Merck defends Vioxx research

WASHINGTON, Oct. 13 (UPI) -- Merck & Co. defended its clinical research on Vioxx and said it withdrew the arthritis drug from the market as soon as data showed a safety hazard.

Earlier this month the pharmaceutical company pulled Vioxx after a clinical trial spanning some 4.5 years showed patients taking it daily for 18 months or more had double the risk for a heart attack.

In a teleconference Wednesday, Peter Kim, president of Merck Research, said: "It was not until last month ... 4.5 years after the approved trial was initiated ... that the safety board found an issue and recommended the trial be stopped."

Kim said an earlier trial comparing Vioxx to naproxen, which showed more Vioxx patients had cardiovascular events, was of concern but not a real comparison because it did not compare Vioxx to a placebo to determine if Vioxx was the problem.

Dr. Alise Reicin, vice president for clinical research, said in light of studies showing naproxen "inhibits platelets clumping similar to aspirin," researchers concluded it was the naproxen protection that led to fewer patients on that drug having cardiac events.