Prometheus patents shot down by Supreme Court

Managing IP is part of Legal Benchmarking Limited, 1-2 Paris Gardens, London, SE1 8ND

Copyright © Legal Benchmarking Limited and its affiliated companies 2026

Accessibility | Terms of Use | Privacy Policy | Modern Slavery Statement

Cookies Settings

Prometheus patents shot down by Supreme Court

In the most important ruling on patentable subject matter since Bilski v Kappos, Mayo has successfully convinced the highest US court that the diagnostic method patents owned by Prometheus are invalid

The Court unanimously ruled today that the patent claims directed to a method of determining the proper dosage of the thiopurine drug in patients did not sufficiently transform the naturally occurring correlations on which they were based to be deemed patent eligible under section 101 of the US patent law.

The decision will come as a shock to the patent community, as the Federal Circuit ruled in favour of Prometheus for a second time in December 2010, and many expected the Supreme Court to affirm that analysis under the machine-or-transformation test.

In the Bilski case, although the Court found the patent at issue unpatentable, the justices clarified that the machine-or-transformation test remained a viable way of proving that a patent involving laws of nature or abstract ideas successfully transformed or employed physical machinery to render it patent eligible.

The Federal Circuit drew upon that analysis to once again find the Prometheus patents eligible under US law. It said the so-called administering and determining steps of the patent claims transformed laws of nature into useful applications of those laws.

But the Supreme Court disagreed, and criticised the Federal Circuit's interpretation: "In stating that the 'machine-or-transformation' test is an 'important and useful clue' to patentability, we have neither said nor implied that the test trumps the 'law of nature' exclusion," said Justice Breyer, writing for the unanimous Court.

With respect to the Prometheus patents, he explained: "The 'administering' step simply identifies a group of people who will be interested in the correlations, namely, doctors who used thiopurine drugs to treat patients suffering from autoimmune disorders…. The 'wherein' clauses simply tell a doctor about the relevant natural laws, adding, at most, a suggestion that they should consider the test results when making their treatment decisions. The 'determining' step tells a doctor to measure patients' metabolite levels, through whatever process the doctor wishes to use. Because methods for making such determinations were well known in the art, this step simply tells doctors to engage in well-understood, routine, conventional activity previously engaged in by scientists in the field.

"Finally, considering the three steps as an ordered combination adds nothing to the laws of nature that is not already present when the steps are considered separately."

The Court also notably rejected the US government and other amici's suggestions that sections 102 and 103 are better suited to invalidate patents such as these. "This approach would make the 'law of nature' exception to §101 patentability a dead letter," said the Court.

Many speculated that the Supreme Court has been waiting for the Prometheus judgment to be released before deciding whether or not to hear the Myriad gene patent case. That case could further clarify the Court's approach to section 101, this time with respect to composition of matter claims.

Check back with Managing Patents for continuing coverage of this case.

more from across site and SHARED ros bottom lb

More from across our site

Lawyers at Bowmans Kenya discuss the digital blind spots posed by the transition from physical ledgers to cloud databases and digital co-development models
The Powell Gilbert co-founder discusses the confidence required to launch a firm, building an enduring patent litigation practice and why developing the next generation has changed her measure of success
Cabinet M Oproiu’s Raluca Vasilescu explains why AI is changing what clients expect from patent attorneys, where the technology is overhyped and what the next generation will need to do differently
As clients demand more flexible fees and AI-driven efficiencies, IP firms are rethinking pricing without abandoning the value of their work
HG Law was formed largely by ex Fish & Neave lawyers who left after the latter's merger with Ropes & Gray; now those experiences are shaping its latest combination
David Rodrigues and Evan Lazerowitz – attorneys at Robinson & Cole – offer practical guidance on the steps a business might consider to preserve and maximise IP value before entering financial distress or insolvency
Daniel Law CEO Alicia Daniel-Shores may have stepped into a family business, but she has spent two decades building her own vision around technology and litigation
Law firms don't particularly like saying no to clients. Perhaps they should get better at it
The office, which has a relatively new patent litigation team as well as a wider ‘soft’ IP offering, would remain independent if the rejection is rubberstamped
The IP boutique is betting that growing investment in quantum and semiconductors will fuel demand as technology shifts toward physical systems
Gift this article