Feasibility trial for daily oral administration of the hypoxic sensitizer AK-2123 (Sanazole) in radiotherapy

To examine the feasibility of daily oral administration of the hypoxic tumor radiation sensitizer, sanazole (AK-2123). We analyzed the toxicity associated with 44 treatments of 42 patients, who received daily oral administration of 1 g/day sanazole (level A, 1-9g, 12 treatments; Level B, 10 g, 33 treatments) 2 h before radiotherapy. Eligibility criteria were as follows: Patients who were unable to receive standard treatment because of older age and/or fragile status and/or refractory disease. Five patients with advanced tumors treated with pre- or postoperative adjuvant radiotherapy were also included. Toxicity was assessed during 44 treatment sessions. Eight patients (18%) showed sanazole-related paresthesia in the extremities, similar to the rate (15%) reported in a preceding multi-institutional international phase III study, which used intravenous administration. No sanazole-related toxicity rated grade 3 or higher was observed. Forty out of the 44 treatment sessions (91%) were completed. This study validates the feasibility of daily oral administration of sanazole. Further studies to establish suitable applications are warranted.