Washington Editor

The FDA's Gastrointestinal Drugs Advisory Committee on Wednesday rejected Serono Inc.'s application to market Serostim as a treatment for short bowel syndrome in patients receiving specialized nutritional support.

Serostim (somatropin [rDNA origin] for injection) is sold in the U.S., Japan, Canada and a few other small countries as a treatment for AIDS wasting. In 2002, worldwide sales of the product reached a little more than $95 million.

The panel voted 6-3 against recommending approval of Serostim to treat the 10,000 to 20,000 Americans who suffer from the rare, sometimes fatal condition of short bowl syndrome (SBS). Serostim has received orphan status in that disease.

The committee criticized Serono's application because it contained one pivotal trial in which a majority of the patients (38 of 41) were studied at a single center, said Carolyn Castel, spokeswoman for Serono, of Rockland, Mass., the U.S. affiliate of Serono SA. Also, the committee raised questions about the generalized ability of the data and whether they could be replicated in another setting.

"We're disappointed, of course, but we are going to continue working very closely with the FDA as we continue through the review period," Castel told BioWorld Today. "We want to understand and address the appropriate issues with them, and we'll see how it all turns out."

The FDA is not bound by the committee's recommendation.

Castel said Serono expects action from the agency later this year. She would not release the company's Prescription Drug User Fee Act date. (By federal law the FDA must take action on drug and biologics applications within a specified period of time set under PDUFA guidelines.)

SBS is a condition that follows extensive surgical removal of the small intestine as a treatment for acute or chronic disorders of the intestine. Removal of a large portion of the bowel results in impaired absorption of nutrients, according to Serono.

Standard treatment for SBS involves management of food intake or parenteral nutrition, feeding through an intravenous tube. Another treatment option is surgical transplant of the intestine.

The Serostim application was based on data from a pivotal study to evaluate the change in total parenteral nutrition requirements in adult patients with SBS who are dependent on parenteral nutrition.

The double-blind, controlled, parallel, Phase III study randomized 41 patients to one of three arms: a specialized diet supplemented with oral glutamine alone, Serostim with a specialized diet alone, or Serostim with a specialized diet with glutamine.

According to the company, results of the study were positive, with total parenteral nutrition volume, total parenteral nutrition calories and frequency of infusion decreasing significantly in the Serostim plus specialized diet group as compared to the glutamine-supplemented specialized diet group (p=0.043, 0.005 and 0.0025, respectively). Reductions in the Serostim plus glutamine-supplemented diet group as compared to the glutamine-supplemented specialized diet group were larger and all were highly significant (p< 0.001).