FDA’s Rick Pazdur Led Rejection of Replimune’s RP1 Melanoma Therapy as New FDA Head Tidmarsh Reassures Staff

The Food and Drug Administration (FDA) recently rejected the biologics license application (BLA) for RP1, an experimental skin cancer therapy developed by Replimune Group. The decision has drawn criticism from the melanoma research community, which has expressed confusion over the rejection and collectively sent an open letter to the FDA. Reports indicate that Rick Pazdur, director of the FDA’s Oncology Center of Excellence and the agency's top regulator of cancer drugs, played a key role in the last-minute rejection during the late stages of the therapy's review. This intervention contributed to the unexpected denial despite the therapy's potential for treating melanoma. Some former FDA officials clarified that Vinay Prasad, previously criticized for his stringent review approach, was not substantively involved in this decision. In response to internal concerns, new FDA Center for Drug Evaluation and Research (CDER) head George Tidmarsh has been meeting with staff to reassure them and has committed to depoliticizing regulatory decisions, although he acknowledged that political pressures remain a factor. Tidmarsh and other FDA leaders are reportedly working to restore normal operations amid ongoing internal challenges.