By Debra Sherman

(Reuters) - U.S. drug advisers on Tuesday backed a drug to treat a rare and serious bowel disorder for which there is no long-term treatment available in the United States.

A panel of outside advisers to the U.S. Food and Drug Administration agreed that NPS Pharmaceuticals Inc had demonstrated that the drug is safe and improves absorption of fluid and nutrients in the intestines of adults with short bowel syndrome.

The 12-member panel voted unanimously in the drug's favor. The FDA usually follows the advice of expert panels.

The drug, called teduglutide, is one of NPS Pharmaceuticals' lead drugs.

Short bowel syndrome - a so-called orphan disease, meaning it affects a small number of people - is a condition in which the body is unable to absorb enough nutrients and/or fluids through the gastrointestinal tract and that forces patients to rely chronically on intravenous feeding. The disease may result from the surgical removal of all or part of the intestine, or the patient may have been born with short intestines.

An estimated 10,000 to 15,000 American adults have short bowel syndrome severe enough to require intravenous feeding.

With such small numbers, there is little financial incentive for drug companies to develop treatments. Patients were left with few options, and this seemed to weigh in the drug's favor with the panel, made up of gastronenterologists, oncologists and other experts.

Reviewers had said they did not think the drug, which is intended to treat patients with the syndrome who are dependent on intravenous feeding, needed to be restricted for safety reasons.

However, risks of the drug can be grave. They include sepsis, liver damage, blood clots, gastrointestinal obstruction, pancreatic disorders, and an acceleration in the growth of new tissue and colon polyps.

Panel members discussed the possibility that the drug could cause cancerous tumors in the small intestines when used over a long period of time.

"We recognize there may be an increased risk ... we can't rule out this possibility," an NPS official told the panel.

Because of these concerns, the company has proposed including a warning on the label and establishing a registry to track patients over time, he added.

PATIENTS TELL OF HARDSHIPS

Mary Patnode has lived with the disease for decades, resulting from the removal of part of her intestines. She pleaded with the panel to consider how her life would change if she did not have to infuse nutrition into her body 12 hours a day.

"I think of my gut as a rapid transit system. I put something in my mouth and it's a very short time before I need to be in a restroom," said Patnode, whose travel accommodations were paid for by NPS Pharmaceuticals.

Others complained of the daily fear of having an accident.

Doctors who treat these patients say other concerns are infection near the catheter site and a leak in their ostomy pouch, a system used to collect waste. Because life is so difficult for these patients, some 70 percent are unemployed, they said.

Teduglutide is approved in Europe and marketed as Revestive by Nycomed, which holds the right to develop and commercialize teduglutide outside North America.

If approved, the drug would be marketed under the brand name Gattex in the United States.

Other treatment options for short bowel syndrome are Merck KGaA's Zorbtive and Emmaus Medical's NutreStore.

Bedminster, New Jersey-based NPS Pharmaceuticals posted a net loss of $36.3 million for 2011.