The United States Supreme Court’s decision in Mayo Collaborative Services v Prometheus Laboratories, Inc (Prometheus) handed down on 20 March 2012 casts doubt on the patentability of process claims, particularly medical diagnostic claims, often referred to as “personalised medicine” claims.
A number of recent US court decisions have subsequently relied upon Prometheus prompting the USPTO to issue guidelines for assessing the patentability of process claims in light of this decision.
These subsequent decisions and guidelines provide hints as to what process claims are likely to be considered patentable and what steps should be included in diagnostic claims.
Mayo v Prometheus
To briefly summarise, Prometheus was concerned with the use of thiopurine drugs to treat patients with autoimmune diseases. The claims at issue before the Supreme Court can essentially be distilled down to a correlation between blood test results and a patient’s health.
The representative claim at issue in Prometheus is shown below:
A method for optimizing therapeutic efficacy for treatment of an immune-mediated gastrointestinal disorder, comprising:
wherein the level of 6-thioguanine less than about 230 pmol per 8 x 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 x108 red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject.
It was already known that patients metabolise thiopurine drugs differently, and because of this, doctors had found it difficult to determine whether a particular patient’s dose was too high, risking harmful side effects or too low, and so likely ineffective. The claimed correlation provided doctors with a means to personalise the dosage for individual patients by measuring the metabolite levels and then adjusting the dosage up or down accordingly.
Rather than being decided on obviousness, the case was decided on the issue of whether such a diagnostic correlation was patentable subject matter. The Court’s reasoning, summarised in the words of Justice Breyer:
Hence an invention is deemed unpatentable if the sole inventive contribution is based on a law of nature (that is, something which naturally occurs in the human body). According to the Supreme Court, “to transform an unpatentable law of nature into a patentable application of such a law, one must do more than simply state the law of nature while adding the words ‘apply it’”. Thus, a claim must recite particular steps to distinguish the invention from the mere application of a law of nature.
It should be noted that US Federal Circuit and the Supreme Court came to opposing findings on consideration of the same claims. In assessing patentability of the claims in Prometheus, the Federal Circuit applied the “machine or transformation” test which was recently articulated in the In re Bilski, 545 F.3d 943 (Fed. Cir. 2008) decision. According to this test, a process claim is patentable if (i) it is implemented with a particular machine or (ii) it transforms an article from one thing or state to another. The Federal Circuit found the claims of the Prometheus patents to exhibit a transformation step by transforming the human body (by thiopurine treatment) and the blood (by analysing metabolite levels). The Supreme Court was critical of the Federal Circuit’s application of this test. Although the Court accepted the notion that the “administering” step transforms the human body, they referred to that transformation as irrelevant because the step “simply helps to pick out the group of individuals who are likely interested in applying the law of nature”. Furthermore the Court disagreed with the Federal Circuit’s conclusion that the “determining” step was transformative, reasoning that the “second step could be satisfied without transforming the blood, should science develop a totally different system for determining metabolite levels that did not involve such a transformation”.
The Supreme Court also qualified that the “machine or transformation test” cannot be regarded as a sole test for determining patent eligibility of medical diagnostic claims, particularly when the transformation adds nothing of significance to the natural laws themselves.
Decisions that have issued subsequent to Prometheus
Decisions which have subsequently relied upon the Supreme Court ruling in Prometheus have resulted in different outcomes.
SmartGene v Advanced Biological Laboratories (ABL) was handed down ten days after Prometheus. The District Court for the District of Columbia relied upon Prometheus to invalidate two patents held by ABL that related to methods (i.e. processes) and systems for an interactive, computerised program for guiding the selection of therapeutic treatment regimens for a patient based on input provided by a physician.
The Court concluded that
The fact that the last step in the method was implemented by means of a computing device which was not a particular machine with any specific programming or algorithms, was found to in no way limit the claim (being merely extra-solution activity) and thus did not help to render the claims patentable.
In Nazomi Communications, Inc v Samsung Telecommunications, where claims at issue related to the telecommunications industry, the District Court for the Northern District of California found that the claims which related to a method of executing an instruction were patentable because the claims recited detailed steps that confined the claims to a specific, useful application and hence “do more than recite an abstract idea and say ‘apply it’”.
For example, the steps set out in the main claim at issue in Nazomi Communications were:
A method of executing an instruction comprising:
obtaining from an instruction storage location, an instruction that references a data structure, the data structure storing an indication of a reference that may need resolution;
obtaining data from the data structure including data from a resolution data field;
using data from resolution data field as an index to a jump table to determine whether to do a resolving step; and
thereafter, if the data in the data resolution field indicates that the reference was not resolved, resolving the reference and, thereafter, modifying the data in the data structure including modifying the data in the resolution data field to indicate that the reference is resolved, wherein the data in the instruction storage location is not modified.
The Court concluded that the claims “specify that the data obtained must include data from a resolution data filed, that the next step to be taken is a resolving step, and that the modification is to indicate that a reference is resolved”. The claims were therefore held to recite “specific implementation details” thus rendering them patentable. The Court noted that the claims involved ideas that had no substantial practical application, except in connection with computer instructions (despite there being no recitation of the term “computer” in claims). This implies that a computer’s ability to carry out method steps may be an important factor in patentability.
Conclusions from Prometheus and subsequent decisions
USPTO guidelines for patentable subject matter
In response to the controversy surrounding the Prometheus decision, the USPTO has now published guidleines for determining the patentability of process claims to assist Examiners in practically interpreting the findings in Prometheus. According to the guidelines, after determining what an applicant invented and establishing the broadest reasonable interpretation of the claimed invention, a patent examiner must make three essential inquiries on the claims as a whole to determine whether the claim is patentable.
Enquiry 1: Is the claim directed to a process? If yes, then:
Enquiry 2: Does the claim focus on a law of nature or natural principle? If yes, then:
Enquiry 3: Does the claim include additional steps that integrate the natural invention to ensure that the claim amounts to more than general application of the natural principle itself? If no, then claim does not cover patentable subject matter.
Enquiry 2: What is a “natural principle/law of nature”?
A natural principle has been defined as the handiwork of nature and occurs without the hand of man. For illustration, the USPTO has provided several examples of natural principles including:
Enquiry 3: additional steps
According to the guidelines, a claim that focuses on use of a natural principle must also include additional elements or steps to show that the inventor has practically applied or added something significant to, the natural principle itself. However, if the elements or steps do not integrate the natural principle and are merely appended to it, then that would not be sufficient for patentability. Examples of situations where patentability would not be satisfied include:
To put the above principles in context, the guidelines offer clear examples of diagnostic claims that would and would not meet the test for patentability.
One example related to a method for determining the likelihood of developing arthritis and the guidelines state:
What method claims are still patentable?
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