Photo of Rachel B. Weil

We have a confession:  we leave the TV on for the Drug and Device Law Little Rescue Dogs when we leave the house.  A couple of days ago, they were watching Love It or List It when we left for the grocery store.  When we returned, the screen was black.  We are told that something called the “main board” failed.  For good.  Because 2020.  We know how lucky we are to have only these sorts of worries in these tragic times.   And we don’t lose sleep over “things” – things can be replaced.  But it still made us a little cranky.

So we were especially happy to open our email, a bit later, to find today’s case.  We have been reporting on the Mirena IIH (idiopathic intracranial hypertension) MDL in these pages for years now.  It all started back in 2017, when we reported on a fiasco involving one of the plaintiffs’ general causation experts, who, while he was on the plaintiffs payroll (a conflict he did not disclose) published a study supporting the plaintiffs’ causation theory.  Ultimately, the expert renounced most of the study’s conclusions and withdrew as an expert.  The following year, we published two posts (here and here) about the Southern District of New York’s decision granting the defendant’s Daubert motions and excluding all (all!) of the plaintiffs’ remaining general causation experts.  Last year, we reported that the court granted summary judgment for the defendant on all of the plaintiffs’ cases.  At the time, we called that the “final nail in the coffin” of the MDL.  But we were wrong.  The plaintiffs appealed both the Daubert decisions and the grant of summary judgment to the Second Circuit, and today’s spectacular case, In re Mirena IUS Levonorgestrel-Related Products Liability Litigation (No. II), — F.3d —, 2020 WL 7214264 (2d. Cir. Dec. 8, 2020), is the decision on that appeal.


At the outset, the court emphasized that “a district court’s decision to admit or exclude expert testimony” is reviewed “under a highly deferential abuse of discretion standard,” and that a Daubert decision “is not an abuse of discretion unless it is manifestly erroneous.”  Mirena, — F.3d —, 2020 WL 7214264 at *2.

With notable illogic, the plaintiffs argued that the district court abused its discretion both by looking too critically at the plaintiffs’ experts methodologies and by focusing only the on the experts’ conclusions and not scrutinizing their methodologies.  Unsurprisingly, the court gave the back of its hand to both arguments.  With respect to the argument that the court abused its discretion by taking a “hard look” at each expert’s methodology, the court explained,

[A]n expert’s methodology must be reliable at every step of the way, and, in deciding whether a step in an expert’s analysis is unreliable, the district court should undertake a rigorous examination of the facts on which the expert relies, the method by which the expert draws an opinion from the those facts, and how the expert applies the facts and methods to the case at hand.

Id. at *3 (emphasis in original, internal punctuation and citation omitted).  The court continued,

Plaintiffs’ contention that the district court impermissibly focused on plaintiffs’ experts’ conclusions instead of their methodologies is similarly unavailing.  The district court provided in-depth analysis of whether the experts applied their methodologies reliably. . . .Plaintiffs may (and do) challenge whether the reliability analysis was correct, but plaintiffs have no basis to argue that the district court did not engage in a detailed analysis of the experts’ methodologies.

Id.  Finally, the plaintiffs argued that “the district court erred by requiring the experts to back their opinions with studies definitively supporting their conclusions.”  Id.  The court held, “Even assuming the district court did impose such a requirement, it did not err in doing so.”  Id.  The court explained that lack of textual support for an expert’s conclusions may go the weight of the expert’s testimony, not to its admissibility, if the expert “reliably uses scientific methods to reach a conclusion.  In other words, an expert need not back his or her opinion with published studies that support his or her conclusion” if the conclusions are the result of a reliable methodology.  But the district court found that the plaintiffs’ experts’ methodologies were not reliable, so it did not err in considering whether the conclusions were supported by other studies.  “Further,” the court continued, “the court was well within its discretion to consider whether plaintiffs’ experts’ conclusions were generally accepted by the scientific community [because] [t]he general acceptance of an expert” is one of Daubert’s enumerated considerations.   While “a court need not consider the Daubert factors, it does not abuse its discretion by doing so.”  Id. 

“In sum,” the court concluded, “the district court appropriately undertook a rigorous review of each of plaintiffs’ experts, and based on that review reasonably found that the experts’ methods were not sufficiently reliable and that their conclusions were not otherwise supported by the scientific community.  Accordingly, the district court did not abuse its discretion in precluding the experts’ conclusions.”  Id. 

Summary Judgment

Next, the court turned to whether the district court erred in granting summary judgment in favor of the defendant.  The court rejected the plaintiffs’ argument that they should have been allowed to proceed with their case after all of their general causation experts were excluded, holding that the plaintiffs “failed to point to any state that does not have a general causation requirement for the types of claims at issue here.”  Id. at *4.

Alternatively, the plaintiffs argued that, “even if they were required to satisfy such a general causation threshold,” the district court’s rulings “prevented them from obtaining and presenting such evidence.”  Id.  First, the plaintiffs argued that the district court erred in precluding differential diagnosis evidence, which, they argued, would have established general causation.  The court explained that a “district judge has broad discretion in determining whether in a given case a differential diagnosis is enough by itself” to support a general causation opinion, and the court “did not abuse its broad discretion” in excluding the plaintiffs’ differential diagnosis evidence.  Second, the plaintiffs argued that the district court “improperly precluded them from obtaining other general-causation discovery.”  Id. at *5.  The court held, “Despite plaintiffs’ arguments to the contrary, the district court considered relevance and proportionality when resolving the discovery disputes.  We conclude that the district court’s well thorough and well-reasoned discovery orders throughout the litigation were well within its wide discretion.”  Id.  And so, “agree[ing] that no reasonable juror could find that it was more likely than not that general causation had been established based on plaintiffs’ admissible evidence,” the court concluded that the district court correctly granted summary judgment in favor of the defendant.

And so, after layer upon layer of plaintiffs’ ineptitude and years of resulting motion practice, the Mirena IIH MDL, in the immortal words of Harold Arlen and E. Y. “Yip” Harburg, is “really most sincerely dead.”  We can’t tell you how much we love this opinion.  It is a primer on the logical syllogism that should frame every drug or device case:  in the absence of a reliable methodology, an expert’s opinion is not admissible.  If that opinion is a general causation opinion, its exclusion is fatal to the specific causation opinions that rely on it.  And without expert specific causation testimony, no drug or device case can reach a jury.  The court did not falter, and it wasn’t swayed by the number of cases that would be out of court if it affirmed the district court’s decision.  The court applied the correct standard, followed precedent, and just got it right.  Keep an eye out for this decision on our “Best of 2020” list.  In the meantime, stay safe out there.