The Federal Circuit has ruled two more Cleveland Clinic medical test (or “method”) patents (9581597 and 9575065) invalid (read decision here) for lack of patent-eligible subject matter (35 U.S.C. 101), following on similar rulings against three similar patents from the Clinic in 2017.

Once again, the Court rested squarely on the precedent of the Supreme Court’s landmark 2012 ruling in Mayo v. Prometheus, that “natural laws’ are not subject to patent. The three-judge panel rejected Cleveland Clinic’s argument that because the patent claimed new techniques in diagnosis, it met eligibility standards. The Court demurred, saying that something is not “any less a natural law because it can only be observed by use of certain techniques.” “These laws of nature exist regardless of the methods used by humans to observe them. Inadequate measures of detection do not render a natural law any less natural,” the Court wrote.

What makes this case a little more interesting than usual is that the Federal Circuit used it to take a sideways swipe at the patent office. The patent office released revised “guidance” on the issue of patent-eligible subject matter under 35 U.S.C. 101 earlier this year ( But in the Cleveland Clinic case, the Federal Circuit went out of its way to remind us of the patent pecking order. The Court wrote:

While we greatly respect the PTO’s expertise on all matters relating to patentability, including patent eligibility, we are not bound by its guidance. And, especially regarding the issue of patent eligibility and the efforts of the courts to determine the distinction between claims directed to natural laws and those directed to patent-eligible applications of those laws, we are mindful of the need for consistent application of our case law.

THE BUSINESS TAKEAWAY: The state of patent-eligible subject matter is a shambles and I can’t see any way other than a revisit of the Mayo doctrine by the Supreme Court in the near future, and I think there will be a broadening of the tests for patent eligibility. There is just too much scientific and commercial development being held up. Delay or forego patent applications at your own risk.