10-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended DECEMBER 31, 2024

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 $562.9 million based on the closing price of the Registrant's common stock as reported on the Nasdaq Global Select Market of $2.36 per share on June 28, 2024, 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 13, 2025 was 283,265,716.

DOCUMENTS INCORPORATED BY REFERENCE

Certain sections of the Registrant’s definitive proxy statement for the 2025 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 58

Item 1B. Unresolved Staff Comments 107

Item 1C. Cybersecurity 108

Item 2. Properties 109

Item 3. Legal Proceedings 109

Item 4. Mine Safety Disclosures 109

PART II

Item 6. [Reserved] 110

Item 7A. Quantitative and Qualitative Disclosures About Market Risk 123

Item 8. Financial Statements and Supplementary Data 123

Item 9A. Controls and Procedures 124

Item 9B. Other Information 124

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections 124

PART III

Item 10. Directors, Executive Officers and Corporate Governance 125

Item 11. Executive Compensation 125

Item 14. Principal Accountant Fees and Services 125

PART IV

Item 15. Exhibits, Financial Statement Schedules 126

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 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 planned 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, and if our competitors develop technologies or product candidates more rapidly than we do or their technologies are more effective, our business and 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 could 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. We have assembled one of the deepest RAS/MAPK pathway-focused pipelines in the industry, which 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. The target breadth and molecular diversity represented in our pipeline enable us to pursue a systematic, data-driven, portfolio-wide clinical development effort to identify single agent and combination 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 one clinical-stage program (a pan-RAF inhibitor), two IND-enabling stage programs (a pan-RAS molecular glue and a pan-KRAS inhibitor), and an additional discovery-stage program (an EGFR D2/D3 biparatopic antibody). 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. Our lead product candidate, naporafenib, targets RAF, a key node of the RAS/MAPK pathway. We are developing naporafenib in combination with trametinib (MEKINIST) (MEK inhibitor) and other targeted therapies to delay emergence of resistance in response to RAS/MAPK pathway inhibition. We are also 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. We refer to this approach as a "MAPKlamp." With this MAPKlamp approach, we hope to induce tumor regression in RAS/MAPK pathway-driven cancers, while also blocking the in-pathway escape routes that lead to tumor resistance.

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 one of the deepest pipelines 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.

Our pipeline also includes ERAS-801, a brain-penetrant EGFR inhibitor in development for patients with EGFR-altered recurrent glioblastoma (GBM) (for which we are concluding a Phase 1 trial and exploring further advancement, including via partnerships and investigator-sponsored trials), ERAS-007 ERK1/2 inhibitor, and ERAS-601 SHP2 inhibitor. ERAS-007 and ERAS-601 are being assessed in preclinical studies as potential combination partners with other programs in our pipeline for RAS/MAPK pathway inhibition. Via Erasca Ventures, LLC (Erasca Ventures), we made an equity investment in Affini-T Therapeutics, Inc. (Affini-T), which is developing TCR T-cell therapies against KRAS G12V, KRAS G12D, and KRAS G12C.

Our lead product candidate is naporafenib, for which we initiated our SEACRAFT-2 pivotal Phase 3 trial in the first half of 2024 for patients with NRAS-mutated (NRASm) melanoma. In October 2024, we announced promising preliminary data from our SEACRAFT-1 Phase 1b trial for patients with NRAS Q61X melanoma in an oral presentation at the 36th EORTC-NCI-AACR (ENA) Symposium (2024 Triple Meeting). Naporafenib is a pan-RAF inhibitor with first-in-class and best-in-class potential for patients with NRASm melanoma and other RAS/MAPK pathway-driven tumors. RAF proteins are ubiquitously expressed serine-threonine kinases that constitute a key node of the RAS/MAPK pathway downstream of RAS and upstream of MEK. The RAF protein family consists of ARAF, BRAF, and CRAF (RAF1) that are activated

through dimerization. Mutations in RAF proteins have been observed in many cancers, such as melanoma, colorectal cancer (CRC), non-small cell lung cancer (NSCLC), and thyroid cancer. We in-licensed naporafenib from Novartis Pharma AG (Novartis) in December 2022. Naporafenib has been dosed in over 600 patients to date, whereby safety, tolerability, and acceptable pharmacokinetics (PK) and pharmacodynamics (PD) have been established in both monotherapy and select combinations, with clinical proof-of-concept (PoC) data in combination with trametinib for patients with NRASm melanoma, which includes NRAS Q61X melanoma. In December 2023, we announced that the US Food and Drug Administration (FDA) granted Fast Track Designation (FTD) to naporafenib in combination with trametinib for the treatment of adult patients with unresectable or metastatic melanoma who have progressed on, or are intolerant to, an anti‐programmed death-1 (ligand 1) (PD‐(L)1)-based regimen, and whose tumors contain an NRAS mutation. Programs that receive FTD may benefit from early and frequent interactions with the FDA during the clinical development process and, if relevant criteria are met, the FDA may consider reviewing portions of a marketing application before the sponsor submits the complete application.

Our development strategy for naporafenib includes our SEACRAFT trials designed to evaluate naporafenib in combination with other targeted therapies. Our SEACRAFT-2 trial is supported by the clinical PoC data in patients with NRASm melanoma that we presented from the SEACRAFT-1 trial at the 2024 Triple Meeting. In addition, we believe such clinical PoC in NRASm melanoma is supported by data presented by Novartis at the European Society for Medical Oncology Congress 2022 (ESMO Congress 2022) medical conference and as published in March 2023 by de Braud et al. in the Journal of Clinical Oncology. In connection with our SEACRAFT-2 trial, we have entered into a clinical trial collaboration and supply agreement (CTCSA) with Novartis for its MEK inhibitor, trametinib. Pursuant to the CTCSA, we are sponsoring and funding the clinical trial and Novartis is providing its drug to us free of charge. In addition, we are evaluating additional combinations of naporafenib with our other RAS/MAPK pathway targeting agents and/or external agents in preclinical models.

On October 24, 2024, we announced preliminary data from our SEACRAFT-1 trial in an oral presentation at the 2024 Triple Meeting. The preliminary clinical activity of naporafenib plus trametinib in the melanoma cohort of SEACRAFT-1 include, as of the efficacy cutoff date*:

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40% (4/10) response rate observed in the efficacy-evaluable patients with NRAS Q61X melanoma, including three confirmed partial responses and one unconfirmed partial response; the melanoma cohort in SEACRAFT-1 is generally representative of the patient population currently being enrolled in the pivotal SEACRAFT-2 trial

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70% (7/10) of patients remained on treatment as of the data cutoff, including all four responders

In addition, we reported that naporafenib plus trametinib was generally well tolerated as of the safety cutoff date*, with mostly low-grade adverse events in the majority of patients. We believe that the use of mandatory primary rash prophylaxis helped reduce the frequency and severity of skin toxicities, reduced the drug discontinuation rate due to adverse events, and improved the observed tolerability results as measured by the increased relative dose intensity, as compared to the prior clinical trials of naporafenib plus trametinib conducted by Novartis, which did not include the use of mandatory primary rash prophylaxis.

* Efficacy data cutoff date was September 5, 2024. Safety data cutoff date was September 3, 2024.

We believe that while the preliminary SEACRAFT-1 data do not support further exploration of a tissue-agnostic indication, they do reinforce the potential of the ongoing Phase 3 SEACRAFT-2 trial in patients with NRASm melanoma. We expect to read out randomized dose optimization data of naporafenib plus trametinib from Stage 1 of the SEACRAFT-2 Phase 3 trial in the second half of 2025. Stage 2 of the SEACRAFT-2 Phase 3 trial is currently designed to compare naporafenib plus trametinib against physician's choice of chemotherapy or trametinib using dual primary endpoints of progression free survival and overall survival for regulatory approval.

Our next two programs are part of our RAS-targeting franchise, which we in-licensed in May 2024. We believe these two programs fit within our second approach of targeting RAS directly, both in its active GTP and inactive GDP states. 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-altered solid tumors. In vitro, ERAS-0015 has shown approximately 8-21 times higher binding affinity to cyclophilin A versus the leading pan-RAS molecular glue in development. We believe this higher binding affinity results in approximately 5 times more potent RAS inhibition than the comparator that has been demonstrated in cell-based assays.

ERAS-0015 also has favorable absorption, distribution, metabolism and excretion (ADME) and 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 leading pan-RAS molecular glue. The initial clinical trial for ERAS-0015 will be AURORAS-1, for which we plan to file an investigational new drug application (IND) in mid-Q2 2025, with an anticipated Phase 1 monotherapy data readout in 2026.

ERAS-4001 is a potential first-in-class pan-KRAS inhibitor in development for the treatment of patients with KRAS-altered 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 wild-type HRAS and NRAS has the potential to provide a wider therapeutic window. ERAS-4001 demonstrated activity against both GDP-bound (“inactive state”) and GTP-bound (“active state”) KRAS G12D with single digit nanomolar IC50s in a biochemical RAS – RAF1 RBD (RAS Binding Domain) assay. In vivo, ERAS-4001 showed good tumor regression in multiple models. In combination with anti-PD-1, ERAS-4001 was able to achieve complete disappearance of tumors in mice on day 31. The initial clinical trial for ERAS-4001 will be BOREALIS-1, for which we plan to file an IND in the second quarter of 2025, with an anticipated Phase 1 monotherapy data readout in 2026.

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 that 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 that is designed to inhibit EGFR through the combination of 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 2024, in connection with entering into the two license agreements related to ERAS-0015 and ERAS 4001, a review of our strategic priorities, and our decision to deemphasize certain drug discovery activities, we approved a strategic reprioritization to focus a substantial portion of our resources on our naporafenib program, ERAS-0015, and ERAS-4001. We deprioritized our HERKULES-3 clinical trial evaluating ERAS-007 in combination with encorafenib and cetuximab (EC) in patients with EC-naïve BRAF mutated colorectal cancer as we believe the clinical efficacy data did not support continued evaluation. We also deprioritized our THUNDERBBOLT-1 clinical trial evaluating ERAS-801 in patients with GBM, although we are exploring further advancement of the ERAS-801 program, including via partnerships and investigator-sponsored trials. Finally, we deprioritized our preclinical ERAS-4 program; however, certain of our existing ERAS-4 molecules may serve as backup compounds for ERAS-4001.

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.

At Erasca, while our mission to erase cancer inspires us, we know we can do more to make an even broader contribution to society. To that end, we are pursuing environmental, social, and governance (ESG) initiatives that are aligned with our core mission.

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Erasca Foundation: 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 2024, the Erasca Foundation provided funding for initiatives to positively impact society, including providing funding to Best Buddies International; Cancer Angels of San Diego; Curebound Cancer Research; Life Science Cares; and The Clearity Foundation.

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Environmental initiatives: Both of our physical buildings limit their carbon footprint. Our San Diego office is Gold Level Leadership in Energy and Environmental Design (LEED) certified, and our San Francisco office is Platinum Level LEED certified. Each building is easily accessible by public transportation and has electric vehicle charging stations and indoor bike racks. We also encourage our employees to recycle, including recycling programs for a subset of our lab supplies. While we rely on third-party vendors to conduct our drug manufacturing, our chemists that are engaged in the manufacturing process are committed to increasing efficiencies, reducing materials, and minimizing waste.

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Code of Conduct and Ethics: Our Code of Business Conduct and Ethics applies to all of our employees, officers and directors, and requires the highest standards of business ethics. The Code of Business Conduct and Ethics and other corporate governance documents are located in the “Corporate Governance” section of the “Investors” page of our website located at www.erasca.com.

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Inclusive clinical trial participation: We intend to make clinical trials of our product candidates more accessible to diverse patientpopulations and plan to partner with others who are like-minded in this regard.

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Drug access program: If our products become commercially available, we intend to pursue initiatives to provide patients with access to such drugs, including through patient assistance programs andcompassionate use programs.

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 deep, modality-agnostic RAS/MAPK pathway-focused pipeline. OurRAS/MAPK pathway-focused pipeline, comprising several targeted therapy programs, is one of the deepest in the industry. 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. Naporafenib (our pan-RAF inhibitor) is 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, other than with respect to ERAS-0015 in China, Hong Kong, and Macau. 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.

SHP2

SHP2 is a protein tyrosine phosphatase and a key positive regulator of the growth signals from the RTK growth factor receptors to the intracellular signaling pathways (including RAS/MAPK and PI3K) that promote growth and survival of normal cells and cancer cells. As such, SHP2 is a convergent node for upstream RTK signaling, such that activated SHP2 upregulates (“turns up”) the positive signals and downregulates (“turns down”) the negative signals in the signaling cascades. SHP2 also serves as a central node in relaying the growth and survival signals from RTKs such as EGFR to RAS/MAPK and other intracellular pathways. SHP2 is an attractive target because SHP2 inhibition ubiquitously blocks the growth signals from multiple RTKs, thereby preventing cancer cells from bypassing the blockade on a specific RTK (e.g., EGFR inhibitor) through activation of other RTK growth factor receptors (e.g., MET).

NF1

NF1, or neurofibromin, is a protein that accelerates the transition of RAS proteins from the active RAS-GTP state to the inactive RAS-GDP state. NF1 is classified as a GTPase activating protein (GAP) because it boosts the ability of RAS to hydrolyze bound GTP to GDP. Although RAS can autonomously hydrolyze GTP, it is dependent on GAPs such as NF1 to rapidly cycle it from the active state to the inactive state and thereby prevent overactive signaling. If NF1 is inactivated due to a mutation (NF1 loss-of-function mutation), RAS proteins may spend more time in the active RAS-GTP state. This can result in hyperactive RAS/MAPK pathway activation that drives aberrant cell growth and ultimately tumorigenesis. This is observed in patients affected by a genetic disorder caused by somatic mutations in the NF1 gene called neurofibromatosis type 1. NF1 loss-of-function mutations are observed in a variety of cancers, including melanoma and CRC, where they activate RAS/MAPK signaling alone or in conjunction with other RAS/MAPK pathway activating mutations.

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.

ERK

The extracellular signal-regulated kinases (ERK), ERK1 and ERK2, are ubiquitous serine-threonine kinases that regulate cellular signaling in both physiological and pathological states and comprise the terminal node of the RAS/MAPK pathway. Once activated by MEK, ERK proteins phosphorylate thousands of downstream proteins, propagating RAS/MAPK signaling across multiple cellular functions. In contrast to currently approved allosteric MEK inhibitors, ERK inhibitors in development are ATP-competitive and as a result, their potency is robust against the activated state of ERK. Based on this property, ERK inhibitors potentially can overcome drug resistance mechanisms that involve reactivation of RAS/MAPK pathway signaling, such as a rebound of RAS/MAPK signaling resulting from the alleviation of negative feedback or an upstream RAS/MAPK pathway protein adopting an acquired resistance mutation.

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, comprising several targeted therapy programs, is one of the deepest in the industry. The target breadth and molecular diversity represented in our pipeline enable us to pursue a systematic, data-driven, portfolio-wide clinical development effort to identify single agent and combination 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. Our lead product candidate, naporafenib, targets RAF, a key node of the RAS/MAPK pathway. We are developing naporafenib in combination with the MEK inhibitor trametinib and other targeted therapies to delay emergence of resistance in response to RAS/MAPK pathway inhibition. We are also 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. With our MAPKlamp approach, we hope to induce tumor regression in RAS/MAPK pathway-driven cancers, while also blocking the in-pathway escape routes that lead to tumor resistance.

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 one of the industry’s deepest, 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 our lead program, naporafenib, which we in-licensed from Novartis, ERAS-0015, which we in-licensed from Guangzhou Joyo Pharmatech Co., Ltd. (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 one of the deepest RAS/MAPK pathway-focused pipelines in the industry, 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. Other than with respect to ERAS-0015 in China, Hong Kong, and Macau, we have exclusive worldwide development and commercial rights for all of our programs.

Our pipeline also includes ERAS-801, a brain-penetrant EGFR inhibitor in development for patients with EGFR-altered GBM (for which we are concluding a Phase 1 trial and exploring further advancement, including via partnerships and investigator-sponsored trials), ERAS-007 ERK1/2 inhibitor, and ERAS-601 SHP2 inhibitor. ERAS-007 and ERAS-601 are being assessed in preclinical studies as potential combination partners with other programs in our pipeline for RAS/MAPK pathway inhibition. Via Erasca Ventures, we made an equity investment in Affini-T, which is developing TCR T-cell therapies against KRAS G12V, KRAS G12D, and KRAS G12C.

Naporafenib: our pan-RAF inhibitor

Our lead product candidate is naporafenib, for which we initiated a pivotal Phase 3 trial in the first half of 2024 for patients with NRASm melanoma. Naporafenib is a pan-RAF inhibitor with first-in-class and best-in-class potential for patients with NRASm melanoma and other RAS/MAPK pathway-driven tumors. In-licensed from Novartis, naporafenib has been dosed in over 600patients to date, whereby safety, tolerability, and acceptable PK and PD have been established in both monotherapy and select combinations, with clinical PoC data in combination with trametinib for patients with NRASm melanoma.

Our development strategy for naporafenib includes our SEACRAFT trials designed to evaluate naporafenib in combination with other targeted therapies. Our SEACRAFT-2 trial is supported by the clinical PoC data in patients with NRASm melanoma that we presented from the SEACRAFT-1 trial at the 2024 TripleMeeting. Clinical PoC in NRASm melanoma is also supported by data presented by Novartis at the ESMO Congress 2022 medical conference and as published in March 2023 by de Braud et al. in the Journal of Clinical Oncology. In connection with our SEACRAFT-2 trial, we have entered into a clinical trial collaboration and supply agreement (CTCSA) with Novartis for its MEK inhibitor, trametinib. Pursuant to the CTCSA, we are sponsoring and funding the clinical trial and Novartis is providing its drug to us free of charge. In addition, we are evaluating additional combinations of naporafenib with our other RAS/MAPK pathway targeting agents and/or external agents in preclinical models.

Preclinical profile of naporafenib

Naporafenib is designed to be a reversible, potent and selective ATP-competitive type 2 pan-RAF kinase inhibitor. It has been shown to be most potent against BRAF and CRAF with biochemical IC50 values of 0.1 and 0.2 nM, respectively, and also showed biochemical activity against ARAF with an IC50 of 6.4 nM. Naporafenib is designed to be selective for RAF family kinases, biochemically inhibiting only three non-RAF kinases at >80% at 1 μM (i.e., PDGFRB, DDR1, and DDR2).

As a pan-RAF inhibitor, naporafenib is differentiated from BRAF V600E inhibitors since naporafenib inhibits both RAF monomers and dimers. BRAF V600E inhibitors inhibit monomeric BRAF V600E proteins while simultaneously enabling dimerization of these inhibited monomers with uninhibited RAF proteins, thereby resulting in paradoxical activation of downstream RAS/MAPK pathway signaling. Naporafenib’s ability to inhibit both RAF monomers and dimers enables it to effectively inhibit RAS mutants from signaling downstream without the paradoxical activation observed with BRAF V600E inhibitors.

Naporafenib and trametinib are ideal combination partners since they target two vertically adjacent nodes in the RAS/MAPK pathway, RAF and MEK, and both stabilize their targeted proteins in the inactive state; naporafenib in an ATP-competitive manner and trametinib in an allosteric manner.

Clinical Overview

Novartis dosed over 500 patients with naporafenib either as monotherapy or in combination with other anti-cancer agents (investigational or approved). These agents included trametinib (MEK inhibitor), LTT462 (rineterkib; ERK inhibitor), dabrafenib (BRAF V600E inhibitor), ribociclib (CDK4/6 inhibitor), EGF816 (EGFR inhibitor), and spartalizumab (anti-PD-1). The safety, tolerability, and acceptable PK and PDhave been established in both monotherapy and select combinations. Specifically, the doublet combinations of naporafenib with trametinib, rineterkib (LTT462), and ribociclib have been evaluated in both Phase 1b dose finding and Phase 2 clinical trials, and we believe PoC has been achieved for the combination of naporafenib and trametinib in patients with NRASm melanoma, the focus of our pivotal SEACRAFT-2 study.

Our initial development strategy is focused on the naporafenib combination with trametinib in patients with NRASm melanoma, an indication with high unmet medical need and no approved targeted therapy options. We will also continue to evaluate activity with other combinations in biomarker-defined populations. Our ultimate goal is to maximize the clinical benefit of naporafenib in the greatest number of patients with cancer.

Clinical safety and tolerability

Monotherapy. A total of 87 patients were enrolled in the monotherapy dose escalation portion of the first-in-human trial (CLXH244X2101) of naporafenib in patients whose tumors had MAPK pathway alterations and progression following standard-of-care (SOC) treatment. A total of 43 patients were enrolled in six QD dosing cohorts (range 100 mg to 1200 mg QD), and 44 patients in total were enrolled in four BID dosing cohorts (200 mg to 800 mg BID). An MTD was not identified for the QD schedule while the MTD/recommended dose for expansion (RDE) for the BID schedule was determined to be 600 mg twice a day (BID). The monotherapy dose expansion portion of the trial was not opened in order to focus on combination development. During naporafenib monotherapy dose escalation, five patients experienced seven dose-limiting toxicities: decreased platelet count (1200 mg QD); neuralgia, maculopapular rash, pruritus (600 mg BID); increased blood bilirubin, hyponatremia, peripheral sensory neuropathy (800 mg BID). For the single-agent cohort, treatment-related adverse events (TRAEs) of any grade were reported in 79 (90.8%) patients. The most frequent (occurring in ≥20% of patients) were dermatitis acneiform (maculopapular pustular eruptions) (24.1%, no Grade 3/4 events), rash (24.1%, Grade 3/4: 1.1%), and fatigue (20.7%, Grade 3/4: 2.3%).

Naporafenib plus trametinib. Three trials have evaluated the combination of naporafenib plus trametinib: the dose finding Phase 1b CLXH254X2102 trial, the Phase 2 CLXH254C12201 trial, and the Phase 1b SEACRAFT-1 trial.

The CLXH254X2102 trial enrolled patients who had advanced or metastatic KRAS or BRAF mutant NSCLC or NRASm melanoma with progression following SOC treatment. A total of 115 patients were treated with naporafenib plus trametinib in combination in 5 dose cohorts. Four cohorts received naporafenib and trametinib (doses are listed as naporafenib mg BID/trametinib mg QD): 200/0.5 (6 patients), 200/1 (54 patients), 400/0.5 (44 patients), 400/1 (5 patients), and a fifth cohort was administered 400 mg naporafenib BID continuously and trametinib 1 mg QD following a 2 weeks on/2 weeks off schedule (6 patients). Thirty-six patients in total were enrolled in dose escalation while 30 were enrolled in the NRASm melanoma expansion cohorts. During dose escalation, six patients reported 6 DLTs: dermatitis acneiform (one patient each in the 200/1 and 400/0.5 cohorts), maculopapular rash (one patient each in the 200/1 and 400/1 cohorts), increased lipase (one patient in the 200/1 cohort), and Stevens-Johnson syndrome (one patient in the 400/1 cohort). Two RDEs were identified: naporafenib 200 mg BID plus trametinib 1 mg QD and naporafenib 400 mg BID plus trametinib 0.5 mg QD. For the dose expansion portion of the trial, TRAEs of any grade were reported in 100% of patients. The most frequent (occurring in ≥20% of patients enrolled in dose expansion) TRAEs were rash (80.0%, Grade 3/4: 33.3%), nausea (30.0%, no Grade 3/4 events), diarrhea (30.0%, no Grade 3/4 events), blood creatinine phosphokinase increased (30.0%, Grade

3/4: 13.3%), constipation (23.0%, no Grade 3/4 events), stomatitis (20.0%, Grade 3/4: 3.3%) and vomiting (20.0%, no Grade 3/4 events).

The CLXH254C12201 trial enrolled patients with NRASm or BRAFm melanoma who have received prior systemic therapy for unresectable or metastatic melanoma with an anti-PD-1/L1-based regimen and were restricted to a maximum of two prior lines of systemic immune checkpoint inhibitor (ICI)-containing immunotherapy for unresectable or metastatic melanoma. The combination of naporafenib plus trametinib was evaluated at the RDEs of 200/1 (30 patients) and 400/0.5 (22 patients) where both naporafenib plus trametinib were administered continuously BID and QD, respectively. The most frequent (occurring in ≥20% of patients) TRAEs were rash (39.6%, Grade 3/4: 9.4%), dermatitis acneiform (34.0%, Grade 3/4: 7.5%), pruritis (26.4%, Grade 3/4: 1.9%), blood creatinine phosphokinase increased (20.8%, Grade 3/4:1.9%), and fatigue (20.8%, Grade 3/4: 1.9%).

The SEACRAFT-1 trial enrolled patients with RAS Q61X mutations across multiple tumor types including melanoma, lung, thyroid, and GI malignancies. As presented at the 2024 Triple Meeting, thecombination of naporafenib plus trametinib, evaluated at the 200/1 dose (52patients), was generally well tolerated with primarily Grade 1 and 2 TRAEs observed. In addition, the frequency of Grade 3 or higher TRAEs was approximately 5% or less across the various categories of events.

In particular, the incidence and severity of skin toxicities improved dramatically in SEACRAFT-1 relative to the prior Phase 1 and 2 trials. We believe these improved AE outcomes were likely due to the implementation of mandatory primary rash prophylaxis as part of our SEACRAFT-1 and -2 trials. More specifically, in SEACRAFT-1, the rate of Grade 3 or higher dermatological toxicities decreased from about 37% in the historical Phase 1 and 2 trials to around 12% in SEACRAFT-1.

Furthermore, although differences exist between trial designs, sites, and patient characteristics, which limit our ability to compare across clinical trial programs, the rate of drug discontinuations due to adverse events markedly decreased from about 19 to 20% in the Phase 1 and 2 trials conducted by Novartis to less than 10% in our SEACRAFT-1 trial. The relative dose intensity (RDI), which is a measure of how much drug a patient receives relative to the trial’s intent, also showed a marked improvement. More specifically, the median RDI of naporafenib increased from 66% and 57%, respectively, for the Novartis Phase 1 and 2 trials to nearly 99% in SEACRAFT-1. Additionally, the median RDI for trametinib increased to nearly 100% in SEACRAFT-1 compared to 59-62% in the Novartis Phase 1 and 2 trials.

Summary. Naporafenib administered as monotherapy was generally well tolerated when administered using either a QD or BID schedule. Naporafenib was also generally well tolerated when administered with multiple other therapies with a variety of mechanisms of action (e.g., trametinib, LTT462, spartalizumab) without clinically relevant drug-drug interactions suggesting that naporafenib may be a potential partner for combination approaches.

As would be expected for combination therapies, the combination of naporafenib and trametinib in the Novartis clinical trials demonstrated an increased frequency and severity of AEs, the most common of which were skin toxicities, as compared to either naporafenib or trametinib administered as a monotherapy. However, more recent results from our SEACRAFT-1 trial suggest that mandatory primary rash prophylaxis improved the tolerability results as measured by reduced frequency and severity of dermatological toxicities, reduced drug discontinuation rate due to adverse events, and increased RDI as compared to the historical Novartis trials which did not include the use of mandatory primary rash prophylaxis. We believe this approach increases the potential for improvement in long-term tolerability and consequently increased efficacy.

Clinical Pharmacology

Monotherapy naporafenib showed a relatively rapid absorption with a median time to reach peak plasma concentration (Tmax) ranging from approximately 2 to 4 hours. Similar median Tmax ranges were observed when naporafenib was administered in combination with trametinib, LTT462, and ribociclib. The effective half-life is approximately 20-25 hours. The clinical exposure was approximately dose proportional across the dose range tested between 100 mg and 1200 mg QD as well as 200 mg and 600 mg BID. No significant drug-drug interactions have been observed between naporafenib and trametinib, LTT462, or ribociclib in the dose ranges tested. Other clinical pharmacology studies are ongoing.

Clinical Efficacy

Monotherapy. In the first-in-humandose escalation trial CLXH254X2101, two patients achieved confirmed partial responses (PRs): a patient with KRAS G12V-mutated ovarian cancer was treated with naporafenib 300 mg QD, and a patient with HRAS G13R-mutated head and neck cancer was treated with naporafenib 400 mg QD.

Naporafenib plus trametinib. A total of 71 patients with NRASm melanoma were dosed with the combination of naporafenib and trametinib at two different doses across two different trials (Phase 1b CLXH254X2102 and Phase 2 CLXH254C12201) in the post immuno-oncology (IO) setting. A pooled analysis across these trials showed a 31% confirmed overall response rate (ORR) for the 39 patients who received naporafenib 200 mg BID and trametinib 1 mg QD

(200/1; one of the two RDEs) and a 22% confirmed ORR for the 32 patients who received naporafenib 400 mg BID and trametinib 0.5 mg QD (400/0.5; the other RDE). The duration of response (DOR) for the 200/1 pooled dataset was 7.4 months, the median progression-free survival (mPFS) was 5.1 months, and the median overall survival (mOS)was 13.0 months. The DOR for the 400/0.5 pooled dataset was 10.2 months, the mPFS was 4.9 months, and the mOS was 14.1 months. Both the mPFS and mOS for the pooled dataset at each dose were longer than their comparable benchmarks.

For both ORR and PFS, we believe the most robust benchmark is the randomized Phase 3 NEMO trial, which was a randomized Phase 3 trial evaluating binimetinib versus dacarbazine in NRAS melanoma. Since both ORR and PFS directly measure the activity of trial treatments, we believe the data in this trial are generalizable to the patient population enrolled in both Novartis’ Phase 1b and Phase 2 trials referenced above, despite the NEMO trial primarily enrolling treatment-naïve patients (~80%).In contrast to ORR and PFS, the OS results observed for the Phase 3 NEMO trial reflect not only the trial treatments (dacarbazine or binimetinib) but also the therapies received by patients after discontinuing the trial treatment. More specifically, since (i) ~45% of patients in either arm of the NEMO trial were reported to have received IO-based therapy after dacarbazine or binimetinib and (ii) IO-based therapy prolongs overall survival compared to other therapies available at that time, the mOS as measured by a Kaplan-Meier analysis would be predicted to overestimate the OS benefit provided by either dacarbazine or binimetinib without the IO-based therapy. In contrast, in the two naporafenib plus trametinib studies, all patients received IO-based therapy prior to enrollment, and since OS in clinical trials is measured from when a patient enters the trial, we believe that the results in NEMO likely overestimate the mOS values compared to the two naporafenib plus trametinib studies. In addition, while we believe that the mOS results from NEMO likely overestimate the potential OS benefit from dacarbazine or binimetinib, the mOS from the naporafenib plus trametinib combination is still quantitatively longer than that observed in either arm in the NEMO trial.

Since no randomized trials have been completed for patients with NRASm melanoma in the post-IO setting, otherpotential OS benchmarks available for comparison to the results from the pooled naporafenib plus trametinib analysis are either from published literature describing retrospective chart reviews of comparable patient populations or from data generated in similar patient populations enrolled in either the Phase 1b or Phase 2 trials themselves. In four publicationsdescribing retrospective chart reviews in patients with melanomareceiving either cytotoxic chemotherapy or MEK inhibitor monotherapy in the post-IO setting, the mOS was approximately 7 months. Similarly, for patients with BRAF/MEK-inhibitor resistant BRAFm melanoma enrolled in the Phase 2 trial and treated with naporafenib plus trametinib, which did not induce responses in this particular patient population, the mOS was approximately 7months. We believe that the consistency of the mOS values for both the retrospective chart reviews and BRAF/MEK-inhibitor resistant BRAFm melanoma patients in the Phase 2 trial suggest that for patients with melanoma being treated in the post-IO setting, the natural history of their disease is represented by a mOS of approximately 7 months. In contrast, the mOSobserved for patients with NRASm melanoma treated with naporafenib plus trametinib was approximately 13 to 14 months.This near doubling of OS demonstrated by naporafenib plus trametinib compares favorably relative to the historical benchmarks described above.

Anadditional 10 efficacy-evaluablepatients with NRAS Q61X melanoma were dosed with naporafenib and trametinib (200/1 dose) in our SEACRAFT-1 trial in the post-IO setting. As presented at the 2024 Triple Meeting, a 40% response rate was observed, including three confirmed responses and one unconfirmed response (uPR). The patient with uPR was still on treatment as of the data cutoff (September 5, 2024). The disease control rate was encouraging at 80%, especially given that these patients have limited treatment options. Finally, 70% of patients remained on treatment as of data cutoff, including all confirmed and unconfirmed responders.

Summary. We believe clinical PoC in patients with NRASm melanoma has been established for the combination of naporafenib and trametinib. Although clinical trial data across separate trials may not be directly comparable due to differences in trial protocols, conditions, and patient populations, these data compare favorably with the clinical activity observed with the standard of care agents used to treat patients with NRASm melanoma who have progressed on immunotherapy.

Development strategy for naporafenib

Naporafenib’s clinical development plan is centered on the quick and efficient capitalization on the clinical PoC established in patients with NRASm melanoma in the post-IO setting. In December 2023, we announced that the FDA granted FTDto naporafenib in combination with trametinib for the treatment of adult patients with unresectable or metastatic melanoma who have progressed on, or are intolerant to, an anti‐programmed death-1 (ligand 1) (PD‐(L)1)-based regimen, and whose tumors contain an NRAS mutation.

NRAS-mutated melanoma. The frontline standard of care for patients with NRASm melanoma is an anti-PD-1/L-1-based regimen (immunotherapy) where the PD-1/L-1 inhibitor is administered as monotherapy or in combination. The highest unmet medical need in this population is in the post-IO setting, where there is no single global regulatory or accepted SOC. Rather, an analysis of regulatory approvals of drugs for patients with melanoma, published treatment guidelines, and the feedback from an advisory board attended by treating physicians in North America, Europe, and Australia indicate that the treatment choices for this post-IO patient population include cytotoxic chemotherapy (e.g., dacarbazine, temozolomide, etc.), single agent MEK inhibitors (e.g., trametinib, binimetinib, cobimetinib), and clinical trials. In addition, there is no clear preference for what type of chemotherapy or MEK inhibitor should be administered. The best reference data for chemotherapy in patients with NRASm melanoma are from the NEMO trial. The patient composition was 82% treatment-naïve, 16% 2nd line, 2% 3rd line or more. The major strength of these reference data is this is the largest and most recent phase 3 dataset in which all patients had NRASm melanoma and are relatively homogeneous, with the vast majority being treatment-naïve. The major weakness is that only 21% of patients had received prior IO therapy. In the NEMO trial, the ORR for chemotherapy was 7%, the mPFS was only 1.5 months, and mOS was 10.1 months. Furthermore, the NEMO trial showed that the MEK inhibitor binimetinib had an ORR of 15%, a mPFS of 2.8 months, and a mOS of 11.0 months. As described above, the mOS observed for chemotherapy and binimetinib in NEMO may overestimate what will be observed in the control arm of the SEACRAFT-2 trial. A cross-trial comparison suggests that the combination of pan-RAF inhibitor plus MEK inhibitor may be superior to MEK inhibition alone or standard of care chemotherapy. We are testing this hypothesis in the SEACRAFT-2 randomized controlled trial in the post-IO setting for potential registration.

Clinical development plan for naporafenib

Naporafenib is our most advanced clinical-stage program. We believe it has the potential to change the standard of care indications with high unmet medical need, such as patients with NRASm melanoma, as well as patients with RAS/MAPK solid tumors.

SEACRAFT-1. The SEACRAFT-1 trial is a signal-seeking Phase 1b trial in patients with RAS/MAPK solid tumors. We believe that while the preliminary SEACRAFT-1 data do not support further exploration of a tissue-agnostic indication, they do reinforce the potential of the ongoing Phase 3 SEACRAFT-2 trial in patients with NRASm melanoma.

SEACRAFT-2. The SEACRAFT-2 trial, which we initiated in the first half of 2024, is formally testingthe hypothesis supported by the clinical PoC data in patients with NRASm melanoma. In Stage 1 of the SEACRAFT-2 trial, we are evaluating two combination doses of naporafenib and trametinib [400/0.5 and 100/1 (doses are listed as naporafenib mg BID/trametinib mg QD)] as well as single-agent trametinib. Along with the 200/1 dose from the SEACRAFT-1 trial, we aim to identify one dose to incorporate into the potentially registration-enabling portion of the trial.

In Stage 2 of the SEACRAFT-2 trial, we plan to enroll NRASm melanoma patients who have progressed on, or are intolerant to, SOC ICI therapy into a potentially registration-enabling randomized Phase 3 trial in which patients will receive either naporafenib plus trametinib or physician’s choice of therapy (dacarbazine, temozolomide, or trametinib monotherapy). We have designed the trial to demonstrate superiority in PFS and/or OS based on benchmarks from published literature. Important details of the trial design, such as the primary endpoints and choice of therapy in the physician’s choice comparator arm, have been discussed with regulatory authorities. SEACRAFT-2 has the potential for approval based on the high unmet medical need of these patients as well as the alignment with US and European regulators on the NRASm melanoma indication.

We expect to have Phase 3 Stage 1 randomized dose optimization data in the second half of 2025.

In addition, we have introduced proactive safety management, including mandatory primary rash prophylaxis, that is designed to improve the safety and tolerability of this regimen for patients participating in our trials.

Other development opportunities. A strong motivation to add naporafenib to our precision oncology pipeline is the potential synergy of naporafenib with our other agents that target the RAS/MAPK pathway. These combinations may enable targeting of other RAS/MAPK pathway mutations beyond NRASm melanoma and may expand the potential impact of naporafenib to larger patient populations.

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

Our RAS franchise consists of two preclinical molecules: ERAS-0015, a pan-RAS molecular glue for which we plan to file the IND in mid-Q2 2025, and ERAS-4001, a pan-KRAS small molecule inhibitor for which we plan to file the IND in the second quarter of 2025. Phase 1 monotherapy data readouts are expected for each of the ERAS-0015 AURORAS-1 and ERAS-4001 BOREALIS-1 clinical studies in 2026.

Both molecules exceed our target product profile across three key attributes: potency, favorable ADME/PK properties including oral bioavailability, and strong IP position. Improved potency and oral bioavailability may enable dosing at a lower dose, particularly for ERAS-0015, 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.

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 program. We also plan on capitalizing on our unique portfolio which has complementary proposed mechanisms of action and target profiles to develop these novel combinations.

ERAS-0015: our pan-RAS molecular glue

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.

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 on the right. (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 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, the tumor regression that was observed with RMC-6236 at 3 mpk was comparable to the regression that was 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 was stopped on Day 31. Furthermore, tumors did not form after a rechallenge with tumor cells, which involved injecting the 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 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 hERG IC50 was greater than 10 micromolar which suggests potentially lower concern for cardiovascular risk.

Initial clinical development strategy for ERAS-0015

We are planning an initial clinical trial for ERAS-0015 which we refer to as AURORAS-1. The AURORAS-1 trial is expected to assess ERAS-0015 as a monotherapy and in combination with approved and unapproved therapies for the treatment of patients with RASm solid tumors. We plan to file an IND for the AURORAS-1 trial in mid-Q2 2025, with an anticipated Phase 1 monotherapy data readout in 2026.

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 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

We are planning an initial clinical trial for ERAS-4001, which we refer to as BOREALIS-1. The BOREALIS-1 trial is expected to assess ERAS-4001 as a monotherapy and in combination with approved and unapproved therapies for the treatment of patients with KRASm solid tumors. We plan to file an IND for the BOREALIS-1 trial in the second quarter of 2025, with an anticipated Phase 1 monotherapy data readout in 2026.

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 are developing a bpAb 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.

ERAS-12 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, this 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.

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.

ERAS-007: our ERK inhibitor

ERAS-007 is designed to be a potent and selective oral inhibitor of ERK1/2. In preclinical studies, ERAS-007 demonstrated the highest potency and longest target residence time of any ERK inhibitors of which we are aware. We evaluated the safety, tolerability, PK, PD, and preliminary antitumor activity of ERAS-007 in patients with advanced or metastatic solid tumors in our HERKULES series of clinical trials. The final HERKULES trial was deprioritized in May 2024, even though ERAS-007 administered as a monotherapy or in combination was safe and tolerable and achieved confirmed responses in combination with encorafenib and cetuximab in patients with BRAF-mutant CRC. We consider ERAS-007 a potential combination agent with other RAS/MAPK pathway targeting compounds in our pipeline, as well as with standard of care agents.

ERAS-801: our central nervous system (CNS)-penetrant EGFR inhibitor

ERAS-801 is designed to be a potent, selective, reversible, and orally available small molecule with both: (1) highly enhanced CNS penetration (achieved 8.2:1 brain:plasma ratio in mice, and a mean cerebrospinal fluid (CSF) to unbound plasma concentration ratio (Kp,uu,csf) of 0.9 in human patients), and (2) the ability to target both EGFR mutants such as EGFRvIII, the most common mutant form of EGFR found in GBM, and wtEGFR, which heterodimerizes with EGFRvIII. We evaluated the safety, tolerability, PK, PD, and preliminary antitumor activity of ERAS-801 in patients with recurrent GBM in our THUNDERBBOLT-1 clinical trial. In May 2024, we announced that we had deprioritized the THUNDERBBOLT-1 trial, even though ERAS-801 was tolerable and achieved a confirmed partial response. We are exploring further advancement of the ERAS-801 program, including via partnerships and select investigator-sponsored trials.

ERAS-601: our SHP2 inhibitor

ERAS-601 is designed to be a potent and selective oral inhibitor of SHP2. In preclinical studies, ERAS-601 demonstrated strong in vitro potency relative to other SHP2 inhibitors (RMC-4550 and TNO155) and favorable ADME and PK results, which we believe support its evaluation in a broad range of potential combination therapies. We evaluated the safety, tolerability, PK, PD, and preliminary antitumor activity of ERAS-601 in patients with advanced or metastatic solid tumors in the FLAGSHP-1 clinical trial. The FLAGSHP-1 trial was deprioritized in November 2023, even though ERAS-601 administered as a monotherapy and in combination was tolerable and achieved confirmed responses as a monotherapy and in combination with cetuximab. We consider ERAS-601 a potential combination agent with other RAS/MAPK pathway targeting compounds in our pipeline, as well as with standard of care agents.

Our acquisition and license agreements

Novartis

In December 2022, we entered into an exclusive license agreement (as amended, 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. We have the right to sublicense (through multiple tiers) our rights under the Novartis Agreement, subject to certain limitations and conditions, and are required to use commercially reasonable efforts to commercialize licensed products in certain geographical markets.

The license granted under the Novartis Agreement is subject to Novartis’ reserved right to: (i) develop, manufacture, use, and commercialize compounds unrelated to naporafenib under the licensed patent rights and know-how, (ii) use the licensed patent rights and know-how for non-clinical research purposes, and (iii) use the licensed patent rights and know-how to the extent necessary to perform ongoing clinical trials and its obligations under existing contracts and under the Novartis Agreement.

Under the Novartis Agreement, we made an upfront cash payment to Novartis of $20 million and issued 12,307,692 shares of our common stock to Novartis. We are obligated to make future regulatory milestone payments of up to $80 million and sales milestone payments of up to $200 million. We are also obligated to pay royalties on net sales of all licensed products, in the low-single digit percentages, subject to certain reductions.

The Novartis 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 Novartis Agreement, on a licensed product-by-licensed product and country-by-country basis, we will have a fully paid-up, perpetual, and irrevocable license to develop, manufacture, use, and commercialize the licensed products.

The Novartis Agreement may be terminated in its entirety by either party in the event of an uncured material breach by the other party. Novartis may terminate the Novartis Agreement upon written notice in the event we become subject to specified bankruptcy, insolvency, or similar circumstances. We may terminate the Novartis Agreement in its entirety at any time upon the provision of prior written notice to Novartis.

Upon termination of the Novartis Agreement for any reason, all rights and licenses granted to us will terminate. In addition, upon termination of the Novartis Agreement for any reason other than its natural expiration, Novartis 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.

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. We have 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. 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.

The license granted under the Joyo License Agreement is subject to Joyo’s reserved right to develop, manufacture, use, and commercialize licensed products in mainland China, Hong Kong and Macau, unless we exercise our option to expand the license to include mainland China, Hong Kong and Macau.

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 (or up to $57.5 million if our territory is expanded 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. In addition, the licenses granted to Joyo under certain patent and other intellectual property rights owned or controlled by us to develop, manufacture, use, and commercialize the licensed products in mainland China, Hong Kong and Macau will survive the termination of the Joyo License Agreement for any reason, unless we exercise our option to expand the license to include mainland China, Hong Kong and Macau, in which case such licenses to Joyo will terminate automatically; 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 million, which represent all of the consideration payable to ELS under the ELS Purchase Agreement.

Asana BioSciences

In November 2020, we entered into an agreement and plan of merger with Asana and ASN Product Development, Inc. (ASN) (the Asana Merger Agreement), pursuant to which 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, and collectively with the Asana Merger Agreement, the Asana Agreements), 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. We have the right to sublicense (through multiple tiers) the licensed rights under the Asana Agreements, subject to certain conditions. The foregoing license is subject to Asana’s non-exclusive right to practice the licensed rights to research and conduct preclinical pharmacology activities with a specified combination of compounds, subject to certain specified conditions. Pursuant to the Asana License Agreement, neither Asana nor ASN can directly or indirectly exploit certain classes of competing products, subject to specified exceptions. In addition, we are required to use commercially reasonable efforts to develop and obtain regulatory approval for ERAS-007 in the United States, at least one major market country in Europe, and either China or Japan.

Under the Asana Merger Agreement, we made an upfront payment of $20 million and issued 4,000,000 shares of our Series B-2 convertible preferred stock to Asana. In connection with our IPO, these shares of Series B-2 convertible preferred stock were converted into 3,333,333 shares of our common stock. We are obligated to make future development and regulatory milestone cash payments for a licensed product in an amount of up to $90 million. Additionally, upon achieving a development milestone related to demonstration of successful proof-of-concept in a specified clinical trial, we will be required to issue 3,888,889 shares of our common stock to Asana. We are not obligated to pay royalties on the net sales of licensed products.

Upon our payment to Asana of all merger consideration, including upfront cash and equity payments, the milestone payments, the equity payment related to the proof-of-concept development milestone, and all other development milestone payments, with the exception of a specific milestone that does not need to be achieved at such time and will remain subject to payment in the event that such milestone occurs at a later time, all licensed rights will become fully paid-up, perpetual, and irrevocable. The License Agreement may be terminated by either Asana or us in the event of an uncured material breach by the other party. Asana also has the right to terminate the Asana License Agreement if we fail to engage in material activities in support of clinical development and commercialization of ERAS-007 for a period of 12 consecutive months, excluding reasons outside of our reasonable control and subject to certain limitations. However, Asana’s right to terminate the Asana License Agreement for any reason ends once we have paid to Asana all merger consideration, or if Asana’s equity interest in us is publicly traded and exceeds a certain threshold value. We may terminate the Asana License Agreement at any time upon the provision of prior written notice to Asana.

Katmai Pharmaceuticals

In March 2020, we entered into a license agreement (the Katmai 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. We have the right to sublicense (through multiple tiers) our rights under the Katmai Agreement, subject to certain limitations and conditions, and are required to use commercially reasonable efforts to develop, manufacture, and commercialize licensed products and to meet certain specified development and launch milestones by certain dates. We are obligated to use commercially reasonable efforts to develop the licensed products first for use within the neuro-oncology field before expanding our development efforts to include other indications in the oncology field. Following the first achievement of a clinical proof-of-concept for any indication, we have the right to submit a non-binding offer to Katmai for: (i) the purchase of all licensed patent rights, know-how, and other assets owned by Katmai that are necessary or useful for the exploitation of the licensed products, or (ii) for the purchase of Katmai. Pursuant to the Katmai Agreement, neither Katmai nor we can directly or indirectly exploit certain specified classes of competing products.

The license granted under the Katmai Agreement is subject to The Regents of the University of California’s reserved right to: (i) use the licensed patent rights and know-how for educational and non-commercial research purposes, and to publish results arising therefrom, and (ii) grant licenses to the licensed know-how to third parties without notice because the licensed know-how is non-exclusively licensed to Katmai by The Regents of the University of California. Further, the license granted under the Katmai Agreement is subject to the rights of the United States government under the Bayh-Dole Act, including: (i) a non-exclusive, non-transferable, irrevocable, paid-up license to practice or have practiced the invention claimed by the licensed patent rights throughout the world, and (ii) the obligation that any licensed products used or sold in the United States be manufactured substantially in the United States.

Under the Katmai Agreement, we made an upfront payment of $5.7 million and Katmai agreed to purchase shares of our Series B-1 convertible preferred stock and Series B-2 convertible preferred stock having an aggregate value of $2.7 million. In connection with our IPO, these shares of Series B-1 convertible preferred stock and Series B-2 convertible preferred stock were converted into 395,555 shares of our common stock, in the aggregate. We are obligated to make future development and regulatory milestone payments of up to $26 million, of which $2 million was paid in March 2022, and commercial milestone payments of up to $101 million. We are also obligated to pay tiered royalties on net sales of each licensed product, at rates ranging from the mid- to high-single digit percentages, subject to a minimum annual royalty payment in the low six figures and certain permitted deductions.

Our royalty obligations and the Katmai Agreement will expire, on a licensed product-by-licensed product and country-by-country basis, on the earlier of: (i) the ten-year anniversary of the expiration of all valid claims included in the licensed patents covering the composition of matter or method of use of such licensed product in such country, or (ii) the twentieth anniversary of the first commercial sale of such licensed product in such country. Upon the expiration of the Katmai Agreement, we will have a fully paid-up and irrevocable license.

The Katmai Agreement may be terminated in its entirety by either party: (i) in the event of an uncured material breach by the other party, or (ii) in the event the other party becomes subject to specified bankruptcy, insolvency, or similar circumstances. Provided that we are in full compliance with the Katmai Agreement, we may terminate the Katmai Agreement upon written notice to Katmai. Upon termination of the Katmai Agreement for any reason, all rights and licenses granted to us thereunder will terminate. Upon termination of the Katmai Agreement, we are obligated, among other things, to: (i) grant an exclusive license to Katmai under all of our right, title and interest in all inventions and know-how developed under the Katmai Agreement existing at the time of termination that are specific to the licensed compounds or products, including without limitation all data and results related to their exploitation, and (ii) transfer to Katmai ownership and possession of all regulatory filings related to the licensed compounds and products. Unless the Katmai Agreement is terminated for our material breach, the parties will negotiate in good faith the financial terms pursuant to which the foregoing actions will be conducted, provided that our performance of such actions may not be conditioned upon the conduct or completion of such negotiations. If the parties are unable to agree upon such terms within the specified time period, then the parties will submit all unresolved matters for resolution by arbitration.

NiKang Therapeutics

In February 2020, we entered into a license agreement (the NiKang 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. We have the right to sublicense (through multiple tiers) our rights under the NiKang Agreement, subject to certain conditions, and are required to use commercially reasonable efforts to develop and commercialize licensed products. The parties are obligated to negotiate in good faith for a certain period of time to grant NiKang the exclusive commercial distribution rights in greater China once a licensed product reaches a certain development stage.

Under the NiKang Agreement, we made an upfront payment of $5 million to NiKang and reimbursed NiKang $0.4 million for certain initial manufacturing costs. In addition, we paid an additional $7 million after publication of a US patent application that covered the composition of matter of ERAS-601. We are also obligated to pay (i) development and regulatory milestone payments in an aggregate amount of up to $16 million for the first licensed product, of which $4.0 million was paid in January 2021, and $12 million for a second licensed product, and (ii) commercial milestone payments in an aggregate amount of up to $157 million for the first licensed product and $151 million for a second licensed product. We are also obligated to: (i) pay tiered royalties on net sales of all licensed products in the mid-single digit percentages, subject to certain reductions; and (ii) equally split net sublicensing revenues earned under sublicense agreements that we enter into with any third party before commencement of the first Phase I clinical trial for a licensed product.

The NiKang 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, (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 NiKang Agreement, on a licensed product-by-licensed product and country-by-country basis, we will have a fully paid-up, non-exclusive license to conduct research and to develop and commercialize the licensed products.

The NiKang Agreement may be terminated in its entirety by NiKang in the event of our uncured material breach, which includes our failure to use commercially reasonable efforts to satisfy certain specified clinical development diligence milestones. In addition, NiKang may terminate if we, directly or indirectly, commence a legal action challenging the validity or enforceability of any licensed patents. Further, if we acquire more than 50% of the equity or assets of a company that owns a competing small molecule that is designed to prevent the same target as set forth in the NiKang Agreement from switching to an enzymatically active state, then we must either divest such competing product or terminate the NiKang Agreement. We may terminate the NiKang Agreement at any time upon the provision of prior written notice to NiKang. Upon termination of the NiKang Agreement for any reason, all rights and licenses granted to us, as well as any sublicenses that we granted thereunder, will terminate. In addition, upon any termination (but not expiration) of the NiKang Agreement and upon NiKang’s request, the parties are obligated to meet and negotiate in good faith the terms of a license from us to NiKang to allow NiKang’s continued development, manufacture, and commercialization of the licensed products.

Commercialization

We intend to maintain exclusive worldwide development and commercialization rights to our product candidates (excluding programs in our pipeline that arise from an investment made by Erasca Ventures in a third party), other than with respect to ERAS-0015 in China, Hong Kong, and Macau, 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, Amgen, Boehringer Ingelheim, BridgeBio, Bristol Myers Squibb, Eli Lilly, 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, 2024, our patent estate for the programs listed below, which consists of owned and in-licensed patent families, includes nineteen issued US patents, eight pending US provisional applications, twenty-six pending US non-provisional patent applications, two hundred one issued foreign patents, eight pending international patent applications filed under the Patent Cooperation Treaty (PCT application), and one hundred sixty-two pending 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.

Naporafenib

As of December 31, 2024, we have in-licensed ten patent families from Novartis. The ten patent families relate to RAF inhibitors, their preparation, and methods of use. One of the families covers the naporafenib product candidate compound and additional RAF inhibitor compounds, their preparation and methods of use, and includes four issued US patents, eighty-six issued foreign patents, and five pending foreign patent applications. The nine additional in-licensed families cover further methods of using naporafenib, diagnostic methods, and additional RAF inhibitor compounds, their preparation and methods of use, and includesix issued US patents, seven pending US non-provisional applications, one pending PCT patent application, fifty issued foreign patents, and forty-nine pending foreign patent applications. The granted patents and any further patents that issue from applications from the ten in-licensed families are expected to expire between 2034 and 2043, absent any patent term adjustments or extensions.

As of December 31, 2024, we own two patent families relating to naporafenib and their methods of use and include two pending PCT patent applications and two pending foreign patent applications. Any patents issued from these patent applications are expected to expire in 2044, absent any patent term adjustments or extensions.

ERAS-0015

As of December 31, 2024, 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 pending foreign patent application and one pending PCT patent application. 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, 2024, we own six patent families relating to methods of using ERAS-0015 and include six pending US provisional applications. Any patents issued from these applications are expected to expire in 2045, absent any patent term adjustments or extensions.

ERAS-4001

As of December 31, 2024, we have in-licensed one patent family from Medshine relating to RAS inhibitors, their preparation, and methods of use. The patent family includes one pending US non-provisional patent application, seven pending foreign patent applications, and one pending PCT patent application. 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, 2024, we own three patent families relating to additional RAS Inhibitors, their preparation, and methods of use. The patent families include one pending US non-provisional patent application, two pending US provisional patent applications, two pending foreign patent applications, and two pending PCT patent applications. Any patents issued from these applications are expected to expire between 2042 and 2044, absent any patent term adjustments or extensions.

ERAS-12

As of December 31, 2024, 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 two pending foreign patent applications. Any patents issued from these applications are expected to expire between 2042 and 2043, absent any patent term adjustments or extensions.

ERAS-007

As of December 31, 2024, we have in-licensed three patent families from Asana. The three patent families relate to ERK 1/2 inhibitors, their preparation, and methods of use. One of the families covers the ERAS-007 product candidate compound and additional ERK1/2 inhibitor compounds, their preparation and methods of use, and includes five issued US patents, one pending US non-provisional patent application, fifty issued foreign patents, and one pending foreign patent application. The additional in-licensed families cover methods of using ERAS-007 and include two pending US non-provisional patent applications and fourteen pending foreign patent applications. The granted patents and any further patents that issue from applications from the three in-licensed families are expected to expire between 2036 and 2042, absent any patent term adjustments or extensions.

As of December 31, 2024, we also own seven patent families relating to ERAS-007. The patent families include five pending US non-provisional patent applications, one pending PCT patent application and thirty-seven pending foreign patent applications. Any patents issued from these patent applications are expected to expire between 2042 and 2043, absent any patent term adjustments or extensions.

ERAS-801

As of December 31, 2024, we have sub-licensed four patent families from Katmai, which Katmai in-licensed from the University of California, Los Angeles (UCLA). One of the families covers the ERAS-801 product candidate compound and additional EGFR inhibitor compounds, their preparation and methods of use, and includes one issued US patent, one pending US non-provisional patent application, four issued foreign patents, and twenty four pending foreign patent applications. The three additional in-licensed families relate to additional EGFR inhibitor compounds, their preparation and methods of use, and include three pending US non-provisional patent applications, one issued foreign patent, and eleven pending foreign patent applications. The granted patent and any further patents that issue from applications from the four in-licensed patent families are expected to expire between 2038 and 2041, absent any patent term adjustments or extensions.

As of December 31, 2024, we co-own with UCLA one patent family, relating to additional EGFR inhibitor compositions, their preparation and methods of use. This patent family includes one pending US non-provisional patent application. Any patents issued from this application are expected to expire in 2041, absent any patent term adjustments or extensions.

As of December 31, 2024, we own two patent families relating to EGFR inhibitor polymorph forms and methods of using EGFR inhibitor compositions. These patent families include one pending US non-provisional patent application, twelve pending foreign patent applications, and one pending PCT patent application. Any patents issued from these applications are expected to expire between 2042 and 2044, absent any patent term adjustments or extensions.

ERAS-601

As of December 31, 2024, we have in-licensed two patent families from NiKang. These two patent families relate to SHP2 inhibitor compositions, their preparation, and methods of use. One of the families covers the ERAS-601 product candidate compound, its preparation and methods of use, and includes three issued US patents, one pending US non-provisional patent application, twelve issued foreign patents and fourteen pending foreign patent applications. The second family covers additional SHP2 inhibitor compositions, their preparation and methods of use, and includes one issued US patent application, three issued foreign patents and three pending foreign patent applications. The granted patents and any further patents that issue from applications from the two in-licensed families are expected to expire in 2039, absent any patent term adjustments or extensions.

As of December 31, 2024, we also own six patent families relating to ERAS-601 and their methods of use, and include six pending US non-provisional patent applications, and twenty-five pending foreign patent applications. Any patents issued from these applications are expected to expire between 2041 and 2042, 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

ERAS US Equity

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ERAS US Equity☆

ERAS · 10-K · period ended 2024-12-31

Item 1. Business.

ERAS US Equity