Revolution Medicines shares fell 6 percent Thursday after the release of FDA review documents suggesting the company’s closely watched pancreatic cancer drug Rasonque might be less broadly effective than previously thought. Rasonque gained FDA approval in August based on data showing it nearly doubled survival compared with chemotherapy in patients who had already progressed on chemo, and the documents showed tumor responses were markedly better than chemo in trial enrollees with a specific KRAS mutation called G12V.
The difference was more modest among patients with the G12D mutation, who represent the largest share of pancreatic cancer patients, and worse in people with the G12R mutation. Many Wall Street analysts rushed to Revolution’s defense, calling the sell-off overdone or misguided in client notes. Leerink Partners analyst Andrew Berens was the exception, referring to the disclosure as a “crack in the armor” for Rasonque and viewing it as an opportunity for competitors with G12D-specific inhibitors or next-generation medicines. Endpoints News separately reported that new Rasonque data leaves a potential opening for other treatments.
The episode is a reminder that subgroup heterogeneity can bite even after approval. Rasonque’s August clearance was one of the year’s biggest oncology events and helped ignite the molecular glue modality, drawing deals like Roche’s Defand collaboration this week. The G12D population is the largest addressable slice of KRAS-mutant pancreatic cancer, so a therapy that underperforms there invites competition from the G12D-focused programs now in development.