FDA approves once-daily BPH treatment

Watson Pharmaceuticals has received FDA approval to market silodosin (Rapaflo), an alpha-blocker for the treatment of BPH signs and symptoms.

Approval was based on data from two 12-week, randomized, double-blind, placebo-controlled, multicenter phase III studies and a 40-week open-label study. In the two phase III studies, 923 patients (mean age, 64.6 years) were randomized to receive either silodosin, 8 mg once daily, or placebo.

In the trials, men in the silodosin cohort reported significant, rapid relief of BPH symptoms compared with the placebo group, as measured by International Prostate Symptom Score. Silodosin also has been shown to significantly improve Qmax scores as early as 2 hours following first dose and after 12 weeks of treatment.

The therapy demonstrated minimal effects on the cardiovascular system, and clinical studies have shown that it does not cause meaningful prolongation of the QT interval. The most common drug-related side effect was retrograde ejaculation, which resolved after discontinuation of therapy.

Silodosin is expected to be available early in 2009.