Replimune Presents Late-Breaking Abstract and Additional Posters on RP1 at 40th Annual Meeting of the Society for the Immunotherapy of Cancer (SITC 2025)

Oral presentation of biomarker data shows RP1 plus nivolumab reverses multiple resistance mechanisms to PD-1 blockade in advanced melanoma following definitive anti-PD-1 failure

WOBURN, Mass., Nov. 07, 2025 (GLOBE NEWSWIRE) -- 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 40^th 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: