The FDA has granted accelerated approval to Replimune’s engineered oncolytic virus therapy Tudriqev (RP1) for patients with advanced melanoma that has progressed after prior PD-1–blocking immunotherapy. The clearance follows two prior FDA rejections and came after an advisory committee vote supported the program despite staff concerns about trial design and response attribution. Tudriqev is approved for use with Bristol Myers Squibb’s Opdivo. The decision relies on single-arm data showing tumor response in roughly a quarter of enrolled patients, with effects lasting a median of just over 14 months. Continued approval is contingent on results from an ongoing Phase 3 confirmatory study. The accelerated pathway tightens the scrutiny on how the sponsor measured efficacy and on whether the confirmatory trial can validate the signal. The FDA’s Center for Biologics Evaluation and Research emphasized the urgency for a post-PD-1 population with limited options as the regulator accepted the evidence package available at this stage.