FDA reviewers doubt Replimune’s melanoma therapy as shares tumble 40%

Replimune's shares fell nearly 40% after FDA reviewers released briefing documents expressing skepticism about its experimental melanoma drug RP1.

RP1 has been rejected twice before; the company launched a third approval attempt in late May after what it described as productive talks with the agency and alleged White House involvement.

FDA reviewers noted that the pivotal study lacked a control group and did not provide interpretable survival data, making it impossible to confirm a benefit for patients.

An advisory committee is slated to meet on Thursday, and reviewers anticipate a likely negative vote.

Meanwhile, ProMIS Neuroscience saw a modest rise in its stock after presenting first‑of‑its‑kind Alzheimer’s data, but investor reaction was muted.