Erasca's stock plummeted following the disclosure that a 66-year-old male patient died in a Phase 1 trial of its lead candidate, ERAS-0015, for metastatic pancreatic cancer. The patient had a grade 3 treatment-related pneumonitis that progressed to grade 5 after supportive care was withdrawn at the patient's direction.
The patient, described as "heavily pretreated" by Erasca, received a 24 mg dose of the drug. The death was attributed to a treatment-related adverse event (TRAE), marking a significant safety signal for the experimental therapy.
ERAS-0015 is an oral ERK1/2 inhibitor being developed for solid tumors with RAS/MAPK pathway mutations. The drug is currently in dose-escalation cohorts, and its clinical timeline remains uncertain pending further safety review.
Compounding the bad news, a rival company filed a patent challenge against Erasca, though details of the opposition were not disclosed in the report. The twin setbacks erased billions in market value, with shares falling sharply in after-hours trading.
"This is a devastating blow for Erasca," said an analyst cited by GEN. "A single patient death in a Phase 1 trial can derail the entire program, especially when combined with intellectual property headwinds." However, another expert noted that single fatalities in heavily pretreated populations are not always predictive of broader toxicity.