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

Abstract 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.