Trial to Determine Optimal Phase II Dose of the Oral Dual CAIX Inhibitor/ Radiosensitizer

This is a Phase I multicenter, open-label, dose-escalation study of DTP348. DTP 348 is an oral dual drug with two mechanisms of action: 1. carbonic anhydrase IX inhibitor which acidifies the intracellular pH through the sulfamide components 2. radio sensitizer of hypoxic cells through its 5-nitroimidazole moiety The study will be conducted in 2 parts. The phase I trials will be on the standard 3+3 design first as single agent then combined with radiotherapy: 1. A single agent dose-escalation phase in patients with solid tumours. 2. A dose-escalation phase in patients with HNSCC in combination with radiotherapy The main objective is to determine the recommended phase II dose of DTP348 in combination with radiotherapy