Replimune Group (REPL) RP1 BLA Rejection Case

Attorneys review the case details to decide whether to proceed with a class action.

D. Massachusetts

Court

1:26-cv-13612

Case number

10/20/2025

Class period Start

04/10/2026

Class period End

10/05/2026

Lead Plaintiff motion deadline

$REPL stockholder filed a claim against Replimune Group for touting FDA acceptance of its resubmitted Biologics License Application for RP1, its lead melanoma immunotherapy, while concealing that the FDA's underlying study design concerns had not been addressed and that key supporting data came from an early, incomplete analysis.
After the FDA issued a Complete Response Letter rejecting the RP1 BLA, followed by Replimune's own disclosure detailing the FDA's rejection rationale, $REPL fell a combined 72.3% over two trading days on April 13, 2026.
$REPL investors can join this case to be notified about potential recovery.
Case Details:

Between October 20, 2025 and April 10, 2026, Replimune repeatedly told investors that the FDA had accepted the resubmission of its BLA for RP1 in combination with nivolumab as a complete response to its prior rejection letter, that it was in productive, collaborative engagement with the agency, and that commercial launch preparations were well underway ahead of an April 10, 2026 target decision date.

However, investors allege Replimune omitted that the FDA's study design concerns from its earlier rejection had not actually been resolved, and that to support the resubmission, the company relied on an early, unplanned analysis of data from only 40 patients, just 10% of the trial's planned 400-patient enrollment, data the FDA would later deem insufficient to support an efficacy claim.

Then, on April 10, 2026, the FDA published a Complete Response Letter rejecting the RP1 BLA, stating that Replimune's study design concerns were never addressed and that the submitted data could not establish the drug's contribution to the observed treatment response. 

On this news, $REPL fell 19.5%, closing at $4.76 before trading was halted. Additional developments followed later that day when Replimune issued its own press release detailing the FDA's rejection, conceding the agency had preferred a randomized controlled trial design. 

On this news, $REPL fell a further 64.3%, closing at $1.70 per share on April 13, 2026.

Based on these events, $REPL investors filed a claim against Replimune Group, alleging the company:
It overstated the strength and completeness of its BLA resubmission for RP1.
It hid that key FDA study design concerns remained unresolved and that supporting data came from a small, unplanned analysis.
It caused investor losses when the FDA's rejection revealed the true state of the application.
Investors argue Replimune Group misled the market about the readiness of its RP1 BLA, causing losses when the FDA's rejection revealed the truth.

Case Type

US Securities Class Action

Case Status

Attorney Investigation

Alleged Offence

Misleading Statements,

Failure to Disclose

Suspected Party

Directors,

Management

Security Type

Stocks

Trade Direction

Long

Shock Event Date

04/10/2026

Filing date

08/06/2026

Lead Plaintiff Deadline

10/05/2026