The Supreme Court issued an opinion in the highly anticipated Mayo Collaborative Servs. v. Prometheus Labs., Inc., No. 10-1150, 2012 U.S. LEXIS 2316 (U.S. Mar. 20, 2012), involving method claims for optimizing therapeutic treatments for autoimmune diseases. The claims employed the inventors' discovery that certain metabolite levels in the blood correlated either to efficacy, or harmful side effects, in administering drugs for treatment of Crohn's disease and ulcerative colitis. According to the Court, this correlation was simply a law of nature, which itself was unpatentable. And because the additional steps of administering a drug, determining blood metabolite levels and taking into account the relevant natural laws in treating a patient were well-understood activities routinely performed by physicians, the claims erroneously elevated the basic law of nature into patentable subject matter.
Although the case will negatively impact diagnostic testing claims, its application to other method claims more generally remains to be seen.