Takeda Pharmaceutical Co.'s $2.37 billion settlement of thousands of lawsuits over its Actos diabetes medicine did not attract enough takers ahead of a deadline, raising doubts about whether the deal will survive.

Asia's largest drugmaker is obligated to fund the deal after 95 percent of those with claims join it. By Wednesday's deadline, about 75 percent had signed up, said Andy Birchfield, a lawyer overseeing cases consolidated in federal court in Louisiana. Claimants now have until Sept. 11.

A resolution is crucial for Osaka-based Takeda, which is pushing to settle about 10,000 lawsuits over claims the drug causes cancer and end five years of litigation. The company denies Actos poses any risk.