An open label, multi-center Phase 2 study in which the pharmacokinetics, safety, tolerability and efficacy of TH-4000 will be assessed in participants with recurrent or metastatic squamous cell carcinoma of the head and neck or skin.~Hypoxia PET scans will be obtained in select centers to analyze potential predictors of tumor response.
This phase 2 study is designed to evaluate the safety and activity of TH-4000, a hypoxia-activated prodrug in participants with recurrent or metastatic squamous cell carcinoma of the head and neck or skin.