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Last year, the federal court decision to exclude plaintiffs’ general causation expert in the In re: Onglyza and Kombiglyze XR Products Liability Litigation, MDL 2809 (E.D. Ken.),took a spot in our top ten best of 2022 (original post on that decision here).  Without a general causation expert, it is not surprising that summary judgement followed shortly after.   In re Onglyza and Kombiglyze Prods Liab. Litigation, 2022 WL 3050665 (E.D. Ky. Aug. 2, 2022) (discussed here).  What we have not discussed is the parallel litigation pending in state court in California.  Until today.

Thirteen cases were coordinated in California and the California judge further coordinated with the MDL judge, including conducting a joint Rule 702/Sargon hearing.  After which, the California court reached the same conclusion as the federal court – plaintiffs’ general causation expert’s opinion was excluded because it did “not contain a reliable methodology for weighing the evidence but a shifting results-based methodology that fails to logically and consistently weigh all the relevant evidence.”  Onglyza Products Cases, — Cal.Rptr.3d –, 2023 WL 3001055 (Cal. App. Apr. 19, 2023).  Again, the next step was summary judgment based on a lack of expert evidence on general causation.  Now, the California trial court decision, both as to exclusion and summary judgment, has been affirmed by the appellate court.

The drugs at issue are in class used to treat diabetes.  Plaintiffs allege that the drug causes heart failure and related cardiac conditions.  At the request of the FDA, manufacturers conducted a cardiovascular outcomes study, a randomized controlled trial (“RCT”) with multiple cardiac endpoints.  The result of the trial was that there was no statistically significant difference between the drug and placebo for any primary endpoint (cardiac death, non-fatal heart attack, non-fatal stroke) or secondary endpoint except for hospitalization due to heart failure.  Id. at *1.  Following the cardiac trial, the authors of the study explained that heart failure finding was “unexpected and should be considered within the context of multiple testing that may have resulted in a false positive result.”  Id.  The authors cautioned that the outcome regarding hospitalization for heart failure warranted further investigation.  Id.  Further study was done in the form of observational studies and meta-analyses, none of which found an association between the drug and heart failure.  Id

Plaintiffs proffered two experts, a cardiologist who opined, based on the findings of the RCT and animal studies, that the drug was capable of causing heart failure; and a biostatistician.  Plaintiffs argued that the trial court overstepped in excluding the cardiologist’s opinion because the law allows the expert to place more weight on certain evidence, like the RCT, and less weight on other evidence, like everything else.  Id. at *5.  It may be one thing to place more weight on an RCT, it is another to conclude that “the finding from [the RCT] alone showed a causal link between [the drug] and heart failure.”  Id.   This conclusion is particularly flawed when the authors of the RCT concluded that the heart failure outcome “needs to be confirmed in other ongoing studies.”  A finding plaintiff’s expert agreed with.

A trial court does not abuse its discretion in excluding expert testimony on general causation when the expert’s opinion is based on a single study that provides no reasonable basis for the opinion offered.

Id. at *6.

Plaintiffs’ next argument was that their expert reliably performed the Bradford Hill analysis despite the trial court’s finding that the expert misapplied six of the nine Bradford Hill factors.  For example, one factor is “strength of association.”  The relative risk for hospitalization for increased heart failure was 1.27, but plaintiffs’ expert “could not say whether 1.27 was a strong association,” with “strong” being too subjective for him.  Id.  The court viewed this as the expert “refusing to engage with a factor of the Bradford Hill analysis on its terms.”  Id.  Another factor is consistency – “when the same finding is shown in multiple studies across different populations and settings.”  Plaintiffs’ expert, however, “disregarded inconsistent data from human studies and relied on data from preclinical animal studies,” to support this factor.  But, at the hearing, plaintiff’s expert conceded he was not qualified to interpret animal data, so instead he switched his position arguing that the RCT alone showed consistency because it examined 16,000 patients.  But the consistency factor requires an expert to see if different studies using different methodologies reached the same conclusion.  Plaintiffs’ expert’s cherry-picking of data shows the “unreliability of his shifting, results-based methodology.”  Id.  On the “analogy” factor, plaintiffs’ expert had to concede that heart failure studies done of other drugs in the same class likewise found no association.  So, instead, he analogized the drug at issue to drugs in a different class of diabetes medications where a link to heart failure had been found.  The trial court saw through the ploy:  the only reason to analogize to a different class of drugs was because it “supported his ultimate conclusion,” where the data on the drug at issue and its class did not.  Id. at *7.    

For all of these reasons, and more, the appellate court determined the trial court was well within its discretion in excluding plaintiffs’ expert based on its reasoned conclusion that the expert’s opinion was “shifting and unsound.”  Id. at *8.    

Plaintiffs also tried to argue that summary judgment was improper because expert causation evidence was not necessary.  That flies directly in the face of settled law that “in a personal injury action causation must be proven within a reasonable medical probability based upon competent expert testimony.”  Id. at *9.  Even if plaintiff had provided any authority that complex medical causation, such as heart failure, could be proven through non-expert evidence, the non-expert evidence plaintiffs relied on was insufficient to cross the summary judgment threshold.  The drug’s updated label that said consider the risks before using to treat patients at high risk for heart failure.  The RCT authors’ statement that the risk of heart failure needs to be further investigated.  FDA statements after the RCT that the drug may cause or increase the risk of heart failure.  All of these statements are based solely on the results of the RCT – which cannot support causation for all the same reasons plaintiffs’ expert’s reliance on the RCT alone could not.  [P]laintiffs cannot attempt to circumvent the shortcomings of [the RCT] by pointing to other evidence that merely relies on [the RCT’s] finding.”  Id. at *11.

Finally, the court did not abuse its discretion in denying plaintiffs’ request for additional time to designate a new expert.  Plaintiff chose to designate one causation expert, that was their strategic decision.  Asking for a do-over would prejudice defendants and tax the court’s resources as it would require additional expert discovery and another Sargon hearing.  Summary judgment was affirmed.