Phase II trial of single-agent foretinib (GSK1363089) in patients with recurrent or metastatic squamous cell carcinoma of the head and neck

Summary: Background Foretinib is a small-molecule, oral multikinase inhibitor primarily targeting the mesenchymal epithelial transition (MET) factor receptor, and the vascular endothelial growth factor receptor 2. We conducted a phase II study to evaluate the single-agent activity and tolerability of foretinib in patients with recurrent/metastatic squamous cell carcinoma of the head and neck (SCCHN). Methods An open-label, single-arm, multicenter trial employing a Simon 2-stage design was conducted with a total of 41 patients planned for the study. One or more responses in the first 14 patients were required in order to progress to the second stage. Foretinib was administered as 240 mg orally for 5 consecutive days of a 14-day treatment cycle (5/9 schedule) to patients with recurrent and/or metastatic SCCHN. Results Fourteen patients were enrolled. The study did not meet criteria for continuing to the second stage. A maximum of 30 cycles were administered (median = 4.0). Fifty percent of patients (7/14) showed stable disease (SD), 43 % of patients (6/14) experienced tumor shrinkage and two patients had prolonged disease stabilization for ≥13 months. The most common adverse events were fatigue, constipation and hypertension, which were manageable with additional medication or adjustments to the dosing schedule. Conclusion Foretinib 240 mg on a 5/9 schedule was generally well tolerated. SD was the best-observed outcome, with minor tumor shrinkage detected in nearly half of all patients. The efficacy results, prolonged disease stabilization and tolerable side-effect profile, support further investigation, possibly in combination with other targeted agents or cytotoxic chemotherapy for SCCHN.