Ardelyx, Inc. (ARDX) reported positive results from T3MPO-2, its second Phase 3 study of tenapanor for irritable bowel syndrome with constipation (IBS-C). The study hit statistical significance for the primary endpoint and all secondary endpoints evaluated for the topline results and demonstrated the ability to normalize bowel movements. The primary endpoint, the combined responder rate for six of 12 weeks, showed that a greater proportion of tenapanor-treated patients compared to placebo-treated patients (36.5% vs. 23.7%, p<0.001) had at least a 30 percent reduction in abdominal pain and an increase of one or more complete spontaneous bowel movements (CSBM) in the same week for at least six of the 12 weeks of the treatment period. In addition, tenapanor achieved statistical significance for the CSBM and abdominal pain responder rates in the six of 12 and nine of 12-treatment weeks, with a consistent response across the 26 weeks of the study. Tenapanor was well-tolerated in treated patients.

"These results are a game-changer for patients with IBS-C, their treating physicians and for Ardelyx as a company," said Mike Raab, president and chief executive officer of Ardelyx. "They demonstrate the significant benefit tenapanor can have for patients with IBS-C, importantly, leading to a normalization of bowel movements for many patients. These results show that tenapanor has significant potential in the market and bolsters our commitment to identify the ideal collaboration partner to help ensure that we reach the most patients possible who would benefit from therapy."

"IBS-C is a highly burdensome and difficult-to-treat condition affecting more than 11 million people in the United States, and often preventing them from engaging in day-to-day activities, such as going to work, exercising and even meeting socially with family and friends," said William Chey, M.D., University of Michigan. "Based on tenapanor's unique mechanism of action, which relies upon the inhibition of sodium absorption, and the exciting data reported today, tenapanor has the potential to be an important advancement and a new treatment option for patients suffering from IBS-C."

T3MPO-2 Trial Design

T3MPO-2 is a 26-week, double-blind, placebo-controlled, multi-center, randomized trial. The trial was conducted in a total of 593 patients meeting the ROME III criteria for the diagnosis of IBS-C. Patients were randomized one-to-one to receive either 50 mg of tenapanor (n=293) or placebo (n=300) twice-daily. The trial included a two-week screening period, during which patients with active disease, based on bowel movement frequency and abdominal pain score recorded in a daily phone diary, were randomized into the trial.