On March 20, 2012, the US Supreme Court issued an opinion in Mayo Collaborative Services v. Prometheus Laboratories, Inc. (No. 10-1150) regarding the patent eligibility of method claims, finding the particular claims in Prometheus’ patents, relating to methods of treatment, patent-ineligible under 35 U.S.C. § 101. The Court also remanded the Association for Molecular Pathology v. USPTO and Myriad Genetics, Inc. (No. 11-725) case to the Federal Circuit for consideration in light of the decision in Mayo v. Prometheus. Both cases have been avidly followed by the life sciences industry for guidance on the standard for patent eligibility under Section 101.

The Supreme Court’s decision in the Mayo case reinforces that, under Section 101, claims must not embody laws of nature. Also, importantly, the Supreme Court made it clear that such claims must not preempt essentially all uses of such laws of nature. The Court emphasized that a patentee must not monopolize an entire field (in this case a method of medical treatment) by broadly claiming a method that covers mental processes and natural phenomenon. Instead, the claims must be limited to the actual method the patentee invented which, by virtue of being useful, must be limited to a particular application of the natural phenomenon.

As we discuss further below, the Supreme Court’s decision differs from the Federal Circuit’s application of Section 101 in important respects; for example, placing greater emphasis on preemption. It remains to be seen if the Federal Circuit will follow suit, starting with the upcoming remand in Myriad.

A. Background: The Lower Court Decisions in the Mayo Case

The patent claims in the Mayo case are directed to treating gastrointestinal disorders by optimizing the drug dose based on levels of certain metabolites. Below is a representative claim from the patents-in-suit, US Patent No. 6,355,623 and US Patent No. 6,680,302:

  1. 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.

Prometheus sold a diagnostic kit that embodied this process. The controversy arose when Mayo announced that it intended to begin using and selling its own test (using different metabolite levels to determine toxicity than in Prometheus’ test). The district court determined that Mayo’s test infringed, but found the above (and additional) claims unpatentable as claiming only correlations between thiopurine drug metabolite levels and therapeutic efficacy and toxicity. Prometheus Labs. v. Mayo Collaborative Services, No. 04-CV-1200 (S.D.Cal. 2008). The court found that the “administering” and “determining” steps were merely data-gathering steps and the “warning” step, embodied by the wherein clauses, was only a mental step that did not specify any actual step or change in dosage.

The Federal Circuit reversed and held the above (and additional) claims patentable, in large part because it considered the “administering” and “determining” steps as transformative under the “machine-or-transformation” test. Prometheus Labs. v. Mayo Collaborative Services, 628 F.3d 1347, 1352 (Fed. Cir. 2010). Even though the court held that the claims covered a “particular application of naturally occurring correlations, and accordingly did not preempt all uses of the recited correlations between metabolite levels and drug efficacy or toxicity,” id. at 1355, its opinion focused on the transformative steps that actively changed the patient or determined correlations and not on preemption (either generally or in the area of personalized medicine).

B. The Supreme Court’s Decision in the Mayo Case

The Supreme Court, in a unanimous opinion delivered by Justice Breyer, reversed the Federal Circuit, stating, “Prometheus’ patents set forth laws of nature … namely, 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.” Mayo Collaborative Services v. Prometheus Labs, Inc., No. 10-1150, at 8 (March 20, 2012) (emphasis added). The Court noted that, “[w]hile it takes a human action (the administration of a thiopurine drug) to trigger a manifestation of this relation in a particular person, the relation itself exists in principle apart from any human action.” Id. Essentially, in the Court’s opinion, the claims did not have statements that “apply natural law”; instead, they merely embodied natural relationships between metabolite levels and therapeutic efficacy or toxicity. Id.

The Court explained that the “administering” step refers to the relevant audience (the doctors), and that simply limiting abstract ideas to application in a particular technological environment would not be enough to impart patentability. Id. at 9. Next, the “determining” step simply instructs doctors to determine metabolite levels, regardless of the process used. Id. at 10. These processes, which the patent stated were well known in the art, could not be used to impart patentability. Id. Also, 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.” Id. at 9. Lastly, the combination of these steps added nothing to the laws of nature that each embodied separately. Id. at 10.

One of the Court’s major concerns was the potential inhibition of further discovery by allowing patents that might preempt future and unpredicted directions in technology (here methods of treatment in the area of personalized medicine). For example, the Court rejected Prometheus’ argument that the claims were sufficiently narrow to have limited applications or threaten preemption of a broad area of technology. Narrow or not, the Court expressed concern that such claims “threaten to inhibit the development of more refined treatment recommendations … that combine Prometheus’ correlations with later discovered features of the metabolites, human physiology or individual patient characteristics.” Id. at 18. The Court also noted that the “‘determining’ step [was] set forth in highly general language covering all processes that make use of the correlations after measuring metabolites, including later discovered processes that measure metabolite levels in new ways.” Id.

C. What Can We Do in Light of Mayo?

The Federal Circuit on remand in the Myriad case may shed more light on what level of articulation a method-oftreatment claim must contain and to what extent it will synchronize its view of Section 101 in the life sciences field with that of the Supreme Court. Importantly, it remains to be seen if preemption will figure prominently in the Federal Circuit’s view of patent eligibility. Also, the Supreme Court did not place much stock in the transformative nature of process steps, which was important to the Federal Circuit’s ultimate conclusion of patent eligibility. One factor that may influence the outcome is that, while the Prometheus claims were directed to a method, the claims in Myriad call for a composition.

Presently, in light of the Mayo case, the requirement broadly appears to be that, to be patent-eligible, a process must articulate clear steps that go beyond those that are “obvious, already in use, or purely conventional.” Id. at 12.

Thus practitioners should continue to stress, if applicable, that their diagnostic applications, e.g., correlations of drug level and efficacy/toxicity, are poorly understood and not routine, conventional activity engaged in by the scientific community.

In applying the decision in Mayo however, it would also be prudent to include specific steps that impart novelty and neutralize concerns of preemption of future improvements. For example, if one discovers a natural phenomenon, e.g. that a mutation causes a particular disease, certain diagnostic applications of this phenomenon should be patentable. However, drafting a claim to include simply detecting the mutation and correlating it with the disease may not be enough. To be patent-eligible, the claim may have to articulate more specific steps. While it remains unclear what the “more” needs to be, it would likely include adding therapeutic (or method of treating) steps based on the diagnostic information, rather than simply detecting or considering natural phenomenon, for example, steps for treating the patient based on this information. Bottom line, including at least one specific physical or biological claim element that is not “conventional” (see PTO memo below) would presently appear to be a good approach for addressing the issue presented in Mayo when drafting claims to biological or chemical processes.

While more particularized guidance in light of the Mayo decision is expected, the USPTO has instructed examiners to continue to analyze method claims for compliance with Section 101 under the USPTO’s July 27, 2010 Bilski guidance. Examiners are to weigh factors in favor of and against eligibility and to use the machine-or-transformation test as an investigative tool, but not as the sole or determinative test for deciding whether an invention is patent-eligible.

Examiners must continue to ensure that claims, particularly process claims, are not directed to an exception to eligibility such that the claim amounts to a monopoly on the law of nature, natural phenomenon, or abstract idea itself. In addition, to be patent-eligible, a claim that includes an exception should include other elements or combination of elements such that, in practice, the claimed product or process amounts to significantly more than a law of nature, a natural phenomenon, or an abstract idea with conventional steps specified at a high level of generality appended thereto.

The Mayo decision may be applied narrowly, such as to claims that are broad, like the ones at issue in the case, or where there is a threat of preemption. Also, it remains to be seen how the Federal Circuit will apply Mayo, both with respect to patent eligibility in the area of personalized medicine and diagnostic claims, and in articulating a standard under Section 101.