA currently requires as a condition for accelerated approval pre-approval of promotional materials, which could adversely impact the timing of the commercial launch of the product.

Fast track designation, breakthrough therapy designation, priority review, and accelerated approval do not change the standards for approval but may expedite the development or approval process. Even if a product qualifies for one or more of these programs, the FDA may later decide that the product no longer meets the conditions for qualification or decide that the time period for FDA review or approval will not be shortened.

Orphan drug designation

Under the Orphan Drug Act, the FDA may grant ODD to a drug or biologic intended to treat a rare disease or condition, which is a disease or condition that affects fewer than 200,000 individuals in the United States, or more than 200,000 individuals in the United States for which there is no reasonable expectation that the cost of developing and making available in the United States a drug or biologic for this type of disease or condition will be recovered from sales in the United States for that drug or biologic. ODD must be requested before submitting an NDA or BLA. After the FDA grants ODD, the generic identity of the therapeutic agent and its potential orphan use are disclosed publicly by the FDA. The ODD does not convey any advantage in, or shorten the duration of, the regulatory review or approval process.

If a product candidate that has ODD subsequently receives the first FDA approval for the disease or condition for which it has such designation, the product is entitled to orphan drug exclusive approval (or exclusivity), which means that the FDA may not approve any other applications, including a full NDA or BLA, to market the same drug or biologic for the same approved indication or use within such disease or condition for seven years, except in limited circumstances, such as a showing of clinical superiority to the product with orphan drug exclusivity in the relevant indication or if the FDA finds that the holder of the orphan drug exclusivity has not shown that it can assure the availability of sufficient quantities of the orphan drug to meet the needs relating to the approved indication or use of patients with the disease or condition for which the drug or biologic was designated. Orphan drug exclusivity does not prevent the FDA from approving a different drug or biologic for the same indication or use, or the same drug or biologic for any indication or use in a different disease or condition. Among the other benefits of orphan drug designation are tax credits for certain research and a waiver of the NDA or BLA application user fee.

A designated orphan drug may not receive orphan drug exclusivity if it is approved for a use that is broader than the disease or condition for which it received ODD. In addition, exclusive marketing rights in the United States may be lost if the FDA later determines that the request for designation was materially defective or if the manufacturer is unable to assure sufficient quantities of the product to meet the needs relating to the approved indication or use of patients with the rare disease or condition.

Post-approval requirements

Any products manufactured or distributed pursuant to FDA approvals are subject to pervasive and continuing regulation by the FDA, including, among other things, requirements relating to record-keeping, reporting of adverse experiences, periodic reporting, product sampling and distribution, and advertising and promotion of the product. After approval, most changes to the approved product, such as adding new indications or other labeling claims, are subject to prior FDA review and approval. There also are continuing user fee requirements, under which the FDA assesses an annual program fee for each product identified in an approved NDA or BLA. Drug and biologic manufacturers and their subcontractors are required to register their establishments with the FDA and certain state agencies, and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with cGMPs, which impose certain procedural and documentation requirements upon us and our third-party manufacturers. Changes to the manufacturing process are strictly regulated, and, depending on the significance of the change, may require prior FDA approval before being implemented. FDA regulations also require investigation and correction of any deviations from cGMPs and impose reporting requirements upon us and any third-party manufacturers that we may decide to use. Accordingly, manufacturers must continue to expend time, money and effort in the area of production and quality control to maintain compliance with cGMPs and other aspects of regulatory compliance.

The FDA may withdraw approval if compliance with regulatory requirements and standards is not maintained or if problems occur after the product reaches the market. Later discovery of previously unknown problems with a product, including adverse events of unanticipated severity or frequency, or with manufacturing processes, or failure to comply with regulatory requirements, may result in revisions to the approved labeling to add new safety information; imposition of post-market trials or clinical trials to assess new safety risks; or imposition of distribution restrictions or other restrictions under a REMS program. Other potential consequences include, among other things:

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restrictions on the marketing or manufacturing of a product, complete withdrawal of the product from the market or product recalls;

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fines, warning letters or holds on post-approval clinical trials;

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refusal of the FDA to approve pending applications or supplements to approved applications, or suspension or revocation of existing product approvals;

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product seizure or detention, or refusal of the FDA to permit the import or export of products;

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consent decrees, corporate integrity agreements, debarment or exclusion from federal healthcare programs;

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mandated modification of promotional materials and labeling and the issuance of corrective information;

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injunctions or the imposition of civil or criminal penalties.

The FDA closely regulates the marketing, labeling, advertising and promotion of drug products. A company can make only those claims relating to safety and efficacy, purity and potency that are approved by the FDA and in accordance with the provisions of the approved label. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses. Failure to comply with these requirements can result in, among other things, adverse publicity, warning letters, corrective advertising and potential civil and criminal penalties. Physicians may prescribe, in their independent professional medical judgment, legally available products for uses that are not described in the product’s labeling and that differ from those approved by the FDA. Physicians may believe that such off-label uses are the best treatment for many patients in varied circumstances. The FDA does not regulate the behavior of physicians in their choice of treatments. The FDA does, however, restrict manufacturer’s communications on the subject of off-label use of their products. The federal government has levied large civil and criminal fines against companies for alleged improper promotion of off-label use and has enjoined companies from engaging in off-label promotion. The FDA and other regulatory agencies have also required that companies enter into consent decrees or permanent injunctions under which specified promotional conduct is changed or curtailed. However, companies may share truthful and not misleading information that is otherwise consistent with a product’s FDA-approved labeling.

In addition, the distribution of prescription biopharmaceutical products is subject to the Prescription Drug Marketing Act (PDMA) which regulates the distribution of drugs and drug samples at the federal level, and sets minimum standards for the registration and regulation of drug distributors by the states. Both the PDMA and state laws limit the distribution of prescription pharmaceutical product samples and impose requirements to ensure accountability in distribution.

Drug product marketing exclusivity

Market exclusivity provisions under the FDCA can delay the submission or the approval of certain marketing applications. For example, the FDCA provides a five-year period of non-patent data exclusivity within the United States to the first applicant to obtain approval of an NDA for a new chemical entity. A drug is a new chemical entity if the FDA has not previously approved any other new drug containing the same active moiety, which is the molecule or ion responsible for the action of the drug substance. During the exclusivity period, the FDA may not approve or even accept for review an abbreviated new drug application (ANDA), or an NDA submitted under Section 505(b)(2), or 505(b) (2) NDA, submitted by another company for another drug based on the same active moiety, regardless of whether the drug is intended for the same indication as the original innovative drug or for another indication, where the applicant does not own or have a legal right of reference to all the data required for approval. However, an application may be submitted after four years if it contains a certification of patent invalidity or non-infringement to one of the patents listed with the FDA by the innovator NDA holder.

The FDCA alternatively provides three years of non-patent exclusivity for an NDA, or supplement to an existing NDA if new clinical investigations, other than bioavailability trials, that were conducted or sponsored by the applicant are deemed by the FDA to be essential to the approval of the application, for example new indications, dosages or strengths of an existing drug. This three-year exclusivity covers only the modification for which the drug received approval on the basis of the new clinical investigations and does not prohibit the FDA from approving ANDAs or 505(b)(2) NDAs for drugs containing the active agent for the original indication or condition of use. Five-year and three-year exclusivity will not delay the submission or approval of a full NDA. However, an applicant submitting a full NDA would be required to conduct or obtain a right of reference to any preclinical studies and adequate and well-controlled clinical trials necessary to demonstrate safety and effectiveness.

Pediatric exclusivity is another type of marketing exclusivity available in the United States. Pediatric exclusivity provides for an additional six months of marketing exclusivity attached to another existing period of regulatory exclusivity or patent term if a sponsor conducts clinical trials in children in response to a Written Request from the FDA. The issuance of a written request does not require the sponsor to undertake the described clinical trials. In addition, orphan drug exclusivity, as described above, may offer a seven-year period of marketing exclusivity, except in certain circumstances.

Biosimilars and reference product exclusivity

The Biologics Price Competition and Innovation Act of 2009 (BPCIA) created an abbreviated approval pathway for biological products that are highly similar, or “biosimilar,” to or interchangeable with an FDA-approved reference biological product. Biosimilarity, which requires that there be no clinically meaningful differences between the biological product and the reference product in terms of safety, purity, and potency, is generally shown through analytical studies, animal studies, and a clinical trial or trials. Interchangeability requires that a product is biosimilar to the reference product and the product must demonstrate that it can be expected to produce the same clinical results as the reference product in any given patient and, for products that are administered multiple times to an individual, the biologic and the reference biologic may be alternated or switched after one has been previously administered without increasing safety risks or risks of diminished efficacy relative to exclusive use of the reference biologic. A product shown to be biosimilar or interchangeable with an FDA-approved reference biological product may rely in part on the FDA’s previous determination of safety and effectiveness for the reference product for approval, which can potentially reduce the cost and time required to obtain approval to market the product.

Under the BPCIA, an application for a biosimilar product may not be submitted to the FDA until four years following the date that the reference product was first licensed by the FDA. In addition, the approval of a biosimilar product may not be made effective by the FDA until 12 years from the date on which the reference product was first licensed. During this 12-year period of exclusivity, another company may still market a competing version of the reference product if the FDA approves a full BLA for the competing product containing that applicant’s own preclinical data and data from adequate and well-controlled clinical trials to demonstrate the safety, purity and potency of its product. The BPCIA also created certain exclusivity periods for biosimilars approved as interchangeable products.

A biological product can also obtain pediatric market exclusivity in the United States, as described above, if the BLA sponsor voluntarily completes a pediatric study that fairly responds to a "written request" from the FDA to conduct such study.

FDA regulation of companion diagnostics

If safe and effective use of a drug or biologic depends on an in vitro diagnostic, then the FDA may require approval or clearance of that diagnostic, known as a companion diagnostic, at the same time that the FDA approves the therapeutic product. In August 2014, the FDA issued final guidance clarifying the requirements that will apply to approval of therapeutic products and in vitro companion diagnostics. According to the guidance, if FDA determines that a companion diagnostic device is essential to the safe and effective use of a novel therapeutic product or indication, FDA may not approve the drug or new indication if the companion diagnostic device is not also approved or cleared for that indication. Approval or clearance of the companion diagnostic device will ensure that the device has been adequately evaluated and has adequate performance characteristics in the intended population. The review of in vitro companion diagnostics in conjunction with the review of our product candidates will, therefore, likely involve coordination of review by the FDA’s Center for Drug Evaluation and Research or the FDA’s Center for Biologics Evaluation and Research and the FDA’s Center for Devices and Radiological Health Office of In Vitro Diagnostics and Radiological Health.

Under the FDCA, in vitro diagnostics, including companion diagnostics, are regulated as medical devices. In the United States, the FDCA and its implementing regulations, and other federal and state statutes and regulations govern, among other things, medical device design and development, preclinical and clinical testing, premarket clearance or approval, registration and listing, manufacturing, labeling, storage, advertising and promotion, sales and distribution, export and import, and post-market surveillance. Unless an exemption applies, diagnostic tests require marketing clearance or approval from the FDA prior to commercial distribution. The two primary types of FDA marketing authorization applicable to a medical device are clearance of a premarket notification pursuant to Section 510(k) of the FDCA, also called 510(k) clearance, and approval of a premarket approval application (PMA).

The PMA process, including the gathering of clinical and preclinical data and the submission to and review by the FDA, can take several years or longer. It involves a rigorous premarket review during which the applicant must prepare and provide the FDA with reasonable assurance of the device’s safety and effectiveness and information about the device and its components regarding, among other things, device design, manufacturing and labeling. PMA applications are subject to an application fee. In addition, PMAs for certain devices must generally include the results from extensive preclinical and adequate and well-controlled clinical trials to establish the safety and effectiveness of the device for each indication for which FDA approval is sought. As part of the PMA review, the FDA will typically inspect the manufacturer’s facilities for compliance with the Quality Management System Regulation (QMSR) which imposes elaborate testing, control, documentation and other quality assurance requirements.

If the FDA’s evaluation of the PMA application is favorable, the FDA typically issues an approvable letter requiring the applicant’s agreement to specific conditions, such as changes in labeling, or specific additional information, such as submission of final labeling, in order to secure final approval of the PMA. If the FDA’s evaluation of the PMA or manufacturing facilities is not favorable, the FDA will deny approval of the PMA or issue a not approvable letter. A not approvable letter will outline the deficiencies in the application and, where practical, will identify what is necessary to make the PMA approvable. The FDA may also determine that additional clinical trials are necessary, in which case the PMA approval may be delayed for several months or years while the trials are conducted and then the data submitted in an amendment to the PMA. If the FDA concludes that the applicable criteria have been met, the FDA will issue a PMA for the approved indications, which can be more limited than those originally sought by the applicant. The PMA can include post-approval conditions that the FDA believes necessary to ensure the safety and effectiveness of the device, including, among other things, restrictions on labeling, promotion, sale and distribution. Once granted, PMA approval may be withdrawn by the FDA if compliance with post-approval requirements, conditions of approval or other regulatory standards are not maintained or problems are identified following initial marketing.

After a device is placed on the market, it remains subject to significant regulatory requirements. Medical devices may be marketed only for the uses and indications for which they are cleared or approved. Device manufacturers must also establish registration and device listings with the FDA. A medical device manufacturer’s manufacturing processes are required to comply with the applicable portions of the QMSR, which covers the methods and documentation of the design, testing, production, processes, controls, quality assurance, labeling, packaging and shipping of medical devices. Domestic facility records and manufacturing processes are subject to periodic unscheduled inspections by the FDA. The FDA also may inspect foreign facilities that export products to the United States.

Other US regulatory requirements

In addition to FDA regulation of pharmaceutical products, pharmaceutical companies are also subject to additional healthcare regulation and enforcement by the federal government and by authorities in the states and foreign jurisdictions in which they conduct their business and may constrain the financial arrangements and relationships through which we research, as well as sell, market and distribute any products for which we obtain marketing authorization. Such laws include, without limitation, state and federal anti-kickback, fraud and abuse, false claims, and transparency laws and regulations related to drug pricing and payments and other transfers of value made to physicians and other healthcare providers. If their operations are found to be in violation of any of such laws or any other governmental regulations that apply, they may be subject to penalties, including, without limitation, administrative, civil and criminal penalties, damages, fines, disgorgement, the curtailment or restructuring of operations, integrity oversight and reporting obligations, exclusion from participation in federal and state healthcare programs and imprisonment.

US coverage and reimbursement

Significant uncertainty exists as to the coverage and reimbursement status of any product candidate for which we may seek regulatory approval. Sales in the United States will depend, in part, on the availability of sufficient coverage and adequate reimbursement from third-party payors, which include government health programs such as Medicare, Medicaid, TRICARE and the Veterans Administration, as well as managed care organizations and private health insurers. Prices at which we or our customers seek reimbursement for our product candidates can be subject to challenge, reduction or denial by third-party payors.

The process for determining whether a third-party payor will provide coverage for a product is typically separate from the process for setting the reimbursement rate that the payor will pay for the product. In the United States, there is no uniform policy among payors for coverage or reimbursement. Decisions regarding whether to cover any of a product, the extent of coverage and amount of reimbursement to be provided are made on a plan-by-plan basis. Third-party payors often rely upon Medicare coverage policy and payment limitations in setting their own coverage and reimbursement policies, but also have their own methods and approval processes. Therefore, coverage and reimbursement for products can differ significantly from payor to payor. As a result, the coverage determination process is often a time-consuming and costly process that can require manufacturers to provide scientific and clinical support for the use of a product to each payor separately, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance. In addition, companion diagnostic tests require coverage and reimbursement separate and apart from the coverage and reimbursement for their companion pharmaceutical or biological products. Similar challenges to obtaining coverage and reimbursement, applicable to pharmaceutical or biological products, will apply to companion diagnostics.

Third-party payors are increasingly challenging the price and examining the medical necessity and cost-effectiveness of medical products and services, in addition to their safety and efficacy. Third-party payors may not consider our product candidates to be medically necessary or cost-effective compared to other available therapies. Adoption of price controls and cost-containment measures, and adoption of more restrictive policies in jurisdictions with existing controls and measures, could further limit sales of any product that receives approval.

US healthcare reform

In the United States, there have been, and continue to be, legislative and regulatory changes and proposed changes regarding the healthcare system that could prevent or delay marketing approval of product candidates, restrict or regulate post-approval activities, and affect the profitable sale of product candidates. Among policy makers and payors in the United States, there is significant interest in promoting changes in healthcare systems with the stated goals of containing healthcare costs, improving quality and/or expanding access. In the United States, the pharmaceutical industry has been a particular focus of these efforts and has been significantly affected by major legislative initiatives.

By way of example, in March 2010, the Patient Protection and Affordable Care Act (the ACA) was passed, which substantially changed the way healthcare is financed by both governmental and private insurers, and significantly affected the pharmaceutical industry. The ACA, among other things, increased the minimum level of Medicaid rebates payable by manufacturers of brand name drugs from 15.1% to 23.1% of the average manufacturer price; required collection of rebates for drugs paid by Medicaid managed care organizations; imposed a non-deductible annual fee on pharmaceutical manufacturers or importers who sell certain “branded prescription drugs” to specified federal government programs; implemented a new methodology by which rebates owed by manufacturers under the Medicaid Drug Rebate Program are calculated for drugs that are inhaled, infused, instilled, implanted, or injected; expanded eligibility criteria for Medicaid programs; creates a new Patient-Centered Outcomes Research Institute to oversee, identify priorities in, and conduct comparative clinical effectiveness research, along with funding for such research; and established a Center for Medicare and Medicaid Innovation at the Centers for Medicare & Medicaid Services (CMS) to test innovative payment and service delivery models to lower Medicare and Medicaid spending, potentially including prescription drug spending. Since its enactment, there have been judicial, executive and political challenges to certain aspects of the ACA. On June 17, 2021, the US Supreme Court dismissed a challenge on procedural grounds that argued the ACA is unconstitutional in its entirety because the “individual mandate” was repealed by Congress. Thus, the ACA will remain in effect in its current form.

In addition, other legislative changes have been proposed and adopted since the ACA was enacted. These changes included aggregate reductions to Medicare payments to providers, which went into effect on April 1, 2013 and, due to subsequent legislative amendments to the statute, will remain in effect through 2032, with the exception of a temporary suspension from May 1, 2020 through March 31, 2022, unless additional Congressional action is taken. On January 2, 2013, the American Taxpayer Relief Act of 2012 was signed into law, which, among other things, reduced Medicare payments to several providers, including hospitals, and increased the statute of limitations period for the government to recover overpayments to providers from three to five years. In addition, on March 11, 2021, the American Rescue Plan Act of 2021 was signed into law, which eliminated the statutory cap on manufacturers’ Medicaid drug rebate liability, beginning January 1, 2024. The rebate was previously capped at 100% of a drug's average manufacturer price.

ERAS US Equity

ERAS · 10-K · period ended 2025-12-31

Item 1. Business.

ERAS US Equity☆

ERAS · 10-K · period ended 2025-12-31

Item 1. Business.

ERAS US Equity