Erasca Announces Updated Preliminary Phase 1 Data and Registration-Enabling Plans for Potentially Best-in-Class Pan-RAS Molecular Glue ERAS-0015 in KRAS-Mutant Solid Tumors

At RDE of 32 mg QD, encouraging monotherapy responses with 57% uORR in 2L+ KRAS G12X pancreatic cancer in U.S. trial and median relative dose intensity of 100%

Monotherapy has been generally well-tolerated at RDEs

Promising combination potential, including no DLTs, encouraging safety data, and clearance of first dose escalation combination cohort of ERAS-0015 (16 mg) with approved commercial dose of panitumumab

Additional ERAS-0015 monotherapy and combination data expected H1 2027, including panitumumab combination data

Company plans to initiate a potentially registration-enabling trial in lung cancer in H1 2027, a Phase 3 trial in pancreatic cancer in 2027, and an additional Phase 3 trial in lung cancer in H2 2027 to H1 2028

SAN DIEGO, July 13, 2026 (GLOBE NEWSWIRE) -- Erasca, Inc. (Nasdaq: ERAS), a clinical-stage precision oncology company singularly focused on discovering, developing, and commercializing therapies for patients with RAS/MAPK pathway-driven cancers, today announced updated preliminary Phase 1 data for its potentially best-in-class, pan-RAS molecular glue ERAS-0015 in patients with RAS-mutant solid tumors. The Company also announced clinical development plans for the ERAS-0015 program, including potentially registration-enabling trials in lung and pancreatic cancers.

Updated preliminary data from Erasca's ongoing AURORAS-1 Phase 1 trial in the U.S. builds on the Company's April 2026 announcement, with additional patients and longer follow-up.

“We believe the continued notable responses in patients with pancreatic cancer in the U.S., together with the encouraging data in lung cancer and early signal in combination with panitumumab in metastatic colorectal cancer that we have seen in Phase 1, underscore the broad potential of ERAS-0015 to become a foundational therapy for multiple RAS-mutant solid tumors,” said Jonathan E. Lim, M.D., Erasca’s chairman, CEO, and co-founder. “We look forward to additional preliminary monotherapy and combination data expected in the first half of 2027. We believe that we are well positioned to execute our robust clinical development plan and transition into Phase 3 development.”

**Encouraging Monotherapy Responses Observed in Second Line or Greater (2L+) KRAS G12X Pancreatic Ductal Adenocarcinoma (PDAC)**1

• 57% uORR8wk (N=7) at recommended dose for expansion (RDE) of 32 mg QD2
• Across doses, all patients with either confirmed or unconfirmed responses remained on treatment
• At RDE of 32 mg QD, 6 of 7 enrolled patients remained on treatment; at RDE of 24 mg QD, 6 of 8 enrolled patients remained on treatment

With Additional Patients and Longer Follow-up, Monotherapy Safety Data Remained Consistent with Prior Disclosure and ERAS-0015 Continued to be Generally Well-Tolerated****1

• Frequency and severity of treatment-related adverse events (TRAEs) remained consistent with the Company’s April 2026 announcement
• Mostly low-grade TRAEs, no dose-limiting toxicities (DLTs), low rate of dose interruptions or reductions due to TRAEs, and no discontinuations due to TRAEs
• Median relative dose intensity (RDI) was 100% at both 24 mg QD and 32 mg QD

Promising Combination Potential with Panitumumab in Metastatic Colorectal Cancer (CRC), including Clearance of First Dose Escalation Cohort****3

• No DLTs were observed for the combination in the 16 mg cohort during dose escalation in four DLT-evaluable patients
• Backfill enrollment is ongoing in the 16 mg combination cohort
• Dose escalation is ongoing with continued enrollment in the 24 mg combination cohort

Accelerating Potentially Registration-Enabling Development Plans in Highest Value Indications

• Initiate potentially registration-enabling trial in 2L+ NSCLC in 1H27
• Initiate 1L PDAC Phase 3 pivotal trial in 2027
• Initiate RASm NSCLC Phase 3 pivotal trial in 2H27-1H28

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1 Data cutoff (DCO) May 25, 2026 2 The uORR8wk is the overall response rate (ORR) (confirmed and unconfirmed responses) for patients who received first dose of ERAS-0015 at least 8 weeks prior to the May 25, 2026 cutoff date 3 DCO July 6, 2026

About ERAS-0015

ERAS-0015 is an investigational, oral, highly potent pan-RAS molecular glue designed to inhibit RAS signaling with a potential best-in-class profile. Erasca is evaluating ERAS-0015 in the AURORAS-1 Phase 1 trial in patients with RAS-mutant solid tumors. Early dose escalation data in AURORAS-1 demonstrated favorable safety and tolerability results, well-behaved, linear PK, and confirmed and unconfirmed partial responses in multiple patients across multiple tumor types with different RAS mutations, including confirmed partial responses at doses as low as 8 mg once daily (QD). ERAS-0015 is also designed to prevent resistance against mutant-selective inhibitors through inhibition of RAS wildtype variants. In addition, ERAS-0015 has demonstrated favorable absorption, distribution, metabolism, and excretion (ADME) and pharmacokinetic (PK) properties in multiple animal species.

About ERAS-4001

ERAS-4001 is an investigational, oral, highly potent, and selective pan-KRAS inhibitor with a potential first-in-class and best-in-class profile. Erasca is evaluating ERAS-4001 in the BOREALIS-1 Phase 1 trial in patients with KRAS-mutant solid tumors. ERAS-4001 demonstrated favorable preclinical in vitro potency against KRAS G12X mutations as well as KRAS wildtype amplifications, which may limit treatment resistance mediated through KRAS wildtype activation. No activity was observed for ERAS-4001 against HRAS or NRAS wildtype proteins in preclinical studies, which may enable a better therapeutic window compared to pan-RAS inhibitors. ERAS-4001 showed potent activity against both GTP-bound (active state) and GDP-bound (inactive state) KRAS with single digit nanomolar IC50s. In vivo, ERAS-4001 induced tumor regression in multiple KRAS-mutant models. In preclinical studies, ERAS-4001 showed encouraging ADME and PK properties.

About Erasca

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. 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 believe our team’s capabilities and experience, further guided by our scientific advisory board which includes the world’s leading experts in the RAS/MAPK pathway, uniquely position us to achieve our bold mission of erasing cancer.

Contact

Joyce Allaire LifeSci Advisors, LLC [email protected]

Source: Erasca, Inc.