Supreme Court Rules in Mayo v. Prometheus

Law of Nature Patentability Exclusion Not Trumped by Machine-or-Transformation Test

March 21, 2012

In the continuing wake of In re Bilski, the Supreme Court again clarified what does and does not constitute patent-eligible subject matter. The unanimous Court reinforced the long-held judicial exception to patentable subject matter under Section 101 of the Patent Act, namely that laws of nature are ineligible for patent protection. This is a “bright-line prohibition” that can be overcome only upon claiming other elements that are sufficient to establish an inventive concept and ensure that the patent amounts to significantly more than merely a patent covering the natural law itself.

At issue is a patent that is exclusively licensed to Prometheus and claims a so-called medical diagnostic procedure:

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.

Starting with the principle that this claim set forth a law of nature — namely, the relationship between concentrations of certain metabolites in the blood and the likelihood that a dosage of drug will be either ineffective or cause harm — the Court framed the relevant inquiry as to whether the claim does “significantly more” than describe this natural relationship. The Court reasoned that while the “administering,” “determining,” and “wherein” steps are not themselves natural laws, they are nonetheless insufficient to transform the claim into something significantly more than simply a process reciting a law of nature. Rather, the Court found that the claim merely informs a relevant audience (i.e., physicians treating patients with certain diseases with thiopurine drugs) about a certain law of nature, and that any additionally claimed steps are well-understood, routine, conventional activities already practiced by the scientific community that add nothing significant beyond the sum of their parts taken separately.

The Court’s analysis takes into account case law precedent and policy considerations. It considered Prometheus’ patent claims — in a patent eligibility context — to be weaker than that in Diamond v. Diehr (patent-eligible method for molding rubber using a known mathematical equation in a claimed process that resulted in an inventive application of the equation) and no stronger than that in Parker v. Flook (unpatentable method for adjusting alarm limits in the catalytic conversion of hydrocarbons by measuring process parameters, applying an algorithm to calculate alarm limits and adjusting the system to reflect the limits). In response to the Federal Circuit’s determination that the claims were patent-eligible based upon the machine-or-transformation test, the Court made clear that although the test represents an important and useful clue to patentability as articulated In re Bilski, it does not trump the well-established law of nature exclusion to patentability. Further, the Court expressed the view that enforcement of Prometheus’ patent would limit a doctor’s subsequent treatment decisions and threaten to inhibit the development of more refined treatment recommendations that combine Prometheus’ correlations with later discovered features of metabolites, human physiology of individual patient characteristics.

The Court’s overall guidance is that to transform an unpatentable law of nature into a patent-eligible application of such a law, one must claim other elements or combination of elements sufficient to ensure that the patent amounts to “significantly more” than a patent upon the natural law itself. In application, the practitioner should consider claim elements in isolation from any underlying laws of nature to separately assess patentability. There are obvious implications for the medical diagnostics industry, as there may be for related industries such as pharmaceuticals, biotechnology and other medical technologies. Cases such as American Molecular Pathology v. Myriad Genetics, in which the patent eligibility of certain genes is at issue, will be closely watched and may have a significant impact upon the validity of similar existing patents and the way in which such patents are drafted in the future.

This article was originally published by Bingham McCutchen LLP.