In a big win for drug manufacturers, the 3rd U.S. Circuit Court of Appeals has ruled that federal law bars a suit alleging false-advertising claims under state law because the U.S. Food and DrugAdministration has “exclusive authority” to regulate prescription drug advertising.

“To allow generalized state consumer fraud laws to dictate the parameters of false and misleading advertising in the prescription drug context would pose an undue obstacle to both Congress’ and the FDA’s objectives in protecting the nation’s prescription drug users,” U.S. Circuit Judge D. Brooks Smith wrote in his 51-page opinion in Pennsylvania Employees Benefit Trust Fund, et al. v. Zeneca Inc.