NEW YORK, – Former users of Merck & Co.’s Vioxx arthritis drug could be at risk of developing strokes for years, a prominent public health expert said on Thursday after examining new data from the drug maker.
“It may be that Vioxx is causing permanent damage to the cardiovascular system, accelerating atherosclerosis or a sustained increase in blood pressure,” said Dr. Curt Furberg, a member of the U.S. Food and Drug Administration’s Drug Safety and Risk Management Advisory Committee.
Furberg, a professor of public health at Wake Forest University, said his stroke concerns stem from a new 107-page report on patients who were followed for a year after they stopped taking Vioxx. Furberg made his comments in response to questions from Reuters.
The drug, used by 20 million Americans, was recalled in late 2004 after it was shown to double heart attack risk among patients taking it 18 months or longer in Merck’s so-called APPROVe trial of the drug.
Merck issued a news release last week that briefly described the lengthy report, and made the report available to Reuters on Thursday.
It said 28 people from the three-year trial had heart attacks and strokes a year after they stopped taking Vioxx, compared with 16 patients from the trial that had taken placebos. The difference, however, was not deemed statistically significant.
Furberg said his examination of the full report shows 7 Vioxx users had strokes, while two Vioxx users had mini-strokes in the year-long follow-up period—compared with no such incidents in the placebo group.
“These data raise some very important questions because for a while we assumed Vioxx caused temporary problems, and here it is more than that. It could be causing permanent damage,” Furberg told Reuters.
“In the past we weren’t quite sure of the stroke risk, so stroke is now back on the agenda in a bigger way,” he said.
Merck spokesman Michael Heinley said the stroke risk from Vioxx had not been seen in earlier trials of the drug, including a long-term trial of Vioxx to prevent Alzheimer’s disease.
“We’ve consistently seen no increased risk of stroke in people taking Vioxx,” Heinley said.
He said the risk for stroke would not have been statistically significant in the the follow-up of patients in the latest APPROVe trial if data for several placebo patients who developed strokes had become available before the cut-off date for the review.
Even so, strokes were four times more common among those who took Vioxx than those who took placebos.
Dr. Christopher Cannon, a cardiologist at Brigham and Women’s Hospital in Boston, said it was too early to assume the new stroke data indicate long-term risk to patients.
“We need longer-term follow-up of the same patients and need to follow patients from other trials” of Vioxx and similar medicines, he said, including Pfizer Inc.’s Celebrex arthritis drug.
The stroke news followed a report by National Public Radio on Wednesday that said data from the review suggested that patients were at higher risk of heart problems and strokes almost as soon as they started taking Vioxx. Merck, however, repeated that only long-term use of Vioxx poses a risk.
Merck is facing more than 11,500 lawsuits alleging harm from Vioxx.
“This new stroke data should open the door a little wider for more lawsuits because it means stroke risk is significant even after people are off the drug,” Mehta Partners analyst Shaojing Tong said on Thursday.
Tong said Merck’s description last week of the stroke data suggested the risk was seen among patients while they were taking the drug, rather than when they had already stopped taking it.
“The way they handled this is very fishy,” said Tong, echoing criticism of Merck’s alleged lack of forthrightness lodged last week by cardiologist Steven Nissen, interim chairman of the Cleveland Clinic. “They should definitely make things more clear to doctors and to patients.”
Merck declined immediate comment on that issue.