Take Merck, Pfizer on a Strong Stomach

Although Kim didn't identify the new data, it appears that he was referring to one Bextra test and one Celebrex test indicating that each drug raised the risk of cardiovascular injury.

"Given this new information," Kim added, "it is not clear that the cardiovascular risk observed" in the Merck test that convinced the company to withdraw Vioxx makes the drug a special case among Cox-2 drugs.

If the FDA advisers and the full FDA "conclude that the benefits of this class outweigh the risks in some patient populations, then we would have to consider the implications of these new data, given the unique benefits Vioxx offers," he said.

Analyst Moskowitz said Merck's embrace of the Cox-2 "class effect" idea indicates it believes this theory "could reduce its responsibility for the ill effects seen with Vioxx." Still, he said, last week's hearings didn't do much to help Merck's legal case.

"In fact ... the information discussed could have provided some fuel to litigants," said Moskowitz, who doesn't own shares and whose firm seeks to do business with companies mentioned in research reports.

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