A federal judge has shaved several theories from a cluster of cases against Bayer Corp. over its Essure birth control device, finding that express pre-emption applied to many of the plaintiffs’ claims.

U.S. District Judge John R. Padova of the Eastern District of Pennsylvania on Tuesday in Strimel v. Bayer dismissed liability theories stemming from failure to warn, failure to train and other claims. Although the plaintiffs can still proceed on most causes of action, Padova pared down the theories that the plaintiffs can make, finding that many of the allegations were pre-empted by federal regulations.