Multinational prospective study of association of B-cell infiltration with survival outcomes after nivolumab for R/M HNSCC

PD-1 axis blockade has become the mainstay of treatment for recurrent and or metastatic head and neck squamous cell carcinoma (R/M HNSCC). PD-L1 expression is the only approved biomarker for patient selection; however, response rate is limited even among high expressors. A multinational prospective study evaluated the association of immune-cell-related biomarkers in the tumor and tumor microenvironment with outcomes of nivolumab for R/M HNSCC. The The study showed that high pre-treatment density of stromal B-cells was associated with prolonged progression-free survival (p=0.011). This result was validated by gene set enrichment analysis, as stromal enrichment with B-cell associated genes showed association with response to nivolumab. PD-L1 positivity combined with high B-cell counts in stroma defined a subgroup with significantly longer progression-free survival (p=0.013) and overall survival (p=0.0028). The authors conclude that increased B-cell levels in pre-treatment HNSCC biopsy samples correlated with prolonged benefit from nivolumab and could further enhance the predictive value of PD-L1 expression.