Comparative Mechanistic Insights and Therapeutic Potential of Pembrolizumab, Durvalumab, and Ipilimumab as Immune Checkpoint Inhibitors in the Targeted Management of Oral and Head and Neck Squamous Cell Carcinoma.

Immune checkpoint inhibitors (ICIs) have transformed the landscape of cancer therapy by reactivating immune surveillance mechanisms against tumor cells. In the context of oral squamous cell carcinoma (OSCC) and broader head and neck squamous cell carcinoma (HNSCC), agents such as pembrolizumab, durvalumab, and ipilimumab target PD-1, PD-L1, and CTLA-4, respectively. This review comprehensively examines their clinical efficacy, safety profiles, mechanisms of action, and therapeutic potential in OSCC management, with an emphasis on strategies to overcome therapeutic resistance. A systematic analysis of the literature was conducted, focusing on clinical outcomes, ongoing trials, and emerging combination therapies. Pembrolizumab has demonstrated significant improvements in overall survival (OS) and progression-free survival (PFS) in OSCC patients. Durvalumab, mainly utilized in locally advanced or recurrent disease, has shown survival benefit, particularly in combination or maintenance settings. Ipilimumab exhibits durable responses in advanced OSCC, with enhanced efficacy observed when used alongside nivolumab in dual checkpoint blockade regimens. Although both pembrolizumab and nivolumab target PD-1, they differ in clinical indications and regulatory approvals. Notably, ICIs are associated with immune-related adverse events (irAEs), requiring careful monitoring. Collectively, these agents represent promising therapeutic options in oral cancer, though future studies must prioritize the identification of predictive biomarkers and the development of optimized combination strategies to maximize therapeutic benefit while minimizing toxicity.