Salix Pharmaceuticals, Ltd. (NASDAQ:SLXP) today announced the successful outcome of two Phase 3, randomized, double-blind, placebo-controlled, multicenter trials, TARGET 1 and TARGET 2, designed to evaluate the efficacy and safety of rifaximin 550 mg TID in the treatment of patients with non-constipation irritable bowel syndrome (non-C IBS). In each trial rifaximin versus placebo treated patients demonstrated a statistically significant improvement for the primary endpoint of the adequate relief of IBS symptoms as assessed over one month (weeks 3, 4, 5 and 6) following completion of a 14-day course of therapy (weeks 1 and 2). Consistent with the primary endpoint in each trial, the key secondary endpoint of relief of IBS-related bloating also demonstrated statistical significance of rifaximin versus placebo in each trial. These two large confirmatory trials with 600 patients each were conducted following the previously reported positive results from a Phase 2 trial.
“We are extremely pleased with the outcome of our pivotal Phase 3 trials of rifaximin in the treatment of non-constipation irritable bowel syndrome,” stated Bill Forbes, Pharm.D., Senior Vice President and Chief Development Officer, Salix Pharmaceuticals. “Irritable bowel syndrome, characterized by abdominal pain, bloating and altered bowel habits, is one of the most common chronic medical conditions. Non-constipation IBS comprises the most common forms of IBS by including patients that have either diarrhea-predominant or diarrhea-constipation alternating symptoms. Based on the most current understanding of IBS, TARGET 1 and TARGET 2 were designed to investigate the utility of rifaximin, a broad spectrum, minimally absorbed, gut-selective antibiotic, with minimal side effects, in relieving the symptoms of IBS by altering the bacteria believed to be responsible for creating the symptoms. TARGET 1 and TARGET 2 will serve as the confirmatory trials for the Company’s New Drug Application seeking marketing approval for rifaximin as a treatment option in this condition which is associated with widespread prevalence, incapacitating symptoms and substantial medical costs. The Company is targeting to submit the NDA during the first half of 2010.”
Commenting on the results of TARGET 1 and TARGET 2, Mark Pimentel, MD, FRCP (C), Associate Professor of Medicine, Geffen School of Medicine at UCLA, Director, GI Motility Program, Cedars-Sinai Medical Center, stated: “Over the past decade, scientific discovery has continued to mount evidence for the role of gut bacteria in IBS and the effectiveness of antibiotics in alleviating symptoms of this condition. These two large-scale, multicenter trials affirm the rationale for a gut-selective antibiotic in the treatment of this common, chronic and debilitating condition and may provide pivotal evidence in the effort to deliver a significant therapeutic advancement to these patients.”