Suppose a plaintiff brings an action against a pharmaceutical manufacturer by asserting a claim of failure to warn. The plaintiff alleges that the prescription drug used to treat a medical condition caused, or created an increased risk of, a separate illness. The plaintiff claims that the defendant pharmaceutical manufacturer therefore should be liable for damages owing to its failure to warn of this risk on the drug's labeling.
In response, the pharmaceutical manufacturer may be able to assert the defense of conflict preemption. Specifically, the defendant would argue that federal law preempts state law because state tort law, which the plaintiff claims the defendant failed to satisfy, imposes a duty impossible to meet in light of U.S. Food and Drug Administration (FDA) regulations. Because state tort law has been preempted under the circumstances, the manufacturer would argue, the plaintiff cannot maintain a claim for failure to warn.
The defense of conflict preemption imposes a high burden on its proponent. Under the evidentiary standard articulated by the U.S. Supreme Court in Wyeth v. Levine,555 U.S. 555 (2009), the party proposing conflict preemption must show "clear evidence" that the FDA would not have approved a change in the label of the relevant drug correcting the specific labeling deficiency alleged by the plaintiff. The Court, however, did not define what constitutes "clear evidence," and lower courts have been grappling with this evidentiary issue ever since. To this point, the November 9, 2015, decision by the U.S. District Court for the Southern District of California in In re Incretin-Based Therapies Products Liability Litigation (No. 13-2452)—a case that, by the court's own estimation, involved "unprecedented facts"—provides new guidance as to what factual support will cross the clear-evidence threshold to establish conflict preemption.
Incretin-Based Therapies is a multidistrict litigation concerning four prescription medications used to treat type 2 diabetes. The plaintiffs in the action consist of individuals who were prescribed and consumed one of the four medications at issue. The defendants are the pharmaceutical companies that manufacture and market the four drugs. Each of the medications, which fall under the category of incretin mimetics or incretin-based therapies, received FDA approval. The plaintiffs claimed that the pharmaceutical companies had failed to warn in the product labeling that the drugs cause, or create an increased risk, of pancreatic cancer. As a defense, the defendants asserted conflict preemption. They claimed that it would have been impossible to comply with FDA labeling regulations while also referencing pancreatic cancer on the drugs' labels. After a significant period of discovery, the pharmaceutical companies moved for summary judgment on this issue.
In granting the defendants' motion for summary judgment, the court in Incretin-Based Therapies found clear evidence that the FDA would have rejected a reference to pancreatic cancer in the labeling of the four drugs at issue. In particular, the court focused on seven instances in which the FDA expressed an opinion on the pancreatic safety of the relevant drugs and concluded that the current scientific data did not support a reference to pancreatic cancer. Those seven instances were: (1) an FDA assessment of pancreatic safety in the New England Journal of Medicine, (2) the FDA's rejection of a citizen petition requesting the withdrawal of one of four medications at issue, (3) an FDA "conclusion that the causal association between incretin mimetics and pancreatic cancer is indeterminate," and (4)–(7) the approval by the FDA of four other incretin-based therapies without any reference to pancreatic cancer on the labeling of each drug. Incretin-Based Therapies, at 17. Based on this evidence, the court found that the FDA considered the issue of pancreatic risk in incretin-based therapies but, rather than requiring a label change, had concluded that the causal association between the drugs and pancreatic cancer was indeterminate.
In opposing summary judgment in the defendants' favor, the plaintiffs argued that conflict preemption imposes a higher evidentiary standard. They proposed that the defendants could not satisfy the "clear evidence" requirement absent a showing that the FDA had expressly rejected a proposed labeling change. The court rejected this position as contrary to the Supreme Court's holding in Wyeth v. Levine. "The Supreme Court stated a manufacturer must demonstrate by clear evidence the FDA would have rejected a label change, not whether the FDA did reject the labeling change sought by a plaintiff." Incretin-Based Therapies, at 22 (emphasis in original).