The Supreme Court’s decision in Mayo v. Prometheus (2012) raised the 35 USC §101 bar on patentable process claims in the health sciences. Prometheus’ patented processes adjusted the dosage of thiopurine, based on the concentration of drug metabolites in a patient’s blood. The Supreme Court found that these metabolite-efficacy relationships embodied laws of nature: “the 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” are “laws of nature.” Moreover, the additional steps of “administering” the drug and “determining” the metabolite levels did not make the claims patentable. The Court noted that doctors already “administered” thiopurine drugs to treat patients with autoimmune diseases, and methods for “determining” metabolite levels were “well known in the art.” Therefore, these two additional steps were “purely conventional or obvious pre-solution activity” and they were not sufficient to make the entire processes patentable.
While Prometheus may have narrowed the scope of §101, it also left clues for how to successfully draft patentable health sciences process claims. These clues are: (1) root the process in a physical transformation; and (2) frame a robust inventive concept.
1. Root the process in a physical transformation
Considering the last several decades of jurisprudence, the processes that were held unpatentable by the Supreme Court under §101 were all linked to another process. For example: in Benson, the claimed process identified the pure binary numeral value from a binary-coded decimal numeral for further computer processes (“The method of converting signals from binary coded decimal form into binary . . .”); in Flook, the claimed process identified values for an alarm process monitoring catalytic conversion reactions (“A method for updating the value of at least one alarm unit . . .”); in Bilski, the claimed process identified values for hedging payment processes (“A method for managing the consumption risk costs of a commodity . . .”); and in Prometheus, the claimed process identified values for a process of administering drugs (“A method of optimizing therapeutic efficacy . . .”).
In contrast to these process claims that were unpatentable under §101, the process claim in Diehr was patentable under §101. In Diehr, the patentable process was a computer code operating a machine that molded a rubber tire (“A method of operating a rubber-molding press . . .”). Since the machine running the process made rubber, the process was rooted in a physical transformation.
Claim 1 of the ‘623 patent in Prometheus could be rooted in a physical transformation as follows:
“A method of optimizing therapeutic efficacy for treatment of an immune-mediated gastrointestinal disorder, comprising . . .”
Revised claim 1:
“A method of optimally administering a thiopurine drug for treatment of an immune-mediated disorder, comprising . . .”
In contrast to the original claim 1, the revised claim 1 process directly causes a physical transformation, i.e. the drug activity in the patient, by framing the claim as “administering” instead of “optimizing” a calculation.
2. Frame a robust inventive concept
The patent claims should create a robust “inventive concept,” which is the essence of the invention in a claim. In Prometheus, the Supreme Court mentions “inventive concept” in quoting Flook, but, in addition, the inventive concept theme underlies the Court’s §101 patentability analyses.
In a process claim, an inventive concept should be drafted where, beyond the law of nature, the extra steps are sufficient in quality and are sufficiently integrated with the law of nature. On the quality of extra steps, the Supreme Court stated that a patentable process should have additional steps beyond the law of nature that consist of more than “well-understood, routine, conventional activity already engaged in the scientific community.”
On the integration of extra steps, the Court stated that additional steps should be integrated into in a patentable process, so that “when viewed as a whole add [something] significant [to the law of nature] beyond the sum of their parts taken separately.” On adding limitations to a patentable process, the claims should not attempt “to limit the use of the formula to a particular technological environment or [add] insignificant postsolution activity.” Instead, a patentable process should explain “how the variables used in the formula were to be selected” and the claims should contain disclosures “relating to the chemical process at work so the other steps in the process [would] limit the claim to a particular application.”
In sum, a robust inventive concept will, beyond any law of nature, include additional steps that:
1. Are more than well-understood, routine activity.
2. Are integral to and limiting to the particular application.
Claim 1 of the ‘623 patent in Prometheus could be amended to have a robust inventive concept 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 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 8×10^8 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 8×10^8 red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject.
Revised claim 1:
“A method of optimally administering a thiopurine drug for treatment of an immune-mediated disorder, comprising:
(a) administering a 6-thioguanine providing drug
wherein the administered dosage of the drug is adjusted to maintain the metabolite levels of 6-thioguanine between 230 pmol and 400 pmol per 8×10^8 red blood cells.”
The optimum values of metabolites to signal the therapeutic window were not known and, therefore, using the metabolite parameters to administer thiopurine drugs was a previously poorly-understood activity. Additionally, the law of nature is minimized and more integrated into the revised claim 1, because the law is only a indirect subpart within the administering step, rather than a separate step from administering the drug.
The Supreme Court’s decision in Prometheus raised the bar in patenting health sciences process claims under §101. However, Prometheus provides clues on how to successfully patent health science process claims under §101. Two claim drafting rules can be deduced from Prometheus. They are: (1) root the process in a physical transformation; and (2) frame a robust inventive concept. More specifically, a robustly framed inventive concept will, beyond the law of nature, include additional steps that: (a) are more than well-understood, routine activity and (b) are integral to and limiting to the particular application. Ultimately, patent drafters should be able to use techniques such as these to overcome §101 caselaw and patent processes in the health sciences.