The risk of death linked to Merck's anti-inflammatory drug Vioxx was minimized in trial studies the company made public, according to a study out Tuesday.
The report, appearing in the April 18 issue of the Journal of the American Medical Association (JAMA), compares Merck's internal data from 2001 with the results of clinical tests made public in 2004 and 2005.
Merck voluntarily withdrew Vioxx from sale in September 2004 after a 2001 company internal study showed the drug doubled the risks of heart attack in patients who took it for 18 months or longer.
"Sponsors have a marketing interest to represent their products in the best light. This approach conflicts with scientific standards that require the symmetric and comparable reporting of safety and efficacy data," wrote doctors Bruce Psaty and Richard Kronmal with the University of Washington, Seattle, the study co-authors.
The analysis was based on clinical tests carried out in 2000 and 2001 on 3,000 Alzheimer patients.
"The mortality findings and the Alzheimer disease findings would, in our judgment ... (led to) to stop the trial early," the researchers wrote.
Merck's internal analyses dating from April 2001 of pooled data from the two trials "identified a significant three-fold increase in total mortality."
But, the new study said, "These mortality analyses were neither provided to the FDA nor made public in a timely fashion."
Merck said in a statement it was not given a chance to respond to the article prior to publication.
"We are disappointed that such false and misleading statements about Merck from trial lawyers have made their way into a medical journal," said Peter Kim, president of Merck Research Laboratories.
According to Merck, "a full, unbiased evaluation of the Merck documents shows significant errors in the conclusions put forward by the authors of the JAMA articles."