Salix Pharmaceuticals (SLXP +0.5%) submits its response to the March 7, 2011 CRL it received from the FDA regarding its sNDA for Xifaxan (rifaximin) 550 mg tablets for the treatment of irritable bowel syndrome with diarrhea (IBS-D).
One of the required actions was a clinical trial to assess the safety and efficacy of rifaximin when administered beyond the first cycle of treatment. The company initiated the trial in February 2012. On July 1, 2014 Salix reported that rifaximin achieved the primary endpoint of a statistically significant greater proportion of refaximin-treated patients that responded to repeat treatment in the double-blind repeat treatment phase of the trial. On August 11, 2014 it reported acceptable safety data regarding repeat treatment with refaximin.
The FDA will have six months to respond to Salix's submission.