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. Continue reading


