This agreement supports a clinical proof-of-concept study, AURORAS-1, evaluating the pan-RAS molecular glue ERAS-0015 in combination with KEYTRUDA® (pembrolizumab), Merck's anti-PD-1 therapy, for the treatment of patients with RAS-mutant (RASm) solid tumors. Erasca is sponsoring the study, and Merck is supplying pembrolizumab at no cost.

"We are excited to work with Merck to advance this promising investigational combination in RAS-driven cancers," said Jonathan E. Lim, M.D., Erasca's chairman, CEO, and co-founder. "RAS mutations activate the RAS/MAPK pathway and promote an immunosuppressive environment. Non-clinical data suggest that targeting the pathway with ERAS-0015 may complement PD-1 blockade by reducing immunosuppression and driving more robust and durable tumor responses."

Worldwide, approximately 2.7 million patients are diagnosed annually with RASm tumors. Lack of effective treatments targeting multiple mutations and emergence of resistance mechanisms continue to challenge the ability to achieve and maintain responses across RAS-driven tumors. Erasca is exploring whether pan-RAS inhibition with ERAS-0015 in combination with pembrolizumab can further improve therapeutic benefits and limit the development of treatment resistance.