Federal Circuit Holds That Claims Directed To Diagnosing Neurotransmission Or Developmental Disorders Are Invalid For Failing To Recite Patent Eligible Subject Matter

In Athena Diagnostics, Inc. v. Mayo Collaborative Servs., LLC,¹ the Federal Circuit affirmed the district court's ruling that claims covering methods for diagnosing neurological disorders by detecting autoantibodies are directed to a natural law together with conventional steps, and are therefore invalid under 35 U.S.C. § 101. Although the claims at issue were said to be directed to patent ineligible subject matter, the court offered further guidance for applicants in the diagnostic space.

Athena Diagnostics, Inc. ("Athena") is the exclusive licensee of U.S. Patent 7,267,820 (the "820 patent"), which claims methods for diagnosing neurological disorders by detecting autoantibodies to a membrane protein called muscle specific tyrosine kinase ("MuSK"). The claimed methods are said to be useful in diagnosing patients with myasthenia gravis ("MG"), a neurological disorder that causes patients to experience muscle weakness and symptoms including drooping eyelids, double vision and slurred speech. About 80 percent of patients with MG produce acetylcholine receptor autoantibodies. The inventors of the 820 patent discovered that, of the remaining 20 percent of patients who do not produce acetylcholine receptor autoantibodies, many generate autoantibodies to MuSK. Claim 1 of the 820 patent recites:

1. A method for diagnosing neurotransmission or developmental disorders related to muscle specific tyrosine kinase (MuSK) in a mammal comprising the step of detecting in a bodily fluid of said mammal autoantibodies to an epitope of muscle specific tyrosine kinase (MuSK).

Mayo Collaborative Services, LLC ("Mayo"), developed two competing tests for detecting MuSK autoantibodies. Athena sued Mayo for allegedly infringing the 820 patent, and Mayo filed a Rule 12(b)(6) motion to dismiss, asserting that the claims are invalid under 35 U.S.C. § 101. The United States District Court for the District of Massachusetts found in favor of Mayo, holding that claims 6 – 9 of the 820 patent are invalid under § 101, and dismissed Athena's complaint under Rule 12(b)(6).²

Claims 6 ‒ 9 of the 820 patent recite:³

6. A method according to claim 3 whereby the intensity of the signal from the anti-human IgG antibody is indicative of the relative amount of the anti-MuSK autoantibody in the bodily fluid when compared to a positive and negative control reading.
7. A method according to claim 1, comprising contacting MuSK or an epitope or antigenic determinant thereof having a suitable label thereon, with said bodily fluid, immunoprecipitating any antibody/MuSK complex or antibody/MuSK epitope or antigenic determinant complex from said bodily fluid and monitoring for said label on any of said antibody/MuSK complex or antibody/MuSK epitope or antigen determinant complex, wherein the presence of said label is indicative of said mammal is suffering from said neurotransmission or developmental disorder related to muscle specific tyrosine kinase (MuSK).
8. A method according to claim 7 wherein said label is a radioactive label.
9. A method according to claim 8 wherein said label is 125I.

The Federal Circuit, in applying the two-part test set forth by the Supreme Court in Alice Corp. v. CLS Bank International,⁴ held that claims 6 ‒ 9 of the 820 patent (1) are directed to a natural law and (2) require only the standard techniques to be applied in a standard way. Regarding part 1 (whether the claims are directed to a law of nature), the court held that the claims are directed to "the correlation between the presence of naturally-occurring MuSK autoantibodies in bodily fluid and MuSK related neurological diseases like MG [which] exists in nature apart from any human action."⁵ Regarding the "directed to" aspect of part 1, the court stated that "[t]he claims at issue here involve both the discovery of a natural law and certain concrete steps to observe its operation."⁶ The court also focused on claim 9, which is referred to as "the most specific claim at issue," and stated that "[t]he claim ⁶ concludes in the wherein clause with a statement of the natural law, i.e., the discovery that MuSK autoantibodies naturally present in a patient sample, detected with the 125I label bound to the MuSK/antibody complex, indicate that the patient is suffering from a MuSK-related neurological disorder."⁷ The court concluded that therefore the claims are directed to a natural law.

Regarding step 2 (whether the additional elements transform the nature of the claim into a patent-eligible application), the court stated that the steps of the claims, "whether viewed individually or as an ordered combination, only require standard techniques to be applied in a standard way."⁸ To reach its conclusion, the court looked to the specification of the 820 patent, which states that "[t]he actual steps of detecting autoantibodies in a sample of bodily fluids may be performed in accordance with immunological assay techniques known per se in the art."⁹ Thus, the claims were held to be invalid under § 101.

Although the court ruled that the claims at issue in the 820 patent were directed to patent ineligible subject matter, the court did offer some guidance to applicants in the diagnostic space. In particular, the court stated that:

• "Claiming a natural cause of an ailment and well-known means of observing it is not eligible for patent because such a claim in effect only encompasses the natural law itself. But claiming a new treatment for an ailment, albeit using a natural law, is not claiming the natural law."¹⁰ Thus, the Federal Circuit continues to rule that claims reciting methods of treatment are patent eligible.
• "[T]he use of a man-made molecule is not decisive [to the subject matter eligibility of a diagnostic claim] if it amounts to only a routine step in a conventional method for observing a natural law."¹¹ Thus, simply reciting a man-made molecule in a diagnostic claim is not sufficient.
• "[W]e cannot hold that performing standard techniques in a standard way to observe a newly discovered natural law provides an inventive concept."¹² Thus, the novel discovery of a protein's role in a disease is not sufficient to confer eligibility.

To increase the chances of obtaining valid claims in the diagnostic space, applicants should consider including a treatment step (thus framing the claims as a method of treating disease X in a subject having the discovered correlation) and/or including claims directed to an intermediate in the diagnostic pathway (such as an isolated 125I-labeled MuSK receptor-autoantibody complex).

Footnotes

1 Athena Diagnostics, Inc. v. Mayo Collaborative Servs., LLC, No. 2017-2508, 2019 WL 453489 (Fed. Cir. Feb. 6, 2019).

2 Athena Diagnostics, Inc. v. Mayo Collaborative Servs., LLC, 275 F.Supp.3d 306 (D. Mass. 2017).

3 In the District Court, Athena represented that it would not assert claims 1 ‒ 5 or 10 ‒ 12.

4 Alice Corp. v. CLS Bank International, 573 U.S. 208 (2014).

5 Athena Diagnostics, Inc., 2019 WL 453489 at *4.

6 Id. at *5.

7 Id.

8 Id. at *8.

9 Id.

10 Id. at *6.

11 Id.

12 Id. at *8.

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