Despite a highly critical US FDA briefing document released ahead of the meeting, the FDA's Cellular, Tissue, and Gene Therapies Advisory Committee (CTGTAC) voted 10 to 3 on July 30 that the efficacy results from the IGNYTE study of Replimune Group's vusolimogene oderparepvec (RP1) in combination with nivolumab are evaluable and clinically meaningful. The vote provides a significant regulatory boost for the Massachusetts-based Replimune Group (Nasdaq: REPL) ahead of the August 2, 2026 target action date for the resubmitted Biologics License Application (BLA). The committee's recommendation contrasted sharply with the FDA's briefing documents, which questioned whether the single-arm study could reliably demonstrate efficacy or distinguish RP1's contribution from nivolumab rechallenge.
The indication covers advanced melanoma in patients who have progressed on prior anti-PD-1 therapy — a refractory population with no broadly approved standard of care and a recognized high unmet need. The BLA is a Class 1 resubmission, indicating Replimune had previously addressed specific deficiencies identified by the agency. As reported in June, the resubmission followed an FDA alignment meeting.
The committee addressed two specific questions: whether the single-arm IGNYTE study design allows for a reliable determination of expected response rate and durability, and whether the observed responses are indicative of systemic antitumor activity attributable to RP1 rather than to the combination partner nivolumab. The 10–3 majority found the evidence sufficient on both counts.
The IGNYTE trial enrolled patients with unresectable or metastatic cutaneous melanoma who had progressed on prior anti-PD-1 therapy. A central mechanistic question before the committee was whether responses in non-injected lesions — including visceral disease — could be attributed to RP1's proposed mechanism of inducing systemic immune activation, rather than to re-challenge with nivolumab alone. The committee's affirmative vote indicates a majority accepted this evidence.