Hexamethylmelamine: an evaluation of its role in the treatment of ovarian cancer.

Hexamethylmelamine (HMM), NSC 13875, a synthetic agent structurally related to triethylenemelamine, has clinical antitumor activity and a role in the treatment of ovarian cancers of epithelial origin. Fifty-four patients, with International Federation of Gynecology and Obstetrics Stage III or IV carcinomas, previously untreated with chemotherapy or irradiation therapy, were treated with HMM (8 mg/kg/day) as a single agent at the M. D. Anderson Hospital and Tumor Institute in Houston, Texas, between January, 1973, and May, 1976. The response end points analyzed were complete plus partial response rate, duration of remission, and survival time. The complete and partial responses were verified whenever possible by "second-look" operation. Seventeen patients (31.8%) responded to HMM and three had no evidence of cancer, determined by multiple biopsies at second-look operation. Gastrointestinal, hematologic, and nervous system toxic effects were severe in 10 patients, requiring discontinuation of HMM. This study shows that HMM can induce a complete response and provide an extended disease-free interval without maintenance chemotherapy.