The justices heard arguments in Merck’s appeal of a lower court ruling that revived the lawsuits filed in federal court by patients who said they suffered debilitating bone breaks after taking the drug.
Some conservative justices as well as liberal Justice Stephen Breyer emphasized that the U.S. Food and Drug Administration had been uncertain about the fracture risk and rejected Merck’s proposal to add a warning label to the medication.
The nine-justice court, which has a 5-4 conservative majority, must decide whether a pharmaceutical company can be held liable under such circumstances.