The U.S. Supreme Court is showing some preliminary interest in reviewing biologic drug patents and the proper way to claim them, an issue potentially worth many billions of dollars.

The court on Monday asked Solicitor General Elizabeth Prelogar’s office to weigh in on Amgen v. Sanofi. The question presented is whether Section 112 of the Patent Act requires that patents enable persons of skill in the art to identify and make all of the embodiments of an invention without undue experimentation.