Phase II trial of the association of a methionine-free diet with cystemustine therapy in melanoma and glioma.

In a previous phase I clinical trial of dietary methionine (MET) restriction with cystemustine treatment for melanoma or glioma, we determined the optimal MET-free diet duration to be 1 day. On this basis, a phase II clinical trial was initiated to evaluate safety and efficacy of this combination. Twenty-two patients (20 with metastatic melanoma and 2 with recurrent gloma) received a median of 4 cycles of the association of a 1-day MET-free diet with cystemustine (60 mg/m(2)) every two weeks. This association was well tolerated (toxicity and nutritional status). Toxicity remained mainly hematological and consisted of WHO grade 3-4 thrombocytopenia, leucopenia and neutropenia in 36, 27 and 27% of patients respectively. The median disease-free survival was 1.8 months and the median survival was 4.6 months, with 2 long-duration stabilizations. The plasmatic MET depletion obtained was of 40 + or - 31%.