Zantac MDL Decision Reinforces Principle That Lack Of General Acceptance Of An Expert's Conclusions Raises A Red Flag

• Jurisdiction: United States,Federal
• Law Firm: Winston & Strawn LLP
• Subject Matter: Consumer Protection, Litigation, Mediation & Arbitration, Food, Drugs, Healthcare, Life Sciences, Product Liability & Safety, Trials & Appeals & Compensation, Biotechnology & Nanotechnology
• Author: Mr Terrence J. Dee and Sarah Bily
• Published date: 16 February 2023

The Zantac MDL Court recently reinforced the important role of general acceptance of an expert's conclusions to a court's Rule 702 admissibility analysis.

The U.S. District Court for the Southern District of Florida granted summary judgment against more than 2,450 plaintiffs who had cases pending in the MDL, ruling that they had failed to produce reliable expert testimony necessary to support their claims under Rule 702. In re Zantac (Ranitidine) Prod. Liab. Litig., No. 20-MD-2924, ---F. Supp. 3d---, 2022 WL 17480906, at *4, *6, *167 (S.D. Fla. Dec. 6, 2022).

The litigation involves claims against manufacturers of ranitidine, a heartburn medication sold under the brand name of Zantac. After Zantac had been on the market for several decades, a testing laboratory filed a Citizen Petition with the FDA and called for a recall of ranitidine. Id. at *2, *5. The petition explained that the private company's testing found high levels of a carcinogen in the drug. Id. at *5. Simultaneously, plaintiffs filed cases alleging Zantac caused several types of cancer. Id. The FDA subsequently issued a voluntary recall of ranitidine from the market. Id.

The court excluded Plaintiffs' general causation experts under Rule 702 because 'there is no scientist outside this litigation who concluded ranitidine causes cancer, and the Plaintiffs' scientists within this litigation systemically utilized unreliable methodologies with a lack of documentation on how experiments were conducted, a lack of substantiation for analytical leaps, a lack of statistically significant data, and a lack of internally consistent, objective, science-based standards for the evenhanded evaluation of data.' Id. at *4. The court made clear that 'if an expert makes an analytical leap from available data that no other scientist outside of the litigation has made, a court may consider that fact.' Id. at *83.

The court emphasized the distinction between litigation experts' conclusions and those of impartial scientists. See id. While acknowledging that Rule 702 is focused on evaluating an expert's methodology to determine whether their opinions are reliable, the court clarified that 'when an expert's theory 'lacks any acceptance, let alone general acceptance, in the scientific community' it is an indication of an unreliable methodology.' Id. at *124 (quoting In re Mirena IUS Levonorgestrel-Related Prods. Liab. Litig. (No. II) (Mirena II), 341 F. Supp. 3d 213, 268 (S.D.N.Y. 2018)); see also Mirena...