Before Wallach, Clevenger, and Stoll. Appeal from the United States District Court for the District of Delaware.

Summary: Claims directed to a specific method of treatment for specific patients using a specific compound at specific doses to achieve a specific outcome may be patent eligible, despite using a natural law or phenomenon.

Endo sued Actavis Pharma and Teva alleging infringement of a patent (‘737 Patent) covering a method of using oxymorphone to treat pain in patients with impaired kidney function. In response, Actavis moved to dismiss Endo’s patent infringement claims under § 101. The magistrate Judge recommended granting Actavis’s motion, reasoning that the claims are directed to a natural law under the Alice/Mayo framework. The district court adopted the magistrate judge’s recommendation and entered partial judgment of ineligibility in the Actavis case and final judgment of ineligibility in the Teva case. Endo appealed.

The Federal Circuit, reviewing the grant of the motion to dismiss and the patent eligibility determination de novo, reversed, finding the claims to be directed to the patent-eligible method of using oxymorphone to treat pain in a renally impaired patient. The Federal Circuit found that the claims, like those in Vanda Pharmaceuticals Inc. v. West-Ward Pharmaceuticals International Ltd, 887 F.3d 1117 (Fed. Cir. 2018), recite a method for treating a patient, wherein the method comprises the steps of carrying out a dosage regimen based on the results of some form of testing. Additionally, the claims require specific treatment steps, such as requiring doctors to orally administer the drug to a patient at a lower dosage based on the measured test results in such a way that the concentration of the drug over time did not exceed a recited level in the patient’s body. Thus, the claims are directed to a specific method of treatment for specific patients using a specific compound at specific doses to achieve a specific outcome.

The Federal Circuit also distinguished this case from Mayo, explaining that the claims in Mayo sought to claim the relationship between dosage of a drug and a particular condition, while the ‘737 claims are directed to an application of that relationship, specifically, a method of treatment including specific steps to adjust or dosage for patients with the condition.

Thus, the Federal Circuit found that the claims were patent eligible and reversed the district court’s decision.

This case is: ENDO PHARMACEUTICALS INC. v. TEVA PHARMACEUTICALS USA, INC.