Phase 2 study of dasatinib in the treatment of head and neck squamous cell carcinoma.

Background: Treatment options for patients with advanced head and neck squamous cell carcinoma (HNSCC) are scarce. This phase 2 study was conducted to evaluate the safety, tolerability, pharmacokinetics, and efficacy of dasatinib in this setting.

Methods: Patients with recurrent and/or metastatic HNSCC after platinum-based therapy were treated with dasatinib either orally or via percutaneous feeding gastrostomy (PFG). Primary endpoints were 12-week progression-free survival (PFS) and objective response rate with a 2-stage design and early withdrawal if the 12-week PFS rate was ≤20% and no patients had an objective response (OR). Forty-nine serum cytokines and angiogenic factors (CAFs) were analyzed from treated patients.

Results: Of the 15 patients enrolled, 12 were evaluable for response, and all patients were evaluable for toxicity. No OR was observed and 2 patients (16.7%) had stable disease (SD) at 8 weeks. The median treatment duration was 59 days, the median time to disease progression was 3.9 weeks, and the median survival was 26 weeks. One patient required a dose reduction, 3 patients required dose interruptions, and 4 patients were hospitalized for toxicity. Dasatinib inhibited c-Src both when administered orally and via PFG. Greater mean drug exposure, decreased half-life, and greater maximum concentration were observed in patients receiving dasatinib via PFG. Eleven baseline CAFs were associated with treatment outcome and 1 CAF, macrophage migration inhibitory factor, was found to be differentially modulated in correlation with SD versus disease progression.

Conclusions: Single-agent dasatinib failed to demonstrate significant activity in patients with advanced HNSCC, despite c-Src inhibition. The toxicity profile was consistent with that reported in other solid tumors, and the drug can be given via PFG tube.