Erasca, Inc. Announces Updated Phase 1 Data for ERAS‑0015

What Happened
Erasca, Inc. (filed July 13, 2026) announced updated preliminary Phase 1 results for ERAS‑0015 from its AURORAS‑1 trial (data cutoff May 25, 2026 for most data; July 6, 2026 for a combo cohort). At the recommended dose for expansion (RDE) of 32 mg once daily (QD), ERAS‑0015 showed a 57% unconfirmed overall response rate at 8 weeks (uORR8wk, N=7) in second‑line or later (2L+) KRAS G12X pancreatic ductal adenocarcinoma (PDAC). The company reported generally consistent safety versus prior disclosures and said ERAS‑0015 remains generally well tolerated.

Key Details

• RDE and response: 32 mg QD RDE; uORR8wk = 57% (7 patients evaluated) in 2L+ KRAS G12X PDAC.
• Treatment duration: At 32 mg QD, 6 of 7 patients remained on treatment; at 24 mg QD, 6 of 8 remained. Across doses, responders (confirmed or unconfirmed) remained on therapy.
• Safety (N=72 at PAD 16–32 mg): TRAEs ≥10% — rash 72%, diarrhea 32%, stomatitis 19%, nausea 14%. No dose‑limiting toxicities (DLTs) in monotherapy; TRAE interruptions 13%, reductions 8%, discontinuations 0%. One Grade 3 pneumonitis progressed to death after withdrawal of care (patient received 24 mg).
• Combination data: ERAS‑0015 + panitumumab in metastatic colorectal cancer had no DLTs in the 16 mg escalation cohort (4 DLT‑evaluable patients); backfill and escalation to 24 mg are ongoing (DCO July 6, 2026).
• Development plans: company intends to start a potentially registration‑enabling NSCLC 2L+ trial in H1 2027, a Phase 3 pivotal PDAC first‑line trial in 2027, and a Phase 3 RAS‑mutant NSCLC pivotal trial in H2 2027 or H1 2028.

Why It Matters
These updated Phase 1 data show early signs of anti‑tumor activity for ERAS‑0015 in hard‑to‑treat RAS‑mutant tumors (notably KRAS G12X PDAC) and a tolerable safety profile at planned expansion doses, supporting the company’s plan to move into larger, potentially registrational trials starting in 2027. For investors, the results and the stated development timeline are material because positive registrational trials could significantly advance the program’s value—but the company also cautions these are preliminary, unconfirmed responses and lists many risks (including possible patent disputes and regulatory delays).