The legal action, filed by Hagens Berman, targets the period between January 14, 2025, and April 26, 2026. At the center of the dispute is ERAS-0015, an oral pan-RAS molecular glue intended to treat solid tumors. Plaintiffs allege that the company improperly compared its drug’s efficacy to Revolution Medicines’ RMC-6236 and misrepresented the strength of its patent portfolio, which Erasca had previously touted as a robust competitive moat.

The situation deteriorated on April 27, 2026, when the company disclosed a legal challenge from Revolution Medicines regarding trade secrets and patent validity. On the same day, Erasca revealed that a patient treated with ERAS-0015 had died following an adverse event. The dual revelation erased $2.8 billion in market capitalization, prompting Hagens Berman to investigate whether Erasca intentionally obscured safety data and the precarious nature of its proprietary claims. Lead plaintiff applications are due by August 10, 2026.