Watson Pharmaceuticals, Inc. Announces Positive Data for Its New Investigational Products for Benign Prostatic Hyperplasia and Overactive Bladder

ORLANDO, Fla., May 21 /PRNewswire-FirstCall/ -- Watson Pharmaceuticals, Inc. , a leading specialty pharmaceutical company, announced today that investigators presented clinical data on two Phase 3 products at the American Urological Association’s annual meeting. The abstracts include a cardiac safety trial involving silodosin, an investigational treatment for benign prostatic hyperplasia (BPH, or prostate enlargement) and a pharmacokinetic study of oxybutynin chloride topical gel (OTG), an investigational product for overactive bladder.

“Watson is committed to helping urologists offer their patients the highest standard of care through providing novel treatments that continually address areas of urology with limited therapeutic options,” said Edward Heimers, Jr., Executive Vice President and President of Watson’s Brand Division. “We are extremely encouraged by the results demonstrated in these two trials, as they support the safety of silodosin and the potential efficacy of OTG as well as offer important patient benefits. A marketing application for silodosin has been filed with the FDA, and one for OTG will be filed. Both products represent potentially important additions to the expanding Watson urology franchise.”

In the first trial (abstract #2037), investigators conducted a double-blind, randomized, parallel-group trial to assess whether or not silodosin -- an investigational alpha blocker -- would prolong the QT interval on an electrocardiogram (ECG). QT is a measure of the heart’s electrical activity. A prolongation of the QTc (corrected for heart rate) interval favors the development of cardiac arrhythmias, which can lead to sudden death. The investigators concluded that silodosin did not demonstrate any meaningful effect on heart rate or QTc interval duration. The most common side effects seen greater than 2% were retrograde ejaculation (reduced semen) and dizziness. The abstract (Double-blind, Randomized, Parallel-Group Study to Define Electrocardiographic Effects of Silodosin, a Uroselective alpha-Adrenergic Antagonist) was presented by Herbert Lepor, M.D., Department of Urology, New York University School of Medicine, NY, on Wednesday, May 21 at 2:10 pm.

“The effects of silodosin on the QTc interval were rigorously evaluated,” said Dr. Lepor. “Our results found that silodosin does not affect the QT interval. QTc prolongation has been observed with other alpha blockers. Therefore, this is an important study for the development of any alpha blocker.”

The second trial (abstract #1508) found that OTG produces serum levels similar to an already-approved oxybutynin transdermal patch (Oxytrol(R)), but demonstrates improved skin tolerability that may lead to greater patient acceptability and use. As expected, dry mouth and application site dermatitis were the only treatment-related side effects reported in more than 2% of participants. OTG is designed to provide the same advantages as the patch over a pill formulation, in terms of convenience, ease of delivery, and a lower risk of anticholinergic side effects such as dry mouth and constipation. The abstract (Steady-State Pharmacokinetics of an Investigational Oxybutynin Topical Gel in Comparison with Oxybutynin Transdermal System) was presented by David R. Staskin, M.D., Department of Urology, Weill Medical College of Cornell University, NY, on Tuesday, May 20 at 2:30 pm.

“I would expect that based on the comparative serum levels of oxybutynin and desethyloxybutynin, the gel formulation will preserve many of the advantages associated with the transdermal patch with the potential for a significant improvement in skin-related side effects,” Dr. Staskin said.

“Watson Urology is making a broader, more visible commitment to the medical and patient communities,” said Heimers. “Through our innovative pipeline, we are focused on developing effective, safe and convenient treatments that not only treat the symptoms of common urological conditions but also offer patients quality of life advantages.”

The two trials presented at AUA are part of Watson’s comprehensive R&D program, and represent the company’s focus on providing products and services that improve the quality of patients’ lives. In addition, Watson recently announced the approval of MIXJECT(R), a new delivery system for TRELSTAR(R) DEPOT 3.75 mg and TRELSTAR(R) LA 11.25 mg (triptorelin pamoate for injectable suspension), a palliative treatment for advanced prostate cancer. MIXJECT(R) combines the proven efficacy of TRELSTAR(R) with new features that make preparation, administration and disposal easier, including: a thinner 21-gauge needle for improved patient comfort; reconstitution without the use of a needle; and a shield covering the needle both before and after drug administration. The system, developed and manufactured by West Pharmaceutical Services, Inc., is specifically designed to encourage compliance with OSHA (Occupational Safety and Health Administration) regulations within the medical community.

About Silodosin

Silodosin is a novel, highly uroselective alpha (1A)-adrenoceptor antagonist originally developed by Kissei Pharmaceutical Co., Ltd. in Japan and licensed to Watson for the US, Canada and Mexico markets. Silodosin preferentially binds to the alpha (1A) receptors in the prostate and bladder neck relative to cardiovascular associated receptors, thereby maximizing target organ activity while minimizing the potential for blood pressure effects. Urief(R) (silodosin) 4mg, dosed twice daily, was launched in Japan in May 2006 and is marketed by Kissei in cooperation with Daiichi Sankyo Co., Ltd. Silodosin is under development in the US for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH).

About Oxybutynin Chloride Topical Gel (OTG)

OTG is a clear, odorless, ethanolic gel that provides for delivery of oxybutynin hydrochloride in a non-patch transdermal form. OTG is under development for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency and frequency.

About TRELSTAR(R)

TRELSTAR(R), developed by Debiopharm Group, a Swiss biopharmaceutical specialist, is a synthetic hormone known as a luteinizing hormone releasing hormone (LHRH) agonist, which suppresses the production of testosterone in the testicles. The growth of the prostate is regulated in part by the level and activity of testosterone. TRELSTAR(R) is available in a 4-week depot formulation (TRELSTAR(R) DEPOT) and a 12-week long-acting formulation (TRELSTAR(R) LA), offering an alternative treatment for advanced prostate cancer when orchiectomy (removal of the testicles) or estrogen administration are either not indicated or unacceptable to the patient. TRELSTAR(R) does not require refrigeration and should be stored at controlled room temperature.

In clinical trials, the most common adverse events occurring in patients were hot flushes, skeletal pain, impotence and headache. As with all LHRH agonists, triptorelin causes an initial transient increase in testosterone levels and may initiate or worsen symptoms during this transient period. Rare post-marketing reports of anaphylactic shock and angioedema have been reported. TRELSTAR(R) is contraindicated for use in women who are or may become pregnant. For additional information, please discuss with your physician or contact Watson Medical Communications at 866-75-J3315.

About Watson Pharmaceuticals, Inc.

Watson Pharmaceuticals, Inc., headquartered in Corona, CA, 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.

The mission of Watson Urology is to offer products and services that improve the quality of patients’ lives, and satisfy the needs of physicians who specialize in the diagnosis, management, and treatment of urological disorders. By advancing education and support for urological diseases, we are creating the differences that make life more livable.

In the U.S., the Watson portfolio includes: Oxytrol(R); TRELSTAR(R) LA; TRELSTAR(R) Depot; Androderm(R); ProQuin(R) XR, under a co-promotion agreement with Depomed, Inc.; and AndroGel(R), under a co-promotion agreement with Solvay Pharmaceuticals, Inc. The Watson portfolio also includes a number of products under development including: silodosin, a product under development for the treatment of benign prostatic hyperplasia; a six-month formulation of TRELSTAR(R) (triptorelin pamoate for injectable suspension), under development for the treatment of advanced prostate cancer; and OTG, under development for overactive bladder.

For press releases and other company information, visit Watson Pharmaceuticals’ Web site at http://www.watson.com.

Forward-Looking Statement

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; difficulties or delays in manufacturing; 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, 2007.

MIXJECT(R) is manufactured by and is a registered trademark of Medimop Medical Projects Ltd., a subsidiary of West Pharmaceutical Services, Inc., and is manufactured by West Pharmaceutical Services, Inc.

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CONTACT: Patty Eisenhaur of Watson Pharmaceuticals, Inc., +1-951-493-5611;
or Trina Chiara, +1-646-420-3365, or Rashelle Isip, +1-212-880-5354, both
of Ogilvy Public Relations, for Watson Pharmaceuticals, Inc.

Web site: http://www.watson.com/

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