Neutrophil to lymphocyte ratio and peripheral blood biomarkers correlate with survival outcomes but not response among head and neck and salivary cancer treated with pembrolizumab and vorinostat

Abstract Background Associations between peripheral blood biomarkers and oncologic outcomes were explored in recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HN) and salivary gland cancer (SGC) treated with pembrolizumab and vorinostat on a phase II trial (NCT02538510). Experimental Design Twenty‐five HN and 25 SGCs were treated with pembrolizumab and vorinostat. Baseline peripheral blood was available in 21 HN and 20 SGCs and evaluated for associations with grade ≥3 adverse events (G ≥ 3AE) by CTCAEv4, objective response rate (ORR), overall survival (OS), and progression‐free survival (PFS). Results Higher pretreatment neutrophil‐to‐lymphocyte ratio (NLR) and neutrophils, as well as lower pretreatment lymphocytes and T helper cells correlated with worse OS and PFS. Higher NLR further predicted increased rates of G ≥ 3AEs. No correlations with ORR were observed. Conclusions In a prospectively evaluated cohort of HN and SGCs treated with pembrolizumab and vorinostat, we observed novel associations between peripheral blood biomarkers and oncologic outcomes and toxicities.