Review of the results of Phase 2b clinical trial on PASCAL announced

ARYx Therapeutics, Inc. (NASDAQ:ARYX), a biopharmaceutical company, announced that a review of the results of the Phase 2b clinical trial, PASCAL, testing the efficacy and safety of ARYx’s compound for the treatment of atrial fibrillation, budiodarone, was presented today at the American Heart Association meeting in Orlando, Florida. The primary efficacy and safety results from PASCAL were announced in early 2009, demonstrating that budiodarone significantly reduces atrial fibrillation (AF) burden, or the time spent in AF, in patients suffering from paroxysmal AF. The details reviewed today focused on budiodarone’s rapid on-set of action, with a significant reduction in patients’ AF burden occurring within the first thirty days of treatment in two of three doses tested. In addition, the effect of budiodarone was sustained over the course of three months of treatment. Budiodarone is a novel oral antiarrythmic therapy modeled on the efficacy of amiodarone, the gold standard treatment for atrial fibrillation.

“The primary efficacy results from the PASCAL study clearly demonstrate evidence of budiodarone’s effect in significantly reducing the time spent in atrial fibrillation by patients suffering from paroxysmal AF,” stated Dr. Michael Ezekowitz of The Lankenau Institute for Medical Research and who chaired the AHA session at which the PASCAL data was reviewed. “We further observe that the reduction in AF burden occurred rapidly, with a highly significant reduction in AF burden occurring in the first month of treatment in the 400mg BID and 600mg BID dose groups. These promising results, if sustained in subsequent Phase 3 clinical studies, together with the 75% reduction in AF burden previously demonstrated, create a promising profile for this drug.”

The primary efficacy results from the Phase 2b PASCAL clinical trial were announced in December 2008 and the safety results were announced in January 2009 (see press releases dated December 18, 2008 and January 12, 2009). The primary efficacy results showed that budiodarone significantly reduced patients’ AF burden in two doses tested, 400 mg BID>

The efficacy analysis also included a month-by-month assessment of the patients' burden. The reduction in atrial fibrillation burden was statistically significant in each of the 3 months of treatment in both the 400 mg BID group and the 600 mg BID group. By significantly reducing AF burden within the first month of treatment, budiodarone appears to have a rapid on-set of action. The maximal effect of the drug was seen in the third month on 600 mg BID where the percentage reduction was 83%>