Regina Kelly began taking the prescription drug Byetta in 2007 to help manage her Type 2 diabetes. Two years later, she switched to another drug called Januvia. One year after that, she was diagnosed with pancreatic cancer — and in 16 months, she was dead.

Kelly's brother, Moses Scott, who lives in Alexandria, Va., sued the manufacturers of those drugs on September 20, 2012. The case is the first of thousands expected on behalf of people who claim that taking the diabetes drugs or others like them caused pancreatic cancer.

So far, the cases have targeted four drugs, but plaintiffs lawyers anticipate that others could end up as part of litigation that could grow to as many as 2,500 cases. On July 25, lawyers on both sides asked the U.S. Judicial Panel on Multidistrict Litigation to coordinate the actions for pretrial purposes in federal court in San Diego, where U.S. District Judge Anthony Battaglia already is overseeing most of the litigation.

"We're looking at an MDL of at least 1,000 cases, potentially more, as advertising picks up and people become more aware and as the litigation gets into an MDL," said Ryan Thompson of Watts Guerra in San Antonio.

The lawsuits represent the second wave of legal troubles affecting diabetes drugs. Already, thousands of cases have been filed blaming bladder cancer on diabetes drugs including Actos.

In Type 2 diabetes, the pancreas does not produce enough of the insulin the body needs to process glucose, and that causes blood-sugar levels to rise. The new spate of lawsuits cite recent scientific and medical studies on the side effects of so-called "incretin mimetic" drugs. "Basically, the way the drugs work is they mimic the incretin hormones the body uses naturally to stimulate the response of insulin," Thompson said.

The suits allege that the plaintiffs developed pancreatic cancer after taking one or a combination of four drugs: Byetta, Janumet, Januvia and Victoza. Pancreatic cancer is particularly deadly, with an average survival time of 18 months, according to court records. "We're just seeing a very big spike in the number of pancreatic and thyroid cancer cases in the last year," said Hunter Shkolnik of New York's Napoli Bern Ripka Shkolnik, who co-chaired a plaintiffs' bar conference with Thompson the day before the MDL hearing in Portland, Maine. Plaintiffs attorneys also discussed the litigation during the American Association for Justice's annual conference in San Francisco last month.

The four drugs are made by different companies. Byetta, introduced in 2005, was the first to obtain U.S. Food and Drug Administration (FDA) approval, followed by Januvia in 2006, Janumet in 2007 and Victoza in 2010. None of the drugs has been withdrawn from the market.

Merck Sharp & Dohme Corp., a Merck & Co. Inc. subsidiary that makes Janumet and Januvia, "will vigorously defend itself in the litigation," spokeswoman Lainie Keller wrote in an emailed statement to The National Law Journal.

'NO COMPELLING EVIDENCE'

"Merck has reviewed all of the safety data on sitagliptin currently available to us and, based on that review, we find no compelling evidence establishing a causal relationship between the use of sitagliptin and pancreatic cancer," she wrote, referring to the generic name of Merck's drug. "Nothing is more important to Merck than the safety of our medicines and the people who take them. We will continue to vigorously monitor the safety of sitagliptin in close collaboration with regulatory agencies and scientific experts."

Ken Dominski, a spokesman for Amylin Pharmaceuticals LLC, which made Byetta with Eli Lilly and Co., declined to comment. Bristol-Myers Squibb Co., which now owns Amylin, and AstraZeneca PLC, with which it is jointly developing diabetes drugs, defended their "unwavering commitment to patient safety" in a formal statement, adding, "AstraZeneca and Bristol-Myers Squibb will take appropriate actions as warranted in the best interest of patients."

Kelley Murphy, a spokeswoman for Eli Lilly, declined to comment. Ken Inchausti, a spokesman for Victoza manufacturer Novo Nordisk Inc., owned by Denmark's Novo Nordisk A/S, did not return calls for comment.

The complaints base much of their evidence of cancer links on studies by academics, primarily one co-authored by Dr. Peter Butler, professor at the David Geffen School of Medicine at the University of California at Los Angeles. They also point to Dr. Sidney Wolfe, founder of the health research arm of Public Citizen. Last year, Public Citizen, based in Washington, petitioned the FDA to withdraw Victoza from the market due to increased risks of thyroid cancer, pancreatitis, allergies and kidney failure.

Wolfe said his concerns go beyond Victoza. "We are concerned that the whole family of drugs increases the risks of pancreatitis and probably pancreatic cancer," he said.

But regulators have resisted such conclusions. On March 14, the FDA announced an investigation into whether incretin mimetic drugs could increase the risks of precancerous cells in the pancreas. "The FDA has not reached any new conclusions about safety risks with incretin mimetic drugs," it said at the time.

On July 26, regulators in Europe concluded there was little evidence that the drugs could cause pancreatic inflammation or cancer. "Presently available data do not confirm recent concerns over an increased risk of pancreatic adverse events with these medicines," the European Medicines Agency said, although it added that "some uncertainties remain" about the drugs' long-term effects.

Meanwhile, the American Diabetes Association joined with the European Association for the Study of Diabetes and the International Diabetes Federation in a June 28 statement: "At this time, there is insufficient information to modify current treatment recommendations."

Plaintiffs attorneys brushed off questions about their data. Thompson, of Watts Guerra, said the litigation has grown to 100 cases. In court records, he said, he was aware of more than 500 potential claimants "under contract with various law firms." He expected additional drugs to be added to the litigation, including Onglyza, made by Bristol-Myers Squibb and AstraZeneca.

"Some of the other drugs, candidly, are just newer to the market so haven't entered into any litigation yet," Thompson said. "I certainly expect in the coming months those drugs will also be involved in litigation."

Cases also have been added to a separate docket of about 100 claims pending in California state court alleging that Byetta causes pancreatitis. The first bellwether trial in that litigation, coordinated in Los Angeles County Superior Court, is scheduled for November 18.

Brian Depew, a partner at Engstrom, Lipscomb & Lack in Los Angeles, a lead plaintiffs attorney in the California pancreatitis cases, said: "I think everyone agrees that the cancer cases are the real serious public health concern."

'THRESHOLD LEGAL QUESTIONS'

In court records, the defendants deny the allegations pertaining to cancer. Douglas Marvin, a partner at Williams & Connolly in Washington who represents Merck, wrote: "It is Merck's position — and that of other defendants, respectively — that there is no reliable scientific basis for asserting a causal connection between the incretin-based therapy medication that each manufactures and pancreatic cancer."

And Raymond Williams, a partner at DLA Piper in Philadelphia who represents Novo Nordisk, wrote that the cases present "threshold legal questions concerning medical causation."

Nina Gussack, a Philadelphia partner at Pepper Hamilton who represents Eli Lilly, declined to comment, and Amylin attorney Richard Goetz, a Los Angeles O'Melveny & Myers partner who is chairman of the firm's class action, mass torts and insurance litigation practice, did not return a call for comment.

In a rare show of consensus, lawyers for the defendants agreed to coordinate the pancreatic cancer cases before Battaglia in the Southern District of California. They also suggested alternative venues in Colorado and the Western District of Oklahoma, according to court records.

The MDL panel usually rules on coordination within a few weeks.

Amanda Bronstad can be contacted at abronstad@alm.com.