Last week, in Cleveland Clinic Foundation v. True Health Diagnostics LLC, the Federal Circuit affirmed a decision by the U.S. District Court for the Eastern District of Virginia holding claim 1 of U.S. Patent No. 9,575,065 and claims 1 and 2 of U.S. Patent No. 9,581,597 invalid under 35 U.S.C. § 101 as directed to an ineligible natural law.  Finding the asserted claims to be patent eligible, the District Court had dismissed a complaint for patent infringement filed by Cleveland Clinic Foundation and Cleveland HeartLab, Inc. ("Cleveland Clinic") against True Health Diagnostics LLC under Rule 12(b)(6) (see "Cleveland Clinic Foundation v. True Health Diagnostics, LLC (E.D. Va. 2017)").  In affirming the District Court, the Federal Circuit determined that its precedent, and not the U.S. Patent and Trademark Office's guidance, must control.

The '065 and '597 patents disclose "diagnostic test[s] which can be used to determine whether an individual . . . is at a lower risk or higher risk of developing or having cardiovascular disease," which are "based on the discovery that patients with coronary artery disease (CAD) have significantly greater levels of leukocyte and blood myeloperoxidase (MPO) levels" ('065 patent, col. 1, ll. 21–25, and col. 2, ll. 36-39).  The sole claim of the '065 patent recites:

1.  A method of detecting elevated MPO mass in a patient sample comprising:
    a)  obtaining a plasma sample from a human patient having atherosclerotic cardiovascular disease (CVD); and
    b)  detecting elevated MPO mass in said plasma sample, as compared to a control MPO mass level from the general population or apparently healthy subjects, by contacting said plasma sample with anti-MPO antibodies and detecting binding between MPO in said plasma sample and said anti-MPO antibodies.

The only two claims of the '597 patent recite:

1.  A method for identifying an elevated myeloperoxidase (MPO) concentration in a plasma sample from a human subject with atherosclerotic cardiovascular disease comprising:
    a)  contacting a sample with an anti-MPO antibody, wherein said sample is a plasma sample from a human subject having atherosclerotic cardiovascular disease;
    b)  spectrophotometrically detecting MPO levels in said plasma sample;
    c)  comparing said MPO levels in said plasma sample to a standard curve generated with known amounts of MPO to determine the MPO concentration in said sample; and
    d)  comparing said MPO concentration in said plasma sample from said human subject to a control MPO concentration from apparently healthy human subjects, and identifying said MPO concentration in said plasma sample from said human subject as being elevated compared to said control MPO concentration.

2.  The method of claim 1, further comprising, prior to step a), centrifuging an anti-coagulated blood sample from said human subject to generate said plasma sample.

The opinion notes that the Federal Circuit had previously addressed the subject matter eligibility of a parent patent, U.S. Patent No. 7,223,552, in Cleveland Clinic Foundation v. True Health Diagnostics, LLC, 859 F.3d 1352 (Fed. Cir. 2017) ("Cleveland Clinic I"), in which the Court affirmed a motion to dismiss granted by the District Court for the Northern District of Ohio, which in turn found the asserted claims of four Cleveland Clinic patents, including the '552 patent, as being directed to patent-ineligible subject matter.  Claim 11 of the '552 patent, which the opinion notes is exemplary, recites:

11.  A method of assessing a test subject's risk of having atherosclerotic cardiovascular disease, comprising
    comparing levels of myeloperoxidase in a bodily sample from the test subject with levels of myeloperoxidase in comparable bodily samples from control subjects diagnosed as not having the disease, said bodily sample being blood, serum, plasma, blood leukocytes selected from the group consisting of neutrophils, monocytes, sub-populations of neutrophils, and sub-populations of monocytes, or any combination thereo[f];
    wherein the levels of myeloperoxidase in the bodily [samples] from the test subject relative to the levels of [m]yeloperoxidase in the comparable bodily samples from control subjects is indicative of the extent of the test subject's risk of having atherosclerotic cardiovascular disease.

The opinion also notes that In Cleveland Clinic I, the Court held the methods of the '552 patent invalid under § 101 as being "directed to the ineligible natural law that blood MPO levels correlate with atherosclerotic CVD," and also held that "because the patent did not purport to have invented any of the biological techniques used to detect MPO or the statistical methods used to compare a patient's MPO levels to the control group, the claims recited no further inventive concept sufficient to transform the nature of the claims into a patent-eligible application of the natural law."  According to the opinion, the asserted claims of the '065 and '597 patents recite methods of identifying and detecting MPO, in contrast to the method of assessing atherosclerotic CVD risk from blood MPO levels in the '552 patent.

On appeal, Cleveland Clinic argued that the claims are not directed to a natural law, but to the technique of using an immunoassay to measure the blood MPO levels of patients with atherosclerotic CVD, that the correlation between blood MPO levels and atherosclerotic CVD is not a natural law because it can only be detected using certain techniques (since prior art techniques were too invasive or failed to predict CVD risk), and that using an immunoassay to detect the correlation between blood MPO levels and atherosclerotic CVD supplies an inventive concept sufficient to transform the claims into patent-eligible subject matter.  True Health countered by arguing that the correlation between atherosclerotic CVD and blood MPO levels is a natural law because it exists in nature apart from human intervention and that using known techniques in a standard way to observe a natural law neither renders the claims directed to something other than the natural law nor supplies an additional inventive concept.

The Federal Circuit agreed with True Health, concluding as the Court did in Cleveland Clinic I that the claims are directed to the natural law that blood MPO levels correlate with atherosclerotic CVD.  In response to Cleveland Clinic's argument that the claims of the '552 patent, which were previously found to be invalid as patent-ineligible, could be distinguished from the claims of the '065 and '597 patents because the former are directed to methods of "assessing a test subject's risk of having atherosclerotic [CVD]" by comparing the subject's MPO levels to a control group, and the latter are directed to "techniques for detecting elevated levels of MPO in the blood of patients having CVD," the Federal Circuit found this distinction (quoting the District Court) to be "overly superficial."  The opinion explains that the asserted claims:

[A]re not directed to new techniques for performing an immunoassay to detect a patient's blood MPO levels.  They only recite applying known methods to detect MPO levels in plasma, comparing them to standard MPO levels, and reaching a conclusion:  that the patient's blood MPO levels are elevated in comparison to a control group.  This conclusion is simply another articulation of the natural law that blood MPO levels correlate with atherosclerotic CVD.  Thus, as we held in Cleveland Clinic I, the claims are directed to the patent-ineligible natural law that blood MPO levels correlate with risk of atherosclerotic CVD.

The Federal Circuit also disagreed with Cleveland Clinic's argument that the correlation of blood MPO levels with atherosclerotic CVD is not a natural law because blood MPO levels can only be observed using certain techniques, stating that "[i]nadequate measures of detection do not render a natural law any less natural."  The Court also found Cleveland Clinic's argument that the inventive concept was supplied by using an immunoassay to detect the correlation between blood MPO levels and atherosclerotic CVD to be unpersuasive, stating that the argument that "using a known technique in a standard way to observe a natural law can confer an inventive concept—has been consistently rejected by this court in circumstances nearly identical to this case" (citing Athena Diagnostics, Inc. v. Mayo Collaborative Servs., LLC, 915 F.3d 743, 747 (Fed. Cir. 2019), and Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371 (Fed. Cir. 2015)).

On appeal, Cleveland Clinic also argued that the District Court failed to give the appropriate deference to the subject matter eligibility guidance published by the U.S. Patent and Trademark Office, as required by Skidmore v. Swift & Co., 323 U.S. 134 (1944), and also erred by not granting Skidmore deference to the Examiner's decision to allow the '065 and '597 patent applications in light that guidance.  As was noted by the District Court in its opinion, during prosecution of the application that issued as the '065 patent, the Examiner initially rejected the claims under 35 U.S.C. § 101 as being directed to an unpatentable abstract idea.  Cleveland Clinic overcame that rejection by citing Example 29 of the U.S. Patent and Trademark Office's "May 2016 Subject Matter Eligibility Update" (see "Subject Matter Eligibility Guidance -- Example on Diagnosing and Treating Julitis").  Example 29 sets forth seven claims directed to the detection of a hypothetical protein, JUL-1, and the diagnosis and/or treatment of a hypothetical autoimmune disease, julitis.  The first two claims of Example 29 recite:

1.  A method of detecting JUL-1 in a patient, said method comprising:
    a.  obtaining a plasma sample from a human patient; and
    b.  detecting whether JUL-1 is present in the plasma sample by contacting the plasma sample with an anti-JUL-1 antibody and detecting binding between JUL-1 and the antibody.

2.  A method of diagnosing julitis in a patient, said method comprising:
    a.  obtaining a plasma sample from a human patient;
    b.  detecting whether JUL-1 is present in the plasma sample by contacting the plasma sample with an anti-JUL-1 antibody and detecting binding between JUL-1 and the antibody; and
    c.  diagnosing the patient with julitis when the presence of JUL-1 in the plasma sample is detected.

According to Example 29, claim 1 is considered to be patent eligible and claim 2 is considered to be patent ineligible.  The Example explains that claim 1 is eligible because steps (a) and (b) of the claim "do not recite or describe any recognized exception."  As a result, the analysis of this claim ends with Step 2A of analytic framework set forth in the Interim Guidance (i.e., determining whether the claim is directed to a judicial exception), and the Example notes that there is no need to proceed with Step 2B of the analytic framework (i.e., determining whether any element, or combination of elements, in the claim is sufficient to ensure that the claim amounts to significantly more than the judicial exception).

In overcoming the § 101 rejection, Cleveland Clinic argued that the rejected claims more closely resembled claim 1 of Example 29 as opposed to exemplary claim 2 because the rejected claims were directed to a method of detecting myeloperoxidase rather than a method of diagnosing atherosclerotic cardiovascular disease.  The Examiner withdrew the rejection and the '065 patent proceeded to issuance.  As for the '597 patent, which was similarly rejected under § 101 as being directed to patent ineligible subject matter, Cleveland Clinic overcame the rejection by citing Example 29 and arguing that the claims amount to significantly more than the judicial exception.

On appeal, True Health countered that the USPTO guidance is neither persuasive nor relevant to the eligibility of the asserted claims, and that the District Court correctly found that claim 1 of Example 29 of the USPTO guidance is directed to a method of detecting a protein in a plasma sample without linking the results to a disease or other natural phenomenon.

With respect to Cleveland Clinic's argument that the District Court failed to give the appropriate deference to the USPTO's guidance, the Federal Circuit agreed with True Health that the District Court did not err in finding the asserted claims ineligible, stating that:

While we greatly respect the PTO's expertise on all matters relating to patentability, including patent eligibility, we are not bound by its guidance.  And, especially regarding the issue of patent eligibility and the efforts of the courts to determine the distinction between claims directed to natural laws and those directed to patent-eligible applications of those laws, we are mindful of the need for consistent application of our case law.

The Court also noted that claim 1 of Example 29 of the guidance "is strikingly similar to claim 1 of U.S. Patent 6,258,540 at issue in Ariosa."  Claim 1 of the '540 patent recites:

1.  A method for detecting a paternally inherited nucleic acid of fetal origin performed on a maternal serum or plasma sample from a pregnant female, which method comprises
    amplifying a paternally inherited nucleic acid from the serum or plasma sample and
    detecting the presence of a paternally inherited nucleic acid of fetal origin in the sample.

Thus, the Court declared that:

We have considered Example 29 and the arguments relating to it, but to the extent that Example 29–Claim 1 is analogous to the claims at issue, Ariosa must control.  Accordingly, we decline to follow the PTO's Example 29–Claim 1 and conclude that the district court did not err in its consideration of the PTO's subject matter eligibility guidance.

Thus, the Court determined that the District Court correctly concluded that the asserted claims are directed to a natural law and recite no other inventive concept, and therefore affirmed the District Court's decision finding the claims to be patent ineligible and dismissing Cleveland Clinic's complaint.

Cleveland Clinic Foundation v. True Health Diagnostics LLC (Fed. Cir. 2019)
Nonprecedential disposition
Panel:  Circuit Judges Lourie, Moore, and Wallach
Opinion by Circuit Judge Lourie