Replimune Soars Upon FDA Resubmission for Advanced Melanoma Drug
Last month, investors’ hopes were dashed as Replimune suggested alignment had not yet been reached with the FDA on RP1’s future. Now, the regulator has accepted a refiled application after all.
In a reversal of course, Replimune announced Monday that the FDA has accepted a resubmission for RP1 in advanced melanoma, a month after setting expectations low for the drug’s future.
RP1, also called vusolimogene oderparepvec, is intended to be used in combination with Bristol Myers Squibb’s checkpoint inhibitor Opdivo (nivolumab). The FDA in July rejected Replimune’s initial biologics license application (BLA) for the therapy, an engineered, proprietary strain of the herpes simplex virus that replicates in tumors and induces a heightened immune response.
Last month, Replimune dashed the dreams of some shareholders, who, according to BMO Capital Markets, had been “holding out hope,” for a regulatory path forward for RP1. Replimune said in a press announcement following a Type A meeting with the FDA that RP1’s path forward under the accelerated approval pathway “has not been determined.”
The company’s shares crashed 40% on the news. As of publication on Monday, they were up around 93% to $8.69 apiece.
Now, RP1 has a “potential path forward,” according to BMO.
“Today’s announcement comes as a change of tune at the FDA,” BMO analysts wrote on Monday. “We see a reversal of this sentiment in today’s announcement with the company noting that the FDA has accepted Replimune’s resubmission and is considering it a complete response.”
Additional information, data and analyses have been included in the resubmission, which will be part of the BLA review, according to Replimune’s Monday announcement.
The FDA has set a target action date of April 10, 2026, based on a Class II resubmission timeline.
Replimune Soars Upon FDA Resubmission for Advanced Melanoma DrugIn a reversal of course, Replimune announced Monday that the FDA has accepted a resubmission for RP1 in advanced melanoma, a month after setting expectations low for the drug’s future.
The agency’s rejection of RP1 came as a surprise to many, including Replimune CEO Sushil Patel, who said in a statement at the time, “The issues highlighted in the CRL [complete response letter] were not raised by the agency during the mid- and late-cycle reviews.”
The FDA’s CRL indicated it did not consider the company’s Phase III IGNYTE an “adequate and well-controlled clinical investigation,” according to Replimune’s statement announcing the rejection.
In August, 22 scientists who designed and ran the IGNYTE trial penned an open letter to the FDA responding to the issues outlined in the CRL, including the drug’s efficacy and the “heterogeneity” of the trial patient population. The researchers urged the FDA to “re-review” the company’s application.
Adding to the controversy surrounding RP1 is that Richard Pazdur, director of the FDA’s Oncology Center of Excellence (OCE) and acting director of the Office of Oncologic Diseases, reportedly directly intervened in the decision. An unnamed FDA official told STAT News on Aug. 4 that the Center for Biologics Evaluation and Research “mishandled the RP1 review from the beginning,” compelling Pazdur and his team to get involved—a situation that was allegedly exacerbated by the leadership upheaval within CBER.
“We are pleased the agency has accepted the resubmission of our BLA for RP1,” Patel said in the company’s statement. “RP1 plus nivolumab offers a strong risk benefit profile where there are few options for patients with advanced melanoma, who have progressed on PD-1 based therapy.”
