Mitozolomide (NSC 353451), a new active drug in the treatment of malignant melanoma. Phase II trial in patients with advanced disease.

A phase II trial with mitozolomide was carried out in patients with malignant melanoma, since in preclinical studies this new imidazotetrazine had shown promising effects against human melanoma xenografts. Twenty-one evaluable patients with advanced malignant melanoma were treated with 115 mg m-2 of mitozolomide, given orally every 6 weeks. None of the patients had received prior chemotherapy. Two partial responses (10 and 7+ months) were observed. The responding patients had lung metastases, and one of them had, in addition, a huge (17 X 14 cm) lymph node metastasis in the groin. Also, one patient had a 48% tumour volume reduction of lung metastases. The dose limiting side effect of the treatment was bone marrow depression, with delayed leukopenia and thrombocytopenia. The median white blood cell counts and platelet nadirs were 2.5 X 10(9) 1(-1) (range 1.1-3.8) and 59 X 10(9) 1(-1) (range 14-95), respectively. Non-haematological adverse reactions were limited to mild or moderate nausea. It is concluded that orally administered mitozolomide is active against malignant melanoma and seems to have a response rate comparable to those of the most active established drugs.