More than a dozen plaintiffs suing Bayer over its birth control device Essure are fighting to have their cases remanded to state court.

Fifteen plaintiffs alleging that the company negligently misrepresented the safety of the medical device and failed to warn about its risks filed a motion Monday contending that their cases needed to be sent back to the Philadelphia Court of Common Pleas where they were originally filed. Keeping the cases in the U.S. District Court for the Eastern District of Pennsylvania, where they are currently being litigated, could spell the end for some of the plaintiffs’ claims, as the district court has already determined some claims in similar Essure cases to be pre-empted under federal law.