A Summary of the Supreme Court’s Prometheus Decision

On March 20, 2012, the Supreme Court issued its much-anticipated decision in Mayo Collaborative Services v. Prometheus Laboratories, Inc., unanimously holding that Prometheus’s claims, directed to methods for optimizing the efficacy of a drug, are directed to laws of nature and, consequently, not patent-eligible under 35 U.S.C. § 101. The Court’s decision may have broad implications with respect to the applicability of the Federal Circuit’s “machine or transformation” test and more specifically in defining patent-eligible subject matter in the fields of diagnostic testing, personalized medicine, and biotechnology.

Writing for the Court, Justice Breyer started his analysis by noting that this case “lies at the intersection” of the Court’s basic principles that that “‘laws of nature, natural phenomena, and abstract ideas’ are not patentable” and “to transform an unpatentable law of nature into a patent-eligible application of such a law, one must do more than simply state the law of nature while adding the words ‘apply it.’” Slip. Op. at 3. As the Federal Circuit did in its analysis, the Court treated the following claim as a typical claim of the patents-at-issue:

                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 8x10⁸ 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 8x10⁸ red blood cells indicates a need to decrease the amount
                of said drug subsequently administered to said subject. 

                Id. at 5-6.

The Federal Circuit had twice previously, once pre-Bilski and once post-Bilski, reversed the district court’s summary judgment ruling of invalidity, holding that the claimed “administering” and “determining” steps satisfied the “machine or transformation” test and thereby “led to the ‘clear and compelling conclusion . . . that the . . . claims do not encompass laws of nature or preempt natural correlations.’” Id. at 7-8. The Court disagreed with the Federal Circuit, concluding that Prometheus’s claims do nothing more than simply describe the natural relationships between concentrations of certain metabolites in the blood and the likelihood that a dosage of a thiopurine drug will prove ineffective or cause harm.

Specifically, Justice Breyer explained that while the “administering,” “determining,” and “wherein” steps are not themselves natural laws, they are not sufficient to transform the nature of the claim. “Beyond picking out the relevant audience, namely those who administer doses of thiopurine drugs, the claim simply tells doctors to: (1) measure (somehow) the current level of the relevant metabolite, (2) use the particular (unpatentable) laws of nature (which the claim sets forth) to calculate the current toxicity/inefficacy limits, and (3) reconsider the drug dosage in light of the law.” Id. at 13. After comparing the claim to the Court’s past precedent in Diehr (held patent eligible) and Flook (held not patentable), the Court concluded the claims provide “instructions” that “add nothing specific to the laws of nature other than what is well-understood, routine, conventional activity, previously engaged in by those in the field.” Id.

In reaching its decision, the Court also rejected several arguments in support of Prometheus’s position. First, the Court explained that while the Federal Circuit’s “machine or transformation” test is “an ‘important and useful clue’ to patentability,” the Court has “neither said nor implied that the test trumps the ‘law of nature’ exclusion” and that the test fails in this case. Id. at 19 (emphasis in original). Second, in response to Prometheus’s argument that the particular laws of nature that its patent claims embody are narrow, the Court concluded that its past precedent “[has] not distinguished among different laws of nature according to whether or not the principles they embody are sufficiently narrow” and that “the cases have endorsed a bright-line prohibition against patenting laws of nature, mathematical formulas and the like” because courts and judges “are not institutionally well suited to making the kinds of judgments needed to distinguish among different laws of nature.” Id. at 20. Third, in response to the government’s argument that virtually any step beyond a statement of law of nature itself should transform an unpatentable law of nature into a potentially patentable claim sufficient to satisfy § 101 and that invalid claims would be weeded out by other provisions of the patent law, the Court explained that this approach would make the “law of nature” exception to § 101 a “dead letter” and is not consistent with Bilski, Diehr, Flook, and Benson. Moreover, the Court reasoned that shifting the patent-eligibility inquiry entirely to §§ 102, 103, and 112 “risks creating significantly greater legal uncertainty, while assuming that those sections can do work that they are not equipped to do.” Id. at 21. Fourth, in response to the policy argument that a principle of law denying patent coverage here will inhibit medical research, particularly in the diagnostic area, the Court declined to determine “whether, from a policy perspective, increased protection for discoveries of diagnostic laws of nature is desirable,” recognizing that it is “the role of Congress to craft more finely tailored rules where necessary.” Id. at 24.

The Court’s decision represents a shift in the law on patent-eligible subject matter under § 101, though its impact will only be fully understood as the PTO and courts move forward and apply Prometheus to pending and existing claims. Moreover, while the Court did not outright reject the “machine or transformation” test, the importance of this test has been weakened, particularly in the context of claims implicating laws of nature, such as diagnostics. For example, the Court noted that the “determining” step in Prometheus’s claim, which the Federal Circuit had held was transformative because it required taking a blood sample, “could be satisfied without transforming the blood, should science develop a totally different system for determining metabolite levels that did not involve such a transformation.” Id. at 19. Accordingly, at least in the diagnostics field, the Court’s decision makes clear that reliance on the “machine or transformation” test does not guarantee that a patentee or applicant may overcome a § 101 challenge.