A jury in Louisiana on Monday ordered Takeda Pharmaceutical Co. to pay $6 billion in punitive damages, acknowledging that Japan's largest drugmaker concealed the risks of cancer associated with its diabetes drug Actos, according to Takeda and U.S. media reports.

In the case, Terrence Allen, a former Actos user, claimed that his bladder cancer was caused by the medicine and Takeda failed to provide adequate information about the risks. The drugmaker denied any relation between Allen's cancer and the medicine.

Following the news reports, Takeda shares on the first section of the Tokyo Stock Exchange ended Tuesday down nearly 5.2 percent at ¥4,572.

Kenneth Greisman, senior vice president of Takeda Pharmaceuticals U.S.A. Inc., said in a statement, "Takeda respectfully disagrees with the verdict and we intend to vigorously challenge this outcome through all available legal means, including possible post-trial motions and an appeal."

The jury also ordered Takeda's co-defendant, Eli Lilly and Co., to pay $3 billion.

According to Bloomberg, the $9 billion in combined damages, the seventh-largest in U.S. history, is almost certain to be reduced by a higher court.

Last year, state juries in California and Maryland ordered Takeda to pay a total of $8.2 million in damages to former Actos users, but judges in both states rejected the verdicts, the news agency said.