GlaxoSmithKline plc Sponsored ADR (GSK.US) and Pfizer Inc. (PFE.US) win lawsuit, Delaware Supreme Court rejects Zantac carcinogen testimony.

The Delaware Supreme Court's ruling on Thursday supported companies including GlaxoSmithKline plc Sponsored ADR (GSK.US), Pfizer Inc. (PFE.US), and Boehringer Ingelheim, rejecting the validity of expert testimony that claimed the heartburn drug Zantac was linked to tens of thousands of cancer cases. The Delaware Supreme Court sided with these companies, stating that the lower court judge, Vivian Medinilla, erred in accepting the relevant testimony and allowing claims from nearly 75,000 patients to proceed to trial. According to the Delaware Supreme Court's ruling, these cases will be remanded back to the lower court for a review of the expert testimony. Judge Medinilla had supported the plaintiffs' expert testimony in 2024, stating that it properly examined evidence linking Zantac to ten types of cancer. The pharmaceutical companies then appealed Medinilla's ruling. Since its approval in the United States in 1983, Zantac has been manufactured by several pharmaceutical companies. However, due to concerns about the drug's potential link to the human carcinogen N-Nitrosodimethylamine (NDMA), Zantac was pulled from the market in 2020. Since then, the manufacturers of Zantac have faced tens of thousands of cancer lawsuits, alleging that the drug's active ingredient, ranitidine, can become carcinogenic when not stored at appropriate temperatures.