Phase I/II Study of S-1 plus Cisplatin Combination Chemotherapy in Patients with Advanced/Recurrent Head and Neck Cancer

Objective: The objectives of this study were to determine the maximum tolerated dose (MTD) and recommended dose (RD) of S-1 plus cisplatin (CDDP) and to evaluate safety and efficacy using the defined RD in advanced/recurrent head and neck cancer (HNC). Methods: S-1 was administered orally at 40 mg/m 2 twice daily for 14 consecutive days, and CDDP was infused on day 8 at a dose of 60 and 70 mg/m 2 . Each course was repeated every 4 weeks. Results: A total of 38 patients were registered, 10 patients for the Phase I study and an additional 28 patients for the Phase II study. Although no dose-limiting toxicity (DLT) was observed in the CDDP 60 mg/m 2 (Level 1) group, two of six patients in the CDDP 70 mg/m 2 (Level 2) group exhibited DLT (fatigue/diarrhea). The MTD was not achieved in the Phase I study. Level 2 was therefore determined as the RD. In the Phase II study, 34 patients, including 6 patients from the Phase I study, were evaluated. At the termination of treatment, the confirmed response rate was 44.1% (15/34, 95% CI: 27.4‐60.8). The best response rate without an adequate duration time was 67.6% (95% CI: 51.9‐83.4). The median survival period was 16.7 months, and the 1-year survival rate was 60.1%. The main toxicities of Grade 3 or above were anorexia (26.5%), nausea (14.7%), neutropenia/thrombocytopenia (11.8%) and anemia/fatigue (8.8%). Conclusions: This is considered to be an effective regimen with acceptable toxicities for HNC.