Clinical trials with etanidazole (SR-2508) by the Radiation Therapy Oncology Group (RTOG)

Following the completion of a phase I study of etanidazole (SR 2508), a new hypoxic cell sensitizer, the RTOG, began a phase II/III trial. The objectives of the study were to determine the toxicity and efficacy of SR 2508, combined with conventional radiotherapy for the management of unresectable stage III and IV head and neck squamous carcinomas. During the first step (or the Phase II portion) of the study, 33 patients received radiotherapy plus SR 2508 (RT + SR 2508). The incidence of drug toxicities was modest; including 24% grade I peripheral neuropathy (PN), 6% grade II PN, 27% grade I or II nausea and vomiting, 9% allergy and 15% reversible neutropenia. Because observed toxicities were deemed acceptable, the second step (or phase III portion) was then activated. Patients were randomized to receive either RT or RT + SR 2508. As of November 20, 1989, a total of 242 patients have been entered onto the Phase III portion of the study. One hundred twenty-two patients were randomized to the RT + SR 2508 arm and 120 patients were randomized to the RT alone arm. The analyses presented in this report are based on data available. The incidence of drug toxicities has been low, with 18% grade I or II PN, 26% nausea and vomiting (including one grade III), 14% allergy (including one grade III) and 13% reversible neutropenia.(ABSTRACT TRUNCATED AT 250 WORDS)