Response to salvage chemotherapy after progression on immune checkpoint inhibitors in patients with squamous cell carcinoma of the head and neck.

6015Background: Immune checkpoint inhibitors (ICI) have shown efficacy in patients with recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) with an overall response rate (ORR) ranging from 13 to 17%. Recent data suggest that exposure to ICI potentially improves ORR to salvage chemotherapy (SCT) in advanced non-small cell lung carcinoma. We evaluated responses to chemotherapy in R/M SCCHN patients after progression on ICI. Methods: A retrospective study was conducted at 4 French referral centers. Eligibility criteria were patients treated with ICI for R/M SCCHN, who progressed after treatment with ICI (primary or secondary resistant to ICI) and received SCT between September 2014 and January 2018 and for whom efficacy data were available. Clinical and radiological data were collected from review of medical records. Results: Of 232 patients treated with ICI (anti-PD-1, anti-PD-L1, anti-CTLA-4 and anti-KIR), 82 met eligibility criteria: 84% were male, median age was 60 years old. IC...