UPDATE: Replimune (REPL) - The Hammer Drops

Regulatory Whiplash and the Death of Single-Arm Approvals

Executive Summary: The Bear Case Materializes

If you read my February deep dive into Replimune, you’ll recall the core thesis: the biological rationale behind their fusogenic super-virus (RP1) was elegant, but betting on the FDA to approve a non-randomized, single-arm trial after they had already rejected it once was a massive regulatory gamble.

Today, that gamble failed.

On April 10, 2026, the FDA issued a second Complete Response Letter (CRL) for Replimune’s Biologics License Application (BLA) for RP1 combined with nivolumab in advanced melanoma. Management’s response in their press release is blistering, but the financial reality is bleak.

Here is the autopsy of the regulatory failure and what it could mean for the stock moving forward.