Erasca announces preliminary dose escalation data for ERAS-0015

Erasca (ERAS) announced preliminary Phase 1 dose escalation data for its pan-RAS molecular glue ERAS-0015 in patients with RAS-mutant solid tumors. The preliminary data are from Erasca’s ongoing AURORAS-1 Phase 1 dose escalation trial in the U.S. and the ongoing JYP0015M101 Phase 1 dose escalation trial in China sponsored by Joyo Pharmatech, both evaluating ERAS-0015 in patients with RAS-mutant solid tumors. Well-behaved PK, with dose-dependent increase in PK exposure up to the maximum administered dose of 40 mg once daily and no exposure plateau observed. Pharmacologically active dose range of 16-32 mg once daily defined based on mean steady-state average exposures that exceeded target exposure threshold. Substantial reductions in KRAS G12X circulating tumor DNA were observed at the PAD doses, with 100% of patients showing at least 75% reduction in KRAS G12X variant allele fraction, including 5 out of 14 patients showing 100% reduction. Robust monotherapy overall response rates in patients with KRAS G12X non-small cell lung cancer, or NSCLC, and with KRAS G12X pancreatic cancer, in each case as of the relevant data cutoff. Nearly all responding patients-including all unconfirmed responders-remain on treatment as of the DCO. NSCLC 23 out of 24 responding patients remain on treatment, including all responders treated at 24-32 mg QD RDEs PDAC. Overall, 20 out of 23 responding patients remain on treatment, including all responders treated at 24-32 mg QD RDEs. Generally well-tolerated with mostly low-grade adverse events, no dose-limiting toxicities, low rate of dose interruptions or reductions due to treatment-related adverse events, and no discontinuations due to TRAEs. Based on the totality of the preliminary Phase 1 dose escalation data, 24 mg and 32 mg once daily were selected as the go-forward monotherapy RDEs. ERAS-0015 showed clinical potential to combine with panitumumab. ERAS-0015 showed promising clinical potential to combine with panitumumab. No DLTs observed through the 31Mar2026 DCO with 1 unconfirmed partial response in 1 efficacy-evaluable patient with metastatic colorectal cancer.