Activity and safety of afatinib in a window pre-operative EORTC study in patients with squamous cell carcinoma of the head and neck (SCCHN)

Background: To investigate the activity and safety of afatinib in the preoperative treatment of squamous cell carcinoma of the head and neck (SCCHN). Patients and methods: This study was an open-label, randomized, multicenter, phase II window of opportunity trial. Treatment-naive SCCHN patients selected for primary curative surgery were randomized (5 : 1 ratio) to receive afatinib during 14 days (day-15 until day-1) before surgery (day 0) or no treatment. Tumor biopsies, 2-[fluorine-18]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET), and magnetic resonance imaging (MRI) were carried out at diagnosis and just before surgery. The primary end point was metabolic FDG-PET response (according to EORTC guidelines). Other end points included response assessment based on the Response Evaluation Criteria In Solid Tumors (RECIST) v1.1, dynamic contrast-enhanced (DCE)-MRI, diffusion weighted (DW)-MRI, safety, and translational research (TR). Results: Thirty patients were randomized: 25 to afatinib and 5 to control arm. Of the 23 eligible patients randomized to afatinib, 16 (70%; 95% CI: 47% to 87%) patients had a partial metabolic FDG-PET response (PMR). Five patients (22%; 95% CI: 8% to 44%) showed a partial response by RECISTv1.1. Responses assessed via DCE-MRI and DWI-MRI did not show a strong association with PMR or RECIST. One patient discontinued afatinib after 11 days for grade 3 diarrhea with subsequent renal failure and 24 days delay in surgery. No grade 4 toxicities or surgical comorbidities related to afatinib were reported. TR results indicated that PMR was more frequent in the tumors with high Cluster3-hypoxia score expression and with TP53 wild type. Conclusion: Afatinib given for 2 weeks to newly diagnosed SCCHN patients induces a high rate of FDG-PET partial metabolic response and partial response according to RECISTv1.1. Afatinib can be safely administered before surgery. Although exploratory, the hypoxic gene signature needs further investigations as a predictive biomarker of afatinib activity.