Phase I trial of 10-deaza-aminopterin in patients with advanced cancer.

The clinical effects of 10-deaza-aminopterin, an inhibitor of dihydrofolate reductase with a better therapeutic index against several murine tumors than that of methotrexate, were examined during the course of a phase I study in patients with advanced malignant neoplasms. Three escalating dose schedules were explored: single iv injections once daily, single iv injections twice weekly, and continuous infusion. The maximum tolerated doses were: single injections at a dose of 7 mg/m2/day for 5 days; single injections at a dose of 15 mg/m2 twice weekly for four to six doses; and continuous infusion at a dose of 3 mg/m2/day for 5-6 days in patients with solid tumors and until bone marrow hypoplasia in patients with leukemia. Mucositis was dose-limiting in all schedules. Occasionally, mild leukopenia, thrombocytopenia, and skin rash were noted. A minor antitumor response was seen in a patient with gallbladder carcinoma. Marked leukemic cell kill was observed in several patients with acute leukemia or blastic phase of chronic myelogenous leukemia. Disease-oriented phase II trials are planned at this Center for several tumor varieties.