NEW YORK, Dec. 27, 2012 (GLOBE NEWSWIRE) -- Synergy Pharmaceuticals, Inc. (Nasdaq:SGYP), a developer of new drugs to treat gastrointestinal (GI) disorders and diseases, announced today that dosing has commenced in a Phase IIb clinical trial of plecanatide to treat patients with constipation-predominant irritable bowel syndrome (IBS-C). This trial is being conducted at 70 sites in the United States and includes 350 patients with IBS-C who will be treated with one of four doses of plecanatide (0.3, 1.0, 3.0, or 9.0 mg) or placebo, taken once daily over a period of 12 weeks. PAREXEL International is the Contract Research Organization for the trial. "We are pleased to be developing plecanatide for the treatment of IBS-C, a functional GI disorder of significant burden to patients," said Gary S. Jacob, Ph.D., President and Chief Executive Officer of Synergy. "Synergy is about to complete an independent study of plecanatide in patients with chronic idiopathic constipation, and will be releasing top-line data from this trial early in January, 2013. We believe that plecanatide, which is an analog of the natural GI hormone uroguanylin, has the potential to produce an ideal combination of efficacy and safety for patients with IBS-C." Clinical Trial Design Patients must meet the Rome III criteria for IBS as demonstrated by a history of recurrent abdominal pain or discomfort covering at least 3 days/month in the last 3 months associated with two or more of: 1) improvement with defecation, 2) onset associated with a change in frequency of stool, and 3) onset associated with a change in form (appearance) of stool. Patients must also meet the criteria for the IBS-C subtype, which is further characterized by stool pattern such that ≥ 25% of defecations are hard or lumpy stools and ≤ 25% of defecations are loose or watery stools.