NEW YORK (CNNMoney.com) - Merck is just weeks away from its next trial over the former blockbuster drug Vioxx, and lawyers from both sides have fresh fodder for the courtroom battle.

Two key Vioxx stories broke in recent days that will provide new ammunition for legal teams from either side, who will try to spin it to their advantage June 5, when plaintiff and former Vioxx patient Elaine Doherty faces off with Merck at New Jersey Superior Court in Atlantic City. Doherty took Vioxx for three years and blames the drug for causing her heart attack.

Merck, the number 2 U.S. drug maker, faces at least 11,500 lawsuits from former Vioxx patients and their families. Merck, based in Whitehouse Station, N.J., pulled the arthritis painkiller off the market on Sept. 30, 2004 after the company's "Approve" study showed an increased risk on blood clot-related heart attacks and strokes in patients who took the drug for at least 18 months.

Not only did this evaporate $2.5 billion in annual sales from the drug, but Merck's (down $0.65 to $34.48, Research) stock price has taken a 22 percent dive since the withdrawal.

So far, five cases have gone to trial, resulting in two wins and two losses for Merck, with a split verdict in the another. New information from the Approve study has emerged in the last few days that could make the next legal battle all the more contentious.

On Thursday, The Wall Street Journal reported that an internal document from Merck that summarizes the results of a Vioxx study revealed that blood clot-related heart attack risks actually increase in the first four months after taking the drug. Merck, which has acknowledged an increase in heart attack and stroke risks after 18 months of Vioxx use but nothing less, dismissed the news report as "not scientifically appropriate."

This is an important detail for Merck, which has fought cases from short-term Vioxx users by arguing that they didn't take the drug long enough to cause their heart attacks.

A week earlier, on May 11, Merck announced the results of an "off-drug" follow-up study, that patients did not suffer an increased risk of heart attacks after they stopped taking Vioxx. Peter Kim, president of Merck Research Laboratories, said there was "no statistical difference" in heart attack risks in post-Vioxx patients.

But the company did acknowledge a slight increase in risk, which the plaintiff lawyers could use to fuel their legal arsenals.

All of this information stemmed from Merck's "Approve" study, which is the study that prompted the drug maker to pull Vioxx off the market on Sept. 30. 2004 because the drug increased the risk of blood clot-related heart attacks and strokes after 18 months of use.

Though Merck dismisses the idea that any of these studies show an increase in health risks from Vioxx, the plaintiff lawyer in the upcoming case sees it differently.

Michael Galpern, an attorney from Locks Law Firm representing Doherty, said that both reports "confirm that Vioxx substantially increases the risk of heart attacks and strokes" and "completely undercut" Merck's ongoing defense that Vioxx does not increase risk in short-term users.

If the information is malleable enough to be used by either side, the presentation might carry more weight than the actual data. It's not what they say, but how they say it, said Bryan Liang, professor of health law studies at California Western School of Law, who is not involved in Vioxx litigation.

"The Merck lawyers will say there is no statistical difference, but plaintiff attorneys may say, in terms of absolute difference numbers, that there is a difference," said Liang, referring to the post-Vioxx off-drug study.

While Liang warned against lawyers sliding into a war of numbers, he said that a winner could emerge from that strategy.

"If this goes too much into statistics, the jurors aren't going to understand it and they're going to fall asleep because it gets boring," said Liang. "It's really going to be incumbent upon the lawyers to make it understandable, and the ones that make it the most understandable from their point of view are the ones who are going to win."

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