Erasca’s shares fell sharply after the company reported Phase 1 dose-escalation results for ERAS-0015, a pan-RAS molecular glue in RAS-mutant solid tumors including non-small-cell lung cancer and pancreatic ductal adenocarcinoma. The company is running Auroras-1 in the U.S. and JYP0015M101 in China after licensing from Joyo Pharmatech. The update included a reported patient death associated with pneumonitis in the context of the trial, which drove investor reaction. Separately, the same broader trial program has been cited in market coverage for early efficacy signals, but the immediate news flow centered on safety and tolerability considerations. For investors and trial operators, the episode underscores how quickly clinical early-stage narratives can shift when individual safety events are disclosed alongside efficacy readouts.