Shareholder rights law firm Robbins LLP informs investors that a class action was filed on behalf of all persons and entities that purchased or otherwise acquired Replimune Group, Inc. (NASDAQ: REPL) securities between October 20, 2025 and April 10, 2026 (“Class Period”). Replimune purports to be a clinical-stage biotechnology company focused on novel oncolytic immunotherapies. According to the complaint, the Company’s lead product candidate is RP1 (vusolimogene oderparepvec).

The lawsuit alleges that the Company misled investors regarding the efficacy and viability of its lead product candidate RP1.

If you purchased or otherwise acquired REPL securities during the applicable class period and suffered a loss, you may have legal rights. For more information about the Replimune Group Inc., submit a form, email attorney Aaron Dumas, Jr., or call Robbins LLP at (800) 350-6003.

Why Was Replimune Sued?

On October 20, 2025, Replimune announced that the U.S. Food and Drug Administration (“FDA”) had accepted the resubmission of the Biologics License Application (“BLA”) for RP1 in combination with nivolumab for the treatment of advanced melanoma in patients who progress on an anti-PD-1 containing regimen. The Company claimed that “[a]dditional information, data and analyses were included in the resubmission which will be part of the BLA review.” The Company also stated that “[t]he FDA indicated this resubmission is considered to be a complete response to the complete response letter received in July 2025.”

The complaint alleges that defendants failed to disclose to investors:

(1) that in connection with the BLA, the study design concerns previously communicated by the FDA were not addressed;

(2) that the Company had submitted data from an early unplanned analysis from RP1-104, which included only 40 patients (10% of the planned enrollment of 400 patients);

(3) that, as a result, RPL-001-16 and RP1-104 both had deficiencies which were likely to cause the FDA to reject the BLA; and

(4) that, as a result of the foregoing, Defendants’ positive statements about the Company’s business, operations, and prospects were materially misleading and/or lacked a reasonable basis.

Why Did REPL Stock Drop?

The complaint alleges that on April 10, 2026, during market trading, the FDA published a Complete Response Letter (“CRL”) rejecting Replimune’s Biologics License Application (“BLA”) for RP1 in combination with nivolumab. The FDA identified several deficiencies for each of the studies—RPL-001-16 (IGNYTE) and RP1-104 (IGNYTE-3)—submitted by Replimune and found that “the evidence as presented does not meet the evidentiary standards required for regulatory approval, and the results of the additional exploratory analyses of the RPL-001-16 data do not alter our initial conclusion that the RPL-001-16 trial is not an adequate and well-controlled clinical investigation that demonstrates substantial evidence of effectiveness.”

The FDA further revealed that “[t]o support resubmission of the BLA on October 9, 2025, [Replimune] provided [objective response rate] data from an early unplanned analysis” from RP1-104 which included only 40 patients, 10% of the planned enrollment of 400 patients.

In the CRL, the FDA further revealed that it had “clearly communicated” its “concerns with the study design in multiple FDA interactions throughout [Replimune’s] development program,” but that “the study design concerns previously communicated were not addressed, and the contribution of [RP1] to the observed response rate in RPL-001-16 could not be determined.”

On this news, the Company’s share price fell $1.15 or 19.46%, before trading was halted, to close at $4.76 per share on April 10, 2026, on unusually heavy trading volume.

The complaint continues that on April 10, 2026, after the market closed, the Company issued a press release discussing the FDA’s response letter for the RP1 BLA. In the press release, Replimune conceded that “a randomized controlled trial was preferred” by the FDA, but also claimed that the FDA communicated that “if the data was sufficiently compelling, a single arm trial could be acceptable for consideration under accelerated approval.”

On this news, the Company’s share price continued to fall $3.06 or 64.29%, to close at $1.70 per share on April 13, 2026.

Who May Be Eligible to Participate in the Replimune Class Action?

Investors who purchased or otherwise acquired REPL securities between October 20, 2025 and April 10, 2026, may be eligible to participate in the proposed securities class action. If you purchased REPL shares during the Class Period and suffered losses, you may have rights under the federal securities laws.

What Is a Lead Plaintiff?

The lead plaintiff is a representative investor appointed by the court to act on behalf of other members of the proposed class and help direct the litigation. Investors do not have to become lead plaintiff to potentially participate in any recovery obtained through the litigation.

Does it cost anything to participate?

No. Robbins LLP represents investors on a contingency fee basis. Investors never pay attorneys’ fees or litigation expenses. If there is a recovery for shareholders, defendants pay fees and expenses.

Contact Robbins LLP

Investors seeking additional information about the Replimune Group Inc. securities class action may submit an inquiry, email attorney Aaron Dumas, Jr., or call (800) 350-6003.

About Robbins LLP

A recognized leader in shareholder rights litigation, Robbins LLP has helped restore more than $1 billion in value to shareholders, secured some of the largest recoveries in shareholder derivative litigation history, and achieved governance reforms at over 400 Fortune 1000 companies.

“Behind everything we do is the belief that companies should be governed responsibly, fiduciaries should be held accountable, and shareholders deserve transparency and fairness,” said Brian J. Robbins, Founding Partner of Robbins LLP.

To be notified if a class action against Replimune Group Inc. settles or to receive free alerts when corporate executives engage in wrongdoing, sign up for Stock Watch today.

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