Phase II trial of cystemustine, a new nitrosourea, as treatment of high-grade brain tumors in adults.

This study included 39 patients (37 evaluable, of whom 30 patients with recurrent gliomas and 7 patients with gliomas untreated by radiotherapy); they were enrolled into a phase II trial using a new nitrosourea, cystemustine, administrated every 2 weeks at 60 mg/m2 as a 15 min-infusion. Pathology at inclusion was (WHO classification): 14 glioblastomas, 20 grade 3-4 astrocytomas and 3 grade 3 oligodendrogliomas. Four partial responses have been obtained, giving an overall response rate of 10.8%. Four additional patients had a partial response, which for various reasons was not confirmed 4 weeks later; 12 patients had a stable disease for at least 8 weeks, 15 patients had progressive disease. Of the 4 responses, 2 were with a grade 3 oligodendroglioma and 2 glioblastoma. Toxicity (WHO grading) was mainly hematological: leukopenia (16.2% grade 3-4), neutropenia (29.7% grade 3-4), thrombopenia (27% grade 3-4). No other toxicity greater than grade 2 was observed. In conclusion, cystemustine at 60 mg/m2 has moderate clinical activity in relapsing glioma. Our results warrant further investigation of this agent with an increased dose or modified scheme.