The U.S. solicitor general has asked the U.S. Supreme Court to review a case that addresses one of the most significant federal pre-emption issues for brand drug companies since Wyeth v. Levine.

In a brief filed on Tuesday, Principal Deputy Solicitor General Jeffrey Wall urged the high court to take up a petition filed by Merck & Co. asking to reverse the U.S. Court of Appeals for the Third Circuit’s reinstatement of more than 500 cases brought over osteoporosis drug Fosamax. At issue is the Supreme Court’s “clear evidence” holding in its 2009 decision in Wyeth and who—a jury or a judge—should decide whether the U.S. Food and Drug Administration would have rejected a drug manufacturer’s proposed labeling changes.