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March 26, 2012

Mayo Collaborative Services v. Prometheus Laboratories, Inc.: US Supreme Court Finds Blood Test Ineligible for Patent Protection

Arnold & Porter Advisory

On March 20, 2012, in Mayo Collaborative Services v. Prometheus Laboratories, Inc., the US Supreme Court handed down a noteworthy decision on the subject of patent eligibility. In a unanimous opinion (authored by Justice Breyer), the Court held that certain method claims in two US patents, relating to a process for determining proper patient dosages of a drug used to treat autoimmune diseases were not patentable subject matter under Section 101 of the Patent Act. The Court explained that the claimed invention did nothing more than reflect a fundamental "law of nature" and teach medical practitioners how to use that law of nature to obtain beneficial results. Because the claims merely "inform a relevant audience about certain laws of nature[,]" and because "any  additional steps consist of well understood, routine, conventional activity already engaged in by the scientific community;" the Court concluded that the claims were not patentable and were thus invalid.

In our view, the Court's decision is problematic in the breadth of certain of its statements and in the implications of its reasoning. At the very least, the decision is likely to create uncertainty for companies developing diagnostic or prognostic testing methods that employ known compositions and/or "laws of nature." For such companies, Prometheus may suggest that the disclosure mechanisms of the patent system may be an inadequate form of intellectual property protection.

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