Treatment sequence of cetuximab and immune checkpoint inhibitor in head and neck squamous cell carcinoma differentially affects outcomes.

OBJECTIVES:To examine the impact of treatment sequences of Immune checkpoint inhibitor (ICI) and cetuximab on clinical outcomes in patients with recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS:Clinicopathologic data were retrospectively collected on patients with R/M HNSCC who received ICI treatment. Association between treatment sequence and clinical outcomes were assessed. RESULTS:A total of 113 patients with R/M HNSCC were analyzed. Patients who had cetuximab prior to ICI had worse overall (HR, 1.83) and progression-free survival (HR, 1.76) compare to those without prior cetuximab. Among patients who had subsequent therapy after ICI, cetuximab-based therapy was associated with a trend toward higher response rate and longer survival than non-cetuximab regimen. CONCLUSION:Our single institution analysis showed that treatment sequence of cetuximab and ICI in R/M HNSCC may affect clinical outcomes. Cetuximab prior to ICI was associated with worse outcomes while the efficacy of cetuximab may be enhanced after ICI therapy.