Personalized and HPV cancer vaccines in head and neck squamous cell carcinoma: from concept to clinical implementation

Head and neck squamous cell carcinoma (HNSCC) remains a challenging malignancy, with limited survival improvements despite recent advances with immune checkpoint inhibitors (ICIs). Within this context, personalized neoantigen vaccines and HPV-targeted therapeutic vaccines are emerging as innovative strategies aimed at enhancing antitumor immunity. Personalized vaccines exploit tumor-specific mutational landscape to generate highly individualized T cell responses, demonstrating favorable safety profiles and durable immunogenicity in early-phase trials. Compounds such as TG4050, mRNA-4157, and PGV001 have shown early, hypothesis-generating signals of activity (from small early-phase studies), particularly in the adjuvant setting. HPV-targeted vaccines, including PDS0101, BNT113, and CUE-101, are being explored in HPV-positive HNSCC, mainly in combination with ICIs. While some early clinical activity has been observed, these signals should be interpreted cautiously given limited sample sizes, heterogeneous populations, and exploratory endpoints in many studies, and randomized trials such as ISA101b have failed to show survival benefits over ICIs alone. Overall, therapeutic vaccination appears safe and immunologically active, yet its efficacy is constrained by the immunosuppressive tumor microenvironment. The greatest clinical potential of therapeutic vaccination may lie in earlier disease stages, where the tumor burden is lower and immune modulation more feasible. Further clinical and translational research is needed to define the optimal integration of vaccine-based therapies into multimodal treatment paradigms for HNSCC.