IP Alert
IP Alert: Supreme Court Holds Prometheus Patents Invalid

March 27, 2012

On March 20, 2012, in Mayo Collaborative Services v. Prometheus Laboratories, Inc., the U.S. Supreme Court issued a landmark decision on patent eligibility under the patent statute, a decision that specifically addressed the “laws of nature” exclusion for patent eligibility. Unanimously reversing the Court of Appeals for the Federal Circuit, the Court ruled that Prometheus's method claims were not eligible for patent protection because they set forth “laws of nature.” In addition, although the patent at issue specified a diagnostic method, the Court held that the steps in the claimed methods added "nothing of significance to the natural laws themselves." The Mayo decision is expected to have a broad-ranging impact on a number of industries, especially in the life sciences and biotechnology areas.

In Mayo, Prometheus held patents directed toward methods for use of thiopurine drugs in the treatment of autoimmune diseases. The Court focused on one patent claim deemed to be archetypical; this claim called for a method for “optimizing therapeutic efficacy for treatment of an immune-mediated gastrointestinal disorder.” The claim specified administering a drug and determining the level of the drug metabolite in the bloodstream, wherein the level of metabolite indicates if there is a need to increase or decrease the amount of the drug administered.

Specifically, the Court accepted claim 1 in U.S. Patent No. 6,355,623 as typical:

"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."

In analyzing these patent claims, the Court began with the governing statute, 35 U.S.C. §101, which provides, “Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title.” Historically, the Court noted, courts have construed this provision to have certain unenumerated exclusions, these including “laws of nature,” “natural phenomena,” and “abstract ideas.” In the Court’s view, “monopolization of those tools through the grant of a patent might tend to impede innovation more than it would tend to promote it.” On the other hand, too loose an interpretation of these exclusions “could eviscerate patent law.”

The Court determined the Prometheus patents rested at the intersection of these competing principles. The Court found that Prometheus’s patent claims involved applying “natural laws describing relationships between the concentration in the blood of certain thiopurine metabolites and the likelihood that the drug dosage will be ineffective or induce harmful side-effects,” while it was already previously understood by those skilled in the art that “that levels in a patient’s blood of certain metabolites … were correlated with the likelihood that a particular dosage of a thiopurine drug could cause harm or prove ineffective.”

The Court explained its precedents “insist that a process that focuses upon the use of a natural law also contain other elements . . . sometimes referred to as an ‘inventive concept,’ sufficient to ensure that the patent in practice amounts to significantly more than a patent upon the natural law itself.” In the Court’s view, “to transform an unpatentable law of nature into patent-eligible application of such a law, a patent must do more than simply stated the law of nature while adding the words ‘apply it’” [emphasis added].

The Court therefore framed the question as “whether the [Prometheus] patent claims add enough to their statements of the correlations to allow the processes they describe to qualify as patent-eligible processes that apply natural laws?” The Court declared, “In particular, the steps in the claimed processes (apart from the natural laws themselves) involve well-understood, routine, conventional activity previously engaged in by researchers in the field. At the same time, upholding the patents would risk disproportionately tying up the use of the underlying natural laws, inhibiting their use in the making of further discoveries.”

According to the Court, the claimed method was not saved by the recitation of several steps, even though “these additional steps are not themselves natural laws,” because “they [are not] sufficient to transform the nature of the claim.” To arrive at this conclusion, the Court parsed each step. According to the Court “the ‘administering’ step simply refers to the relevant audience, namely doctors who treat patients with certain diseases with thiopurine drugs.” The Court noted that “doctors used thiopurine drugs to treat patients suffering from autoimmune disorders long before anyone asserted these [patent] claims.”

Next, the Court said “the ‘wherein’ clauses simply tell a doctor about the relevant natural laws, at most adding a suggestion that he should take those laws into account when treating his patient.” The implication is the Court was troubled because Prometheus’s “wherein” clauses did not recite an affirmative tangible method step. In other words, with this claim construction, the Court apparently considered the “wherein” clauses as describing a doctor’s mental judgments.

The Court then considered that the “determining” step simply “tells the doctor to determine the level of relevant metabolites in the blood, through whatever process the doctor or the laboratory wishes to use.” Again, the Court specifically pointed out that “this step tells doctors to engage in well-understood, routine, conventional activity previously engaged in by scientists who work in the field.”

The Court’s ensuing detailed discussion measured the Prometheus patent claims against the range of possible patent-eligible subject matter treated in the earlier Supreme Court cases Diamond v. Diehr and Parker v. Flook. In Diehr, the Court upheld a method for molding raw uncured rubber using a mathematical equation in which the method had specific physical and computational steps as patent-eligible. In Flook, on the other hand, the Court held a method for updating alarm limits in the catalytic conversion of hydrocarbons to be patent-ineligible because, putting the formula to one side, the patent “did not limit the claim to a particular application.” The Court explained the Prometheus patent claims were weaker than the patent-eligible claims in Diehr, but no stronger than the patent-ineligible claims in Flook. This discussion suggests that careful review of the Diehr case may offer guidance for what the Court meant by “a particular application” of a law of nature.

The Court concluded that Prometheus's claims "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. And since they are steps that must be taken in order to apply the laws in question, the effect is simply to tell doctors to apply the law somehow when treating their patients." 

Along the way, the Court introduced further uncertainty by acknowledging, “We recognize that, in evaluating the significance of additional steps, the §101 patent-eligibility inquiry and, say, the §102 novelty inquiry might sometimes overlap.” But the Court specifically rebuffed the U.S. Government’s suggestion to employ the latter provisions as a screening function because it would make the “‘law of nature’ exception to §101 patentability a dead letter.” This is ultimately consistent with the opinion’s focus throughout on Prometheus’s patent specification and claims as relating to a law of nature, which tends to support the argument that analysis under §101 should not be conflated with the inquiries under the other patentability provisions in Title 35.

While acknowledging the tension between the concern against interfering with the need for capital intensive diagnostic research, on the one hand, and the concern against allowing claims to a “body’s natural responses to illness and medical treatment” to create “a vast thicket of exclusive rights over the use of critical scientific data that must remain widely available if physicians are to provide sound medical care,” on the other hand, the Court declined to depart from the existing statutory framework. The Court observed that it is “the role of Congress . . . [to craft] more finely tailored rules where necessary.”

The Mayo decision is expected to embolden challenges against patents directed to broadly worded diagnostic method claims. Conversely, the ruling is expected to prompt pharmaceutical and biotech companies, as well as companies focused on diagnostics, to budget for reviewing and revising their patent strategies. In the emerging field of personalized medicine, diagnostic assays typically detect a marker or other indicator and involve a comparison between a detected level and a baseline level, and efforts to patent associated diagnostic methods must take into account the pronouncements in Mayo. And while it is unclear how courts and the USPTO will apply the Mayo ruling, an early indication is the memo that the USPTO distributed to its Patent Examining Corps on March 21, 2012, offering preliminary guidance to patent examiners.

Fitch Even attorneys will continue to report on developments concerning patent-eligible subject matter after Mayo. If you have questions regarding this important decision, please contact Fitch Even partner Kendrew H. Colton, the author of this alert. 

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