Immunology Expert’s Anecdotal Observations Permitted in Opinion on Class-Wide Harm

Wendy Ketner, M.D.

Written by
— Updated on February 16, 2021

Immunology Expert’s Anecdotal Observations Permitted in Opinion on Class-Wide Harm

Court: United States District Court for the District of Kansas
Jurisdiction: Federal
Case Name: IN RE: EpiPen Epinephrine Injection
Citation: 2020 U.S. Dist. LEXIS 40788

In this MDL against the makers of the EpiPen, the defendant’s immunology expert’s testimony is challenged in part. The plaintiffs seek to exclude a portion of the expert’s report that draws on anecdotal experience from working with patients and opining on whether EpiPen users would be motivated to switch to a generic version.

The plaintiffs argue this testimony lacks necessary economic authority or other data sources. The court, however, finds the plaintiffs’ objections should impact only the expert testimony’s weight, not its admissibility. In fact, the court finds this testimony valuable in addressing class certification issues on how, or if, the plaintiffs were harmed by a delay in the release of a generic alternative.

Facts

This multi-district litigation involved antitrust, consumer rights, unjust enrichment, and civil RICO claims against the manufacturers and suppliers of the EpiPen. The EpiPen is an epinephrine auto-injector supplying epinephrine to relieve anaphylaxis, a kind of serious allergic reaction.  To support their case, the defendants retained an immunology expert witness.

The Defendants’ Immunology Expert Witness

The defendant’s immunology expert witness was an immunology medical practitioner with over 30 years of experience. The plaintiffs tried to exclude one portion of the expert’s testimony. In the expert’s report, a section opined on the likelihood that current EpiPen customers may have moved to a generic alternative if the generic had been released sooner. Here, the expert concluded that EpiPen users may not have readily switched to a generic alternative since epinephrine auto-injector products are unique, the generic alternative was not similar to EpiPen, and the generic was not readily available.

The expert based his views on patients’ unwillingness to move from EpiPen to the generic on his many years of professional practice in treating patients with anaphylaxis risk and administering EAI drugs to children. Further, the expert checked the generic drug details and found it to be very different from the EpiPen.Thus, the expert concluded that people were likely to stick with their EpiPenrather than learn how to use another drug with another set of instructions.

The plaintiffs asserted this opinion should be excluded because it was not supported by sufficient facts or data. Therefore, the plaintiffs said, the expert’s opinions were unreliable and irrelevant. The plaintiffs described the testimony as “views as founded on indirect data from his personal practice.” The plaintiffs contended that these anecdotal views on patient conversion posed economic concerns, but the expert had no political, accounting, business, marketing, customer behavior, economics, or pharmacy training or education. The plaintiffs argued the expert had not used an empirical approach to draw his conclusions.

Discussion

The court noted that the immunology expert based his views on his experiences and observations as a medical doctor. Criticisms by the plaintiffs over the lack of economic analysis affect only the weight of the expert’s opinion.

The court further noted that the expert’s opinions were relevant to class certification issues. Specifically, plaintiffs claimed that defendants engaged in illegal activity that slowed the competitive entrance of generic alternatives in the epinephrine auto-injector market, and the delay hindered competition, maintained EpiPen’s monopoly, and enabled defendants to keep increasing prices.  The expert’s opinions, based on his own findings and experience, were relevant to his theory of the generic delay and offer an opinion on whether the plaintiffs suffered class-wide harm from that delay. Therefore, the court denied the plaintiff’s claim that the expert’s opinions did not fit the facts of the case.

Ruling

The court rejected the plaintiffs’ motion to exclude the immunology expert witness testimony.

Key Takeaways for Experts

Here, a medical expert was challenged for injecting anecdotal observations into his testimony. But since his opinion was grounded in his immunology expertise, this portion of the report was not found to be out of scope. Despite the report was not entirely empirical, the court still found value. This case demonstrates how the court values observational testimony in addition to strictly scientific findings.

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