Mayo v. Prometheus Laboratories, Inc

Whether the correlation between blood test results and patient health is patentable.

Promotheus Laboratories, Inc. has a patent claim over the correlation between metabolites of a drug and the efficacy of the drug on two thiopurine drugs used to treat intestinal and non-intestinal autoimmune diseases. Mayo Collaborative Services (Mayo) began its own test measuring the same metabolites as Promotheus. Promotheus sued Mayo for infringement of its two patents. The district court granted a motion for summary judgment in favor of Mayo because Promotheus did not “create” the correlation between the drug metabolite levels and efficacy. The Federal Circuit reversed applying a “machine-or-transformation” test.

Mayo argues Promotheus’s patents monopolizes the field of blood testing for thiopurine metabolites because it covers anything about the natural correlation between blood test results and patient health. A patent may not preempt laws of nature, physical phenomena, and abstract ideas. 35 U.S.C. § 101. There is no well-known or long prevalent medical practice that defends Promotheus’s claim that its patents embed in the natural process of administering a drug and testing the blood. Mayo further argues that Congress has never intended that § 101 allow a patent like Promotheus to chill research and prevent identification of metabolite ranges or inexpensive testing. The impact of the decision on this patent has the likely effect to slow rather than advance innovation, thus frustrating goals of patent law.