Denmark's IO Biotech announced its off-the-shelf therapeutic cancer vaccine Cylembio (IO102-IO103) failed to meet the primary progression-free survival (PFS) endpoint in the Phase III IOB-013 trial combining it with pembrolizumab for untreated metastatic melanoma (HR=0.77, P=0.056). The vaccine targeting PD-L1 and IDO1-positive cells showed numerical but not statistically significant PFS improvement (19.4 vs 11.0 months), though clinically meaningful benefit emerged in PD-L1-negative subgroups (16.6 vs 3.0 months, HR=0.54).

Despite the miss, IO Biotech plans discussions with US health authorities about potential regulatory pathways based on encouraging overall survival trends (HR=0.79) and a manageable 56% injection-site reaction rate with no new safety signals. The company will present detailed results at upcoming conferences while continuing development of its T-cell stimulating vaccine platform for other solid tumours. The outcome contrasts with recent successes of mRNA cancer vaccines but confirms the challenges of combining therapeutic vaccines with immune checkpoint inhibitors.

PharmCube's NextBiopharm® database shows that five melanoma vaccines have been approved globally, created by Cuba's Centre of Molecular Immunology, GSK, Genoa Biotechnologia, Agenus, and GemVax & Kael. Click here to request a free trial for NextBiopharm®.