Merck’s Tredaptive Raises Risk of Muscle Pain in Study

Merck & Co.’s cholesterol therapy Tredaptive, which the company stopped selling this year because it was ineffective and possibly harmful, raised rates of muscle pain and weakness in patients, a study found.

Muscle pain and weakness were found to be most common in Chinese patients, researchers said, with rates four times higher than those on placebo or of Europeans in the study of 25,673 patients published today in the European Heart Journal.

Merck, the second-biggest U.S. drugmaker, said in December it wouldn’t seek U.S. approval for the treatment and stopped selling it globally in January. The medicine is approved in 70 countries and was sold in 40. Tredaptive combines the vitamin niacin, which has been shown to help with cholesterol levels, with the experimental medicine laropiprant, added to reduce a face-flushing effect of the vitamin.

“The participants in China seemed to be at more risk than the participants in Europe,” Jane Armitage, the study’s lead investigator and a professor of clinical trials and epidemiology at the University of Oxford, said in a telephone interview. “We saw more effect than we had anticipated.”

Patients were followed for a median of 3.9 years and their side effects were tracked. Of those on Tredaptive, 25 percent stopped taking it, compared with 17 percent of those on placebo. Skin and stomach issues were the most common reasons for quitting the drug.

In Chinese patients, 0.66 percent were found to have muscle pains or weakness when taking Tredaptive, compared with 0.13 percent on placebo. Rates in European patients were lower, and only 0.07 percent were found to have muscle pain or weakness.

Full results of the Merck study, known as HPS2-THRIVE, are scheduled to be released in March. The drug generated less than $20 million in 2012.

Study results released in December showed the medicine failed to lower the number of heart attacks, strokes, the need for artery-clearing procedures or death from cardiovascular disease more than cholesterol-lowering statin drugs. Patients given Tredaptive plus statin drugs alone or with the drug Zocor were more likely to develop serious, though not life-threatening, side effects, the Whitehouse Station, New Jersey-based company said.

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