Phase II clinical trial of DDMP (2,4-diamino-5-(3',4'-dichlorophenyl)-6-methylpyrimidine) and folinic acid (CF) in solid tumors.

DDMP, a 2-4 diaminopyrimidine folate antagonist was administered PO once every 3 weeks at a fixed dose level (90 mg/m2), 24 h before a single IM injection of folinic acid (CF), to 77 patients with advanced solid tumors. CF doses were escalated in sequential sets of patients from 9-108 mg/m2. Therapeutic activity was documented against epidermoid tumors of head and neck and lung only at the lower CF doses (9 and 15 mg/m2). Increasing CF resulted in the absence of hematologic toxicity and therapeutic activity. There was no evidence of selective bone marrow protection in this clinical study.