For the second time, the U.S. Court of Appeals for the Third Circuit vacated the U.S. District Court for the District of New Jersey’s judgment that plaintiffs’ state law failure-to-warn claims in the Fosamax litigation were preempted under federal law. See In re Fosamax (Alendronate Sodium) Products Liability Litigation, 118 F.4th 322 (3d Cir. 2024) (Fosamax II). The Third Circuit found that the court erred because it gave “too little weight to the required presumption against pre-emption” and improperly determined that the Food and Drug Administration informed Merck that it would disapprove a label change. Unless the Third Circuit’s decision is reversed, this decision revives hundreds of cases, many of which have been dormant since at least 2017.

Background

Fosamax is an FDA-approved medication prescribed to treat and prevent osteoporosis in postmenopausal women. At the time of approval, the label did not warn of the risk of atypical femoral fractures even though Merck was aware of the “theoretical risk” of them. In 2008, after receiving additional evidence, Merck submitted a prior approval supplement (PAS) to update the label. A PAS requires FDA approval before label changes can be made. Merck proposed adding information related to “low-energy femoral shaft fracture” in the Adverse Reactions section and additional information in the Precautions section focusing on the association between Fosamax and stress fractures.