Merck Says Vioxx Article Needs Correction

Merck (MRK Quote) said it would correct its previous description of one of the statistical methods used to analyze certain data from a Vioxx study published last year, but the drug giant doesn't believe the original results will be changed.

The company said after the close of trading Tuesday that it has notified the study's authors, the New England Journal of Medicine and regulatory authorities about the need for the correction. Merck discovered the error while reviewing the preliminary analyses of patients who were taken off Vioxx as part of a study called Approve.

In short, the mistake in the published article involved an incorrect description of the methods used for measuring time and changing risk in the Approve study.

Approve stands for Adenomatous Polyp Prevention on Vioxx. The study was designed to evaluate how effective the drug was after three years of treatment in preventing the recurrence of colorectal polyps in patients who had a history of benign colorectal tumors.

Merck reported the results of the three-year Approve study in September 2004. The study found an elevated risk of cardiovascular problems, such as heart attacks and strokes, among patients who took Vioxx for more than 18 months. The results prompted Merck to pull Vioxx, a blockbuster drug the company had sold to alleviate arthritis pain, off the market.

Since then, Merck, of Whitehouse Station, N.J., has been named as a defendant in more than 11,000 lawsuits in which plaintiffs alleged the use of Vioxx resulted in physical injury, death or lost wages.

Even though Merck says the correction shouldn't alter the findings of Approve, it does plan to hire an independent statistical expert to review the data and analyses. The study's authors have told Merck that they intend to submit a correction to the New England Journal of Medicine.

Shares of Merck fell $1.42, or 4.1%, to $33.14 in regular trading. After hours, the stock slipped another 15 cents.