FDA Panel Endorses Replimune Skin Cancer Therapy Ahead of Final Decision

2026-07-30 companies

Woburn, Friday, 31 July 2026.
An FDA advisory panel voted 10–3 supporting Replimune’s skin cancer drug RP1, overcoming previous rejections and agency skepticism ahead of the August 2 final approval decision.

Advisory Committee Delivers Positive Vote

On July 30, 2026, the FDA’s Cellular, Tissue, and Gene Therapies Advisory Committee voted 10 to 3 in favor of the efficacy results from Replimune Group’s IGNYTE study [1][2]. This positive panel outcome represents a significant regulatory milestone for the biotechnology company, moving its lead candidate, RP1 (vusolimogene oderparepvec), closer to potential approval [1]. The committee specifically evaluated the Biologics License Application (BLA) resubmission for RP1 in combination with nivolumab for advanced melanoma patients who had progressed on prior anti-PD-1 therapy [1]. While the advisory committee’s recommendation is non-binding, the FDA historically tends to follow the guidance of its expert panels [2]. The 13 member panel concluded that the efficacy results were evaluable and clinically meaningful, overcoming earlier skepticism regarding the trial design [1][2].

Regulatory History and Staff Concerns

This favorable vote follows a period of intense regulatory scrutiny, including two previous Complete Response Letters (CRLs) issued in July 2025 and April 2026 [6][7]. FDA staff reviewers had previously raised concerns that the IGNYTE study’s single-arm design lacked a control group, making it difficult to determine if RP1 provided meaningful clinical benefit beyond the comparator therapy [3][7]. On July 28, 2026, briefing materials released by the FDA staff questioned whether the drug worked as claimed, citing issues with the response assessment criteria [3][4]. Despite these earlier objections, the advisory committee’s determination suggests a shift in the risk-benefit assessment ahead of the final agency decision [2][7].

Clinical Data and Trial Design

The IGNYTE trial enrolled 140 patients with advanced melanoma who had progressed on prior anti–PD-1–containing therapy [6]. Efficacy data from the registrational cohort showed an objective response rate (ORR) of 33.6% and a median duration of response ranging between 24.8 and 33.7 months across different reports [6][7][8]. FDA reviewers had noted that the absence of a comparator arm prevented the agency from definitively attributing tumor responses to RP1 rather than the combination partner or patient selection factors [5][8]. Replimune maintains that the trial design was conducted in collaboration with the FDA during a period when few options existed for this patient population [6].

Market Reaction and Upcoming Decision

Market volatility preceded the vote, with Replimune shares falling nearly 32% on July 28, 2026, following the release of critical FDA staff documents [3]. Some reports indicated a decline of approximately 31% to 30% in early trading during the same period, reflecting investor anxiety over the regulatory hurdles [5][7]. The FDA’s target action date for the Class 1 resubmission is set for August 2, 2026, providing a clear timeline for the final decision [1][3]. Company leadership expressed encouragement by the outcome and noted the high unmet need for new treatment options in advanced melanoma [1].

Sources

Oncology Market Biotech Regulation