Long‐term sustained improvement in symptoms of benign prostatic hyperplasia with the dual 5α‐reductase inhibitor dutasteride: results of 4‐year studies

Abstract

OBJECTIVE To report additional analyses of efficacy over the initial 2 years and during a 2‐year open‐label extension of the three pivotal phase 3 studies in which dutasteride, a dual inhibitor of type 1 and 2 5α‐reductase, was shown to be effective and well tolerated. PATIENTS AND METHODS All patients in the placebo and active groups were eligible for entry into the 2‐year open‐label extension, with all receiving dutasteride 0.5 mg daily. Mean changes from baseline were calculated for the American Urologic Association Symptom Index (AUA‐SI) score at each scheduled time in the double‐blind and open‐label phase. The additional analyses included a breakdown of the AUA‐SI score, including stratifying patients by symptom severity, assessment by baseline age and prostate volume, and the evaluation of symptoms responders. RESULTS There was a clinically meaningful improvement in AUA‐SI in patients on dutasteride in the double‐blind phase, but not in those on placebo. At 48 months, patients on dutasteride in both study phases had greater improvements in AUA‐SI score and individual question scores than those on dutasteride in the open‐label phase only. The proportion of patients with severe symptoms declined in both study groups, although these changes were more profound in those receiving dutasteride for the 4‐year duration of the study. CONCLUSION In men with symptomatic benign prostatic hyperplasia, long‐term (4‐year) treatment with the dual isozyme 5α‐reductase inhibitor dutasteride resulted in sustained and continued improvements in symptoms and flow rate. For 4 vs 2 years, longer dutasteride therapy resulted in greater symptom improvement.