Replimune Group shares collapsed 84% from a class period high of $10.73 to $1.70 after the FDA rejected the RP1 biologics license application. Investors who bought between Oct 20, 2025 and April 10, 2026 have until Oct 5 to seek lead plaintiff status in the securities class action.
Replimune shares fell 84% after the FDA rejected its RP1 therapy, and investors face an Oct 5 lead-plaintiff deadline.
"A stock that loses more than 80% of its value across two heavily traded sessions raises the question of what shareholders were told before that repricing occurred," Joseph E. Levi, founding partner at Levi & Korsinsky, said. "The complaint alleges investors purchased REPL without material information about how the FDA viewed the underlying trial data."
The FDA on April 10 published a Complete Response Letter rejecting Replimune's biologics license application for RP1 in combination with nivolumab, the checkpoint inhibitor marketed by Bristol Myers Squibb, for advanced melanoma. The agency cited deficiencies in both submitted studies — RPL-001-16 (IGNYTE) and RP1-104 (IGNYTE-3) — and said the resubmission relied on objective response rate data from an early unplanned analysis of just 40 patients, 10 percent of the planned enrollment of 400. The FDA said it had "clearly communicated" study design concerns across multiple interactions that "were not addressed," and that the contribution of RP1 to the observed response rate could not be determined.
Shares fell $1.15, or 19.46 percent, to $4.76 on April 10, then dropped another $3.06, or 64.29 percent, to $1.70 on April 13 — a cumulative decline of about $9.03, or 84.16 percent, from the class period high of $10.73 on Dec 8, 2025. Both sessions traded on unusually heavy volume.
The complaint, filed in the US District Court for the District of Massachusetts, alleges Replimune and certain officers made materially false statements between Oct 20, 2025 and April 10, 2026. The company failed to disclose that FDA study design concerns were not addressed, that it submitted data from an early unplanned analysis covering 10 percent of planned enrollment, and that both studies carried deficiencies likely to trigger rejection. Replimune had announced on Oct 20, 2025 that the FDA accepted the resubmission, calling it "a complete response" to the July 2025 complete response letter.
The Oct 5 deadline applies to investors seeking appointment as lead plaintiff, the class member with the largest documented losses who represents the group. The rejection of RP1, Replimune's lead asset, leaves the company's pipeline under pressure, and the litigation adds to the regulatory uncertainty. Investors will watch for any resubmission plan or financing update from the company.
This article is for informational purposes only and does not constitute investment advice.
