Thousands of plaintiffs who developed bladder cancer from a Japanese pharmaceutical company’s diabetes medication can cash in on its multibillion-dollar settlement offer.

Takeda Pharmaceutical Co., which has its U.S. headquarters in Deerfield, offered in April to pay $2.37 billion to plaintiffs if 95 percent of them agreed to the deal or $2.4 billion if 97 percent agreed to settle claims with the company by Sept. 11.

Almost 4,000 complaints were filed in Cook County Circuit Court, along with about 4,000 in Louisiana courts, about 800 in Florida and several others in seven different states.

Cook County Circuit Judge Deborah M. Dooling acknowledged the tentative deal on Aug. 31. Dooling adopted a final settlement for the Cook County cases on Sept. 14.

The suits stem from thousands of people who allegedly developed bladder cancer after taking the company’s drug Actos. The medication was taken by diabetes patients to control blood sugar levels.

Peter J. Flowers, a partner at Meyers & Flowers in St. Charles and co-lead counsel for the plaintiffs, said the final number of settling plaintiffs is unknown. However, a statement Takeda released on the day of the opt-in deadline indicates about 96 percent of plaintiffs accepted the agreement.

Plaintiffs can expect to receive their share of the settlement toward the middle of next year, Flowers said.

Payments could reach $1 million individually, he said, depending on various factors such as the extent of the plaintiffs’ injuries and the amount of Actos they took.

“It’s a great thing for a ton of plaintiffs that developed cancer as a result of taking this drug,” Flowers said. “This means 5,000 plaintiffs are going to be able to recover some kind of compensation for the hell this medication put them through, and in a timely fashion.”

The settlement is considered to be the country’s largest ever for a drug that remains on the market.

After several studies were conducted to determine a link between the drug and bladder cancer, the Food and Drug Administration issued a warning in June 2011 about possible risks of bladder cancer for people who took Actos for a year or more.

Two months later, the FDA issued a new warning stating that people who took the drug risked developing bladder cancer.

Lawsuits against Takeda began surfacing that same year from people who had fallen ill from taking the drug.

While some Actos users have died from the cancer, others have undergone multiple surgeries, endured chemotherapy or had their bladders removed. Some users also underwent kidney removal if the cancer had spread.

And although the drug’s label has changed to warn doctors and patients that it could cause cancer, Flowers said, it still puts diabetes patients in a bind because they have to decide whether to take that risk, try a different medication or decide against taking any drug at all.

Takeda’s September announcement stated its decision to settle the cases does not change its continued commitment to Actos.

The drug remains an available diabetes treatment option and it has been approved for use in 95 countries, including Japan, Australia, Russia, Canada and several others in Europe.

Sherry A. Knutson, a partner at Sidley, Austin LLP who represents Takeda, could not be reached for comment.

Illinois attorneys who also represent the plaintiffs include Meyers & Flowers partners Craig D. Brown and Ryan P. Theriault and associate Frank Vincent Cesarone; associates Chad A. Finley and Eric M. Terry of Tor Hoerman Law LLC; and associate Craig P. Mannarino of Kralovec, Jambois & Schwartz.

The case is In Re Actos Litigation, 11 L 10011.