Revolution Medicines’ lawyers issued a legal threat targeting Erasca’s RAS program, setting up the risk of a dispute over patents and efficacy claims. Erasca said it received the threat after a rival RAS cancer development reignited market attention. The message increases the probability that competition between closely related RAS-targeting approaches will extend beyond clinical interpretation to include IP enforcement. Investors are likely to watch for follow-on statements on scope, jurisdiction, and how any claims might affect trial operations or timelines. The situation underscores how rapidly the RAS oncology landscape is tightening, with companies now managing both clinical evidence and legal exposure concurrently.