Revolution Medicines Shares Fall as FDA Flags Daraxonrasib Response Gap

Shares of Revolution Medicines (RVMD) fell on October 8, 2026, after FDA documents raised questions about the efficacy of its lead oncology drug, daraxonrasib. The review highlighted differences in response rates across KRAS mutation subtypes, raising concerns among investors about the drug’s broad applicability.

The overall response rate was 32%. It was boosted by a 50% response rate in the G12V subgroup.

The largest patient group, those with the G12D mutation, had a 24% response rate. The findings added uncertainty to the stock’s high valuation after daraxonrasib’s approval in August for metastatic pancreatic cancer.