A single injection of Allergan Inc.’s Botox into a woman’s bladder reduces urinary incontinence as effectively as daily drugs and is better at resolving the problem, a U.S. government-funded study found.
The study published in the New England Journal of Medicine suggests the medicine popularly used to fight wrinkles, migraines and muscle spasms may also be the first line of defense for some women who struggle with frequent urinary leakage. Women in the study getting Botox were more likely to develop infections, retain urine and need catheterization.
Botox is approved to treat overactive bladder caused by neurological conditions such as a spinal cord injury, and many doctors give it without formal regulatory clearance to women with the more common problem of unexplained incontinence. The findings support use for the condition, which may gain U.S. approval next year and might generate $216 million in sales for the indication by 2015, said Larry Biegelsen, an analyst with Wells Fargo Securities in New York.
“Previously, Botox was reserved for women who had tried oral medications but found them ineffective,” said Susan Meikle, senior author of the paper and program director for the National Institutes of Health’s Pelvic Floor Disorders Network. “Because we included some women who had not been treated with oral medications before, these results suggest that Botox could be discussed as an option for first line treatment,” she said in a statement.
The results were presented today at the American Urogynecologic Society meeting in Chicago.
The National Institutes of Health funded the study, known as the Anticholinergic versus Botox Comparison trial. The researchers compared Botox to Astellas Pharma Inc.’s Vesicare, a so-called anticholinergic agent that generates about $1 billion in annual sales, in 241 women. Patients who didn’t respond to the medication subsequently were switched to the generic medication trospium XR. The drugs were taken daily for six months and women recorded episodes of incontinence in three-day intervals for a full year.
The women went from an average of five episodes of urinary incontinence a day before treatment to 1.6 in the drug treatment group and 1.7 in the Botox group after six months. The condition cleared up entirely in 13 percent of women given drugs and 27 percent of those treated with Botox, the study found. About 70 percent of women in both groups responded to treatment, and their self-reported quality of life improvements were similar.
“With the ABC study being sponsored by the NIH, and not industry, we believe the results could carry more weight with the physician community,” Biegelsen wrote in an Oct. 1 note to investors before the results were released. “While we assume that Botox will be used as second-line treatment after failure of oral therapy, any positive data from the ABC trial could yield upside for Botox.”
Urinary incontinence affects about 16 percent of women in America, according to the NIH. While the cause isn’t always known, pregnancy, childbirth and aging all contribute to its development, according to the agency. It is often treated with anticholinergic drugs that work through the nervous system to reduce contractions in the bladder that lead to leakage.
Botox, a purified form of the botulinum toxin, was injected into the bladder to paralyze the overactive muscles.
One year after the Botox injection and six months after women stopped taking their medicine, the condition was still under control for 25 percent of the medication group and 38 percent of the Botox group, the study found.
Within two months of treatment, 5 percent of women given Botox needed to use a catheter to empty their bladders, compared with none of those given the drugs. Urinary tract infections also developed in one-third of Botox-treated women and 13 percent of drug-treated women. Nearly half of those given drugs developed dry mouth, compared with 31 percent of Botox patients.
“The first line of treatment is often oral medications, but these can have bothersome side effects that cause people to quit taking them,” said Anthony Visco, the lead researcher and chief of Urogynecology and Reconstructive Pelvic Surgery at Duke University in Durham, North Carolina. “There is a strong need for additional options.”