Gemcitabine plus mitoxantrone and prednisone in the palliative treatment of hormone-resistant prostate cancer (HRPC): A phase II study (GOAM 01.01 study).

Background: The present exploratory phase II study was performed to evaluate the activity and tolerability of adding a second agent (gemcitabine) to the well-tolerated mitoxantrone/prednisone regimen in patients with locally advanced or metastatic prostate cancer no longer responsive to hormonal treatment. Patients and Methods: Forty-three patients with hormone-refractory prostate cancer (HRPC) were included in the study from May 2000 to April 2004. Their median age was 71 years (range, 56-81) and their median Karnofsky performance status (KPS) was 90 (range, 70-100). The treatment schedule consisted of intravenous (i.v.) mitoxantrone (8 mg/m 2 on day 1), i.v. gemcitabine 800 mg/m 2 on days 1 and 8, recycled every 21 days and oral prednisone administered at a dose of 10 mg per day. Hormonal treatment with LHRH was continued in all patients. Up to six cycles of treatment were planned in the absence of progressive disease. Results: Sixteen patients had measurable disease (six patients only measurable disease, ten patients bone disease plus measurable disease) and 27 patients had only bone disease. Concerning the PSA levels, a partial response (PR) was observed in 15 patients (38%), stable disease (SD) in 16 patients (41%) and progressive disease (PD) in eight patients (21%). The objective response was evaluable in 16 patients; one patient was not evaluable because he had received only one cycle. Ten patients (63%) had SD and five patients (31%) PD. In the ten evaluable patients with objective SD, depending upon the PSA response, three PR, six SD and one PD were observed. Among the five patients who progressed, three PD and two SD were observed as a PSA response. Pain remission was recorded in 15/41 patients (36%) and the KPS remained stable in most patients. The median overall survival was 15 months (range, 1-41) (95% CI: 10-20 months). The 1-year survival rate was 61%. Hematological toxicity was mild: G 3-4 neutropenia was observed in five (12%) patients. There were no neutropenic fevers. No significant non-hematological toxicity was observed. Conclusion: The mitoxantrone, gemcitabine and prednisone combination, in accordance with the present regimen, was feasible, had a palliative effect, good tolerance and antitumor activity. Nonetheless, our results do not seem to be superior to those previously described for mitoxantrone plus prednisone. Prostate cancer is a significant health problem throughout the world and is the most common male malignancy and the most frequent cause of male cancer mortality, second to lung cancer (1). The American Cancer Society estimates that, during 2005, approximately 232,090 new cases of prostate cancer will be diagnosed in the United States and 30,350 men will die of metastatic disease (2). In Europe, the incidence rate is 55 cases per 100,000 and the mortality rate 22.6 per 100,000. About 10-20% of men with prostate cancer present metastatic disease and, in many others, metastases develop despite treatment with surgery