Replimune receives second FDA rejection for lead melanoma drug RP1

Replimune disclosed on April 10, 2026 that the FDA issued a second Complete Response Letter for its biologics license application seeking approval of RP1 (vusolimogene oderparepvec) combined with nivolumab to treat advanced melanoma.

A Complete Response Letter means the FDA has finished reviewing the application but determined it cannot be approved as submitted, requiring the company to address specific deficiencies before resubmission. This is particularly concerning as it's the second CRL for this same application, suggesting the company has not yet resolved the FDA's concerns from the first rejection.

For retail investors, this represents a significant setback for Replimune's lead product candidate and core commercial strategy. The company will need to determine what additional data, studies, or manufacturing changes the FDA requires, then execute on those requirements before resubmitting. This process could take months or years and will likely require additional capital. Watch for the company's next earnings call or investor update where management should detail the specific FDA concerns and their plan to address them, including revised timelines for potential approval.