Laws of nature, natural phenomena, and abstract ideas are not patentable. A new mineral discovered in the earth or a new plant found in the wild is not patentable subject matter. Likewise, Einstein could not patent his celebrated law that E=mc2, nor could Newton have patented the law of gravity. Such discoveries are manifestations of nature, free to all men and reserved exclusively to none.
Respondent, Prometheus Laboratories, Inc. (Prometheus), is the sole and exclusive licensee of the two patents at issue, which concern the use of thiopurine drugs to treat autoimmune diseases. When ingested, the body metabolizes the drugs, producing metabolites in the bloodstream. Because patients metabolize these drugs differently, doctors have found it difficult to determine whether a particular patient's dose is too high, risking harmful side effects, or too low, and so likely ineffective. The patent claims here set forth processes embodying researchers' findings that identify correlations between metabolite levels and likely harm or ineffectiveness with precision. Each claim recites instructions to a doctor to administer the drug to his patient, telling the doctor to measure the resulting metabolite levels in the patient's blood and 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.
Petitioners Mayo Collaborative Services and Mayo Clinic Rochester (Mayo) bought and used diagnostic tests based on Prometheus' patents. But in 2004 Mayo announced that it intended to sell and market its own, somewhat different, diagnostic test. Prometheus sued Mayo contending that Mayo's test infringed its patents. The District Court found that the test infringed the patients but granted summary judgment to Mayo, reasoning that the processes claimed by the patents effectively claim natural laws or natural phenomena--namely, the correlations between thiopurine metabolite levels and the toxicity and efficiency of thiopurine drugs--and therefore are not patentable. The Federal Circuit reversed, finding the processes to be patent eligible under the Circuit's “machine or transformation test.” On remand from this court for reconsideration for a case, which clarified that the “machine or transformation test” is not a definitive test of patent eligibility, the Federal Circuit reaffirmed its earlier conclusion. Certiorari was granted.
Was Prometheus' process patent eligible?
The Court held that Prometheus' process is not patent eligible. Processes that purportedly helped physicians determine proper dosage levels of thiopurine drugs used to treat autoimmune diseases are not patentable under 35 U.S.C.S. § 101. The U.S. Supreme Court unanimously held that the patents were not patent-eligible since the relationships between concentrations of metabolites in the blood and the likelihood that a thiopurine drug dosage would prove ineffective or cause harm were known laws of nature, and the patents did not describe genuine applications of those laws. The steps of administration of the drugs by physicians who already used the drugs, advising the physicians to apply the natural laws in making treatment decisions, and directing the measurement of metabolite levels were well known and simply told the physicians to engage in well-understood, routine, conventional activity previously engaged in by scientists in the field. Further, considering the steps as an ordered combination added nothing to the laws of nature that was not already present when the steps were considered separately, and there was no inventive concept in the claimed application of the natural laws.