Objectives: To compare the pharmacodynamics and tolerability of the new goserelin acetate 10.8-mg depot with the 3.6-mg depot in patients with advanced prostate cancer during the first 3 months of therapy.
Methods: One hundred sixty patients were randomized in two comparative studies to receive either the 10.8-mg goserelin acetate depot every 12 weeks or the 3.6-mg goserelin acetate depot every 4 weeks for 12 weeks and then the 10.8-mg depot every 12 weeks thereafter. Data for pharmacodynamic assessments were collected prospectively, whereas clinical response data were collected retrospectively.
Results: Serum testosterone profiles of the 10.8-mg goserelin acetate depot and the 3.6-mg goserelin acetate depot were similar; testosterone levels in both groups fell below castrate levels by day 21 after administration. Decreases in serum prostate-specific antigen level after 3 months of therapy were also similar in both groups: 94% with the 10.8-mg depot and 92.5% with the 3.6-mg depot. For all patients, the median time to progression was 152.7 weeks and the median time to death was 213.6 weeks. The safety profile of the 10.8-mg goserelin acetate depot was similar to that of the 3.6-mg depot; hot flashes was the most common adverse event. The incidence of injection site reactions was very low (2 [0.3%] of 614 administrations).
Conclusions: The new 10.8-mg depot was pharmacodynamically equivalent to the current 3.6-mg depot and was well tolerated, both locally and systemically. The observed times to progression and survival were as expected in this patient population. The 10.8-mg goserelin-acetate depot provided a dosing schedule that was convenient for the patient and the physician, and it has the potential to reduce health care costs while maintaining the quality of life in patients being treated for advanced prostate cancer.