Merck & Co is celebrating after a judge in Texas rejected a claim made by a plaintiff against the company who said she had not been properly informed about the risks of taking the painkiller Vioxx.

Ruling on the Ledbetter v Merck case, Judge Randy Wilson agreed with the company which had called for the lawsuit to be dismissed on the basis of a Texas law dating from 2003. That piece of legislation does not permit ‘failure-to-warn’ claims against prescription drug manufacturers if the medicine at issue was accompanied by warnings approved by the US Food and Drug Administration, as was the case with the one-time blockbuster COX-2 inhibitor Vioxx (rofecoxib), withdrawn from the market in September 2004.

Ted Mayer of Hughes, Hubbard & Reed, counsel for Merck, said that the firm acted responsibly by providing the FDA with the required data and updated the label with agency-approved language “to reflect what was known at the time".

In Texas, more than 1,300 Vioxx cases were filed after the 2003 Texas law was enacted and there are approximately 2,000 other cases pending that may be subject to this legislation. Judge Wilson, who is overseeing all of the lawsuits in Texas, held that the plaintiff would have to show that Merck ”withheld required, material and relevant information from the FDA” that would have led to a different decision regarding the approved labelling of Vioxx.

Mr Mayer concluded that “the nation's highest court has affirmed that the FDA's role is paramount and that state law cannot be allowed to undermine the FDA's statutory responsibility to ensure the safety and availability of prescription medications for all Americans."

The company has won 10 of 15 cases that have gone to trial starting in 2005 and if this ‘failure-to-warn’ decision is upheld, Merck will be confident of winning many more. The firm also noted that last Monday a California plaintiff asked the court to dismiss his suit which was scheduled to begin last week in Los Angeles.