Diagnostic Testing in the Wake of Bilski v. Kappos

It has long been anticipated that the Bilski v. Kappos decision, though based on business method claims, would have implications that reached far beyond the business method world. Indeed, Justice Kennedy acknowledged that the M-or-T test would create uncertainty for new technologies of the Information Age, including, among other types of technologies, diagnostic medical testing techniques. (Bilski, Slip Op., p. 9.) The removal of the machine-or-transformation test as the sole test is good news for the biotech industry, particularly in the field of personalized medicine.

In the wake of the Supreme Court’s decision in Bilski on June 28, on June 29 the Supreme Court acted in two cases related to the patent-eligibility of diagnostic testing and methods of treatment – Mayo Collaborative Svcs., et al. v. Prometheus Laboratories and Classen Immunotherapies, Inc. v. Biogen Idec, et al. In both cases, petitions for certiorari were granted, immediately followed by a decision vacating the judgment below and remanding the case to the Court of Appeals for the Federal Circuit for further consideration in light of Bilski.

This article explores Prometheus and Classen in further detail. We first revisit relevant Federal Circuit history prior to these decisions. We then discuss the specific facts of each case, and conclude with how the Supreme Court’s Bilski decision is likely to affect the Federal Circuit’s actions on remand.

Diagnostic Testing To-Date

The patent-eligibility of diagnostic testing was first addressed by the Federal Circuit in In re Grams, 888 F.2d 835 (Fed. Cir. 1989). A representative claim from Grams follows:

A method of diagnosing an abnormal condition in an individual, the individual being characterized by a plurality of correlated parameters of a set of such parameters that is representative of the individual’s condition, the parameters comprising data resulting from a plurality of clinical laboratory tests which measure the levels of chemical and biological constituents of the individaul [sic] and each parameter having a reference range of values, the method comprising

performing said plurality of clinical laboratory tests on the individual to measure the values of the set of parameters;

producing from the set of measured parameter values and the reference ranges of values a first quantity representative of the condition of the individual;

comparing the first quantity to a first predetermined value to determine whether the individual’s condition is abnormal;

upon determining from said comparing that the individual’s condition is abnormal, successively testing a plurality of different combinations of the constituents of the individual by eliminating parameters from the set to form subsets corresponding to said combinations, producing for each subset a second quantity, and comparing said second quantity with a second predetermined value to detect a non-significant deviation from a normal condition; and

identifying as a result of said testing a complementary subset of parameters corresponding to a combination of constituents responsible for the abnormal condition, said complementary subset comprising the parameters eliminated from the set so as to produce a subset having said non-significant deviation from a normal condition.

This claim was held unpatentable as being directed to non-statutory subject matter. Although the first step in the claimed method involved performing clinical tests on an individual, the remaining steps were deemed to represent a mathematical algorithm. Since the novelty of the invention centered around the algorithm, the clinical test “to measure the values of the set of parameters” was interpreted as a data-gathering step ancillary to the main invention. Since mathematical algorithms are not considered patent-eligible subject matter, the rejection was upheld.

The Grams decision was made well before the recent activity related to Bilski. More recent than Grams, however, were the Federal Circuit’s decisions in Classen Immunotherapies, Inc. v. Biogen Idec, 304 Fed. Appx. 866 (Fed. Cir. 2008), and Prometheus Laboratories, Inc. v. Mayo Collaborative Svcs, 581 F.3d 1336 (Fed. Cir. 2009).

A representative claim from Classen follows:

A method of determining whether an immunization schedule affects the incidence or severity of a chronic immune-mediated disorder in a treatment group of mammals, relative to a control group of mammals, which comprises:

immunizing mammals in the treatment group of mammals with one or more doses of one or more immunogens, according to said immunization schedule, and

comparing the incidence, prevalence, frequency or severity of said chronic immune-mediated disorder or the level of a marker of such a disorder, in the treatment group, with that in the control group.

In a very brief, non-precedential opinion, the Federal Circuit found that this claim did not meet the qualifications set forth by its then-exclusive machine-or-transformation (M-or-T) test, and was therefore not patent-eligible. The M-or-T test provided that a “claimed process is surely patent-eligible under § 101 if: (1) it is tied to a particular machine or apparatus, or (2) it transforms a particular article into a different state or thing.” In re Bilski, 545 F.3d 943, 954, aff’d, 561 U.S. ___ (2010). Unfortunately, the Classen opinion did not provide the specific reasoning for why this test was not met. Some speculation can be made, however, based on the Federal Circuit’s opinion in Prometheus.

A representative claim from Prometheus recites:

A method of optimizing therapeutic efficacy for treatment of an immune-mediated gastrointestinal disorder, comprising:

(a) administering a drug providing 6-thioguanine to a subject having said immune-mediated gastrointestinal disorder; and

(b) determining the level of 6-thioguanine in said subject having said immune-mediated gastrointestinal disorder,

wherein the level of 6-thioguanine less than about 230 pmol per 8×108 red blood cells indicates a need to increase the amount of said drug subsequently administered to said subject and wherein the level of 6-thioguanine greater than about 400 pmol per 8×108 red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject.

Unlike in Grams and Classen, the Federal Circuit in Prometheus found that this claim satisfied its then-exclusive machine-or-transformation (M-or-T) test, and was patent-eligible. Although the Prometheus claim appears to be very similar in form to the Classen claim, the Federal Circuit approved of the Prometheus claims by stating, “[t]he asserted claims are in effect claims to methods of treatment, which are always transformative when a defined group of drugs is administered to the body to ameliorate the effects of an undesired condition.” Prometheus, 581 F.3d at 1346. In their decision, the Federal Circuit distinguished the Prometheus claims from the claims in Grams. As mentioned above, the Grams claims were determined to be centered on the mathematical algorithm, such that the arguably transformative step of performing a clinical test to obtain data was ancillary. To the contrary, the Federal Circuit decided that the determining step in the Prometheus claims was the central feature of the invention, and required a transformation of the body and/or of collected blood in order to be completed. As such, the determining step was not ancillary to the invention, and contributed to satisfying the M-or-T test.

The Bilski Effect

On June 28, 2010, the Supreme Court issued its decision in Bilski v. Kappos. The Bilski decision had three primary holdings: (1) the underlying claim in Bilski was directed to an abstract idea, and therefore was not patent-eligible; (2) business methods cannot be categorically excluded from patent-eligibility; and (3) the M-or-T test is not the exclusive test to determine patent-eligibility. Bilski, No. 08-964, slip op. at 6-11 and 15-16. The very next day, the Supreme Court granted cert in both Classen and Prometheus. The Federal Circuit’s decisions in both cases were immediately vacated, and the cases were remanded for reconsideration based on the Supreme Court’s opinion in Bilski. (Order list for June 29, 2010, 561 U.S. __ (2010).)

Now that the Supreme Court has vacated and remanded both the Classen and Prometheus decisions, the Federal Circuit must revisit these issues. For Prometheus, the decision may be simpler, because the claims were already held to meet the machine-or-transformation test. Although the Supreme Court’s Bilski decision held that the M-or-T test was not the only test by which patent-eligibility can be determined, the Supreme Court seemed to have agreement from all nine Justices that the machine-or-transformation test was still a useful tool and valid option. See, e.g., Bilski, slip. op. at 2 of J. Breyer’s concurrence. Although a claim that does not meet the M-or-T test may still be patent-eligible under other theories, one can presume that the M-or-T test is still a “safe harbor” for claims that meet its provisions. The Federal Circuit’s re-visitation of Prometheus will be the first opportunity for this presumption to be tested.

The future for Classen is a bit more uncertain. The Bilski opinion noted that the M-or-T test would create uncertainty for, among other types of claims, diagnostic medical testing techniques. Bilski, slip op. at 9. Since the Federal Circuit in Classen used the M-or-T test to find the claims non-statutory, it is possible that its decision on remand could be reversed, since the M-or-T test is no longer the exclusive test. On the other hand, the Federal Circuit may take the completely opposite approach and declare that the Classen claims are directed to non-statutory subject matter even without considering the M-or-T test.

Much of the uncertainty in Classen comes because the Federal Circuit gave no insight whatsoever into its rationale for dismissing the Classen claims. However, the Supreme Court’s denial of certiorari in Laboratory Corp. of America Holdings v. Metabolite Laboratories Inc., 126 S. Ct. 2921 (2006), may have underscored the Federal Circuit’s original Classen decision. Although cert was denied in LabCorp, Justices Breyer, Stevens, and Souter filed a hefty dissent, detailing reasons why they would have found the following claim patent-ineligible:

A method for detecting a deficiency of cobalamin or folate in warm-blooded animals comprising the steps of:

assaying a body fluid for an elevated level of total homocysteine; and

correlating an elevated level of total homocysteine in said body fluid with a deficiency of cobalamin or folate.

The Federal Circuit had originally found the claim to be patent-eligible. Indeed, the patentee (Metabolite) argued that this claim was patent-eligible because it required a transformation of matter. Specifically, the patentee argued that the blood was altered during the assay for determining the homocysteine level. The dissenting Justices on the Supreme Court disagreed, saying that the claim did not describe a process for transforming blood. Rather, the Justices likened the claim to (1) obtaining test results and (2) thinking about them, and equated the correlation to a natural phenomenon.

If anything certain can be gleaned from the Supreme Court’s opinion in Bilksi, it is that there are still three types of subject matter that are excluded from patent-eligibility: laws of nature, natural phenomena, and abstract ideas. Bilski, slip op. at 5. If the Federal Circuit follows the logic from the LabCorp dissent, it could again declare the Classen claims patent-ineligible as being directed to a natural phenomenon. Such a decision would not be contrary to the Supreme Court’s opinion in Bilski, as it would be relying on the long-established exclusion of natural phenomena from patent-eligibility.

Interestingly, Footnote 3 of the Federal Circuit’s opinion in Prometheus discussed the LabCorp dissent, noting that the dissent was not controlling law. It is also worth noting that both Justices Breyer and Stevens, who dissented from the LabCorp dismissal, were again not in the majority for the Bilski decision.

With the remand of Prometheus and Classen, we hopefully will learn the Federal Circuit’s rationale behind distinguishing the two claim sets. In any event, the Federal Circuit will have its first chance to put diagnostic techniques to the test – without being limited to a machine-or-transformation analysis.