Merck, through an affiliate, has decided to discontinue development of MK-1903, an investigational niacin receptor agonist to treat atherosclerosis, being developed in collaboration with Arena Pharmaceuticals, Inc. Merck has also ended the research collaboration with Arena.

The decision follows the evaluation of results from a recently completed Phase IIa trial. The trial evaluated the safety, tolerability and potential efficacy in patients with dyslipidemia. According to Merck, elevation of HDL cholesterol relative to placebo did not meet the trial’s pre-specified primary objective for efficacy.

“We are disappointed that the trial results did not lead to further development of this program, but it has been a pleasure to work with Merck and we welcome the opportunity to collaborate again,” said Jack Lief, Arena’s president and chief executive officer. “We continue to focus on our other internal and partnered programs and the FDA approval of our lead drug candidate, lorcaserin for weight management.”

“This collaboration has led to excellent scientific interaction,” said Dr. Andrew Plump, vice president Cardiovascular Franchise Worldwide Discovery Head, Merck Research Laboratories. “We look forward to the possibility of partnering with Arena in the future.”