The lawsuit, spearheaded by the law firm Hagens Berman, covers investors who acquired Erasca common stock between January 14, 2025, and April 26, 2026. Plaintiffs allege that the company misled shareholders by comparing its drug candidate to Revolution Medicines’ RMC-6236 without a reasonable basis, while simultaneously touting the strength of its intellectual property portfolio.

Market confidence evaporated on April 27, 2026, when Erasca disclosed that Revolution Medicines had challenged its patent claims, citing the alleged misappropriation of trade secrets. Compounding the legal pressure, the company announced that a patient treated with ERAS-0015 had died, an event that occurred a month after the administration of the drug. The news wiped out approximately $2.8 billion in market capitalization as the stock price plunged $9.25. Reed Kathrein, a partner at Hagens Berman, noted that the investigation centers on whether the company intentionally obscured safety data and the viability of its competitive moat in the oncology market. Shareholders have until August 10, 2026, to file for lead plaintiff status.