Ocera Therapeutics presents Phase 2 proof-of-concept study results of AST-120 in non-constipating IBS

Ocera Therapeutics, Inc. presented results yesterday from a Phase 2 proof-of-concept study of AST-120 (spherical carbon adsorbent) in the treatment of patients with non-constipating Irritable Bowel Syndrome (IBS) at DDW, the annual meeting of the American Gastroenterological Association. Data showed that subjects treated with AST-120 responded in a consistent manner with reduction in pain better than placebo at week four and at week eight, the primary time point for analysis. The company plans to initiate a Phase 2b study evaluating AST-120 in non-constipating IBS.

This 115-patient study was the first conducted with AST-120 in IBS, and was designed to include an eight-week randomized, double-blind, placebo controlled trial, followed by a two-week single-blind placebo washout phase and an eight-week single-blind AST-120 treatment phase. Response was defined as a 50% or greater reduction in days with pain compared to baseline. At week four, 27% of AST-120 treated subjects were responders as compared to 10% of placebo subjects. This effect was sustained at week eight, the primary time point for analysis, where the response rate was 32% for the AST-120 subjects and 25% for placebo subjects. Response was also seen with pain severity, bloating severity, stool frequency and the impact of symptoms on daily life. AST-120 was well-tolerated, with fewer adverse events observed in the treatment than in the placebo group.

"The strength of the response across multiple endpoints, and consistent response rates when placebo patients were switched to AST-120 suggest that AST-120 has the potential to be an effective treatment option for IBS patients," said Dr. Jan Tack, Professor and Head of Clinic in the Department of Gastroenterology, University of Leuven, Belgium and the principle investigator of the trial. "It also has an established safety profile that makes it ideally suited for this patient population."

In a retrospective analysis using endpoints specified in the FDA's recently issued guidance document for IBS clinical trials, the company found that at week four AST-120 response rates were two-fold higher than what was observed in the placebo group for both of the FDA-defined endpoints (23% vs. 13% responders for pain reduction and 34% vs. 17% responders for improvement in stool consistency).

"Non-constipating IBS is a disabling disease, and there remains a need for a safe and effective therapeutic option," said Philip Jochelson, M.D., Ocera's Chief Medical Officer. "Since AST-120 is not absorbed and acts locally within the lumen of the GI tract, it has the potential to mitigate or avoid many of the safety issues which accompany systemically-absorbed medications. The efficacy data combined with the safety profile generated in patients with IBS are encouraging, and support the continued development AST-120 for this population."

SOURCE Ocera Therapeutics, Inc.