The second of the two business-friendly decisions issued by the Corporate Court today was PLIVA v. Mensing, a case involving a woman seriously injured by the generic drugs she took. Since the manufacturer knew that the risks were much greater than had been believed at the time the FDA approved its labeling, she sued in state court over its failure to warn of those risks. Today, the five conservatives ruled that she has no right to file such a lawsuit.

All prescription drugs must have warning labels that are approved by the FDA. Under a recent precedent, if a brand-name drug manufacturer fails to warn consumers of a known risk not on the label, it cannot avoid being sued in state court simply by saying its label was okayed by the FDA. Today’s case was similar, except in this case it was a generic drug maker, calling into play a separate federal law that requires generics to use the same warning labels as brand-names.

Gladys Mensing developed a severe and irreversible neurological disorder as a result of her long-term use of a generic drug. At the time, the label indicated that the risk of a disorder of the type she developed was about one in 500 patients. However, according to Mensing, it turned out that the actual incidence was much higher, perhaps as high as one in five patients. Despite mounting evidence that the label greatly understated the risks, none of the companies that manufactured the drug proposed that the FDA modify the warning label.

According to the majority opinion, written by Justice Thomas, the generic drug maker cannot be sued in state court for failing to warn consumers because that state law is preempted by the federal "same label" law. They claimed that the company could not have changed its label without violating federal law. But further than that, they had no obligation to ask the FDA to update the label for the drug (a change that, if adopted, would have applied to the brand name and then, by extension, to the generic). Even if the generic drug maker had gone to the FDA, it could not have changed the label itself until granted permission by the federal government, so Ms. Mensing could not have been warned as required by state law. Compliance with both state and federal law is impossible, according to the majority, so the federal law must preempt the state one under the Supremacy Clause of the United States Constitution.

Justice Sotomayor’s dissent (joined by Ginsburg, Breyer, and Kagan) harshly criticized Justice Thomas’s reasoning. We do not know if it would really have been impossible for the generic drug manufacturer to have complied with state law by getting the FDA to approve a label change in a timely manner, because it did not even try. Justice Sotomayor writes:

We have traditionally held defendants claiming impossibility to a demanding standard: Until today, the mere possibility of impossibility had not been enough to establish pre-emption.

…

The Court strains to reach [its] conclusion. It invents new principles of pre-emption law out of thin air to justify its dilution of the impossibility standard. It effectively rewrites our [2009] decision in Wyeth v. Levine, which holds that federal law does not pre-empt failure-to-warn claims against brand-name drug manufacturers.

So as of today, the ability of a victim to collect under state law for failure to warn of a prescription drug’s dangers depends on happenstance: whether the pharmacist happened to fill the prescription with a brand name or a generic.

Congress has acted over the years to make low-cost generics more widely available to the American people. Surely a result like today’s was not its intent.