Phase-I study of alpha-1,3,5-triglycidyl-s-triazinetrione (NSC 296934)

alpha-1,3,5-Triglycidyl-s-triazinetrione (TGT) is a triepoxide derivative with alkylating properties discovered by random screening. TGT has been found to be active against a wide variety of murine tumors, including a P388 subline resistant to cyclophosphamide. The starting dose in this phase-I study was 30 mg/m2 as a single dose IV, repeated every 3-4 weeks, increasing up to 2,700 mg/m2. Severe dose-limiting toxicity took the form of phlebitis becoming apparent a few days after treatment. This was initially seen at the 480 mg/m2 dose level, and was observed with increasing frequency and intensity at higher dose levels. Leukopenia occurred regularly at dose levels above 1,800 mg/m2 and resulted in life-threatening leukopenia in one patient, and in a toxic death at 2,700 mg/m2 in another patient. Other toxic side-effects included moderate reversible thrombocytopenia, nausea, and vomiting. It is recommended that further trials with TGT await the development of more water-soluble formulations or of other triepoxide derivatives.