Replimune Stock More Than Doubles After Favorable FDA Panel Vote on Melanoma Drug

Replimune (REPL) stock surged more than 125% in pre-market trading Friday after an advisory panel to the U.S. Food and Drug Administration (FDA) backed the company's experimental cancer therapy. The positive recommendation significantly improves the drug's chances for approval ahead of a key regulatory deadline.

Panel Endorses RP1 Efficacy

On Thursday, the FDA’s Cellular, Tissue, and Gene Therapies Advisory Committee voted 10 to 3 that the efficacy data for Replimune's drug candidate, RP1 (vusolimogene oderparepvec), was favorable. The vote concerned the use of RP1 in combination with nivolumab to treat patients with advanced melanoma who have not responded to prior anti-PD-1 therapy.

The panel's conclusion that the results from the single-arm IGNYTE study were "clinically meaningful" marked a significant reversal from the cautious tone set by FDA staff scientists earlier in the week. Pre-meeting documents released on July 28 had raised concerns that the trial's design was insufficient to determine RP1's specific contribution to clinical benefit, which had caused the stock to fall by approximately 30%.

Market Reaction and Analyst Upgrade

The strong advisory committee endorsement triggered a sharp rally in Replimune's shares, which reached $12.19 in pre-market activity. The move, which was amplified by what the source described as significant short-covering, nearly erased the losses incurred after the FDA's initial briefing documents were published.

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Following the vote, analysts at Cantor Fitzgerald upgraded Replimune to Overweight from Neutral. The firm cited a "materially higher probability" that the FDA will grant Accelerated Approval for RP1, highlighting the decisive 10-3 vote and compelling testimony from physicians and patients during the meeting.

What's Next for Replimune

While the advisory committee's recommendation is non-binding, the FDA typically follows the guidance of its expert panels. The agency is expected to make its final decision on the approval of RP1 on or around its Prescription Drug User Fee Act (PDUFA) date of August 2.

Friday's pre-market surge reflects the market rapidly re-pricing the probability of approval for a therapy that targets a high-unmet-need patient population. A positive decision from the FDA would be a transformative event for the company.