Replimune Stock Plummets Nearly 40% After FDA Meeting Leaves Drug Future Uncertain

Replimune Group Inc. (REPL) shares cratered almost 40% Thursday after a pivotal FDA meeting failed to provide clarity on the regulatory path forward for its experimental cancer therapy RP1. The clinical-stage biotech's stock collapse reflects investor frustration with lingering uncertainty about the drug's prospects following a surprising regulatory setback in June.

The Type A meeting with FDA officials addressed RP1's stalled development as a combination therapy with Opdivo for advanced melanoma. While not outright negative, the agency's feedback offered no clear route to accelerated approval—leaving Replimune to evaluate next steps. Market participants voted with their sell orders, demonstrating low tolerance for regulatory ambiguity in high-risk biotech investments.