Response rates and survival to systemic therapy after immune checkpoint inhibitor failure in recurrent/metastatic head and neck squamous cell carcinoma

Abstract Objectives Prior reports have demonstrated a potential enhancement in overall response rate (ORR) to chemotherapy after exposure to immunotherapy. The goal of this study was to evaluate the ORR and survival to chemotherapy and/or targeted therapy in head and neck squamous cell carcinoma (HNSCC) patients who progressed on immune checkpoint inhibitors (ICI). Materials and Methods We retrospectively collected clinical and pathologic data from patients with recurrent/metastatic HNSCC who progressed on ICI and subsequently received chemotherapy or targeted therapy. ORR was assessed by RECIST version 1.1. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Results A total of 43 patients met criteria for inclusion. The majority were male (91%) and former smokers (60%). Most patients received ICI as first-line (58.14%); the vast majority was platinum exposed (90.7%). The ORR to ICI was 21%. The ORR to systemic therapy before ICI was 47%, and the ORR after ICI failure was 42%. After progression on ICI, the median PFS and OS on the subsequent line of therapy were 4.2 and 8.4 months respectively. Conclusion In our cohort of recurrent/metastatic HNSCC patients, the ORR and OS to systemic therapy after progression on ICI were higher than historical controls for second-line or beyond. Further investigations are warranted to better characterize optimal sequencing and combination strategies.