The US Food and Drug Administration on Monday said a new cholesterol drug being tested by Merck was not approvable, while the pharmaceutical giant vowed to press ahead with the application.
The drug, known as MK-0524A, was also denied the right to use the trade name "Cordaptive." Merck said it would "pursue the alternative trade name 'Tredaptive'" in the United States.
"We plan to meet with the FDA and to submit additional information to enable the agency to further evaluate the benefit/risk profile of MK-0524A," said Peter Kim, president of Merck Research Laboratories.
"We firmly believe that MK-0524A provides physicians with an important option to manage their patients' cholesterol," he said in a statement.
"We are encouraged that on April 24, the Committee for Medicinal Products for Human Use (CHMP) recommended marketing approval for MK-0524A in Europe, and we will continue to pursue approval within individual markets in the EU and around the world."
The drug combines niacin and laropiprant.
Earlier this month, Merck played down the risk of death linked to its anti-inflammatory drug Vioxx in trial studies the company made public.
Merck voluntarily withdrew Vioxx from sale in September 2004 after a company internal study in 2001 showed the drug doubled the risks of heart attack in patients who took it for 18 months or longer.
Vioxx last year was the focus of a 4.85-billion-dollar legal settlement.
The November deal, which allowed Merck to settle more than 95 percent of lawsuits over the drug, marked a major reversal of course for the company, which had earlier said it would fight more than 27,000 lawsuits.