Class-action lawsuits can significantly reduce the expense to plaintiffs and give them more clout, as prominent and expensive lawyers simultaneously represent them all.
Merck has said it is not interested in reaching a group settlement with the legions of Vioxx plaintiffs, but instead has vowed to fight them one by one in court.
Its strategy has proved surprisingly successful, according to industry analysts, and bolstered confidence in the company's future ability to withstand the litigation without paying out many billions of dollars in damages.
Merck noted that juries in Vioxx personal injury trials to date have decided in its favor 10 times, although one of the verdicts was recently set aside, and have sided with plaintiffs five times.
Merck shares rose $1.18 to $50.58 in afternoon trading on the New York Stock Exchange. (Additional reporting by Jon Hurdle)
