by Dennis Crouch

Mayo Collaborative Services v. Prometheus Labs., Inc. (Supreme Court 2012)

A unanimous (9–0) Supreme Court has held that the personalized medicine dosing process invented by Prometheus is not eligible for patent protection because the process is effectively an unpatentable law of nature. This decision reverses the Court of Appeals for the Federal Circuit’s holding that the claims were patentable because they included substantial physical limitations.

The Prometheus invention identifies a “relationships between concentrations of certain metabolites in the blood and the likelihood that a dosage of a thiopurine drug will prove [either] ineffective or cause harm. Claim 1, for example, states that if the levels of 6–TG in the blood (of a patient who has taken a dose of a thiopurine drug) exceed about 400 pmol per 8×10(8) red blood cells, then the administered dose is likely to produce toxic side effects.” In addition to claiming the boundaries between over and under dosage of thiopurine based upon measuring 6–TG in the blood, some of the Prometheus claims include additional limitations such as (1) administering thiopurine to a patient and (2) determining the blood level of 6–TG.

Law of Nature: In its decision, the Supreme Court first identified the correlation between 6–TG blood levels and over/under thiopurine dosage as an unpatentable law of nature.

The relation is a consequence of the ways in which thiopurine compounds are metabolized by the body—entirely natural processes. And so a patent that simply describes that relation sets forth a natural law.

As is usual in these cases, the Court referenced the groundbreaking discoveries by Einstein and Newton and noted that neither “E=mc²” nor the “law of gravity” would have been subject matter eligible. Taking that as a premise, the court jumped to the conclusion that, therefore, the discovery that the blood level of 6–TG in a human correlates with either an overdose or underdose of thiopurine is also subject matter ineligible.

Additional Elements: The Supreme Court then considered the additional limitations and held them insufficient to transform the identified natural law into a patentable process. The opinion repeatedly and favorably cites Parker v. Flook, 437 U. S. 584 (1978) in finding that the physical and transformative elements of the invention were not “genuine applications of those laws[, but] rather .. drafting efforts designed to monopolize the correlations.” As to the claimed application of the law of nature, court here found it relevant and important that the additional steps were already known in the art.

Because methods for making such determinations were well known in the art, this step simply tells doctors to engage in well-understood, routine, conventional activity previously engaged in by scientists in the field. Such activity is normally not sufficient to transform an unpatentable law of nature into a patent-eligible application of such a law.

The conclusion here is that (1) a newly discovered law of nature is itself unpatentable and (2) the application of that newly discovered law is also normally unpatentable if the application merely relies upon elements already known in the art. To be clear, the court still maintains the law of Diehr that “an application of a law of nature or mathematical formula to a known structure or process may well be deserving of patent protection.” On the other hand, the “application” must be “significant,” not “too broadly preempt” use of the law, and include other elements that constitute an “inventive concept” that is significant and separate from the natural law itself. Of note, it is likely important that in this decision the court unfavorably cites the limitation of Flook found in Diehr that eligibility under § 101 “must be” based on claims “considered as a whole.”

Process and Presumption: In addition to the legal elements, the decision can be read to create a process for determining patent eligibility for patent claims that include a law of nature. The court wrote that the “additional features” that show an application of the law must “provide practical assurance that the [claimed] process is more than a drafting effort.” This language suggests that the burden will be on the patentee to prove that its limitations are more than patent attorney tricks.

Whither Myriad: Although no action has been taken yet, I presume that the Supreme Court will now vacate and remand the pending Myriad case with instructions to the Federal Circuit to reconsider its holding that isolated human DNA is patentable. Following Mayo, the court could logically find that the information in the DNA represents a law of nature, that the DNA itself is a natural phenomenon, that the isolation of the DNA simply employs an isolation process already well known and expected at the time of the invention, and ultimately that the isolated DNA is unpatentable because it effectively claims a law of nature or natural phenomenon. One distinguishing point is that Prometheus claimed a process while Myriad claims a composition of matter. As we have seen in recent cases, the Federal Circuit already largely rejects formalistic distinctions between process and composition claims. Here, that distinction is further minimized by the reality that the claimed DNA is functionally characterized by the already well known process of isolating human DNA.

Read the opinion by Justice Breyer here: LINK.

The following is the text of the now invalidated Claim 1 of the Prometheus U.S. Patent No. 6,355,623.