Delaware Supreme Court Reverses Ruling Allowing Zantac Cancer Claims

The Delaware Supreme Court has ruled in favor of Zantac manufacturers, rejecting expert testimony linking the heartburn drug to cancer. The court found that the trial judge erred in allowing the testimony, which could have led to a jury trial. The decision is a major win for GSK, Pfizer, and Boehringer Ingelheim Pharmaceuticals, which had challenged the expert testimony. The companies had previously offered to settle thousands of lawsuits for over $2 billion.

The Delaware Supreme Court has ruled in favor of Zantac manufacturers, rejecting expert testimony that linked the heartburn drug to cancer. The court found that Superior Court Judge Vivian Medinilla erred in allowing the testimony, which could have led to a jury trial. This decision is a significant win for GSK, Pfizer, and Boehringer Ingelheim Pharmaceuticals, who had challenged the expert testimony.

The court's unanimous ruling, issued on Thursday, stated that a trial judge must act as the gatekeeper of expert testimony and should not dismiss challenges to the sufficiency or reliability of an expert opinion by viewing the disputes as questions of fact for the jury to decide. The companies, including GSK Plc, Pfizer Inc., and Boehringer Ingelheim Pharmaceuticals, argued that the judge did not properly scrutinize the methodologies of certain expert witnesses who found that Zantac could cause cancer if stored improperly [1].

The case has drawn national attention since the focus of the litigation shifted to Delaware after a Florida judge's ruling undercut thousands of federal suits. Some Delaware Supreme Court justices signaled skepticism of the companies' bid to overturn Medinilla's ruling, which allowed over 80,000 lawsuits to proceed to trial [2].

The decision to reject the expert testimony is a major setback for GSK and other former makers of Zantac. The companies had previously offered to settle thousands of lawsuits for over $2 billion. However, the court's ruling may encourage more lawsuits to proceed, potentially increasing the liability for the companies involved [3].

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

References:
[1] https://news.bloomberglaw.com/pharma-and-life-sciences/delaware-court-sides-with-zantac-makers-in-cancer-claims-suits
[2] https://www.detroitnews.com/story/business/2025/04/17/gsk-zantac-appeal-gets-tough-questions-from-some-us-judges/83137850007/
[3] https://www.tradingview.com/news/reuters.com,2025:newsml_L1N3T70W3:0-delaware-supreme-court-sides-with-zantac-drugmakers-over-evidence/