Erasca Inc. lost $2.8 billion in market value after a patient death and a patent infringement claim from Revolution Medicines Inc. triggered a securities class action.
"The company's positive statements about ERAS-0015 lacked a reasonable basis given the undisclosed risks of patent and trade secret violations," the complaint filed in San Diego federal court alleged.
The stock fell $9.25, or 48 percent, to $9.90 on April 28 after Erasca disclosed that a patient who received 24 milligrams of ERAS-0015 died about one month after starting treatment. A day earlier, shares dropped 11 percent after Revolution Medicines sent a cease-and-desist letter claiming Erasca's pan-RAS molecular glue infringes its patent and that Erasca made "deceptive and untrue comparative statements" between ERAS-0015 and RevMed's RMC-6236.
The class action covers investors who bought Erasca common stock between Jan. 14, 2025 and April 26, 2026. Lead plaintiff motions are due Aug. 10. The lawsuit threatens Erasca's entire pan-RAS program, its most advanced pipeline asset for RAS-mutated solid tumors.
Erasca, a clinical-stage precision oncology company based in San Diego, had touted ERAS-0015 as a potential best-in-class therapy targeting the RAS/MAPK pathway, one of the most common drivers of cancer. The company's preclinical data compared ERAS-0015 directly with Revolution Medicines' RMC-6236, a rival compound in the same class.
Revolution Medicines alleged those comparisons were improper and that Erasca's drug candidate was "substantially equivalent" to compositions covered by its patents. The company also accused Erasca of trade secret misappropriation, though it did not specify the nature of the alleged theft.
Multiple law firms have filed similar complaints, including Robbins Geller Rudman & Dowd LLP, Holzer & Holzer LLC, and the Law Offices of Howard G. Smith. The cases are expected to be consolidated in the Southern District of California.
The dual blow of a patient death and a patent dispute from a well-capitalized competitor severely undermines Erasca's pipeline credibility. Investors will watch for any FDA clinical hold on ERAS-0015 and the outcome of the patent litigation, which could determine whether the company can continue developing its lead asset.
This article is for informational purposes only and does not constitute investment advice.