Replimune Presents New IGNYTE Trial Data Showing RP1 Plus Nivolumab Reverses Resistance To PD-1 Blockade And Delivers Durable Responses In Advanced Melanoma

Author: Benzinga Newsdesk | November 07, 2025 04:49pm

Replimune Group, Inc. (NASDAQ:REPL), a clinical stage biotechnology company pioneering the development of novel oncolytic immunotherapies, today announced that biomarker data and updated clinical data from the IGNYTE clinical trial of RP1 plus nivolumab was presented as a late-breaking abstract during an oral session at the 40th Annual Meeting of the Society for the Immunotherapy of Cancer (SITC 2025) in National Harbor, Maryland. Two additional posters on RP1 are also being presented.

"These data are important because they demonstrate that RP1 plus nivolumab can potentially reprogram the tumor microenvironment and reverse mechanisms of resistance to immune checkpoint blockade," said Kostas Xynos, M.D., Ph.D., Chief Medical Officer of Replimune. "Low T cell levels in tumors, tumor PD-L1 expression, T-cell activation and IFNy gene signature expression, as well as the loss of antigen presentation machinery are well known mechanisms of resistance to immune checkpoint blockade."

Data from the late-breaking abstract (#1327) presented by Trisha Wise-Draper, M.D., Ph.D., show:

• Pharmacodynamic changes that were not achieved during prolonged prior anti–PD-1 therapy demonstrate that the addition of RP1 reverses multiple resistance mechanisms to PD-1 blockade and highlights the contribution of RP1 in melanoma patients who previously failed such treatment.
• Treatment with RP1 plus nivolumab led to upregulation of gene signatures associated with responsiveness to PD-1 blockade.
• With additional follow-up (7 months), RP1 combined with nivolumab continues to demonstrate a clinically meaningful response rate (ORR: 33.6%) and durability (median duration of response: 24.8 months).
• Consistent duration of response was observed across PD-L1–positive and negative tumors, as well as in both primary and secondary resistance settings. Median duration of response for PD-L1-negative patients was 24.8 months and for patients with primary resistance was 22.6 months.

Additional posters being presented at the meeting include:

• Abstract 611: RP1 plus nivolumab in patients with and without prior BRAF-directed therapy: A subgroup analysis of patients with anti-PD-1 failed BRAF-mutant melanoma from the IGNYTE clinical trial (Katy Tsai, M.D.)
  • RP1 plus nivolumab demonstrated comparable efficacy in BRAF-mutant and BRAF–wild-type advanced melanoma.
  • Greater activity was observed in BRAF-naïve patients – similar to findings from the SECOMBIT and DREAMseq trials.
    
     
• Abstract 600: Retreatment with RP1 in combination with nivolumab in patients with advanced anti-PD-1- failed melanoma (Gino K. In, M.D.)
  
  
  • Extended RP1 treatment beyond 8 doses was well tolerated providing clinical benefit in a majority of patients.

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