IO Biotech Announces Publication In Nature Communications Of Long-Term Clinical And Immunological Outcomes From Phase 1/2 Trial MM1636

• Findings provide scientific insights into the contributions of IDO1 and PD-L1 vaccination to PD-1 blockade for the treatment of metastatic melanoma
• Five-year analysis of median progression free survival was 25.5 months
• These results reinforce the potential of immune-modulatory vaccination
   

NEW YORK, Dec. 15, 2025 (GLOBE NEWSWIRE) -- IO Biotech (NASDAQ:IOBT), a clinical-stage biopharmaceutical company developing novel, immune-modulatory, off-the-shelf therapeutic cancer vaccines, today announced the publication in Nature Communications of the long-term clinical and immunological outcomes from MM1636, the Phase 1/2 trial evaluating the investigational peptide vaccine IO102-IO103 targeting both tumor cells and immune-suppressive cells expressing IDO1 and/or PD-L1, in combination with PD-1 blockade in the treatment of first line metastatic melanoma. The results of this trial supported a Breakthrough Therapy Designation for the treatment of unresectable/metastatic melanoma in combination with pembrolizumab by the US Food and Drug Administration (FDA) and, together with the available preclinical and translational data, served as the foundation for IO Biotech's decision to initiate the Phase 3 clinical trial in first-line advanced melanoma (IOB-013/KN-D18).

The MM1636 results published today showed the five-year follow-up analysis of IO102-IO103 in combination with nivolumab in patients with metastatic melanoma, demonstrating durable clinical activity with a 25.5-month median progression-free survival (PFS). The results also showed the identification of potential vaccine-specific immune biomarkers of long-term benefit, not observed in a matched anti-PD-1 monotherapy cohort, suggesting a distinct vaccine-induced immune modulation increasing anti-tumor activity. These overall results provide a compelling rationale for integrating immune-modulatory vaccination into immunotherapy regimens for patients with melanoma.