In a trio of recent decisions arising out of cases alleging that an antipsychotic medication, Risperdal, and its generic, risperidone, had caused gynecomastia (breast tissue growth) in men, the United States District Court for the District of Delaware granted motions for summary judgment for defendant Janssen Pharmaceuticals, Inc. The three opinions clarify that Delaware law would not impose innovator liability on a branded drug manufacturer when the plaintiff had used only a generic drug, and addressed “but-for” warnings causation and proximate cause in prescription drug products liability cases. [Disclosure: Drinker Biddle & Reath. LLP attorneys were co-counsel of record in these cases for Janssen.]
Trower: Delaware Would Not Impose Innovator Liability
In a failure-to-warn case, can a brand name manufacturer be liable for injuries a plaintiff sustains from the use of the generic version of the drug? In Trower v. Janssen Pharmaceutical, Inc., the Court focused on this “issue of first impression in Delaware.” 2019 WL 1571834 (D. Del. Apr. 11, 2019).
Innovator liability is a response to PLIVA, Inc. v. Mensing, 131 S. Ct. 2567 (2011), the Supreme Court decision holding “that federal law preempts state tort liability for a generic drug manufacturer’s inadequate labeling.” To avoid PLIVA, plaintiffs argue the brand name manufacturer is liable for injuries caused by the generic for policy reasons.
Although a handful of state courts have adopted innovator liability theories, most have not, and in Trower the District of Delaware decided that Delaware courts would not do so. The Court held that “Delaware law does not support imposing liability on a brand name defendant for a generic manufacturer’s product,” and that “even if Delaware law provided some basis for imposing liability … it would be imprudent for [the Court] to extend Delaware’s law to that point while sitting in diversity.” The Court also held it would grant summary judgment based on warnings causation issues, discussed more fully in its opinion in Green v. Janssen Pharmaceuticals, Inc., 2019 WL 1567841 (D. Del. Apr. 11, 2019).
Green: Plaintiff Cannot Meet “But-For” Warnings Causation Standards
After a discussion of the learned intermediary doctrine in Green, the Court ultimately held the plaintiff could not meet the but-for warning causation standard and granted summary judgment. The Court noted that in a prescription drug failure-to-warn case, the manufacturer satisfies its duty to warn when it provides the prescribing physician, not the patient, with “an appropriate warning about the drug.” Consequently, to establish proximate cause, plaintiff would have to show that an additional or better warning would have affected the physicians’ prescribing decision.
The Court ultimately held that the plaintiff had not shown that but for the allegedly inadequate warning, his doctor would not have prescribed Risperdal. The one prescriber who was deposed testified that additional risk information would not have impacted his decision to prescribe the drug to the plaintiff. Finding “no evidence that, but for the inadequate warning, he would not have been prescribed Risperdal,” the Court granted summary judgment.
Hopkins: Plaintiff Needs Proof of Specific Causation
A third case, Hopkins v. Janssen Pharmaceuticals, Inc. met a similar fate for many of the same reasons. 2019 WL 1567840 (D. Del. Apr. 11, 2019). Summary judgment was granted based on the plaintiff’s use of a generic version of the drug and a failure to establish warnings causation.
But the Court in Hopkins also granted summary judgment based on another aspect of proximate cause, a failure to establish medical causation. The plaintiff presented expert testimony supporting general causation – i.e., that risperidone can cause gynecomastia. However, the plaintiff overlooked an important component of causation: he had no expert opinion demonstrating that the use of risperidone caused the plaintiff’s injuries. Consistent with the law in other states, the Court held that “evidence of only ‘general causation’ is insufficient to establish a negligence claim under Delaware law.”
Taken together, the Trower, Green and Hopkins cases are an example of a district court sitting in diversity staying firmly in its lane, refusing to go beyond existing state law to adopt expansive theories of innovator liability and proximate cause.