Phase II trial of alternating weekly chemohormonal therapy for patients with androgen-independent prostate cancer.

ABSTRACT

Two distinct regimens of weekly chemotherapy for hormone-refractory prostate cancer were combined in an alternating schedule and tested in a Phase II trial to determine efficacy and toxic effects. Forty-six patients with hormone-refractory prostate cancer and rising prostate-specific antigen (PSA) levels entered the trial. Therapy consisted of doxorubicin (20 mg/m2/week) plus oral ketoconazole (400 mg three times a day) given at weeks 1, 3, and 5 and vinblastine (5 mg/m2/week) plus oral estramustine (140 mg three times a day) given at weeks 2, 4, and 6. No therapy was given at weeks 7 and 8. Replacement doses of hydrocortisone were administered throughout treatment to counteract potential adrenal insufficiency secondary to the ketoconazole. In 67% of patients (31 of 46), the PSA declined by 50% or greater for a minimum duration of 8 weeks (95% confidence interval, 52-80%). Among the 16 patients with measurable soft tissue disease, there were 12 responses (75%; 95% confidence interval, 47-92%). The median duration of response was 8. 4 months (1.8-14.9). The median survival for the entire group was 19 months. The median survival of PSA responders has not been reached, whereas that of nonresponders was 13 months (P = 0.010). Seventy-six percent of symptomatic patients noted improvement. Hematological toxicity was modest and was managed without growth factors. Peripheral edema (49%) and deep venous thrombosis (18%) were the most common nonhematological toxicities. The alternating weekly regimen of chemohormonal therapy is active for hormone-refractory prostate cancer, providing a high rate of symptom control, soft tissue response, and PSA decline.