Arena Pharmaceuticals, Inc announced Merck and Co, Inc's decision (through an affiliate) to discontinue development of MK-1903, an investigational niacin receptor agonist to treat atherosclerosis being developed under its research collaboration with Arena. Merck also informed Arena that the company will not continue the collaboration.

Merck made the decision to discontinue development of MK-1903 following evaluation of the results of a recently completed phase-2a clinical trial. The randomized, double-blind, placebo-controlled 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; no safety signals were implicated as drivers of the decision to discontinue development.

"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 US 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."

Arena is a clinical-stage biopharmaceutical company focused on discovering, developing and commercializing oral drugs that target G protein-coupled receptors, an important class of validated drug targets, in four major therapeutic areas: cardiovascular, central nervous system, inflammatory and metabolic diseases.