Plaintiffs who took the generic version of the osteoporosis drug Fosamax are pre-empted by federal law from pursuing litigation against its manufacturers, says an appellate court, in upholding a lower court ruling.

Generic drugs by law must mimic brand name drugs and prior rulings have found that generic manufacturers should not be held liable for brand name defects, according to Tuesday's ruling by the 3rd U.S. District Court of Appeals in Philadelphia in In re: Fosamax (alendronate sodium) products liability litigation.

In February, 2011, 91 plaintiffs who had used both Fosamax, which is produced by White House Station, New Jersey-based Merck & Co. Inc., and its generic versions filed a products liability suit in Missouri state court against both Merck and generic manufacturers for damages related to bone fractures they suffered after taking prescribed versions of either Fosamax or its generic version, alendronate sodium. Fosamax is a drug used to treat or prevent osteoporosis and other bone diseases. The litigation was later centralized in U.S. District Court in Newark, N.J.

In a series of orders, the federal district court dismissed all the generic defendants from the case, ruling the plaintiffs' claims were pre-empted by federal law. The plaintiffs appealed the dismissal of their design defect claims. A three-judge panel of the appeals court unanimously upheld the lower court.

In its opinion, the panel pointed to two Supreme Court rulings: In Pliva Inc. v. Mensing, the high court held in March, 2013 that litigation against generic drug manufacturers could not go forward because it is impossible for them to comply simultaneously with the state duty to adequately warn and “their federal duty of sameness,” the federal law that requires generic drug labels to be the same as their branded counterpart.”

And in June, 2013, in Bartlett v. Mutual Pharmaceutical Co., the high court held that state law design-defect claims that turn on the adequacy of a drug's warnings are pre-empted by the Pliva ruling.

The prior rulings, “recognize that manufacturers have no control over the design or labeling of generic drugs,” said the appeals court ruling.” The plaintiffs “have failed to identify anything the generic defendants can do to reconcile their conflicting duties under state and federal law,” said the court, in affirming the lower court ruling dismissing generic manufacturers from the case.