Combination of GnRH Antagonist Degarelix and Antiandrogen Is Effective in PSA Reduction and Bone Management in Patients with Prostate Cancer.

OBJECTIVES: To investigate the efficacy of combination treatment of degarelix and antiandrogen in patients with prostate cancer. METHODS: We prospectively investigated the efficacy of combination treatment of degarelix and antiandrogen in 12 patients with treatment-naive prostate cancer. We surveyed PSA, LH, FSH and testosterone at day 3, 7, 14 and 28 during the initial month and thereafter once a month for 1 year. In cases with bone metastasis, we analyzed serum bone markers such as alkaline phosphatase(ALP), bone-type ALP and carboxyterminal telopeptide of type- I collagen once a month. Skeletal related events (SREs) were also monitored. RESULTS: PSA progression free survival was 65%. PSA was reduced from baseline by 80% at day 14 and by 93% at day 28. In all patients serum testosterone immediately reached castrate level at day 3 and was maintained for 1 year without breakthrough escape. Both LH and FSH were reduced to within normal range at day 3. In contrast, all bone markers temporarily increased at day 28, and thereafter decreased. Although 2 patients had suffered from SREs before treatment, there were no SREs after combination treatment. CONCLUSIONS: The present study showed that combination of degarelix and antiandrogen could lead to favorable PSA reduction and immediate castrate level at an earlier phase. However, further study is needed to compare the difference between degarelix monotherapy and these combinations.