Watson Pharmaceuticals Inc, a leading specialty pharmaceutical company, announced that it has entered into an exclusive licensing agreement with Kissei Pharmaceutical Co., Ltd. to develop and market KMD-3213, Kissei's novel agent for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH).

KMD-3213, silodosin, is a highly selective alpha-1a adrenoceptor antagonist that relaxes smooth muscles at the prostate and bladder neck, thereby decreasing urinary resistance and improving dysuria associated with BPH. Kissei, in partnership with Daiichi Pharmaceutical Co., Ltd., has completed clinical development of KMD-3213 in Japan and is currently preparing a New Drug Application (NDA) for the Japanese market. Kissei has completed a Phase II clinical study in the United States.

Under the terms of the agreement, Watson will have exclusive rights to develop and commercialize KMD-3213 in the United States, Canada and Mexico. Kissei will receive payments based on achievement of certain milestones, and royalties based on Watson's sales of the product. Watson will be responsible for conducting Phase III clinical studies and preparing and submitting the NDA to support U.S. Food and Drug Administration (FDA) approval.

"Kissei is a well respected partner in the pharmaceutical industry and we are delighted to have the opportunity to collaborate with them for the commercialization of this BPH product," said Allen Chao, Watson's chairman and chief executive officer. "KMD-3213 represents a significant new product opportunity, as we look to supplement our product portfolio with late-stage product candidates that fit within our urology therapeutic focus area. Kissei has demonstrated the product's safety and efficacy through a successful clinical program in Japan. Watson will be able to directly enter Phase III clinical trials in the U.S. to support the U.S. NDA filing, thus reducing the risks associated with early-stage product development."

Benign prostatic hyperplasia, found only in men, is characterized by enlargement of the prostate gland surrounding the lower bladder and urethra, leading to 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. Alpha blockers, such as KMD-3213, are the most popular therapy for BPH, as they can quickly improve patient symptoms. Preclinical studies confirmed an improved uroselectivity of KMD-3213 compared to tamsulosin, demonstrated by a greater relative binding affinity to prostatic alpha-1a receptors as compared to the vascular alpha-1b receptors. Total U.S. sales of BPH drug therapies were approximately $1 billion in 2003, according to IMS Health data.