Forest Laboratories Inc has discontinued development of dexloxiglumide for the treatment of constipation predominant irritable bowel syndrome (IBS) in the U.S. Forest licensed U.S rights for dexloxiglumide from Rotta Research Laboratorium of Italy. This decision was based on the outcome of two just completed placebo-controlled Phase III clinical studies involving over 1,400 women with constipation predominant IBS and of 12 weeks duration of treatment. Although a numeric trend was observed in favor of dexloxiglumide in both studies, the difference compared to placebo was not statistically significant.

The primary endpoint in the two studies was the Subject Global Assessment, which measures a patient's overall evaluation of abdominal discomfort, pain and altered bowel habit. Both clinical trials suggested that dexloxiglumide had limited side effects and no effect on gallstone formation.

Dexloxiglumide, a CCK-1 antagonist, represents a novel mode of action for the treatment of IBS which demonstrated promising results in a large Phase II study conducted by Rotta Research.

Rotta Research, the originator of dexloxiglumide, is continuing a separate placebo-controlled Phase III trial in Europe of a different design in constipation predominant IBS, in compliance with the current guidelines of the European Medicine Evaluation Agency (EMEA), that has different requirements from the U.S. FDA.

Forest and Rotta Research will also continue to evaluate whether dexloxiglumide may have promise in other indications which may be studied in the future.