Merck Fires Back at Medical Journal

But VIGOR also discovered a higher rate of cardiovascular problems in Vioxx patients compared with those taking naproxen. At the time the article was published, Merck had hypothesized that this disparity was due to a heart-protecting effect of naproxen rather than a heart-damaging effect of Vioxx.

Critics of Vioxx used VIGOR's results to seek restrictions on the drug. A Food and Drug Administration advisory panel discussed the VIGOR trial in early 2001. In April 2002, Merck revised the Vioxx label to include information about cardiovascular risks identified in the VIGOR trial.

The Journal editors on Wednesday repeated their initial assertion that three patients' heart attacks weren't included in the original VIGOR article, even though, they say, the researchers had sufficient time to include the information. "Because these data were not included in the published article, conclusions regarding the safety of [Vioxx] were misleading," the editors said.

Merck officials have said these cases weren't included because the clinical trial had a cut-off date. The information, they added, was quickly reported to the FDA and the scientific community.

The letter from the non-Merck authors noted that, excluding the extra three cases, Vioxx patients had a 4.25 times greater risk of a heart attack. Including the extra cases, Vioxx patients risk went up five times. "We do not accept, therefore, that the addition of three [heart attacks] leads to qualitatively different conclusions," the authors said.

The Journal's editorial incorrectly suggests that relevant data was removed from the manuscript, they added. "Thus, we stand by our original article."

Two Merck officials who worked on the VIGOR article, Dr. Alise Reicin and Deborah Shapiro, said the company "consistently made full and appropriate disclosures" of the cardiovascular findings. The extra heart-attack cases were promptly disclosed to the FDA and were "included in subsequent communications," such as scientific publications and press releases.