Federal Court Excludes All Plaintiffs' Experts In Second Mirena MDL

U.S. District Court, Southern District of New York

In a ruling that may presage the dismissal of a second MDL involving the intrauterine device Mirena®, the U.S. District Court for the Southern District of New York has excluded all seven of the plaintiffs’ general causation experts, finding their proffered testimony inadmissible under the Daubert standard. “In brief, although plaintiffs’ experts in this litigation have now so opined, outside of this litigation, no medical organization, regulatory agency, article in peer-reviewed scientific literature, or other research has found that use of Mirena is a cause of IIH [idiopathic intracranial hypertension],” the court said. Shook Partner James Shepherd and a team of Shook attorneys, scientific analysts, paralegals and support staff represent Bayer HealthCare Pharmaceuticals, Inc., Bayer Pharma AG and Bayer Oy in the litigation, which involves more than 600 plaintiffs. 

The Daubert standard, used in federal courts and some state courts, mandates that  judges act as the “gatekeepers” of expert scientific testimony by assessing whether it is based on valid reasoning; has been tested; has been subjected to peer review or publication; its known or potential error rate; standards controlling its operation; and whether it has gained widespread acceptance within the relevant scientific community. See Daubert v. Merrell Dow Pharmaceuticals Inc., 509 U.S. 579 (1993).

The Mirena contraceptive device functions by releasing levonorgestrel (LNG), a synthetic steroid hormone. The plaintiffs claim LNG causes a disease known as idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri. It is a rare disease marked by increased cerebrospinal fluid pressure in the brain. Left untreated, it may cause headaches, vision problems, and in extreme cases, blindness. The court described IIH as “the clinical syndrome of raised intercranial pressure, in the absence of space-occupying lesions or vascular lesions, without enlargement of the cerebral ventricles, for which no causative factor can be identified.” 

In a 156-page opinion, the court examined the factual background of the Mirena product; LNG; IIH and its history, risk factors and characteristics; the state of scientific research regarding the causes of IIH; and whether contraceptive devices that use LNG, like Mirena, can cause IIH. The court noted that two epidemiological studies of Mirena did not find such causation and that five other studies of contraceptives that contained higher amounts of LNG than Mirena have affirmatively found that such products do not cause IIH. 

The court devoted more than 100 pages of the opinion to an extensive examination of each expert’s background, methodology and theories, and reviewed the extent to which some of the experts’ theories used the Bradford Hill criteria—“the metrics that epidemiologists use to distinguish a causal connection from a mere association.” In the end, the court described the proffered testimony as nothing more than “speculative working theories,” “conjectural and unproven,” and “would, unacceptably, require the jury to accept ‘the ipse dixit of the expert.’” 

In addition to the opinion, the court issued an order directing counsel “to consider whether, as in the earlier multi-district litigation involving Mirena . . . this case should now proceed to summary judgment limited to the issue of general causation.” In 2016, the Southern District of New York dismissed an MDL of nearly 1,300 plaintiffs who alleged that Mirena caused injuries to the uterus or surrounding tissues, after excluding all of plaintiffs’ expert witnesses pursuant to Daubert because of “numerous problems” with their testimony. The U.S. Court of Appeals for the Second Circuit affirmed the dismissal and in March 2018, the U.S. Supreme Court denied the plaintiffs’ writ of certiorari. Shepherd and the Shook team also represented Bayer and its affiliates in that litigation. 

Because complex science-related litigation often demands a high degree of technical skill, Shook has invested in a human infrastructure of more than 120 full-time researchers and analysts who hold undergraduate and advanced degrees (including 16 doctorates) in specialty areas that include biochemistry, chemistry, molecular biology, organic chemistry, mechanical, civil and electrical engineering, statistics and other fields. In addition, many of our attorneys hold advanced degrees in science, medicine, engineering and mathematics. With our deep bench of knowledgeable attorneys and professional staff, Shook is tenacious in rooting out, exposing and disposing of junk science. 

The case is In Re: Mirena IUS Levonorgestrel-Related Prods. Liab. Litig. (No. II), No. 17-2767 (S.D.N.Y.)