The Incretin-Based Therapies MDL has followed a long and winding road, and it all should come to an end with a recent Ninth Circuit opinion affirming the exclusion of the plaintiffs’ only general causation expert.  It all started in 2013 with the MDL transfer of cases involving multiple diabetes drugs to the Southern District of California.  Along the way, the district judge essentially dismissed the entire MDL on implied preemption grounds, only to have the Ninth Circuit reverse and give the plaintiffs a second chance to uncover preemption-defeating “newly discovered evidence.”  We covered that judicial whipsaw here and here.

After a nearly three-year hiatus pending appeal, the district court again essentially dismissed all claims, this time both on implied preemption and on these plaintiffs’ other Achilles heel—the lack of any admissible expert opinion that these drugs can cause pancreatic cancer.  That order was so long, we blogged about it twice (here and here).

This time around, the Ninth Circuit has seen enough, and it affirmed the exclusion of the plaintiffs’ general causation expert and the resulting order granting summary judgment.  In re Incretin-Based Therapies Prods. Liab. Litig., No. 21-55342, 2022 WL 898595 (9th Cir. Mar. 28, 2022).  The science has always been weak in these cases, amounting to little more than speculation and conjecture.  And, to be sure, the science case has not improved for the plaintiffs over time.  The plaintiffs served their expert reports initially in 2015, and while they served an updated report from their general causation expert in 2019, the newer report failed to account for studies published in the interim.  Id. at *1.

It is no wonder why, since every study published between 2015 and 2019 found no causal relationship between the drug (liraglutide) and pancreatic cancer.  Id.  In addition, although the plaintiffs’ expert purported to follow a “weight of the evidence” methodology, he did not explain what that means or how anyone could possibly replicate his results.  Id.  In other words, “the district court had no means to ensure that [the expert’s] ‘conclusions were not mere subjective beliefs or unsupported speculation.’”  Id. (quoting Claar v. Burlington N. R.R. Co., 29 F.3d 499, 502 (9th Cir. 1994)).  Finally, the expert was “alone” in finding a causal link “despite years of research . . . conducted by medical, scientific, and regulatory entities.”  Id.

Given the paucity of scientific support, the Ninth Circuit’s opinion is short and to the point.  Be that as it may, we find this opinion noteworthy for multiple reasons.  First, the result.  By all indications, this MDL has now proceeded for nine years (off and on), despite a profound absence of scientific support and the preemption of all of the plaintiffs’ claims.  Federal preemption can be decided, and often is decided, on the pleadings, not after nearly a decade of litigation.  We are not sure what this says about modern multidistrict litigation, but it’s not good.

Second, in affirming the exclusion of expert opinions, the Ninth Circuit distinguished its own wrongly decided opinion in Wendell v. GlaxoSmithKline, 858 F.3d 1227 (9th Cir 2017), which came in at number nine on our list worst cases of 2017.  Even compared against the low Wendell bar, the expert’s opinion in Incretin still fell short.  The Incretin expert conducted no differential diagnosis and offered no opinions on specific causation.  In re Incretin-Based Therapies, 2022 WL 898595 at *1.  But more importantly, “[N]othing in Wendell absolves expert witnesses of the general and longstanding requirement that they explain their methods with enough detail that their results can be replicated.”  Id.  We would have preferred that the Ninth Circuit overrule Wendell outright, but short of that, we will take the Ninth Circuit’s conclusion and run with it.

Third, the Ninth Circuit came to the correct result, but it could have said much more.  The district court excluded other experts’ opinions and it granted summary judgment also on implied preemption, even after the plaintiffs had the opportunity to search for “newly discovered evidence”—which they presumably did not discover.  The Ninth Circuit kept mum on these important issues.  In fact, the court emphasized that it “need not—and do[es] not—opine on any other theory or argument urged by the parties.”  Id. at *2.  That pointed observation leaves the Ninth Circuit’s prior opinion on implied preemption intact, when it could have and should have acknowledged that implied preemption was ultimately a winning argument for the defense.

But, as Bexis would say, a win is a win, and the Ninth Circuit’s opinion on the plaintiff’s expert makes it eminently blogworthy.