- Uniquely Selective Agent Offers Significant Improvement -
CHICAGO, April 28 /PRNewswire-FirstCall/ -- Data to be presented at the American Urological Association's (AUA) Annual Conference show that RAPAFLO(TM) (silodosin) produces rapid and sustained improvements of both irritative and obstructive urinary symptoms associated with BPH, with statistically significant symptom relief within three to four days of starting treatment. RAPAFLO(TM) is a new, uniquely selective alpha blocker for the treatment of the signs and symptoms of BPH, launched earlier this month by Watson Pharmaceuticals, a leader in generic and specialty branded pharmaceuticals.
A separate abstract, also presented at the conference, found that men taking RAPAFLO(TM) who experienced a treatment related effect called retrograde ejaculation (orgasm with reduced semen) trended to greater improvement in symptom relief and peak flow. This observation suggests that RAPAFLO(TM) relaxes smooth muscles of the lower urinary tract significantly enough to relieve symptoms as well as to induce this effect in some patients. Retrograde ejaculation does not pose a safety concern and is reversible upon discontinuation of treatment. In RAPAFLO(TM) clinical trials, rates of discontinuation due to retrograde ejaculation were low.
"Our observation suggests that retrograde ejaculation is actually an indirect indicator of the relaxation of the smooth musculature that RAPAFLO(TM) induces," said Dr. Steve A. Kaplan, M.D., tenured professor of urology at Weil Cornell Medical College,
BPH is the number one reason patients visit urologists and is characterized by urination problems, including decreased urine flow, more frequent urination and nocturia.
AUA Data Results
The first abstract was a post-hoc analysis of two randomized, placebo-controlled, double-blind clinical trials involving 923 men ages 50 or older with signs and symptoms of BPH, including a peak urine flow rate (Qmax) between 4 and 15 mL/sec (mean of 8.7 to 8.9) and International Prostate Symptom Score (IPSS) greater than or equal to 13 (mean of 21.3). Patients were randomized to either 8 mg RAPAFLO(TM) once daily (n=466) or placebo (n=457) for 12 weeks. In this analysis, researchers assessed changes in IPSS subscales by evaluating seven questions related to irritative symptoms (frequency, urgency and nocturia) and obstructive symptoms (incomplete emptying, intermittency, weak stream and straining). Mean baseline scores for all seven measures were very similar between the two groups.
At the last observation, patients treated with RAPAFLO(TM) versus placebo experienced significantly greater changes in all IPSS subscales from baseline measures. The differences in all symptoms except nocturia were statistically significantly better for RAPAFLO(TM) versus placebo within three to four days (p<0.001). Improvements in nocturia were more significant with RAPAFLO(TM) versus placebo at week one (p=0.0091). Statistically significant differences were maintained throughout the remainder of the 12 weeks (p<0.0001; p=0.0037 for nocturia).
The second abstract -- another post-hoc analysis of the two RAPAFLO(TM) clinical trials -- examined whether retrograde ejaculation might be associated with treatment efficacy. Among the 466 men treated with RAPAFLO(TM) in the two trials, a total of 131 men (28.1 percent) experienced retrograde ejaculation. Overall, baseline IPSS and Qmax scores were comparable in both groups.
Patients who experienced retrograde ejaculation and those who did not both showed significant improvement (p<.02) compared with patients receiving placebo in IPSS and Qmax after 12 weeks of treatment. Mean improvement in IPSS was greater in men experiencing this side effect than men who did not (-7.2 versus -6.1, p=0.3856) and for Qmax (3.1 mL versus 2.4 mL, p=0.0699).
RAPAFLO(TM) is an effective, uniquely selective alpha-1 adrenergic receptor antagonist. RAPAFLO(TM) maximizes target organ activity by binding with high affinity to the alpha (1A) receptors concentrated in the prostate. The antagonism of these receptors cause the smooth muscles in these tissues to relax and results in improved urine flow and a reduction in BPH symptoms. The binding affinity for the alpha (1B) receptors that cause smooth muscle in peripheral vessels is significantly lower, which may minimize orthostatic hypotension.
The most common drug-related side effect was retrograde ejaculation. The second most commonly-reported adverse event was dizziness. The incidence of treatment-related dizziness was low and only slightly higher among RAPAFLO(TM) than placebo-treated patients (11 vs. 3 patients).
Previously presented data included information that in clinical trials RAPAFLO(TM) was administered with a single dose of medications for erectile dysfunction in healthy male subjects (N=24) and that there were no reported events of symptomatic orthostatis or dizziness. RAPAFLO(TM) demonstrated no meaningful electro cardiac effects during Phase 3 trials and during thorough QTc testing as required for new chemical entities by the FDA.
RAPAFLO(TM) was originally developed by Kissei Pharmaceutical Co., Ltd. in Japan, where RAPAFLO(TM) is the BPH market leader, and licensed to Watson for the U.S., Canada and Mexico markets.
About Watson Pharmaceuticals, Inc.
Watson Pharmaceuticals, Inc. (NYSE: WPI) is a global leader in the development and distribution of pharmaceuticals with a broad portfolio of generic products and a specialized portfolio of branded pharmaceuticals focused on Urology, Gynecology and Nephrology (Medical).
In the U.S., the Watson portfolio includes RAPAFLO, GELNIQUE, TRELSTAR(R) LA; TRELSTAR(R) Depot; Ferrlecit(R), INFeD(R) and Oxytrol(R). In addition, Watson markets the following brands under co-promotion agreements: AndroGel(R), with Solvay Pharmaceuticals, Inc., and Femring(R), with Warner Chilcott Limited. The Watson pipeline portfolio includes a number of products, including a six-month formulation of TRELSTAR(R), for the treatment of advanced prostate cancer which is currently under review by the FDA; URACYST(R), under development for cystitis; and a novel new oral contraceptive.
For press releases and other company information, visit the Watson website at http://www.watson.com.
Any statements contained in this press release that refer to future events or other non-historical facts are forward-looking statements that reflect Watson's current perspective of existing trends and information as of the date of this release. Except as expressly required by law, Watson disclaims any intent or obligation to update these forward-looking statements. Actual results may differ materially from Watson's current expectations depending upon a number of factors affecting Watson's business. These factors include, among others, the impact of competitive products and pricing; market acceptance of and continued demand for Watson's products, including RAPAFLO; difficulties or delays in manufacturing; patents and other intellectual property rights held by the Company and the ability to successfully enforce such rights against third parties; and other risks and uncertainties detailed in Watson's periodic public filings with the Securities and Exchange Commission, including but not limited to Watson's Annual Report on Form 10-K for the year ended December 31, 2008.
|SOURCE Watson Pharmaceuticals, Inc.|
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