Certain Medical Diagnostic Methods not Patent Eligible

Transcription

1 April 9, 2012 Certain Medical Diagnostic Methods not Patent Eligible The New England Council James T. Brett President & CEO Healthcare Committee Chairs Frank McDougall Dartmouth Hitchcock Medical Center Laurel Sweeney Philips Healthcare In a March 20, 2012 decision that did not involve the individual mandate, or any other provision from the Affordable Care Act, the United States Supreme Court ruled that certain methods used by doctors to administer the appropriate amounts of medication in treating diseases were not patent eligible because they represented nothing more than laws of nature and "well-understood, routine, conventional activity previously engaged in by researchers in the field." 1 Section 101 of the Patent Act describes patentable subject matter: 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. 2 The Court has historically interpreted this provision to include an implied exception that laws of nature, natural phenomena, and abstract ideas are not patentable. For instance, a new mineral discovered in the earth or a new plant found in the wild is not patentable subject matter. Likewise, Einstein could not patent his celebrated law that E=mc 2 ; nor could Newton have patented the law of gravity. Such discoveries are manifestations of... nature, free to all men and reserved exclusively to none. 3 Nevertheless, an application of a law of nature... to a known structure or process may [deserve] patent protection. But to transform an unpatentable law of nature into a patent eligible application of such a law, a patent must do more than simply state the law of nature while adding the words 1 Mayo Collaborative Services. v. Prometheus Laboratories, Inc., No , slip op. at 4 (2012) U.S.C. s Slip op. at 1-2 (internal citations omitted). 98 North Washington Street Boston, MA (617) Constitution Avenue NE Washington DC (202)

2 apply it - it must limit its reach to a particular, inventive application of the law. 4 Healthcare Committee This case involved patent claims covering the processes that assist doctors using thiopurine drugs for treating patients with autoimmune diseases with determining whether a given dosage level is too low or too high. The patent claims intend to apply natural laws describing the relationships between the concentration in the blood of certain thiopurine metabolites and the likelihood that the drug dosage will either be ineffective or cause harmful side-effects. The Court had to determine whether the claimed processes transformed these unpatentable natural laws into patent-eligible applications of those laws. In a unanimous decision, the Court concluded that the claimed processes did not result in such a transformation and were therefore not patentable. In particular, the Court stated that the steps in the claimed processes, apart from the natural laws themselves, involve wellunderstood, routine, conventional activity previously engaged in by researchers in the field. Likewise, the Court held that upholding the patents would risk disproportionately tying up the use of the underlying natural laws, inhibiting their use in the making of further discoveries. The patent claims were consequently invalidated. I. Background Prometheus Laboratories ( Prometheus ) is the exclusive licensee of U.S. Patent Nos. 6,355,623 ( 623 patent ) and 6,680,302 ( 302 patent ) that involve using thiopurine drugs to treat autoimmune diseases such as Crohn s disease and ulcerative colitis. After a patient swallows a thiopurine compound, it is metabolized by his body, resulting in the formation of metabolites in his bloodstream. Since individual patients metabolize thiopurine compounds differently, the same dose of a thiopurine drug affects people in a different way, and it has been challenging for doctors to determine whether a dosage for a particular patient is too high, risking harmful side effects, or too low, and likely ineffective. 4 Diamond v. Diehr, 450 U. S. 175, 185,187 (1981); see also Bilski v. Kappos, 561 U. S., (2010) (slip op. at 5); Diamond v. Chakrabarty, 447 U. S. 303, 309 (1980): Gottschalk v. Benson, 409 U.S. 63, 67, (1972). Page 2

3 At the time the discoveries embodied in the patents were made, scientists already understood that the levels in a patient s blood of certain metabolites, including, in particular, 6- thioguanine and its nucleotides (6-TG) and 6-methyl-mercaptopurine (6-MMP), were correlated with the likelihood that a particular dosage of a thiopurine drug could cause harm or prove ineffective. But scientists in the field did not know the precise correlations between metabolite levels and their likely harm or ineffectiveness. The patent claims in question identified these correlations with some precision, and set out findings that concentrations in a patient s blood of 6-TG or of 6-MMP metabolite beyond a certain level (400 and 7000 picomoles per 8x10 8 red blood cells, respectively) indicate that the dosage is likely too high for the patient, while concentrations in the blood of 6-TG metabolite lower than a certain level (about 230 picomoles per 8x10 8 red blood cells) indicate that the dosage is likely too low to be effective. The patent claims attempted to express these findings in a set of processes. For instance, the processes described in claim 1 of the 623 patent are as follows: 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 immunemediated gastrointestinal disorder; and (b) determining the level of 6-thioguanine in said subject having said immunemediated gastrointestinal disorder, wherein the level of 6-thioguanine less than about 230 pmol per 8x10 8 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 8x10 8 red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject. Page 3

4 The additional claims in the patents basically involve the same processes. Thus, each patent recites an administering step instructing a doctor to administer the drug to his patient, a determining step telling the doctor to measure the resulting metabolite levels in the patient s blood, and a wherein step describing the metabolite concentrations above which there is a likelihood of harmful side-effects and below which it is likely that the drug dosage is ineffective, and informing the doctor that metabolite concentrations above or below these thresholds indicate a need to decrease or increase the drug dosage. Prometheus sells diagnostic tests that embody the processes described in these patents, and Mayo Collaborative Services and Mayo Clinic Rochester ( Mayo ) bought and used those diagnostic tests for some time. In 2004, however, Mayo announced its intention to begin using and selling its own test using somewhat higher metabolite levels to determine toxicity (450 pmol per 8x10 8 for 6 TG and 5700 pmol per 8x10 8 for 6 MMP). Prometheus then brought this action claiming patent infringement. The Federal District Court granted summary judgment to Mayo, reasoning that the processes claimed by the patents effectively claim natural laws or natural phenomena - specifically, the correlations between thiopurine metabolite levels and the toxicity and efficacy of thiopurine drugs - and therefore are not patentable. The United States Court of Appeals for the Federal Circuit ( Federal Circuit ) reversed this decision, finding the processes to be patent eligible under the Circuit s machine or transformation test. II. Supreme Court Decision The Court explained that Prometheus patents are based on processes that set forth laws of nature - specifically, 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. 5 While it requires human action - dispensing and ingestion of a thiopurine drug - to trigger a manifestation of this relation in a particular person, the relation itself exists in principle not- 5 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 8x10 8 red blood cells, then the administered dose is likely to produce toxic side effects. Page 4

5 withstanding any human action ( [t]he relation is a consequence of the ways in which thiopurine compounds are metabolized by the body - entirely natural processes ). 6 Accordingly, the Court reasoned that a patent that simply describes that relation sets forth a natural law. Furthermore, the Court explained that if a law of nature is not patentable, then neither is a process reciting a law of nature, unless that process has additional features that provide practical assurance that the process is more than a drafting effort designed to monopolize the law of nature itself. The process that each of Prometheus patents recites tells doctors interested in the subject about the correlations that the researchers discovered. In doing so, they recite an administering step, a determining step, and a wherein step. These additional steps are not themselves natural laws but neither are they sufficient to transform the nature of the claim. 7 The administering step refers to the relevant audience, such as the doctors who treat patients having certain diseases with thiopurine drugs. That audience is a pre-existing audience, as doctors used thiopurine drugs to treat patients suffering from autoimmune disorders long before anyone stated these patent claims. The wherein step tells doctors about the applicable natural laws, adding at the most the suggestion that those laws should be considered when their patients are being treated. Stated differently, this step tells the relevant audience about the laws while trusting them to use those laws appropriately where they are relevant to their decision making. 8 The determining step tells doctors to determine the level of the relevant metabolites in the blood through any process that the doctors and/or the laboratory choose themselves to use. Prometheus recognized in the patent itself that methods for determining metabolite levels were already well known and that scientists regularly measured metabolites as part of their research into the relationships between metabolite levels and efficacy and toxicity of thiopurine compounds. Accordingly, this step tells doctors to engage in well-understood, routine, conventional activity previously engaged in by scientists who work in the field, and [p]urely conventional or obvious [pre]-solution activity is normally not 6 Slip op. at 8. 7 Slip op. at 9. 8 Id. Page 5

6 sufficient to transform an unpatentable law of nature into a patent-eligible application of such a law. 9 The Court believed the three steps together [i]nform a relevant audience about certain laws of nature; any additional steps consist of well-understood, routine, conventional activity already engaged in by the scientific community; and those steps, when viewed as a whole, add nothing significant beyond the sum of their parts taken separately. 10 Such activity is normally not sufficient to transform an unpatentable law of nature into a patent-eligible application of such a law. Nevertheless, the Court acknowledged that some new combination of steps in a process could be patentable even where all of the separate steps were already well-known and in common use before such combination was put together or proposed. But this requires a determination that these steps involve more than simply applying the law of nature through the use of conventional steps or activity. And that was not the result in this instance: Beyond picking out the relevant audience, namely those who administer doses of thiopurine drugs, the claim simply tells doctors to: (1) measure (somehow) the current level of the relevant metabolite, (2) use particular (unpatentable) laws of nature (which the claim sets forth) to calculate the current toxicity/inefficacy limits, and (3) reconsider the drug dosage in light of the law. These instructions 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. 11 Moreover, the Court explained that it has repeatedly emphasized a concern through its precedent that patent law not inhibit future discovery by improperly tying up the use of laws of nature and the like. Rewarding with patents those who discover laws of nature might encourage their discovery. But because those laws and principles are the basic tools of scien- 9 Slip op. at 10 (internal citations omitted). 10 Slip op. at Id. Page 6

7 tific and technological work, there is a danger that granting patents that tie up their use will inhibit future innovation, a danger that becomes acute when a patented process is no more than a general instruction to apply the natural law, or otherwise forecloses more future invention than the underlying discovery could reasonably justify. The patent claims at issue implicate this concern. In telling a doctor to measure metabolite levels and to consider the resulting measurements in light of the correlations they describe, they tie up his subsequent treatment decision regardless of whether he changes his dosage in the light of the inference he draws using the correlations. And, they threaten to inhibit the development of more refined treatment recommendations that combine Prometheus correlations with later discoveries. Unlike a typical patent on a new drug or a new way of using an existing drug, the patent claims at issue do not confine their reach to particular applications of the natural laws to those new drugs or uses. The Court held that the presence here of the basic underlying concern that these patents tie up too much future use of laws of nature simply reinforces its conclusion that the processes described in the patents are not patent eligible. III. United States Patent and Trademark Office One day later, on March 21, 2012 the United States Patent & Trademark Office ( PTO ) issued a memorandum providing preliminary guidance to the Patent Examining Corps. based on the Court s decision in this case. The memorandum instructed patent examiners to reject claims that amount to a monopoly on the law of nature, natural phenomenon, or abstract idea itself. Furthermore, the preliminary guidance provided that a claim including a law of nature must also include additional elements, or combinations thereof, that amount to significantly more than a law of nature... with conventional steps specified at a high level of generality. * * * The Opinion of the Court is available at: Page 7

8 The United States Patent & Trademark Office s Memorandum: Supreme Court Decision in Mayo Collaborative Services v. Prometheus Laboratories, Inc. (Mar. 21, 2012) is available at: This Committee Update provides general information and not legal advice or opinions on specific facts Page 8