GSK Zantac appeal gets tough questions from some US judges

Some Delaware Supreme Court justices signaled they may be skeptical of a bid by GSK Plc, Pfizer Inc. and other drugmakers to overturn a judge who allowed more than 80,000 lawsuits to proceed to trial over claims that the heartburn drug Zantac is linked to cancer.

The state’s highest court on Wednesday heard lawyers for the companies attack the findings of Superior Court Judge Vivian Medinilla, who ruled last year that scientific evidence backing the claims was legitimate and could be heard by juries. The companies contend Medinilla didn’t property scrutinize the methodologies of certain expert witnesses, who found the medication could cause cancer if stored improperly.

“This sounds like cross-examination to me,” Chief Justice Collins Seitz Jr. told Paul Mezzina, a lawyer representing one of the companies, Boehringer Ingelheim Gmbh.

Mezzina attacked some testimony by the plaintiffs’ expert witnesses for being based on estimates of how much of a cancer risk Zantac could pose if stored improperly. But Seitz said some estimates can be a legitimate basis for scientific conclusions.

There was no ruling Wednesday. The five-member state Supreme Court will decide later whether to uphold Medinilla’s conclusions about the scientific evidence. If the justices side with her, it would be a major setback for GSK and other former makers of Zantac, including French-based drugmaker Sanofi.

“GSK has settled more than 99% of remaining cases in Delaware,” a spokesperson said, declining to comment further.

The companies wanted Medinilla to follow the lead of a federal judge in Florida, who rejected the cancer evidence as unreliable in 2022. But other states - such as California and Illinois - have signed off on the validity of much of the same evidence, prompting GSK last year to offer more than $2 billion to settle its Zantac liability.

Evaluating evidence

Ex-Zantac users suing in Delaware’s state courts say Medinilla properly carried out her legal duty to evaluate the legitimacy of the scientific evidence. Brent Wisner, a California-based lawyer representing some plaintiffs, argued that appellate courts should defer to the judge unless she used her “gate-keeping role in an arbitrary or capricious manner.”

The case has drawn national attention since the focus of the litigation shifted to Delaware, after the Florida judge’s ruling undercut thousands of federal suits before her.

The US Chamber of Commerce filed a so-called “friend of the court” brief, arguing Medinilla erred by blessing expert-witness testimony in the Zantac cases “that was fundamentally unreliable.” The judge concluded that rather than excluding expert witnesses, their evidence could be properly challenged by the companies via cross-examination.

Advocacy groups for plaintiffs’ lawyers, including the Delaware Trial Lawyers Association and the American Association for Justice, applauded Medinilla’s willingness to allow juries to decide whether the scientific evidence was credible.

Ex-Zantac users have sued branded and generic drugmakers that made the heartburn medicine alleging the product caused breast, stomach and colon cancer, among others. Plaintiffs have argued the companies knew ranitidine - the drug’s active ingredient - turned into the potential carcinogen NDMA under certain conditions. In 2020, the US Food and Drug Administration asked companies to remove all ranitidine-based products.

Zantac owners

Zantac hit the US market as a prescription drug in 1983 before transforming into an over-the-counter heartburn treatment in 1995. GSK and Warner Lambert developed it as part of a joint venture, and the drug was owned by several companies through the years before Sanofi, which acquired it in 2017.

After the FDA recall, Sanofi won approval to return Zantac to US store shelves, but without ranitidine. It’s now made with famotidine, the active ingredient in competitor Pepcid, which is marketed jointly by Merck & Co. and Johnson & Johnson spinoff Kenvue Inc.

Wisner, who argued on behalf of Zantac plaintiffs, faced some pointed questions about whether there is a scientific consensus that ranitidine can transform into NDMA in over heated conditions.

Justice Abigail LeGrow questioned whether a jury should be asked to decide whether ranitidine causes cancer when the studies aren’t conclusive. “How can we ask a jury to decide” such weighty issues when even scientists can’t agree on the specific cancer risk tied to Zantac, LeGrow asked.

Wisner said juries hearing these cases aren’t going to be presented with “junk science” as part of the plaintiffs’ cases.

The case is IN RE Zantac Litigation, No. 255, 2024, Delaware Supreme Court (Dover).

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With assistance from Ashleigh Furlong.