Treatment of leiomyomata uteri with leuprolide acetate depot: a double-blind, placebo-controlled, multicenter study. The Leuprolide Study Group.

The purpose of this study was to evaluate efficacy and safety parameters in women with leiomyomata uteri treated with the GnRH agonist leuprolide acetate depot, 3.75 mg intramuscularly every 4 weeks for 24 weeks. One hundred twenty-eight patients were enrolled in a randomized, double-blind, placebo-controlled multicenter study involving 13 investigative centers. Mean uterine volume decreased by 36% at 12 weeks and 45% at 24 weeks of leuprolide therapy. Patients treated with placebo had increased in mean uterine volume of 16% at 12 weeks and 5% at 24 weeks. Seventy-seven percent of leuprolide-treated patients had a more than 25% reduction in uterine volume, compared with 9% of placebo-treated controls. Mean uterine volume returned to pre-treatment size 24 weeks after cessation of leuprolide treatment. The majority of patients had resolution or improvement of their fibroid-related symptoms after 24 weeks of leuprolide treatment. Of 38 leuprolide-treated patients presenting with menorrhagia, 37 (97%) had resolution of this symptom at the time of the final visit. Although 95% of women treated with leuprolide acetate experienced some side effects related to hypoestrogenism, only five patients (8%) terminated treatment prematurely. We conclude that leuprolide acetate depot treatment of leiomyomata uteri is safe and causes significant but temporary reductions in uterine size and fibroid-related symptoms.