Patent & Trade Mark

The Prometheus decision... six months on

Date: 26 September 2012
Author: Karin Innes
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:
(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 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:
“To put the matter more succinctly, the claims inform 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.  For these reasons we believe that the steps are not sufficient to transform unpatentable natural correlations into patentable applications of these regularities”.
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 steps of the claimed methods were commonly performed by medical professionals in evaluating, considering and constructing treatment options for a patient presenting a specific medical condition; and  
  • the claims consist of “well understood, routine, conventional activity already engaged in by the scientific community” and thus lack the “inventive concept” required to transform unpatentable abstract ideas into patentable applications. 
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
  • So as not to tie up too much future use of laws of nature and thus impede innovation by blocking others from developing future technologies, a claim will need to articulate specific steps, such as adding method of treating steps based on the diagnostic information, rather than simply detecting or considering natural phenomenon.  
  • To be patentable, a process must recite clear steps that go beyond those that are “obvious, already in use, or purely conventional”.  In Prometheus, the Supreme Court found that the “administering” and “determining steps” recited in the claims were conventional and had already been practised by doctors prior to the patent having been filed.  The “wherein” clauses were held to do little more that “simply tell a doctor about the relevant laws, at most adding a suggestion that he should take those laws into account when treating his patient”.  If the claims had been drafted differently so that they included a further step whereby the doctor was then required to administer a particular dose of 6-thioguanine after making a determination of the metabolite levels, it is possible that the Supreme Court might have then found the claim sufficiently transformative and reached a different conclusion. 
  • In the ABL case, the claimed method aided in the selection of a treatment regimen for a patient based on three knowledge bases.  Thus, recitation of a computer-implemented step in the method which adds nothing to the process that doctors do not already regularly engage in mentally when evaluating and treating patients will not be sufficient in itself to render a claim patentable.
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:
  • relationship between blood glucose levels and diabetes in a patient
  • when a man-made product, such as a drug, interacts with a naturally occurring substance, such as blood
  • use of the natural disinfecting properties of sunlight.
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:
  • a claim to diagnosing an infection that recites the step of correlating the presence of a certain bacterium in a person’s blood with a particular type of bacterial infection with the additional step of recording the diagnosis on a chart would not be patentable because the additional step of recording the diagnosis on a chart is extra-solution activity unrelated to the correlation.
  • adding steps to a natural biological process that only recite well-understood, routine, conventional activity previously engaged by researchers in the field. 
  • a combination of steps that amounts to nothing significantly more than an instruction to doctor’s to apply applicable laws when treating their patients.
  • a claim that covers known and unknown uses of a natural principle and which can be performed through any existing or future-devised machinery, or even without any apparatus lack features sufficient for patentability.
  • additional limitations that are necessary for all practical applications of the natural principle, such that everyone practicing the natural principle would be required to perform those steps or every product that natural principle would be required to include those features.
  • a machine or transformation that is merely nominally, insignificantly, or tangentially related to the steps or elements, e.g., data gathering or data storage would not show integration.  For example, a machine that is simply incidental to execution of the method (using a computer as a counter balance weight and not as a processing device) rather than an object that implements the method or a transformation that involves only a change of position or location of an object rather than a change in state or thing does not show that these additional features integrate the natural principle into the invention as they are incidental to the claimed invention.
Practical Example
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:
  • A method comprising the steps of obtaining a sample form a patient, measuring a biomarker and determining the likelihood of developing arthritis will not meet the test for patentability
  • The above method further comprising the use of a positive marker will also not meet the test
  • A method which involves the use of a novel and non-obvious antibody to measure the biomarker will meet the test
  • A method which that requires the biomarker to be measured using a combination of two assays that are “not routinely used together” will meet the test.
What method claims are still patentable?
  • Methods or processes that recite clear steps that go beyond those that are obvious, already in use or purely conventional will be patentable.
  • Claim to a new drug or a new ways of using an existing drug will still be patentable.  It remains to be confirmed in the Courts but it is at least arguable that a “new way of using an existing drug” which involves the identification of new treatment indications for a known drug and to new dosing regimens for a known drug would continue to be patentable.
  • Steps of a method that are seen as requiring substantial computer programming and so could not simply by performed by human kind satisfy the criteria of patentable subject matter (per Ultramercial LLC v Hulu LLC Fed Cir 2011).  Therefore, one strategy is to include “determining” steps that cannot be implemented with a paper and pencil analysis.
  • Claims that recite particular steps that distinguish the invention from the mere application of a law of nature will remain patentable.  For example, a claim based on treating a psychiatric behavioural disorder by treating the patient to a source of white light can be made patentable by reciting additional steps that of manipulating the light and positioning the patient for light exposure.
  • Claims that incorporate an administration step (e.g. immunizing a patient) appear to move the claim from a principle to an application and therefore satisfies patentable subject matter (as per Classen v Biogen Idec Fed Cir 2011).
  • Claims directed to a method of therapy rather than method of diagnosis would have more chance of meeting patent eligibility criteria.  For example, a claim to a method of treating a patient with a particular dosage of drug (thiopurine) wherein the patient was previously diagnosed.
  • Claims that include use of truly novel apparatus or method of analysis for data acquisition or a novel reagent (this can include an isolated DNA as recently affirmed by the Federal Circuit in Myriad in August this year), should still be patentable.
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