FDA Rejects Melanoma Treatment RP1 Amid Commissioner Makary's Resignation

The U.S. Food and Drug Administration withheld approval of RP1, a genetically engineered virus therapy for melanoma developed by Replimune, citing serious deficiencies in the clinical trial design. The agency had warned the company that the trial lacked a control arm and that changes were needed, but Replimune proceeded without compliance. In the trial, about a third of the 140 participants saw tumors shrink or disappear, a result that could have saved up to 2,500 lives, according to oncologists.

Dermatologist Trisha Wise‑Draper described the decision as “devastating news,” and Atlantic Health System oncology director Eric Whitman said it was “life or death for maybe 2,000 patients.” The ruling comes as FDA Commissioner Marty Makary, who took office 13 months ago, resigned amid controversy over the agency’s handling of drug approvals and alleged political pressure. Critics warn the move could have a chilling effect on future cancer drug development.