Trimetrexate in advanced hormone-refractory prostate cancer

Summary The antitumor activity and toxicity of trimetrexate (TMTX) was evaluated in measurable, hormone-refractory, advanced prostate cancer patients. Patients were required to have an ECOG performance status < 3, bidimensionally measurable disease, serum creatinine 1.5 mg/dL, normal bone marrow function, and adequate hepatic function. Prior non-hormonal systemic therapy, active infection, third space effusions were exclusion criteria. TMTX 12 mg/m² daily for five days (8 mg/m² for patients with any prior radiation therapy or age 75 years) was administered every 3 weeks. There were no responses in the 18 eligible patients. Median time to treatment failure and median survival were 6 and 20 weeks, respectively. Myelosuppression was the most frequent toxicity observed and was mild to severe in all but 4 patients. Two patients whom experienced life-threatening reversible leukopenia and grade 4 thrombocytopenia developed in 2 further patients. Non-hematologic toxicity was also reversible and was mild to severe. TMTX at this dose and schedule is inactive in advanced, hormone-refractory prostate cancer.