A federal appeals court declined to reopen hundreds of claims filed by women alleging that GlaxoSmithKline Plc neglected to warn them that using the anti-nausea medication Zofran during pregnancy might result in birth abnormalities.
The 1st U.S. Circuit Court of Appeals in Boston concluded that federal law preempts the plaintiffs' state-law allegations that GSK neglected to warn doctors and pregnant women about animal studies that indicated a relationship between taking Zofran and birth abnormalities.
The verdict affirmed a 2021 decision by a United States district judge that marked the conclusion of 425 complaints consolidated before him in long-running multidistrict litigation.
GSK said in a statement that the verdict was appreciated because the US Food and Drug Administration had consistently rejected the product labelling that plaintiffs' attorneys had asked for in this dispute. A request for a response from the plaintiffs' counsel was not returned.
The FDA authorized Zofran in 1991 to prevent nausea and vomiting induced by surgery, chemotherapy, or radiation therapy; nevertheless, the plaintiffs claimed that GSK pushed the medicine as an off-label treatment for morning sickness without sufficiently advising of the hazards.
The plaintiffs' attorneys argued that the Japanese animal studies that GSK allegedly hid from the FDA would have warranted a revision to the drug's warning label saying the research found detrimental effects on the foetus.
However, a U.S. Circuit Judge writing for the three-judge panel stated that those studies did not constitute newly obtained knowledge and that the FDA was previously aware of the hazards as a consequence of earlier research when it authorised Zofran. The judge also stated that without any new information, GSK could not legally update the label without the FDA's approval. Even if the Japanese studies revealed new evidence, the FDA's later decision in 2021 to approve an amended warning label weakened the plaintiffs' allegations.
The 2021 update came in response to a request by Novartis AG, which had bought Zofran from GSK in 2015 and recommended warnings about the hazards to foetuses.
But the judge stated the FDA, by then, was aware of the Japanese research, instead authorised a label that read "animal data demonstrated "no substantial effects of (Zofran) on the maternal animals or the development of the offspring.
When the FDA legally approves a label expressing one thing with full and apparent notice of the directly opposing opinion, the approval might be seen as rejecting the opposing position.