Watson Announces Silodosin NDA Accepted for Filing by FDA for the Treatment of Benign Prostatic Hyperplasia
CORONA, Calif., Feb. 12 -- Watson Pharmaceuticals, Inc. (NYSE: WPI), a leading specialty pharmaceutical company, today announced that its New Drug Application (NDA) for silodosin, a novel alpha(1)- adrenoreceptor antagonist, has been accepted for filing by the U.S. Food and Drug Administration (FDA). Watson is seeking marketing approval of silodosin from the FDA for the treatment of the signs and symptoms associated with benign prostatic hyperplasia (BPH), or enlarged prostate. Watson anticipates that the FDA will take action on its application in the fourth quarter 2008.
Silodosin was designed to decrease urinary resistance and improve dysuria (difficulty or pain in urination) associated with BPH. In clinical trials, silodosin demonstrated a very low level of the most highly-reported cardiovascular and blood pressure-related side effects associated with existing BPH treatments, including dizziness and first-dose syncope (fainting).
"This filing highlights Watson's capabilities in new drug development and our commitment to this product, providing solutions to the millions of men with BPH symptoms," said Paul Bisaro, Watson's President and Chief Executive Officer. "Watson is expanding the portfolio it offers to urologists and their patients, focusing on symptom management that makes a big difference in their day-to-day lives."
Watson submitted the filing for silodosin with data from two Phase 3 multi-center (88 sites), randomized, double-blind, placebo-controlled trials that evaluated a total of 923 patients with signs and symptoms of BPH for 12 weeks. The trials demonstrated that a once daily 8mg dose of silodosin given for 12 weeks provided significant relief of BPH symptoms, compared with placebo, as measured by the International Prostate Symptom Score (IPSS), the primary endpoint. Secondary endpoints included improvements of maximum urine flow and quality of life. As expected, the most common side effects seen in the two studies greater than 2% were retrograde ejaculation (reduced semen) and dizziness.
Silodosin is highly uroselective for the alpha (1A) receptors located in the prostate and bladder neck. Blocking these receptors relaxes the smooth muscles, resulting in an improvement in urine flow and a reduction in BPH symptoms. The selective binding of silodosin to the alpha (1A) receptors is substantially greater than the binding to the cardiovascular-associated alpha (1B) receptors and thereby maximizes target organ activity while minimizing the potential for blood pressure effects.
The compound was originally developed by Kissei Pharmaceutical Co., Ltd., in Japan and licensed to Watson for the United States, Canada and Mexico. Kissei successfully launched Urief(R) (silodosin) in Japan in May of 2006 at a twice daily dosing of 4mg. Urief(R) is marketed in cooperation with Daiichi Sankyo Pharmaceutical Co., Ltd.
BPH, or an enlarged prostate, is a condition found only in men and is characterized by a non-cancerous enlargement of the prostate gland. Symptoms of BPH include urinary difficulty, urinary frequency and an inability to complete bladder emptying. The number of BPH patients has been increasing with the expansion of the elderly population. In the United States, BPH affects more than half of men in their 60's and as many as 90 percent of men by the age of 85. According to IMS data, BPH symptoms were the primary reason patients visited their urologists in 2006.
About Watson Pharmaceuticals, Inc.
Watson Pharmaceuticals, Inc., headquartered in Corona, California, is a leading specialty pharmaceutical company that develops, manufactures, markets, sells and distributes brand and generic pharmaceutical products. Watson pursues a growth strategy combining internal product development, strategic alliances and collaborations and synergistic acquisitions of products and businesses.
Watson is committed to providing innovative solutions in urology care. With seven products currently available to address conditions ranging from overactive bladder to prostate cancer, Watson continues to support research that not only treats the symptoms associated with urological conditions, but that helps make urology patients' lives more livable. The Watson portfolio in the U.S. includes Oxytrol(R); Trelstar(R) LA; Trelstar(R) Depot; Androderm(R); AndroGel(R), under a co-promotion agreement with Solvay Pharmaceuticals, Inc.; and ProQuin(R) XR, under a co-promotion agreement with Depomed, Inc. In addition to silodosin, the Watson urology portfolio includes a number of products under development; Uracyst(R), for the treatment of interstitial cystitis; a six-month formulation of Trelstar(R) (triptorelin pamoate for injectable suspension), for the treatment of advanced prostate cancer; and oxybutynin topical gel, for overactive bladder.
For press releases and other company information, visit Watson Pharmaceuticals' Web site at http://www.watson.com.
About Kissei Pharmaceutical Co., Ltd.
Kissei Pharmaceutical Co., Ltd., headquartered in Matsumoto, Nagano prefecture, founded in 1946, is a Japanese pharmaceutical company that develops, manufactures, markets, sells and distributes brand pharmaceutical products. Kissei is primarily focused on three important fields of new drug research: urogenital, endocrinology & metabolism and immunology & allergy.
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 difficulty of predicting the timing or outcome of clinical studies, product development efforts and FDA or other regulatory agency approvals or actions; whether the results of clinical trials for silodosin and other information will be sufficient to support approval by FDA and other regulatory authorities; delays regarding the regulatory approval process, including the timing and scope of approval received, if any; market acceptance and continued demand for Watson's products, including silodosin, if approved; our ability to successfully defend and/or enforce our patents and other intellectual property rights against third parties; patents and other intellectual property rights held by competitors and other third parties; successful compliance with FDA and other governmental regulations applicable to Watson's products and/or business; and such 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, 2006.
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