Merck may see a surge in Vioxx lawsuits after an independent study found an increased risk of kidney-related complications and arrhythmia, a JP Morgan Securities analyst believes.
A data analysis of 114 clinical trials involving more than 116,000 patients found that Merck’s (nyse: MRK – news – people ) withdrawn painkiller was associated with an increased risk of “renal events,” which include swelling of the hands and feet, high blood pressure and kidney dysfunction..
The study was conducted by researchers at Harvard University and published online late Tuesday by The Journal of the American Medical Association.
With the statutes of limitations expiring soon for many former patients, JP Morgan pharmaceuticals analyst Chris Shibutani said the studies may prompt many to “pile on” the tens of thousands of Vioxx-related lawsuits already filed against Merck.
“Since few plaintiffs with renal injuries or arrhythmias have likely considered pursuing a Vioxx suit to date, this study may provide the motivation to file,” Shibutani wrote in a note sent to clients Wednesday.
A separate review conducted by medical researchers from Australia confirmed the early association between Vioxx and heart attack risks and indirectly raised concerns about Merck’s Vioxx successor drug, Arcoxia.
The Australian researchers found that Pfizer’s (nyse: PFE – news – people ) competing Celebrex, when taken in normal doses, may not increase the risk of heart attacks and stroke and raised “serious questions about the safety of diclofenac,” an older drug also known as Voltaren. Data from a recent study of Arcoxia showed a risk profile similar to Voltaren’s.
The JP Morgan analyst said the studies were a “moderate negative” for Merck and could provide “extra ammunition” for lawyers.
“We expect that plaintiffs’ attorneys will be adding references to this study to the materials they use to bring in new product-liability clients,” he said. “The results will give plaintiffs an extra arrow in their litigation quiver, and could encourage the filing of suits by plaintiffs who previously believed their cases were too weak.”
Shibutani maintained a “neutral” rating on Merck shares, which tumbled $1.12, or almost 3%, to $41.03 in early afternoon trading.