Randomized phase 2 trial of ketoconazole and ketoconazole/doxorubicin in androgen independent prostate cancer

Eighty-nine patients with progressive prostate cancer despite suppression of testosterone and withdrawal of anti-androgens were studied. This was a relatively advanced population, with 63 of 89 having either osseous metastases (mets) beyond the axial skeleton or visceral mets. Patients were randomly assigned to receive either ketoconazole alone, or ketoconazole with weekly doxorubicin. All patients received replacement hydrocortisone. The primary endpoints were response and survival. Based on PSA reduction criteria (≥ 80% maintained for at least 8 weeks), 14 of 45 patients (31%) in the single-agent ketoconazole arm responded. Sixteen of 44 patients (36%) in the combination ketoconazole/doxorubicin arm responded. There were no important differences between the two treatments in any outcome measure. The median overall survival for all patients was 12.5 months; median time to progression was 3.3 months. Toxicity was significant with both regimens, and more severe in the doxorubicin arm. Fully 20% of patients in each arm discontinued therapy due to intolerable side effects.Each of these regimens is toxic, and produced responses in fewer than half of treated patients. Although the observed median survival does compare favorably with reports from similar cohorts treated in the community, the potential benefit is only modest. In our view, neither of these regimens is sufficiently promising to justify phase 3 evaluation.