First Circuit Upholds Preemption in Zofran MDL

The U.S. Court of Appeals for the First Circuit affirmed the entry of summary judgment in favor of GlaxoSmithKline (GSK) in the Zofran multidistrict litigation (MDL) on January 9, 2023. The MDL involved over 400 lawsuits alleging that GSK failed to warn that Zofran could cause birth defects if taken by pregnant women. Zofran was initially approved by the Food and Drug Administration (FDA) for nausea resulting from chemotherapy treatment but was regularly prescribed off-label by physicians for pregnancy-related nausea. The plaintiffs alleged that an additional warning should have been added to the label regarding the risk of birth defects. These allegations were based upon three Japanese animal studies sponsored by GSK in the 1980s which were not submitted to the FDA when it considered a label change in 2010 related to the use of Zofran during pregnancy.

GSK initially moved for summary judgment in early 2019, which was denied. Subsequently, the U.S. Supreme Court decided Merck Sharp & Dohme Corp. v. Albrecht in May of 2019, holding that preemption is a matter of law for a judge, rather than a jury, to decide. GSK then filed a renewed motion for summary judgment.

Judge Dennis F. Saylor IV of the U.S. District Court for the District of Massachusetts granted summary judgment for GSK on June 1, 2021, holding that federal law preempted the plaintiffs' state law claims on the basis of clear evidence that the FDA would have rejected the warning that plaintiffs alleged was required under state law. Plaintiffs appealed, arguing that the FDA never expressly rejected a label change based upon the three Japanese animal studies.

In deciding the appeal, the First Circuit justices noted that the three Japanese animal studies at issue attributed the birth defect risks to factors other than Zofran, and that GSK had already provided the FDA with similar data from other animal studies during the initial consideration of whether to add a warning to the label. The opinion notes that the three Japanese animal studies at issue had been conducted in the 1980s specifically to satisfy Japanese regulatory requirements and did not constitute “newly acquired information” that would support a label change.

Further, the opinion notes that in 2021, the FDA allowed GSK’s successor Novartis’ request to revise the Zofran label to state that that the animal tests revealed "no significant effects of [Zofran] on the maternal animals or the development of the offspring" after the FDA had received the three Japanese animal studies at issue. Therefore, the FDA’s approval of the revised label “is formal agency action with the force of law” and a clear rejection of the plaintiffs’ position about a warning to the contrary.

The main takeaway from this decision is the clarification of the Merck v. Albrecht decision that the FDA does not need to expressly reject a request for a label change where it approves a different label change directly contrasting the other proposal. As the court noted, “We think it clear that when the FDA formally approves a statement that data reveals no effects, it necessarily rejects the contention that the data does reveal effects.”