Randomized open labelled comparative study of the efficacy, safety and tolerability of leuprorelin acetate 1M and 3M depot in patients with advanced prostatic cancer.

ABSTRACT

OBJECTIVES: In a European, prospective, 12 randomized phase II multicentre study, 237 patients with advanced or metastatic prostate cancer were treated with either the 1M- (80 patients) or 3M-depot formulation (157 patients) of leuprorelin acetate for 9 months to compare efficacy and safety. METHODS: Standard clinical investigations and methods were employed in the study. Leuprorelin levels were determined using a specially modified RIA. RESULTS: The two formulations produced virtually identical effects with a pronounced fall in testosterone and gonadotropin serum levels and a marked reduction in PSA levels. After 9 months' treatment, PSA was normalized (< or = 4 ng/ml) in 65.2 and 66.1% of the 1M and 3M depot patients, respectively. The best response to 1M vs. 3M depot during the study was as follows complete remission in 5 vs. 5.7%, partial remission in 36.3 vs. 33.8% and stabilization in 40.0 vs. 40.8%. The main side effects of both formulations were related to androgen deprivation. CONCLUSIONS: Comparable results were recorded for the two formulations of leuprorelin acetate in terms of clinical response, endocrine effects and tolerability. The newly developed leuprorelin acetate 3M depot, as a refinement of the established 1M depot, offers an opportunity to improve patient compliance and provides individualized and optimized, patient-orientated treatment by reducing the number of injections to four per year.