Immunotherapy for head and neck squamous cell carcinoma: current status and perspectives

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of several solid cancers, including head and neck squamous cell carcinoma (HNSCC). First approved for second-line settings, ICIs are now used for the first-line treatment of HNSCCs, mainly in combination with standard chemotherapy. This review focuses on the results of the main phase III studies evaluating ICIs in recurrent or metastatic HNSCCs. The efficacy and indications according to the PD-L1 status, the main predictive biomarker, are discussed. The results of trials assessing ICI efficacy for locally advanced disease, including the neoadjuvant setting are also discussed. Finally, therapeutic combinations that are potential treatments for HNSCCs, including ICIs and targeted therapies such as anti-EGFR agents, are presented. Head and neck (HN) cancer is common and challenging to treat, especially when it relapses locally (recurrence) or in a different organ (metastatic). Immunotherapy, which strengthens the immune system's ability to target tumor cells, has revolutionized the treatment of several cancers, including metastatic HN cancers. Pembrolizumab, an immunotherapy drug, is now combined with chemotherapy as standard treatment for recurrent or metastatic HN cancers; it has a manageable toxicity profile. However, some patients do not respond to treatment, and the disease may relapse after several injections. Efforts are currently underway to improve the efficacies of these immunotherapy treatments by combining them with other therapies, such as anti-EGFR treatment. Current studies seek biomarkers to identify patients likely to benefit from these treatments and those who may require alternative treatments.