Immunotherapy for recurrent/metastatic head and neck cancer

In the last decade, after cetuximab (anti-epidermal growth factor receptor), none of the novel investigated compounds has demonstrated benefit in head and neck squamous cell cancers (HNSCC), both in advanced and curative settings. Therefore, prognosis of recurrent/metastatic (R/M) HNSCC patients remains dismal, especially in platinum-refractory cohort. In the last few years, a new important class of drugs has affirmed its role. HNSCC, even if less 'immunogenic' than other malignancies (e.g. melanoma), was field of application of several new immune agents. To date, the most important data regard drugs acting on PD-1 (programmed death-1)/PD-L1 (programmed death-ligand 1) axis that is a crucial checkpoint used by tumor for immune escape. Our purpose is to summarize the results of these PD-1/PD-L1 inhibitors, outlining some critical points and few practical suggestions.

Nivolumab was recently approved by main regulatory agencies as second-line treatment for platinum-refractory R/M HNSCC. In the same setting, pembrolizumab was approved by FDA. Atezolizumab and durvalumab have already showed similar benefit in phase Ia and II studies, respectively.

Anti-PD1/PD-L1 agents are new effective therapies in R/M HNSCC. Their combination with conventional/novel compounds, as well as a better selection of responding patients, could lead to improve current results.