Brinks Hofer Gilson & Lione: Supreme Court Rules Certain Medical Method Patent Claims are Akin to "Laws of Nature" and Thus Not Patentable in Mayo Collaborative Services v. Prometheus Laboratories, Inc.

Brinks Hofer Gilson & Lione: Supreme Court Rules Certain Medical Method Patent Claims are Akin to "Laws of Nature" and Thus Not Patentable in Mayo Collaborative Services v. Prometheus Laboratories, Inc.

On March 20, 2012, the Supreme Court issued a highly anticipated decision in Mayo Collaborative Services v. Prometheus Laboratories, Inc., No. 10-1150 [enhanced version available to subscribers]. In a unanimous decision, the Court held that Prometheus' method claims were not eligible for patent protection because they set forth laws of nature, and the additional steps in the claimed methods added "nothing of significance to the natural laws themselves." The Court emphasized that it was following its earlier precedent construing Section 101 of the Patent Act, defining patent eligible subject matter, as most recently stated by In re Bilski, 561 U.S. ___ (2010) [enhanced version available to subscribers].


The patents in the case claimed methods for calibrating the proper dosage of thiopurine drugs - drugs used for treating both gastrointestinal and non-gastrointestinal autoimmune diseases. The challenged method claims included (1) a step of administering a thiopurine drug to a patient, (2) a step of determining the level of thiopurine drug metabolite in the patient after administering the drug, and (3) using the metabolite measurements to inform the calibration of dosages of the drug.

At the district court in 2008, the claims were held invalid under 35 U.S.C. § 101 as ineligible patent subject matter. The district court reasoned that the patents, as construed under Prometheus' view, effectively claim natural laws or natural phenomena - namely the correlations between thiopurine metabolite levels and the toxicity and efficacy of thiopurine drug dosages - and thus were invalid. In 2009, the Federal Circuit reversed the ruling of the district court, holding that the patents were directed to patent eligible subject matter because the claims met the "machine-or-transformation" test. Mayo filed a petition for certiorari. Less than one year, later and while Mayo's petition for certiorari was pending, the Supreme Court decision of In re Bilski rejected the Federal Circuit's application of the "machine-or-transformation" test, and clarified that this test was not definitive, but only an important and useful clue in determining patent eligibility. In re Bilski, 561 U.S. ___ (2010). The Supreme Court thereafter granted Mayo's petition, vacated the Federal Circuit's 2009 Prometheus judgment, and remanded the case to the Federal Circuit to reconsider the issue.

Upon reconsideration, the Federal Circuit reaffirmed its previous holding that the claims covered patent eligible subject matter. The Federal Circuit maintained that the machine-or-transformation test, understood merely as an important and useful clue, supported the conclusion that the claimed methods did not encompass laws of nature or preempt natural correlations. The Supreme Court again granted certiorari on June 20, 2011 and heard oral arguments on December 7, 2011.

Supreme Court Decision

The Supreme Court reversed the Federal Circuit, holding that the claims did not cover patent eligible subject matter. The Court stated:

"[i]f a law of nature is not patentable, then neither is a process reciting a law of nature, unless that process has additional features that provide practical assurance that the process is more than a drafting effort designed to monopolize the law of nature itself."

The Court stated that the claims, as construed, merely set forth relationships between concentrations of certain metabolites in the blood and the likelihood that a dosage of the drug will prove ineffective or cause harm, and that, while it takes human action - namely administration of the drug - to trigger a manifestation of the relationship, the relationship "itself exists in principle apart from any human action" and "is a consequence of the ways in which thiopurine compounds are metabolized by the body - entirely natural processes."

The Court held that the additional features recited by the claims - an "administering" step, a "determining" step, and "wherein" clauses - although not themselves natural laws, were not sufficient to "transform the nature of the claim." The Court stated that the "administering" step simply refers to the relevant audience, namely doctors who treat patients with certain diseases with thiopurine drugs, which was a pre-existing audience, and this step could not make the claim patent eligible. The Court stated that the "wherein" clauses simply tell a doctor about the laws of nature, and, at most, merely add a suggestion to take into account these laws when treating a patient. The Court further stated that the "determining" step tells the doctor to determine the level of the relevant metabolites in the blood, through whatever process the doctor or the laboratory wishes to use. The Court noted that methods for determining metabolite levels were well known in the art, and the Court concluded that the "determining" step simply "tells doctors to engage in well-understood, routine, conventional activity previously engaged in by scientists who work in the field," and thus will not make otherwise patent ineligible subject matter patentable. The Court concluded that considering the steps as an ordered combination "adds nothing to the laws of nature that is not already present when the steps are considered separately."

In support of its conclusion, the Court relied on controlling precedent regarding patent eligibility. The Court addressed its previous decisions in two cases: Diamond v. Diehr, 450 U.S. 175 (1981) [enhanced version available to subscribers] and Parker v. Flook, 437 U.S. 584 (1978) [enhanced version available to subscribers]. The Court held that the claimed method presented a case for patentability that was weaker than the (patent-eligible) claim in Diehr and no stronger than the (unpatentable) claim in Flook. The Court noted that beyond picking out the relevant audience, the claim simply told doctors to: "(1) measure (somehow) the current level of the relevant metabolite, (2) use 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." The Court further noted that other cases, including an English case, Neilson v. Harford, Webster's Patent Cases 295 (1841), and Bilski, supported the view that simply appending conventional steps, specified at a high level of generality, to laws of nature, natural phenomena, and abstract ideas, cannot make those laws, phenomena, and ideas patentable. Lastly, referring to previous decisions in O'Reilly v. Morse, 15 How. 62 (1854) [enhanced version available to subscribers] and Gottschalk v. Benson, 409 U. S. 63 (1972) [enhanced version available to subscribers], the Court noted that it has repeatedly emphasized a concern that patent law not inhibit further discovery by improperly tying up the future use of laws of nature.

The Court addressed several additional arguments in support of Prometheus' position, and held that none led to a different conclusion. In addition, the Court refused to address the policy implications for diagnostic research raised by the decision, noting that it "must hesitate before departing from established general legal rules lest a new protective rule that seems to suit the needs of one field produce unforeseen results in another." The Court recognized the role of Congress in this regard, if "from a policy perspective, increased protection for discoveries of diagnostic laws of nature is desirable."

The Impact of the Decision

The Supreme Court's unanimous decision in Mayo Collaborative Services v. Prometheus Laboratories, Inc. reinforces its prior decision under Bilski, while reaffirming the vitality of its previous decisions in Diamond, Flook, and Benson. The decision also underscores the Court's vigilance in enforcing its precedent against patenting laws of nature, even if the claims pass the "machine-or-transformation" test. The decision provides that claims applying laws of nature must limit the reach of the claims to a particular, inventive application of these laws. In view of this decision, patent applicants may wish to consider drafting claims that specify how a law of nature is applied and incorporated within a specific method. Patent challengers, on the other hand, may wish to consider whether this decision provides a basis to argue the invalidity of any method claims at issue.

If you have any questions or wish to discuss how the Court's decision may impact your company, please contact an attorney in the BioPharma or the new Medical Device practices of Brinks Hofer Gilson & Lione.

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