March 31 (Bloomberg) -- Merck & Co., after settling most of its Vioxx lawsuits in the U.S., persuaded an appeals court to halt one of two national group lawsuits in Canada claiming the painkiller caused heart attacks and strokes. The drugmaker still faces trial in Ontario, Canada’s most-populous province.

A three-judge panel of the Court of Appeal for Saskatchewan ruled unanimously yesterday there were too many different issues involved to resolve in a class-action lawsuit and a lower court judge erred in allowing the plaintiffs to proceed as a group.

The case “gives the impression of commonality, where commonality in fact does not exist,” Judge Gene Ann Smith wrote on behalf of the panel.

The ruling bodes well for Canadian plaintiffs because pursuing one national lawsuit, rather than two, may be quicker, Michael Peerless, a lawyer representing the Ontario plaintiffs, said in a telephone interview today.

“We’ve been on hold because every time Merck appeals, our case is stayed,” Peerless said. “This is very good news for Canadians.”

Merck, based in Whitehouse Station, New Jersey, pulled Vioxx from the market in 2004 after an independent study showed it increased the risk of heart attacks and strokes. The company agreed to pay $4.85 billion to settle lawsuits by thousands of U.S. plaintiffs who blamed their heart attacks and strokes on the drug. That settlement doesn’t include plaintiffs in Canada and other countries.

2004 Withdrawal

Merck was sued in most Canadian provinces after it withdrew the drug in 2004. Typically, lawyers agree to pursue a single national lawsuit, representing everyone affected in the country, with the exception of Quebec, which operates under different legal rules.

In this case, Saskatchewan class-action lawyer Tony Merchant spearheaded the national lawsuit in his province, while Peerless, of Siskinds LLP in London, Ontario, pressed a separate case in Ontario.

Merchant plans to appeal the ruling to the Supreme Court of Canada, the country’s highest court, he said in a telephone interview today.

‘Consequences’

The Saskatchewan ruling “has really long-term consequences” because it’s the first time in Canada a class- action lawsuit against pharmaceutical companies has been decertified, Merchant said.

Class certification provides leverage for plaintiffs, making it easier to finance lawsuits and negotiate a settlement.

Merck may ask an Ontario judge to decertify that lawsuit “as we would now have the Saskatchewan Court of Appeal decision to speak to,” Evan Zelikovitz, a Merck spokesman, said in an e-mail.

Merck already lost a bid to end the group case in Ontario.

The case is Between Merck Frosst Canada Ltd. and Gerald Wuttunee, 2009 SKCA 43, Court of Appeal for Saskatchewan (Regina).

To contact the reporter on this story: Joe Schneider in Toronto at jschneider5@bloomberg.net.

Last Updated: March 31, 2009 14:09 EDT