A New Jersey Appellate Division panel of Judges Fisher, Accurso, and Rose recently rendered a per curiam decision affirming a trial court’s decision to exclude several expert witnesses in litigation that consisted of thousands of cases filed by plaintiffs who alleged they developed inflammatory bowel disease (IBD) in the form of ulcerative colitis or Crohn’s disease as a result of their use of Accutane (isotretinoin).  

In 2015, the trial judge granted a defense motion to exclude two plaintiffs’ experts—a gastroenterologist and a statisticianfrom testifying that Accutane, a prescription acne drug manufactured by Defendants can cause Crohn’s disease. The Superior Court-Appellate Division reversed that determination, but the Supreme Court reversed the judgment and upheld the trial judge’s exclusion of the expert testimony of the two experts. 

In early 2017, the trial judge conducted a 10-day hearing and, for the reasons expressed in a thorough written opinion, granted Defendant’s motion to bar the expert testimony of another gastroenterologist (“G-2”) and an epidemiologist, about whether Accutane caused plaintiffs’ ulcerative colitis. An order identified the 3,231 claims that were dismissed as a result of that determination.   

Plaintiffs appealed, which the Appellate Division stayed while awaiting the Supreme Court’s decision concerning the gastroenterologist and statistician‘s opinions. Once the Supreme Court rendered its decision, the Appellate Division requested supplemental briefs as to whether the Daubert factors of expert admissibility adopted by the Court ought to be applied here, and if so, whether the existing record was sufficient, or a remand was required. In their supplemental briefs, the parties agreed that the Daubert factors applied and a remand wasn’t required.   

After close examination of the record in light of the guidelines and factors adopted in the Supreme Court’s recent Accutane decision, the Appellate Division concluded that although DrG-2 and the epidemiologist appeared to be qualified, the trial judge did not abuse his discretion in excluding their testimony because the opinions of these experts incorporated the same methodological defects identified by the Court. This included the disregarding of eight of the nine epidemiological studies in favor of animal studies and case reports. And, even though the data in the epidemiological studies was slightly more supportive of an association between Accutane and ulcerative colitis, there was insufficient evidence of a difference between these subtypes of IBD to warrant excluding the causation experts’ testimony on Crohn’s disease while allowing similar expert causation testimony as to ulcerative colitis.   

The Supreme Court’s Accutane decision, which came down while this appeal was pending, did not alter Rules 702 or 703, nor would its holding “produce substantial inequitable results if applied retroactively.” As a result, the Appellate Division applied the Court’s recent holding to the issues presented in this appeal.   

The Appellate Division  panel said that an expert’s opinion on causation in prescription drug cases may be admitted when “based on a sound, adequately-founded scientific methodology involving data and information of the type reasonably relied on by experts in the scientific field,” quoting a New Jersey Supreme Court decision. 

The high court also explained that in cases involving novel theories of causation, a court must review the “data and studies relied on by experts proffering an opinion in order to ‘determine whether the expert’s opinion is derived from a sound and well-founded methodology that is supported by some expert consensus in the appropriate field.’” Further, a court must also assess “the soundness of the proffered methodology and the qualifications of the expert. Daubert held that the focus must be “solely on principles and methodology, not on the conclusions that they generate.” 

The Appellate Division said that Supreme Court emphasized that the trial court must ensure compliance with the requirement of some expert consensus that the methodology and the underlying data are generally followed by experts in the field, distinguish scientifically sound reasoning from that of the self -validating expert, and disallow “unsubstantiated personal beliefs.”  

Citing Daubert, the New Jersey Supreme Court in the recent Accutane decision concluded that New Jersey law and Daubert were aligned in their general approach to a methodology-based test for reliability. Both ask whether an expert’s reasoning or methodology underlying the testimony is scientifically valid. 

The Accutane Court went on to state that when a proponent fails to demonstrate the soundness of a methodology, both in terms of its  approach to reasoning and to its use of data, from the perspective of others within the relevant scientific community, the gatekeeper should exclude the proposed expert testimony on the basis that it is unreliable. 

The trial judge conducted a hearing over the course of 10 days, during which he heard the testimony of plaintiffs’ experts, the two gastroenterologists and the epidemiologist. Defendants also provided the testimony of experts: an epidemiologist and biostatistician, and a gastroenterologist. At the hearing’s conclusion, the trial judge entered an order that precluded the expert testimony of plaintiffs’ experts. In his written decision, the judge examined the expert testimony and scientific studies, set forth the relevant legal standard for the admission of expert testimony, and found that plaintiffs’ experts’ testimony failed to meet that standard.   

In determining if the expert testimony was based on a “sound, adequately-founded scientific methodology involving data and information of the type reasonably relied on by experts in the scientific field,” the trial judge correctly considered “whether other scientists in the field use similar methodologies in forming their opinions and also should consider other factors that are normally relied upon by medical professionals,” the Appellate Court panel, wrote, quoting the Supreme Court. 

The trial judge explained that the “appropriate inquiry is not whether the [c]ourt thinks that the expert’s reliance on the underlying data was reasonable, but rather whether comparable experts in the field would actually rely on that information.” Applying that standard, the judge found unsound the experts’ methodology. He found that the epidemiologist appeared to have had “very limited exposure” to issues related to pharmaco-epidemiology, and frequently disregarded “the fundamentals of the scientific method, particularly, the medical-evidence hierarchy.”   

The judge next found that the epidemiologist failed to follow the scientific methodology in placing “unswerving reliance” on only one study, which had never been replicated. The results of another study was cited without more information about the participants and without peer review.  

The judge found that Dr. G-2‘s methodology was unsound because he “frequently disregard[ed] the fundamentals of the scientific method,” that he was “strongly associated with previous isotretinoin exposure,” but there was “no apparent association” between isotretinoin and Crohn’s disease. As this is the first epidemiological study to describe a positive association between isotretinoin and ulcerative colitis, these results should be confirmed by additional studies in other populations, the trial judge remarked. 

The judge also found Dr. G-2‘s “cavalier use of disparaging language toward the peer-reviewed treatises of other scientists [was] indicative of the ‘hired gun’ mentality.” Further, Dr. G-2 hadn’t published a peer-reviewed article or proposed “a hypothesis on the purported causal association between isotretinoin and IBD, nor do any of the peer-reviewed articles cited by him propose such a hypothesis. Without a hypothesis pulling together lines of evidence, the Appellate Division panel said that the trial judge found Dr.  G-2‘s opinions lacked theoretical coherency. Even so, the judge recognized that Dr. G-2‘s failure to write a peer-reviewed article supporting his causation opinion “is not in and of itself, disqualifying to an expert in an expert hearing.” However, that failure did “bespeak[] an expert who expresses a different set of opinions in the courtroom than he is willing to express to his colleagues.  

Notably, while some of the epidemiological studies showed a positive association between Accutane and ulcerative colitis, the experts were unable to point to any consistent showing across the studies, the Appellate Division said. With these views, and aided by expert testimony offered by Defendants, the trial judge barred Plaintiffs’ experts from testifyinga determination that led to the dismissal of the claims.        

The Appellate Division held that there was little to distinguish between the Court’s disposition of the trial judge’s ruling as to the gastroenterologist and statistician, and the disposition under review here. The epidemiological data was only slightly more favorable in the case of ulcerative colitis, but it didn’t support a finding that there was an association, much less a causal association, between Accutane and ulcerative colitis. Further, the panel said that the data has become even less favorable since the prior judge’s March 2014 decision, where she considered six epidemiological studies, and one meta-analysis. Since then, two more epidemiological studies and another meta-analysis pushed the estimate even further away from an association between Accutane and ulcerative colitis. Nonetheless, Dr. G-2 continued to rely on the same lines of evidence that the Supreme Court found problematic in its recent decision. In adhering to the trial judge’s gatekeeping role as described in Accutane, Dr. G-2‘s testimony on ulcerative colitis was similarly unreliable.   

Thus, the Appellate Division found little to distinguish between the record concerning the proffered expert testimony of Drs. G-2 and the epidemiologist, and the record that led the Supreme Court to reinstate the trial judge’s exclusion of the expert testimony of the gastroenterologist and statistician. The trial judge did not abuse his discretion in barring the expert testimony in question. Instead, he engaged in the very same type of gatekeeping which the Supreme Court approved in its prior decision.   

The trial court’s decision to exclude the experts was affirmed.