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

OBJECTIVES

In a European, prospective, 1:2 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.