IO Biotech Reveals Positive Phase 3 Results For Cylembio Plus Keytruda In Advanced Melanoma

(RTTNews) - IO Biotech (IOBT), a clinical-stage biopharmaceutical company focused on cancer vaccines, Monday reported positive phase 3 results for Cylembio, in combination with Merck & Co Inc.'s (MRK) anti-PD-1 therapy KEYTRUDA (pembrolizumab) for the first-line treatment of patients with unresectable or metastatic (advanced) melanoma.

The trial achieved a clinically relevant median progression free survival or mPFS, but narrowly missed progression free survival or PFS primary endpoint for statistical significance.

In the randomized Phase 3 trial, 407 patients with previously untreated advanced melanoma received either Cylembio plus pembrolizumab or pembrolizumab alone. Median progression-free survival was 19.4 months for the combination and 11.0 months for pembrolizumab.

The company noted that the Phase 3 results in advanced melanoma, together with final data from Phase 2 basket trial, continue to build on the encouraging clinical evidence seen with Cylembio in combination with anti-PD-1 therapy.

Mai-Britt Zocca, president and chief executive officer of IO Biotech, said, "These data reinforce Cylembios potential to serve as a first-line treatment option across multiple tumor types, and we remain committed to advancing novel immune-modulatory vaccines that may help people living with cancer."

The company presented the detailed results from its global IOB-013/KN-D18 trial of Cylembio (imsapepimut and etimupepimut, adjuvanted), plus KEYTRUDA at the Melanoma and other skin tumors session of the 2025 European Society for Medical Oncology or ESMO Congress in Berlin.

In addition, final results from the Phase 2 basket trial (IOB-022/KN-D38) evaluating Cylembio in combination with pembrolizumab in the first-line treatment of advanced non-small cell lung cancer or NSCLC and recurrent/metastatic squamous cell carcinoma of head and neck or SCCHN were presented.

The clinical trials are sponsored by IO Biotech and conducted in collaboration with Merck, which is supplying pembrolizumab. IO Biotech holds global commercial rights to Cylembio.