IO Biotech Reports Promising Phase 3 Results for Cylembio and Keytruda in Advanced Melanoma

IO Biotech reported positive Phase 3 trial results for its cancer vaccine Cylembio in combination with Merck's anti-PD-1 therapy Keytruda for first-line treatment of unresectable or metastatic melanoma. The combination therapy achieved a median progression-free survival (mPFS) of 19.4 months compared to 11.0 months for Keytruda alone, narrowly missing the primary endpoint for statistical significance but showing clinically relevant improvement across nearly all patient subgroups, including those with PD-L1-negative tumors and BRAFV600 mutations. A specific analysis excluding patients with prior anti-PD-1 therapy revealed an even greater mPFS of 24.8 months. The combination was well tolerated without increased systemic toxicity or severe adverse reactions compared to Keytruda alone. Additionally, final data from a Phase 2 basket trial demonstrated encouraging results for the combination in advanced non-small cell lung cancer and squamous cell carcinoma of the head and neck. IO Biotech emphasized the potential of Cylembio to serve as a first-line treatment across multiple tumor types and continues to advance its immune-modulatory vaccine development in collaboration with Merck.