Patent Law | Expert Legal Commentary

March 21, 2012

Mayo v. Prometheus: The Supreme Court Reverses the Federal Circuit, Finding Prometheus' Patents Cover Laws of Nature and Therefore Ineligible Subject Matter

By Jeff Zuber of Zuber Lawler & Del Duca and Sarah S. Brooks of Stradling Yocca Carlson & Rauth

Mayo v. Prometheus: The Supreme Court Reverses the Federal Circuit, Finding Prometheus' Patents Cover Laws of Nature and Therefore Ineligible Subject Matter

A unanimous Supreme Court recently reversed the Federal Circuit in Mayo Collaborative Services v. Prometheus Labs Inc., (U.S. S Ct. decided March 20, 2012) holding that the two Prometheus patents do not cover patent eligible subject matter. The Federal Circuit reaffirmed its prior decision holding that Prometheus’ patents covered eligible subject matter after a remand by the Supreme Court in light of its Bilski v Kappos decision which clarified that the “machine or transformation” test is not a definitive test of patent eligibility.


Prometheus is the sole and exclusive licensee of two patents which concern the use of thiopurine drugs to treat autoimmune diseases such as Crohns disease and ulcerative colitis.  Doctors found it difficult to determine whether a given dosage of the drug is too high, thereby causing harmful side effects, or too low, thereby being ineffective because patients metabolize these thiopurine drugs at different rates.  The patents at issue here correlate the metabolite levels in the blood with the likely harm or effectiveness.  Each claim recites an “administering” step whereby the drug is given to a patient, a “determining step” whereby the levels of metabolite in the patient’s blood is determined, and lastly a “wherein” step whereby the levels of metabolite above which the effects are harmful and below which the drug is ineffective are described.

Mayo bought and used diagnostic tests based on Prometheus’ patents.  But, in 2004 Mayo announced that it planned to sell and market its own diagnostic test.  Prometheus sued Mayo contending that its tests infringed its patents.

The Patent Claims do Not Add Enough to Qualify As Patent Eligible Subject Matter

Of course “laws of nature, natural phenomena, and abstract ideas” are not patentable subject matter under §101 of the Patent Act.  Here, the Supreme Court pointed out that the Prometheus patents set forth laws of nature because they simply describe the relationships between concentrations of the metabolite in the blood and the likelihood that a dosage of the drug will be effective or cause harm.  The issue addressed by the Supreme Court is whether the claimed processes transformed the natural laws into patent-eligible subject matter.  The Supreme Court reasoned that the three steps, “administering”, “determining” and “wherein” added nothing to the laws of nature other than what is well-understood and routine to those in the field.  The Supreme Court clarified that while an application of a law of nature may deserve patent protection, simply stating the law of nature with the words “apply it” is not enough. 


Although this decision was unanimous, determining whether a patent covers eligible subject matter under §101 is still not a straightforward analysis.  The Court reiterated that the “machine or transformation test” is not definitive as per Bilski.  But, the Court also notes that Prometheus’ patent claims added nothing to the laws of nature other than what is well-understood and routine to those in the field.  This language sounds similar to the test for obviousness.  A further question is whether this unanimous decision makes it more or less likely that the Supreme Court will grant certiorari to the Myriad case decided by the Federal Circuit in September, 2011.  In that case, the Federal Circuit upheld Myriad’s product claims on cDNA and isolated DNA finding that they did cover patent eligible subject matter under §101.  Alternatively, the Supreme Court may remand the Myriad case in light of the Mayo v. Prometheus decision.

About the Authors

Jeff Zuber is a Partner of Zuber Lawler & Del Duca, focusing on intellectual property litigation and arbitration.

Sarah S. Brooks is an Associate of Stradling Yocca Carlson & Rauth, focusing on intellectual property litigation.

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Jeff Zuber
Sarah S. Brooks

Companies Mentioned

Mayo Collaborative Services d.b.a. Mayo Medical Laboratories

Prometheus Laboratories, Inc.

Also See:

MDS (Canada) Inc. v. RAD Source Technologies: 11th Circuit Finds Federal Circuit Does Not Have Exclusive Jurisdiction When Patents at Issue in Breach of Contract Claim

AMP v. Myriad Genetics, Inc.: Unanimous Supreme Court Limits Patentability of Human Genes

CLS Bank Intl. v. Alice Corp. Pty. Ltd.: En Banc Federal Circuit Cements Confusion Over Patent-Eligibility for Software

Bowman v. Monsanto Co.: Growing Patented Soybeans for Replanting is Infringement

Gunn, et al., v. Minton: Supreme Court Denies Federal Jurisdiction for Patent-Related Malpractice Suit

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Companies Mentioned

Patent Law

The following companies are mentioned in Patent Law Updates:

Boston Scientific Corp.

Microsoft Corp.

Boston Scientific Scimed, Inc.

U.S. Patent and Trademark Office

Samsung Electronics America, Inc.

Stryker Corp.

Cordis Corp.

Ranbaxy, Inc.

Nokia, Inc.

SmithKline Beecham Corp. d.b.a GlaxoSmithKline

Prometheus Laboratories, Inc.

SmithKline Beecham PLC

Mayo Collaborative Services d.b.a. Mayo Medical Laboratories

Sanyo North America Corp.

Glaxo Group Limited d.b.a. GlaxoSmithKline

Scimed Life Systems Inc.

Smithkline Beecham Corp. (d.b.a. GlaxoSmithKline, plc.)

Johnson & Johnson, Inc.

United States Patent and Trademark Office

Honeywell International, Inc.

HT Window Fashion Corp.

Mylan Laboratories, Inc.

Mylan Pharmaceutical, Inc.

Ortho-McNeil Pharmaceutical, Inc.

Acumed, LLC

Stryker Sales Corp.

Teva Pharmaceuticals USA, Inc.

Glamourmom LLC

Audiovox Communications Corp.

Stryker Orthopaedics

Target Corp.

McKesson Information Solutions, Inc.

Howmedica Osteonics Corp.

Kohl’s Department Stores, Inc.

Bridge Medical, Inc.

J.C. Penney Company, Inc.

Smith & Nephew, Inc.

Cohesive Technologies, Inc.

Waters Corp.

Elizabeth Lange LLC d.b.a. Liz Lange Maternity

Association for Molecular Pathology

LG Electronics, Inc.

Quanta Computer, Inc.

Federated Department Stores

Egyptian Goddess, Inc.

Swisa, Inc.

K-Mart Corp.

Motorola, Inc.

Dror Swisa

Sears Holding Corp.

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