IP Law Daily Method claims for pain treatment of renally impaired patients were patentable
Thursday, March 28, 2019

Method claims for pain treatment of renally impaired patients were patentable

By Thomas Long, J.D.

The claims were not directed to a natural law, but instead were directed to a patent-eligible method of using oxymorphone or a pharmaceutically acceptable salt thereof to treat pain in patients with reduced kidney function.

The claims of a method patent related to the treatment of pain in patients with impaired kidney function by using controlled-release oxymorphone compositions were not directed to a natural law, according to the U.S. Court of Appeals for the Federal Circuit. Therefore, a district court erred in holding the claims ineligible for patent protection under 35 U.S.C. §101. The district court had determined that the claims were directed to the natural law that the bioavailability of oxymorphone was increased in people with severe renal impairment, and the method steps of the claims did not add an inventive concept rendering them patentable. However, in the Federal Circuit’s view, the claims were not directed to a natural law, but to a patentable pain-treatment method for renally impaired patients. They were eligible because they were directed to a specific method of treatment for specific patients using a specific compound at specific doses to achieve a specific outcome. Accordingly, the district court’s dismissal of the patent owner’s infringement complaint against rival pharmaceutical companies was reversed (Endo Pharmaceuticals Inc. v. Teva Pharmaceuticals USA, Inc., March 28, 2019, Stoll, K.).

The patent at issue, U.S. Patent No. 8,808,737 ("the ’737 patent"), was owned by Endo Pharmaceuticals Inc. and was titled "Method of treating pain utilizing controlled release oxymorphone pharmaceutical compositions and instruction on dosing for renal impairment." The ’737 patent was derived from the inventor’s discovery that patients with renal impairment in need of pain relief can be treated in a new, different way from other patients. Specifically, the inventor discovered that patients with moderately or severely impaired kidney function need less oxymorphone than usual to achieve a similar level of pain management. The inventor developed a method that allowed renally impaired pain patients to be treated safely and effectively, based on a correlation between plasma AUC (Area Under the Curve—that is, the area underneath the concentration versus time curve) for oxymorphone and a patient’s degree of renal impairment as indicated by the rate of creatinine clearance. Creatinine is a waste byproduct filtered from the bloodstream by the kidneys; its clearance rate reflects how well the kidneys are working. The method of the ’737 patent avoids possible problems in dosing and allows for treatment with the lowest possible dose for patients with reduced kidney function.

Endo sued Actavis LLC, Actavis South Atlantic LLC, Actavis Pharma, Inc., Actavis Elizabeth LLC, Actavis Holdco U.S., Inc. (collectively, "Actavis") and Teva Pharmaceuticals USA, Inc. and Barr Laboratories, Inc. (collectively, "Teva") for infringing the ’737 patent’s claims 1-6. Actavis moved to dismiss the complaint, arguing that the patent claims were ineligible under Section 101. A magistrate judge recommended granting Actavis’s motion. In the magistrate judge’s view, the claims were directed to the natural law that the bioavailability of oxymorphone was increased in people with severe renal impairment. The magistrate judge also determined that the claims’ steps of "providing," "measuring," and "administering" were not sufficiently inventive to render the claims patent-eligible. The district court adopted the magistrate judge’s recommendation and found the claims patent-ineligible. Based on that order, Endo stipulated in the case against Teva that the claims were ineligible, subject to its right to appeal. Endo then appealed to the Federal Circuit.

The appellate court concluded that that asserted claims were not directed to patent-ineligible subject matter; rather, they were directed to a patent-eligible method of using oxymorphone or a pharmaceutically acceptable salt thereof to treat pain in a renally impaired patient. Claim 1 required specific steps: (a) providing a particular dosage range of oral controlled-release oxymorphone or one of its pharmaceutically acceptable salts, (b) testing the patient for reduced kidney function based on creatinine clearance rate, and then (c) administering the pharmaceutical based on the creatinine clearance rate to achieve an average AUC of oxymorphone over a 12-hour period of less than 21 ng·hr/mL. "Consistent with the claims, the abstract, patent title, and summary of the invention all describe the invention as a ‘method of treating pain’ in patients with renal impairment," the court said. "The specification predominantly describes the invention as a method that treats renally impaired pain patients with less oxymorphone while still treating their pain."

The court noted that it had held similar claims patent-eligible in Vanda Pharmaceuticals Inc. v. West-Ward Pharmaceuticals International Ltd., 887 F.3d 1117 (Fed. Cir. 2018). In Vanda, the Federal Circuit held that patent claims reciting a method of using the drug iloperidone to treat schizophrenia were eligible under 35 U.S.C. §101 because they were not "directed to" the recited natural relationship between the patient's genotype and the risk of QTc prolongation (an abnormality in the patient’s heart rhythm), but they claimed an application of that relationship. The claims at issue here were legally indistinguishable from the representative claim in Vanda, in the court’s view. They both recited the steps of carrying out a dosage regimen and required specific treatment steps. The court also noted that the claims of the ’737 patent were directed to the application of a treat to treat a particular disease, unlike the claims found invalid in Mayo.

Because the ’737 patent claims were not directed to patent-ineligible subject matter, the appellate court reversed the district court’s decision.

This case is Nos. 17-1240, 17-1455, and 17-1887.

Attorneys: Martin Jay Black (Dechert LLP) for Endo Pharmaceuticals Inc. William H. Burgess (Kirkland & Ellis LLP) for Teva Pharmaceuticals USA, Inc., Actavis LLC f/k/a Actavis Inc., and Actavis South Atlantic LLC. Huiya Wu (Goodwin Procter LLP) for Barr Laboratories, Inc.

Companies: Endo Pharmaceuticals Inc.; Mallinckrodt LLC; Teva Pharmaceuticals USA, Inc.; Actavis LLC f/k/a Actavis Inc.; Actavis South Atlantic LLC; Barr Laboratories, Inc.; Actavis Pharma, Inc.; Actavis Elizabeth LLC; Actavis Holdco U.S., Inc.

MainStory: TopStory Patent FedCirNews

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