A seeming contradiction between two recent federal district court rulings on preemption and the U.S. Food and Drug Administration’s oversight of pharmaceuticals creates some uncertainty about whether evidence submitted by the drug manufacturer of inaction by the FDA is enough to establish that the FDA would not have approved a heightened warning to the drug’s label.

Preemption is a demanding defense which will not succeed without “clear evidence” that the FDA would not have approved an enhanced drug warning label. Wyeth v. Levine, 555 U.S. 555, 571 (2009). Noting that Wyeth does not define what constitutes clear evidence, and that the application of that standard is necessarily fact specific, in November 2015 a United States District Court Judge from the Southern District of California granted summary judgment on behalf of Merck Sharp & Dohme Corp., Eli Lily & Co. and others on plaintiffs’ state law failure-to-warn claims, finding that the FDA would have rejected earlier pancreatic cancer warning labels for those drugs.

In support of its preemption defense, the defendants cited to seven instances where the FDA had taken a position on pancreatic safety, including a September 2014 conclusion that a casual association between incretin mimetics – the class of drugs at issue – and pancreatic cancer is indeterminate. Plaintiffs argued that absent actual and express rejection by the FDA of a proposed labeling change referencing pancreatic cancer, the drug manufacturers could not meet the clear evidence standard for preemption. The court concluded that the FDA had specifically considered pancreatic cancer risk, commented publicly on the adequacy of drug labeling, and maintained its position that scientific evidence of a causal association is indeterminate. And because indeterminate causal association falls below the federal regulatory standards required for labeling changes, the “FDA’s subsequent inaction regarding drug labeling supports the conclusion that the FDA does not consider available scientific evidence of a causal association sufficient to warrant inclusion in the labeling.” Clear evidence therefore exists that the FDA would have rejected a reference to pancreatic cancer in product labeling. In re: Incretin-Based Therapies Product Liability Litigation, 13md2452, United States District Court, Southern District of California.

In comparison, a four-page February 2016 decision by an Illinois federal district court judge rejected GlaxoSmithKline’s preemption argument, suggesting that simple inaction by the FDA does not suffice. The court found that while GSK’s preemption argument rested on the premise that the FDA had considered and rejected an adult suicide warning label during the relevant time, the record suggested otherwise. The short opinion noted that, in 2007, the FDA had told GSK that if it wanted to discuss the specific adult warning language, it should submit a formal meeting request; GSK never asked for a formal meeting, nor did it seek additional labeling. As such, GSK had failed to meet its “demanding burden” of demonstrating by clear evidence that the FDA would have rejected an adult suicide warning on the label. Dolin v. SmithKline Beecham Corp., 12C6403, United States District Court, Northern District of Illinois.

A close reading of the two opinions suggests that conscious inaction by the FDA may satisfy the “clear evidence” requirement. A strong showing by the drug manufacturer that the FDA had evaluated the risk and a possible causal association and decided not to act should satisfy the burden for establishing preemption. We will update readers with additional decisions on this issue.