Combined approach for predicting the efficacy of nivolumab in head and neck carcinoma by tissue and soluble expressions of PD‐L1 and PD‐L2

Background Predictive biomarkers for nivolumab in recurrent or metastatic head and neck squamous cell carcinoma (RMHNSCC) have not yet been established. Methods The tumor proportion score (TPS), combined positive score (CPS), and soluble forms of programmed cell death ligand‐1 (PD‐L1) and programmed cell death ligand‐2 (PD‐L2) were retrospectively analyzed in patients with RMHNSCC treated with nivolumab. Results The positivity rates for TPS (PD‐L1), CPS (PD‐L1), TPS (PD‐L2), and CPS (PD‐L2) were 73.8%, 78.2%, 56.4%, and 78.2%, respectively. Patients with high TPS (PD‐L1), CPS (PD‐L1), or CPS (PD‐L1 and PD‐L2) showed significantly prolonged progression‐free survival. Favorable overall survival was associated with high CPS (PD‐L1 and PD‐L2) and low soluble PD‐L1 and PD‐L2 levels. The expressions of tissue and soluble PD‐L1/2 were not correlated. Conclusions Our study revealed that compared to PD‐L1 expression alone, dual expression of PD‐L1 and PD‐L2 in tissue or soluble form could be feasible biomarkers in patients with RMHNSCC who received nivolumab.