A US judge has declared a mistrial in the first federal lawsuit against drugs giant Merck and its Vioxx painkiller.
Merck is facing thousands of lawsuits related to Vioxx
The move came after a jury in Houston was unable to agree on whether the drug had caused a man's fatal heart attack.
Merck is facing a mass of Vioxx lawsuits. It withdrew the drug last year after a study found it may double the risk of heart attack or stroke.
Last month a New Jersey state jury found Merck had given doctors adequate warning about possible Vioxx risks.
However, in August, a Texas state jury found the company liable for the death of a man, and Merck was ordered to pay out $253m (£141m).
The nine-member hung jury in Houston failed to reach a unanimous agreement after 18 hours of deliberations running over three days.
Merck's liabilities for Vioxx could be more than $50bn
They were to start a fourth day of deliberations before District Judge Eldon Fallon called them back into court and declared a mistrial.
He reminded that they had to come to their verdict within a "reasonable time".
"It has now been a reasonable time. We cannot get a verdict," said the judge.
Such a federal case requires a unanimous verdict.
Merck still faces more than 7,000 outstanding lawsuits connected to Vioxx, which had previously been a best-seller.
Its total liabilities could top $50bn.
About 20 million people took Vioxx, including 400,000 in the UK, primarily to treat arthritis pain, after its launch in 1999.
Merck voluntarily pulled Vioxx from the market in September 2004.
The firm was reacting to research carried out by its own teams, which discovered that taking the drug for 18 months or longer could double the risk of patients suffering a heart attack or stroke.
UK law firm Irwin Mitchell, which represents 100 alleged Vioxx victims, said it was not surprised by the decision of the US judge.
"The uncertainty for our clients unfortunately is continuing," said Irwin Mitchell partner Sallie Booth.
"However the inability of the jury in this case to reach a unanimous decision is clearly indicative that there remain important questions to be answered by Merck including, what they knew about the health effects of Vioxx, when they knew it and what they did about it."