The U.S. Food and Drug Administration (FDA) on Friday concluded that Replimmune Group Inc. (NASDAQ:REPL) Biologics License Application (BLA) for vusolimogene oderparepvec in combination with nivolumab does not provide sufficient evidence of effectiveness for treating advanced melanoma.



The agency issued a Complete Response Letter to the company’s RP1 for skin cancer treatment.



Bristol-Myers Squibb Co. (NYSE:BMY) markets nivolumab under the Opdivo brand name.



<h2>FDA Maintains Longstanding Concerns On Efficacy</h2>



The agency said its review of the resubmitted application—including updated analyses from study RPL-001-16 and early data from the ongoing Phase 3 trial RP1-104—failed to meet the evidentiary threshold required for approval.



Regulators emphasized that their stance has remained consistent since 2021, reiterating that the submitted data does not establish substantial evidence of clinical benefit in patients with unresectable advanced cutaneous melanoma who progressed on prior PD-1 therapies.



A newly assigned review team, separate from the initial evaluation, independently reached the same conclusion, reinforcing the agency's position.



<h2>Replimmune Trial Design Limitations Undermine Findings</h2>



The FDA highlighted multiple deficiencies in the Phase 2 RPL-001-16 study, including its inability to isolate the contribution of vusolimogene oderparepvec when used alongside nivolumab.



Additional concerns included heterogeneity in the patient population and inconsistencies in response assessments.



The agency noted that deviations from standard RECIST v1.1 criteria complicated the interpretation of tumor response data.



Further, surgical interventions and reinjection of lesions before confirmed disease progression introduced confounding variables, making it difficult to determine whether observed responses were attributable to the therapy.



<h2>Early Phase 3 Data Deemed Insufficient</h2>



The resubmission included early, unplanned data from the Phase 3 RP1-104 trial, representing just 10% of the intended enrollment.



The FDA said this limited dataset—comprising 22 treated patients and 18 controls—was inadequate to support efficacy claims.



Key gaps included a lack of independently verified response assessments, the absence of duration-of-response data, and challenges in interpreting progression-free survival due to missing pre-specified statistical controls.



<h2>Replimmune Path Forward Requires Robust Clinical Evidence</h2>



The agency reiterated that approval would require results from well-controlled clinical trials capable of clearly demonstrating efficacy.



It also indicated that exploratory analyses submitted from earlier studies did not alter its original conclusions.



The FDA added that the sponsor may request a Type A meeting within three months to discuss next steps following the regulatory decision.



REPL Stock Price Activity: Replimmune shares were down 19.46% at $4.76 at the time of publication on Friday, according to Benzinga Pro data.



Image via Shutterstock

LABU

IBBQ

SBIO

REPL

The FDA has rejected Replimmune's melanoma therapy, stating that the evidence provided in the Biologics License Application (BLA) is insufficient. The agency cited flaws in trial design and limited data from the resubmission review, emphasizing that the submitted data does not demonstrate substantial clinical benefit for patients with advanced melanoma. Replimmune's stock fell 19.46% following the announcement.

FDA Again Rejects Replimune Skin Cancer Therapy, Says Evidence Falls Short