NEW ORLEANS, May 3 /PRNewswire/ -- 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."
AST-120 is a novel proprietary spherical carbon adsorbent with a selective adsorption profile for a variety of unwanted substances and toxins, including ammonia, the primary toxin linked to hepatic encephalopathy in patients with liver cirrhosis. AST-120 also adsorbs other substances, which may be responsible for conditions including Irritable Bowel Syndrome (IBS), and pouchitis. Adsorbed substances include ammonia, indoles (serotonin), histamine, bile acids, advanced glycation endproducts (AGE), and certain bacterial toxins. Ocera licensed the compound from Kureha Corporation (Japan) in 2005. AST-120 has been used chronically by over 360,000 patients and studied in over 3,000 patients worldwide.
About Irritable Bowel Syndrome
Irritable bowel syndrome (IBS) is a chronic intermittent condition, affecting ~12% of the population, in which patients experience abdominal pain or discomfort associated with disorder bowel movements. The exact pathophysiology is unknown, but intraluminal mediators such as serotonin and histamine as well as other intraluminal substances such as bile acids and lipopolysaccharide have all been postulated to play a role. The FDA issued new Guidance on IBS trial design in March 2010, clarifying the endpoints required to obtain approval in the U.S.
About Ocera Therapeutics, Inc.
Ocera Therapeutics, based in San Diego, California, USA, is a privately held biopharmaceutical company focused on the development and commercialization of proprietary compounds to treat acute and chronic liver diseases and a broad range of gastrointestinal disorders. In addition to AST-120, Ocera is developing OCR-002, an ammonia detoxification agent, for the treatment of hospitalized patients with acute hepatic encephalopathy and acute liver failure. Ocera has raised $62.5 million dollars in venture financing from Domain Associates, Sofinnova Ventures, Thomas, McNerney & Partners, Montagu Newhall and InterWest Partners. Additional information on the company can be found at www.oceratherapeutics.com.
SOURCE Ocera Therapeutics, Inc.