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

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

AG Barr acquires drinks makers Fentimans and Frobishers, in deals worth more than £50m in total
Tarun Khurana at Khurana & Khurana says corporates must take the lead if patent filing activity is to truly translate into innovation
Michael Moore, head of legal at Glean AI, discusses how in-house IP teams can use AI while protecting enforceability
Counsel for SEP owners and implementers are keeping an eye on the case, which could help shape patent enforcement strategy for years to come
Jacob Schroeder explains how he and his team secured victory for Promptu in a long-running patent infringement battle with Comcast
After Matthew McConaughey registered trademarks to protect his voice and likeness against AI use, lawyers at Skadden explore the options available for celebrities keen to protect their image
The Via members, represented by Licks Attorneys, target the Chinese company and three local outfits, adding to Brazil’s emergence as a key SEP litigation venue
The firm, which has revealed profits of £990,837, claims it is the disruptive force in the IP-legal industry
In the first of a two-parter, lawyers at Santarelli analyse the patentability of therapeutic inventions where publication of clinical trial protocols occurs before the application's filing date
Arun Hill at Clarivate assesses the Top 100 Global Innovators 2026 list, including why AI has assumed a strategic importance for innovation
Gift this article