This case is an appeal from the United States District Court for the District of Delaware and relates to an Abbreviated New Drug Application ("ANDA") with the Food and Drug Administration ("FDA") seeking to market generic versions of Endo’s Opana® ER products (extended release oxymorphone). Specifically, the case involves Endo’s U.S Patent 8,808,737 ("US-737") entitled “Method of treating pain utilizing controlled release oxymorphone pharmaceutical compositions and instructions on dosing for renal impairment.”
Endo Pharmaceuticals Inc., and Mallinckrodt LLC sued for patent infringement against multiple defendants who had ANDAs to market generic versions of Endo’s Opana® ER products. The cases were consolidating the suits based on various combinations related to different defendants and different patents that were at issue.
The district court entered partial, and later final judgement of ineligibility of US-737 for lack for patent-eligible subject matter under § 101. It dismissed Endo’s claims in the Actavis case. Based on that order, Endo stipulated that the patent claims were ineligible (subject to Endo’s right to appeal) in the Teva case, which was before the same district court judge. Accordingly, the district court entered partial, and later, final judgment of ineligibility. In the Actavis case, the court entered a Rule 54(b) partial judgment of ineligibility.
Endo Appealed arguing that the district court was wrong on the substance [in that the US-737 claims were patent eligible as they are directed to a patent-eligible method of treatment] and on the process [in that the factual disputes precluded dismissal based on the pleadings alone].
The Court of Appeals for the Federal Circuit ("CAFC"), reviewing the grant of the motion to dismiss and the patent eligibility determination de novo, held that the claims are not directed to patent-ineligible subject matter and reversed the district court's decision.
Claim 1 of US-737 recites:
A method of treating pain in a renally impaired patient, comprising the steps of:
a. providing a solid oral controlled release dosage form, comprising:
i. about 5 mg to about 80 mg of oxymorphone or a pharmaceutically acceptable salt thereof as the sole active ingredient; and
ii. a controlled release matrix; b. measuring a creatinine clearance rate of the patient and determining it to be (a) less than about 30 ml/min, (b) about 30 mL/min to about 50 mL/min, (c) about 51 mL/min to about 80 mL/min, or (d) above about 80 mL/min; and
c. orally administering to said patient, in dependence on which creatinine clearance rate is found, a lower dosage of the dosage form to provide pain relief;
wherein after said administration to said patient, the average AUC of oxymorphone over a 12-hour period is less than about 21 ng·hr/mL.
Teva argued that the above claim is indistinguishable from the claims held ineligible in Mayo Collaborative Services v. Prometheus Laboratories, Inc., 566 U.S. 66 (2012). On the other hand, Endo argued that the ’737 claims were indistinguishable from the claims held eligible in Vanda Pharmaceuticals Inc., v. West-ward Pharmaceuticals Int’l Ltd., 887 F.3d 1117 (2018).
Focusing its analysis on step one of the two-step framework to determine subject matter eligibility under § 101 established by the Supreme Court in Mayo -- “whether the claims at issue are directed to one of those patent-ineligible concepts” -- CAFC concluded that the claims at issue ("US-737 claims") are not directed to patent-ineligible subject matter. “It is not enough to merely identify a patent-ineligible concept underlying the claim," the panel emphasized "we must determine whether that patent-ineligible concept is what the claim is 'directed to.'"
Weighing heavily on the similarities between the claims at issue here and in Vanda, the panel concluded that US-737 claims are eligible because they are “directed to a specific method of treatment for specific patients using a specific compound at specific doses to achieve a specific outcome.” It highlighted that the claimed invention here, like in Vanda, is not simply a relationship between a (drug) oxymorphone and a patient's condition. " The claim is directed to "an application of that relationship," the panel highlighted - "specifically, a method of treatment including specific steps to adjust or lower the drug oxymorphone dose for patients with renal impairment."
Although US-737 claims contain steps based on the results of kidney function, reciting the specific steps of carrying out a dosage regimen was the important element that differentiates US-737 claims and the claims at issue in Vanda from other cases discussed in the decision (more below), according to the panel. "The claims prescribe a specific dosage regimen through the wherein clause, under which the physician administers oxymorphone to achieve a specific range of AUC of oxymorphone based on the patient’s creatinine clearance rate." Also highlighting similarities between US-737 claims and those at issue in Rapid Litig. Mgmt. Ltd. v. CellzDirect, Inc., 827 F.3d 1042, 1050 (Fed. Cir. 2016), the panel reiterated that "the claims here are directed to a new and useful method of treating pain in patients with impaired renal function" and that "the result of the claims here is not simply an observation or detection."
In addition to an application of a relationship between a drug and patients with related condition specifically, the panel underscored that in the instant case the method of treatment claim includes:
- specific steps to adjust or lower the drug dose for patients with the condition, and
- steps of carrying out a dosage regimen based on the results of testing the patient's response to the drug.
The panel highlighted that it is the combination of the administering step and the wherein clause claim language "taken together, that make the claims-at-issue as specific as those in Vanda such that the patent claims do not “tie up the doctor’s subsequent treatment decision.” It emphasized that the administering step and wherein clause in the present claims allow the claims to "do more than just recognize a need to lower or decrease a dose."
Differentiating US-737 claims from those in Mayo, the panel highlighted that the administering step in the claim here describes giving a specific dose of the drug based on the results of kidney function testing. "Whereas the administering step in Mayo is the first step in the method that simply describes giving the drug to a patient with a certain disorder," the panel reasoned, in addition to highlighting that "the claim in Mayo as a whole was not directed to the application of a drug to treat a particular disease." Further differentiating US-737 claims from those in Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371 (Fed. Cir. 2015) and Athena Diagnostics, Inc. v. Mayo Collaborative Servs., LLC, 915 F.3d 743 (Fed. Cir. 2019), the panel highlighted that in Ariosa and Athena the claims "only encompasses the natural law." Unlike the claims in Ariosa, the claims here "recite a specific method of treatment based on the recognition that patients with severe renal impairment have a mean oxymorphone AUC, on average, 1.7 times greater than healthy subjects."
In summary, the panel highlighted that it already acknowledged “claiming a new treatment for an ailment, albeit using a natural law, is not claiming the natural law,” and stated that "that is exactly the situation we have here." It thus concluded that US-737 claims are directed to "a new treatment for an ailment, albeit using a natural law or phenomenon," and held that they are "not directed to the ineligible subject matter itself and, as such, are eligible."
NOTE: The text in bold is meant to highlight learnings from the decision that can applied during patent prosecution, including drafting specification and claims, in related subject matter. The decision highlights various important points for patent practitioners to use while drafting patent applications. Feel free to contact us to further discuss the decision.
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