IO Biotech announced that it has completed enrollment in the pivotal Phase 3 clinical trial for IO102-IO103, in combination with KEYTRUDA® (pembrolizumab), Merck?s anti-PD-1 therapy, in patients with advanced melanoma. As of today, 380 patients have been randomized in the trial. The primary endpoint of the IOB-013/KN-D18 trial is progression free survival (PFS).

The PFS analysis is event-driven and will be conducted when 226 events have occurred in the trial, which the company estimates will take place in the second half of 2025. Additionally, there is a planned per-protocol interim analysis of overall response rate when the first 225 randomized patients reach one year of treatment in mid-2024. The outcome of this analysis is expected in the third quarter of 2024.

There is a high statistical bar for the Phase 3 interim analysis (p=0.005), which was set to preserve most of the alpha for the primary endpoint of PFS. Regardless of the outcome of the interim analysis, the trial is designed to continue to the primary PFS endpoint. IOB-013/KN-D18 is an open label, randomized Phase 3 clinical trial of IO102-IO103 in combination with pembrolizumab versus pembrolizumab alone in patients with previously untreated, unresectable or metastatic (advanced) melanoma, being conducted in collaboration with Merck.

Patients have been enrolled from centers across the United States, Europe, Australia, Turkey, Israel and South Africa. The primary endpoint of the study is progression free survival. Biomarker analyses will also be conducted.

IO Biotech is sponsoring the Phase 3 trial and Merck is supplying pembrolizumab. IO Biotech maintains global commercial rights to IO102-IO103. IO102-IO103 is an investigational immune-modulating therapeutic cancer vaccine designed to target the immunosuppressive mechanisms mediated by the proteins indoleamine 2,3-dioxygenase (IDO) and programmed death-ligand 1 (PD-L1).

The company is currently conducting a pivotal Phase 3 trial (IOB-013/KN-D18; NCT05155254) evaluating IO102-IO103 in combination with pembrolizumab in first-line advanced melanoma patients, a Phase 2 basket trial (IOB-022/KN-D38; NCT05077709) evaluating IO102-IO103 in combination with pembrolizumab in first-line advanced non-small cell lung cancer and head and neck cancer (SCCHN), and a Phase 2 basket trial (IOB-032/PN-E40; NCT05280314) evaluating IO102-IO103 plus pembrolizumab as a perioperative treatment in solid tumors including melanoma and SCCHN. The clinical trials are sponsored by IO Biotech and conducted in collaboration with Merck and Merck is supplying pembrolizumab. IO Biotech maintains global commercial rights to IO102-IO103.

KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.