On March 17, 2011, Mayo Collaborative Services filed a petition for certiorari to the U.S. Supreme Court, challenging the Federal Circuit’s December 2010 decision in Prometheus Laboratories, Inc. v. Mayo Collaborative Services. Mayo asserts that the case raises the question “whether a patentee can monopolize basic, natural biological relationships,” and urges the Court to decide the issue on which it has twice granted certiorari, and yet failed to address.

I wrote previously about the Federal Circuit’s December 2010 decision, and will not reiterate all of the details here. Still, it is helpful to keep in mind the claims at issue and the Federal Circuit’s rationale for finding them patent-eligible under 35 USC § 101.

Prometheus’s Claims

Prometheus’s claims relate to personalized methods of optimizing the dosing of specific drugs used to treat gastrointestinal autoimmune diseases. Representative claims from the Prometheus’s patents are set forth below.

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 8×108 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 8×108 red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject.

46. A method of optimizing therapeutic efficacy and reducing toxicity associated with treatment of an immune-mediated gastrointestinal disorder, comprising:
(a) determining the level of 6-thioguanine or 6-methylmercaptopurine in a subject administered a drug selected from the group consisting of 6-mercaptopurine, azathiop[u]rine, 6-thioguanine, and 6-methyl-mercaptoriboside, said subject having said immune-mediated gastrointestinal disorder,
wherein the level of 6-thioguanine less than about 230 pmol per 8×108 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 8×108 red blood cells or a level of 6-methylmercaptopurine greater than about 7000 pmol per 8×108 red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject.

Thus, while many claims recite both an “administering” step and a “determining” step, some claims recite only a “determining” step.

The Federal Circuit Decision

The Federal Circuit upheld Prometheus’s claims under a two-part analysis:

1.   The court explained that the claimed methods “recite a patent-eligible application of naturally occurring correlations between metabolite levels and efficacy or toxicity, and thus do not wholly preempt all uses of the recited correlations.”

In reaching this conclusion, the court noted:

[T]he claims recite specific treatment steps, not just the correlations themselves. And the steps involve a particular application of the natural correlations: the treatment of a specific disease by administering specific drugs and measuring specific metabolites.

2.   The court confirmed that the claimed methods satisfy the machine-or-transformation test.

The court expressed its belief that “administering a drug” always involves a transformation, because “[t]he drugs do not pass through the body untouched without affecting it” or without being metabolized.

With regard to the “determining” claims that do not include an “administering” step, the court noted that “[s]ome form of manipulation, such as the high pressure liquid chromatography method specified in several of the asserted dependent claims . . . is necessary to extract the metabolites from a bodily sample and determine their concentration.” Thus, these claims satisfy the test as inherently involving a transformation.

Mayo’s Petition for Certiorari

The “question presented” in Mayo’s new petition for certiorari is this:

Whether 35 U.S.C. § 101 is satisfied by a patent claim that covers observed correlations between blood test results and patient health, so that the claim effectively preempts all uses of the naturally occurring correlations, simply because well-known methods used to administer prescription drugs and test blood may involve “transformations” of body chemistry.

On why the Court should take the case, Mayo emphasizes the Court’s initial willingness to decide similar issues in the Metabolite case.

On the merits, Mayo argues that Prometheus’s claims “preempt all uses of natural correlations,” and that the Federal Circuit’s “broad extension of the ‘machine or transformation’ test” is in “square conflict with [the] Court’s preemption standard.” Mayo also raises public health issues, arguing that the Federal Circuit decision will permit “over-broad patent monopolies that subvert medical research and patient treatment.”

The Meaning of Metabolite

Mayo’s petition asserts that the Federal Circuit decision in Prometheus goes “in a completely different direction” than the views expressed by Justice Breyer (and supported by Justices Stevens and Souter) in Metabolite. Indeed, when I looked at this issue, it was tempting to conclude that the Federal Circuit was setting itself up for a confrontation with Justice Breyer. When I looked more closely, however, I found that the Federal Circuit decision provides a detailed analysis that rebuts Justice Breyer’s position in several respects. Maybe now the Court will decide for itself whether the Federal Circuit did a satisfactory job of justifying a different outcome.

Patience for Prometheus, Myriad Decisions

It still could be some time before we know whether the Supreme Court will grant certiorari in Prometheus, and even longer before the Court decides the issues presented by Prometheus’s claims. Prometheus has an opportunity to respond to Mayo’s petition, and even amici may weigh in at this stage. If the Court grants certiorari, the parties will have time to prepare their briefs, and it is likely that amici on both sides will want their opinions to be heard.

In the meantime, the Federal Circuit is set to hear oral arguments in the Myriad case next week (April 4). While that case also raises issues germane to personalized medicine, the focus there has been on the patent-eligibility of isolated DNA. Although we will try to read the tea leaves after the oral hearing, we won’t know the court’s views until it issues a written decision, which could be a few weeks or months. Given the fundamental issues raised in that case, the “losing” party is likely to petition the Supreme Court for certiorari.

If the Court takes up both cases, this could be a landmark year for pharmaceutical patent law, even if Congress never passes a patent reform law.