PDS Biotechnology reported final topline data from its Phase 2 VERSATILE-002 study, showing that the combination of its therapeutic cancer vaccine PDS0101 with Merck’s immune-checkpoint inhibitor pembrolizumab achieved a median overall survival of 39.3 months in 53 patients with HPV16-positive recurrent or metastatic head and neck squamous cell carcinoma who had a combined positive score of at least 1 for PD-L1 expression. The lower bound of the 95% confidence interval was 23.9 months, while the upper bound has not yet been reached. The survival figure more than doubles the 17.9-month outcome historically reported for pembrolizumab, either alone or with chemotherapy, in the same population. Investigators also highlighted a favourable safety profile: no participants discontinued treatment because of therapy-related adverse events, and the most common side effects were mild injection-site reactions and fatigue. PDS said the data support the durability of immune responses driven by PDS0101, which induces long-lasting HPV16-specific CD8+ T cells. The New Jersey-based company is now running the registrational Phase 3 VERSATILE-003 trial that pits the PDS0101–pembrolizumab regimen against pembrolizumab monotherapy in roughly 351 first-line patients with the same tumour type. Full Phase 2 results are expected to be published later this year.