Merck rested its case Wednesday afternoon in the first federal Vioxx trial after testimony from a pathologist who said the painkiller played no role in the fatal heart attack of 53-year-old Richard "Dicky" Irvin.
Thomas Wheeler of Baylor College of Medicine testified in the Houston court that Irvin's heart attack was triggered by a plaque rupture in his coronary artery. Wheeler said the rupture led to the formation of a blood clot that eventually blocked the flow of blood in Irvin's coronary artery.
Wheeler, who also testified for Merck in the first Vioxx case to go to trial earlier this year, said Irvin's use of Vioxx in the month before his heart attack played no role in the formation of the clot and his death.
On cross-examination, Wheeler was asked about his deposition testimony, in which he stated there were no signs of ruptured plaque at the site of the blood clot. Wheeler did not directly refute that testimony, but suggested that there were signs of ruptured plaque in other parts of the autopsied heart.
Wheeler was also asked if he was aware that Vioxx may play a role in causing plaque ruptures. Wheeler said that theory hasn't been scientifically proven.
A pathologist testifying for the plaintiff told the jury last week that the plaque in Irvin's arteries was intact and that the blood clot that led to Irvin's heart attack was unrelated to the plaque in his arteries.
Earlier, the plaintiff's lawyer cross-examined Alise Reicin, Merck's vice president of clinical research and a key figure in the development of Vioxx.
Plaintiff lawyer Andy Birchfield returned repeatedly to Merck's actions in the wake a large scientific study called "VIGOR." In the study, patients on Vioxx had five times as many heart attacks as those on an older drug, naproxen. Merck knew of those results in 2000.
Reicin testified Tuesday that initially she and other Merck scientists found the VIGOR results worrying. But after a review of several other Vioxx studies, consultations with outside scientists and internal debate, Merck concluded that the correct way to interpret the VIGOR results was that Vioxx wasn't causing heart attacks, but the older drug, naproxen, was protecting against them.
On Wednesday, Reicin was shown press releases that Merck issued soon after it obtained the study's results. One was issued in April 2000 and titled "Merck Confirms Favorable Cardiovascular Safety Profile of Vioxx."
Reicin said the press release was issued in response to media reports. "We believed it was safe," she said about Vioxx. "We were telling the public what we believed."
Birchfield quoted extensively from the Food and Drug Administration's review of the VIGOR data and Merck's analysis of it. In one report, the FDA said Merck's analysis was "not adequate" to address concerns raised by VIGOR that Vioxx, in fact, caused heart attacks.
"You did not tell doctors and the world that you did not have an adequate data base to do a safety analysis of Vioxx, right?" Birchfield asked Reicin.
"No, that's not true," she said.
She said the FDA eventually came to share Merck's opinion that VIGOR hadn't proven the cardiac risks of Vioxx, and that the study's findings should not appear in the label's warning section, but in a less prominent place.
Birchfield asked if Merck had fought the FDA's efforts to prominently warn doctors about the VIGOR study, because such a warning would hurt Vioxx sales.
"It certainly might have had an impact on sales," Reicin said. "I didn't care. I was going to do what was right for patients."
Closing arguments will begin Thursday morning, and the case is expected to go to the jury by midday.