Mayo Collaborative Services v. Prometheus Laboratories, Inc

Facts

Prometheus Laboratories, Inc. (Plaintiff) was the one and only licensee of two patents that concerned the use of thiopurine drugs to treat autoimmune diseases. The body metabolizes the ingested drugs, producing metabolites in the bloodstream. Because patients metabolize these drugs differently, doctors have found it hard to determine whether a particular patient’s dose is too high, risking harmful side effects, or two low, making it ineffective. The patent claims for the patents set forth processes embodying researchers’ findings that identified correlations between metabolite levels and likely harm or ineffectiveness with precision. Each claim recited (1) an “administering” step—instructing a doctor to administer the drug to his or her patient; (2) a “determining” step—telling the doctor to measure the resulting metabolite levels in the patient’s blood; and (3) a “wherein” step—describing the metabolite concentrations above which there is a likelihood of harmful side effects and below which it is likely that the drug dosage is ineffective, and informing the doctor that metabolite concentrations above or below these thresholds “indicate a need” to decrease or increase (respectively) the drug dosage. Plaintiff sold diagnostic tests incorporating these processes. For awhile, Mayo Collaborative Services and Mayo Clinic Rochester (collectively “Mayo”) (Defendant) bought and used Plaintiff tests, but then decided to market and sell its own similar tests using metabolite levels somewhat higher to determine toxicity. Plaintiff brought suit against Defendant for patent infringement. The district court, although concluding that Defendant infringed the patents at issue, still held that the patents were invalid as laws of nature under § 101 of the Patent Act. The Federal Circuit reversed, holding that the processes were patent eligible under the “machine or transformation test” as they included steps that involve the transformation of the human body or blood taken from it. That holding was appealed to the United States Supreme Court, and, on remand from the Supreme Court for reconsideration in light of Bilski v. Kappos, 130 S. Ct. 3218 (2010), which clarified that the “machine or transformation test” is not a definitive test of patent eligibility, the Federal Circuit reaffirmed its earlier conclusion. The United States Supreme Court granted certiorari.