Afatinib as second-line treatment in patients with recurrent/metastatic squamous cell carcinoma of the head and neck: Subgroup analyses of treatment adherence, safety and mode of afatinib administration in the LUX-Head and Neck 1 trial.

•Across all subgroups, a high proportion of patients took ≥80% of assigned afatinib.•Safety findings for afatinib were similar across all patient subgroups assessed.•Dose reduction of afatinib to <40 mg reduced the incidence and severity of key AEs.•PFS with afatinib was similar between oral and feeding tube administration groups.•AEs with afatinib were similar between oral and feeding tube administration groups.