GSK appeals Delaware court’s decision in Zantac cases as plaintiff withdraws lawsuit

Pictured: GSK headquarters in west London/iStock, Tati Campelo

On Monday, GSK provided two updates on legal cases involving the heartburn drug Zantac (ranitidine), including a plaintiff’s voluntary dismissal and an appeal of a recent decision by the State Court of Delaware.

The company said plaintiff Eugenia Kasza voluntarily withdrew her lawsuit against the pharmacy, which otherwise would have gone to trial on Monday in Illinois state court. GSK said it had failed to satisfy Kasza’s claim “and paid nothing in exchange for his voluntary dismissal.”

In her lawsuit, Kasza alleged that Zantac caused her breast cancer. However, GSK claims that 16 studies of human epidemiological data – collectively – have found “no consistent or reliable evidence” that Zantac increases the risk of any cancer.

“GSK will continue to vigorously defend itself and manage this litigation in the best interests of the company and shareholders,” the company said in a statement.

As part of its defense efforts, GSK also announced Monday that it had taken the first step to appeal a recent Delaware State Court ruling that allowed plaintiffs’ expert witnesses to testify in the Zantac cases. That ruling, published last week, sent GSK shares down 10%.

On Monday, the pharmacist said he “strongly disagrees” with the court’s ruling, noting that it is “inconsistent with how the Daubert standard has previously been applied in Delaware and federal courts.” The Daubert Standard helps courts determine whether expert testimony is admissible at trial. This can be brought by both the plaintiff and the defendant.

In its appeal against the court’s decision, GSK requested a preliminary hearing, which is usually granted only in exceptional situations. “GSK believes these circumstances exist here and that it is important to bring this issue before the Delaware Supreme Court now.” Pfizer, Sanofi and Boehringer Ingelheim are part of the application.

First developed by Glaxo Holdings, now part of GSK, Zantac is a histamine 2-receptor antagonist that inhibits the secretion of stomach acid, the main cause of heartburn. In 2019, the FDA said it had detected several ranitidine samples contaminated with NDMA, an environmental contaminant that the regulator classifies as a probable human carcinogen.

In April 2020, the FDA asked ranitidine manufacturers to recall their products because NDMA contaminants may accumulate over time and expose patients to unacceptable levels of toxicity. According to the Delaware Supreme Court, approximately 70,000 Zantac cases are still pending Reuters.

Tristan Manalac is a freelance science writer based in Metro Manila, Philippines. Connect with him on LinkedIn or email him at [email protected] or [email protected].