Prometheus Blood Test Unpatentable, High Court Rules

The recent US Supreme Court decision in Prometheus Labs impacts the patentability of medical diagnostic method claims specifically and, more generally, any method claim relying on a correlation based on a law of nature. In a unanimous ruling, the Supreme Court held that Prometheus' process for determining the proper dosage of thiopurine drugs to treat autoimmune diseases is not patentable subject matter under 35 U.S.C. § 101. Mayo Collaborative Servs. v. Prometheus Labs., Inc., No. 2008-1403, slip. op. (Fed. Cir. Dec. 17, 2010), rev'd, 566 U.S. __ (2012).

The claims at issue had a general format as follows: a method of optimizing therapeutic efficacy for treatment of a disease comprising (a) administering a drug to a subject and (b) determining the level of a metabolite in the subject, wherein a metabolite level less than X indicates a need to increase the amount of drug and a metabolite level greater than Y indicates a need to decrease the amount of drug