Cellegy Pharmaceuticals Inc has been issued patent number 6,747,063 entitled "Combination Therapy for Treatment of Erectile Dysfunction" by the United States Patent and Trademark Office (USPTO). This patent delineates methods of decreasing the pain associated with the use of topical and injectable prostaglandins for treatment of erectile dysfunction (ED) by administering a prostaglandin and a low dose of a nitric oxide (NO) releasing agent such as nitroglycerin or isosorbide dinitrate, a company release said.

Approximately two-thirds of current ED patients respond, at least temporarily, to treatment with of oral type V phosphodiesterase (PDE) inhibitors, such as sildenafil (Viagra, Pfizer), tadalafil (Cialis, Lilly/ICOS) and vardenafil (Levitra, Bayer).

The estimated 5-6 million patients who do not respond or cease to respond to PDE inhibitors are candidates for treatment with injectable prostaglandin E1 (PGE1; also known as alprostadil) sterile power for injection products such as CAVERJECT (Pfizer/Pharmacia) and EDEX (Schwarz Pharma) or other more invasive means. Injectable alprostadil, the first prescription medication approved in the US for the treatment of ED, has been in use for the last decade. Injectable PGE1 products are preferred by some patients due to their quick onset of action and the resulting high quality of erection. For others, the injectable products are the only alternative to use of an inflatable penile implant.

While highly effective, the injectable products have not met with great popularity among American men due to an approximately 40 per cent incidence of PGE1 related penile pain experienced during or after injection. Various topical PGE1 products are currently under development for treating ED or female sexual dysfunction; these products all have reported local irritation and pain as significant adverse events in clinical studies.

Cellegy believes that its invention could significantly reduce or possibly eliminate the pain and irritation produced by injectable and topical prostaglandin products. According to Dr. Vivien Mak, Cellegy's vice president of Research, "the increase of cyclic GMP produced by low dose NO releasing agents could attenuate local nerve fibre hypersensitivity and thus pain sensation induced by PGE1, without causing any additional untoward effects. Additionally, the combination of PGE1 and low dose NO releasing agents for the treatment of ED are therapeutically synergistic."

K Micheal Forrest, CEO of Cellegy, stated, "Alprostadil (PGE1) is one of the most effective treatments for a large number of ED patients. There is a clear need for a PGE1 based product that is more acceptable to these patients in that it does not produce the penile pain experienced by such a large percentage of users. We look forward to finding a marketing partner to bring an improved PGE1 product to market."

An estimated 20 million men in the United States currently suffer from erectile dysfunction (ED), a condition that is expected to become progressively more prevalent due to the expected doubling of the population of men over the age of 65 by 2025.

Cellegy Pharmaceuticals is a biopharmaceutical company engaged in the development and marketing of prescription drugs for the treatment of gastrointestinal disorders, sexual dysfunction, and certain cancers. The Company's lead product, Cellegesic (nitroglyerin ointment), has completed phase 3 testing for the treatment of pain associated with chronic anal fissures. Cellegy expects to file an NDA for Cellegesic during Q2 2004.