Bayer Pharma Aktiengesellschaft v. Mylan Pharms. Inc

Authored by: Jeremy J. Gustrowsky

In a recent patent dispute over treatments for heart disease, Bayer challenged generic drug makers’ efforts to invalidate its patent on combining low-dose rivaroxaban—a blood thinner—with aspirin to reduce risks like heart attacks and strokes in patients with artery problems.

The patent, known as the ‘310 patent, covers specific methods of administering these drugs in exact amounts: 2.5 mg of rivaroxaban twice a day and 75-100 mg of aspirin daily. It includes language stating the doses are “clinically proven effective” based on trial results. Generic companies like Mylan, Teva, and Invagen argued before the Patent Trial and Appeal Board (PTAB) that prior research already suggested this combination, making the claims obvious or anticipated. The PTAB agreed, ruling all challenged claims unpatentable.

The Federal Circuit upheld part of the PTAB decision but sent part of the case back for more review. It decided that the “clinically proven effective” phrase, even if it requires real-world trial evidence, doesn’t make the patent valid because it doesn’t change how the drugs actually work or interact—it’s just a label on an already-known method. However, the court clarified that claims mentioning a “first product comprising rivaroxaban and aspirin” must mean a single pill or form containing both drugs, not separate ones taken together. This narrower interpretation could strengthen those claims on remand.

This decision highlights how courts scrutinize pharmaceutical patents to ensure they protect true innovations rather than merely adding descriptive words to known treatments. This will be relevant to future cases where companies try to extend patents on drug combos using clinical trial results.