Big opportunity seen for better bladder drugs

By Ransdell Pierson

NEW YORK, June 6 (Reuters) - One of the most common problems in the United States -- an overactive bladder -- is so poorly treated by the current crop of drugs that new medicines have big sales potential, according to doctors and industry analysts.

As many as 35 million Americans are believed to have the problem of the over-frequent urge to urinate or an inability to prevent leakage of urine. But relatively few take medicines for the condition because of their limited effectiveness and side effects that can include dry mouth, constipation and confusion.

Surgery is used to correct one form of the problem called stress incontinence, in which urine leaks during coughing, or sneezing or other actions due to weakened pelvic muscles that support the bladder.

A larger group of patients, mostly female, have excessive urges to urinate caused by sudden contractions of the muscle in the wall of the urinary bladder. Emptying the bladder more than eight times a day is often cited as a criterion for the disorder.

Patients rely on a half-dozen very similar drugs, including Pfizer Inc's (PFE.N) Detrol LA and generic forms of Johnson & Johnson's (JNJ.N) Ditropan XL. But sales of the so-called anti-cholinergic medicines, which work by blocking nerve messages to the bladder muscle, have been hobbled by side effects and limited effectiveness.

"When urologists pick out an anti-cholinergic for their patients, many open their cabinet and grab the first one they see because they are all so similar," said Dr. Elizabeth Bozeman, an urologist in Spartanburg, South Carolina.

"This is a huge market and we need something that works by a different mechanism," she said.

Drugs for overactive bladder had combined global sales last year approaching $2 billion. Pfizer's Detrol brands dominated with revenue of $1.1 billion, spurred by the company's large sales force and advertising budget.

Combined sales of all treatments should grow to $3.2 billion in 2011, brokerage Cowen and Co. predicts, reflecting decent but not dramatic growth.

For older patients, Bozeman said she often suggests use of Sanctura, an anti-cholinergic sold by Esprit Pharma and Indevus Pharmaceuticals Inc. IDEV.O, because it may have less risk of causing confusion.

But Cleveland Clinic urologist Raymond Rackley said Enablex, sold by Novartis (NOVN.VX) and Procter & Gamble Co. (PG.N), is likely the best of the class of medicines.

"Enablex has not proven to cause any cognitive problems," he said, nor the slight heart concerns seen with some rival medicines in the class.

Even so, the number of incontinence episodes and urinations among patients taking Enablex in trials was not much lower than those taking placebos, although statistically better.

To get satisfactory relief from overactive bladder drugs, Rackley said patients must also change behaviors, such as avoiding caffeine, restricting salt, getting exercise and curtailing fluids after dinner.