A Food and Drug Administration advisory panel supported a clinical trial designed to test a possible new use for Salix Pharmaceuticals Ltd.’s drug Xifaxan.

Salix, based in Raleigh, N.C., said the FDA’s Gastrointestinal Drugs Advisory Committee supported a planned trial to evaluate the safety and effectiveness of repeated treatment cycles of Xifaxan for irritable bowel syndrome with diarrhea.

The company has been working with the regulatory agency to develop the proposed study, and it still needs FDA approval. But Salix said it aims to start enrolling patients in the trial during next year’s first quarter, and it expects the study to take about two years.

Xifaxan is approved as a treatment for traveler’s diarrhea and for overt hepatic encephalopathy, or neurological problems associated with liver failure. The FDA refused to grant the new approval in March and asked Salix for additional information.

Company shares fell nearly 10% as Salix prepared for the advisory committee meeting. One analyst had said the panel seemed unexpectedly skeptical about the use of Xifaxan as an IBS treatment.

The FDA panel’s review of the drug turned out very positive and included “overwhelming” support for the proposed trial, Caris & Co. analyst Mario Corso said in a research note.

“Fears of negative sentiment surrounding dose selection, trial endpoints, and resistance risk outweighing the potential benefit simply did not materialize,” Corso said.

Stifel Nicolaus analyst Annabel Samimy said in a separate note there is still a lack of clarity on the trial’s final design, but the panel outcome was “as good as we could have hoped.” She added that the FDA seems motivated to bring treatments for irritable bowel syndrome to the market, so it likely will be careful not to impose conditions on the trial that make it too onerous or impractical for Salix to continue.

Date: November 17, 2011
Source: Associated Press