On July 13, 2026 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, reported 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.

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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-Tolerated1

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 Cohort3

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.

(Press release, Erasca, JUL 13, 2026, View Source [SID1234669182])