On April 13, 2018, in a split decision, the Federal Circuit held that Vanda Pharmaceuticals Inc.’s method of treatment claims are directed to patent-eligible subject matter under step one of the Mayo two-step test1. Vanda Pharm. Inc. v. West-Ward Pharm. Int’l Ltd., No. 2016-2707, 2018 WL 1770273 (Fed. Cir. Apr. 13, 2018). Notably, Chief Judge Prost dissented, stating that the asserted claims have “no distinction from Mayo” and “the end result of the claimed process is no more than the conclusion of a natural law.” Id. at *21 (Prost, C.J., dissenting).
The patent-in-suit, U.S. Patent No. 8,586,610 (“the ’610 patent”), claims a method of treating schizophrenia patients with iloperidone wherein the dosage range is based on the patient’s genotype. Id. at *1. The district court of the District of Delaware found that (1) under Mayo step one, the asserted claims—the relationship between iloperidone, CYP2D6 metabolism, and QTc prolongation—are directed to laws of nature, (2) under Mayo step two, the asserted claims are nevertheless patent-eligible because the method “addresses natural relationships to which the claims add conducting CYP2D6 genotyping tests to determine the appropriate dose of iloperidone to reduce QTc-related risks,” and defendants failed to show that the dosing adjustment step was routine or conventional. See id. at *3.
The Federal Circuit affirmed the district court’s holding that the claims at issue were directed to patent-eligible subject matter under 35 USC §101, but reasoned that the asserted claims were not directed to laws of nature under step one of the Mayo
. at *13. Instead, the Federal Circuit found that the claims are directed to an application of a natural law because the claims require a treating doctor to administer iloperidone in a specific amount based upon the relationships between iloperidone, CYP2D6 metabolism, and QTc prolongation. Id
. at *14. The court distinguished the claim in Mayo
, reasoning that the Mayo
claim did not go beyond recognizing (i.e
., “indicates”) a need to increase or decrease a dose. In contrast, the court found that the ’610 patent claims recite the steps of carrying out a dosage regimen based on the results of genetic testing “to achieve a specific outcome.” Id.
at *14; see also id.
at *15 (“the claims here are directed to a specific method of treatment for specific patients using a specific compound at specific doses to achieve a specific outcome. They are different from Mayo
Chief Judge Prost dissented, only on this issue, finding that the ’610 patent claims ineligible subject matter because the majority’s reliance on the claims’ recitation of specific applications cannot withstand scrutiny under the Mayo
. at *18 (Prost, C.J., dissenting). Specifically, Chief Judge Prost explained that
“the claims here do not solely state a law of nature, they do no more than simply direct the relevant audience to apply it.
[…] the law of nature identified by the Supreme Court in Mayo
encompassed not only the bare fact of the relationship between thiopurine metabolite concentrations and efficacy or side effects of a thiopurine drug, but also the precise levels of concentration in question. (‘But those in the field did not know the precise correlations between metabolite levels and likely harm or ineffectiveness. The patent claims at issue here set forth processes embodying researchers’ findings that identified these correlations with some precision.’)
[…] reciting specific metes and bounds in the claims did not prevent the Supreme Court from concluding those claims set forth a natural law in Mayo
. We are not free to depart from the Supreme Court’s holding.”
. at * 19-20. (Internal citation omitted.) Chief Judge Prost further stated that other claim elements cannot rescue the claims: the genetic assay is purely a conventional pre-solution activity that cannot be used to circumvent eligibility under § 101; requiring a dosage instead of indicating a dosage is not sufficient at step two. Id
. at * 21.
Moreover, Chief Judge Prost distinguished the asserted claims from CellzDirect’s, see Rapid Litig. Mgmt. Ltd. v. CellzDirect, Inc.
, 827 F.3d 1042, 1049 (Fed. Cir. 2016), because the “end result” of the claims in CellzDirect
was “a new and useful method of preserving hepatocyte cells,” while here, the fact that a reduction of iloperidone dosage in poor metabolizers may reduce QTc prolongation “is both the means and the ends of this claim.” Vanda
, 2018 WL 1770273, at *21.
In addition to the § 101 issue, the Vanda
majority also affirmed the district court’s finding that if the proposed product were marketed, it would infringe the ’610 patent. Id
. at *6-9. The court reasoned that (1) an ANDA filer would be subject to a 35 U.S.C. § 271(e)(2)(A) infringement claim on a patent that issues after the filing of the ANDA but before FDA approval because an amendment to the ANDA—including a Paragraph IV certification for a later-issued patent—are considered an “application” under § 271(e)(2) and its submission can constitute an act of infringement,id
. at *6-7; (2) a patentee need not prove that a prior use of the NDA-approved drug by a physician satisfies the limitations of the asserted method claims to establish direct infringement under § 271(e)(2)(A); instead, a patentee can satisfy its burden to prove the predicate direct infringement by showing that if the proposed ANDA product—based on the proposed label—were marketed, it would infringe the asserted patent. Indeed, the district court found induced infringement because the proposed label “recommends” that physicians perform all the claimed steps, id
. at *9-11. The Vanda
decision also found that the existence of “substantial noninfringing uses” of the proposed ANDA product does not negate a finding of induced infringement where inducement is based on on-label, as opposed to off-label, uses. Id
. at *12.
decision attempts to provide further clarity on patent-eligibility for method of treatment claims: inclusion of dosing information for a novel method of treating a disease based on a law of nature may render the claim patent-eligible under the Mayo
test. Nevertheless, Chief Judge Prost’s dissenting opinion illustrates the tension between patent eligible methods of treatment and patent-ineligible methods that recite the natural relationship comprising the natural law—where the methods claim both the means and the ends of the natural law.
 Mayo two-step test for assessing patent eligibility under 35 U.S.C. §101: The inquiry in step one is whether the claims at issue are directed to one of those patent ineligible concepts. If not, one need not address step two of the inquiry, and the claims are patent eligible. If the claims are directed to patent ineligible concepts, proceed to step two of the inquiry which is whether the additional elements in a claim transform the nature of the claim into a patent-eligible application. If so, claims are patent eligible. See Mayo Collaborative Services v. Prometheus Laboratories, Inc., 566 U.S. 66, (2012); Enfish, LLC v. Microsoft Corp., 822 F.3d 1327, 1335 (Fed. Cir. 2016).