Phase I--II study of N4-behenoyl-1-beta-D-arabinofuranosylcytosine.

A phase I-II study of N4-behenoyl-1-beta-D-arabinofuranosyl-cytosine (BH-AC) was conducted by a cooperative study group. In phase I study, a total of 126 patients, 64 of whom had metastatic solid tumors and 62 of whom had leukemia, were administered BH-AC in a single IV dose at day 1 only or in daily IV doses for 3 to 21 days, with dose ranges of 1.5--10.0 mg/kg. Side effects included nausea and vomiting, which were significantly less in incidence and severity than those observed with ara-C. Myelosuppressive toxicity became severe with doses 3.6--5.0 mg/kg per day x 10 days. In phase II study, a total of 37 adult patients with acute leukemia were entered in the study. Responses were noted, with an overall rate of 35% complete remission. Of th 26 patients with AML, there were 13 CR. The recommended schedule of treatment for BH-AC, based on our data, is daily infusion of 4--5 mg/kg over 3 h for approximately 3 weeks. The results with BH-AC in patients with acute leukemia are superior to those which have been reported for ara-C.