On August 4, 2017, the U.S. District Court in the District of Massachusetts found U.S. patent 7267820 (the ‘820 patent), owned by Athena Diagnostics, Inc., to be directed to non-patentable subject matter, and therefore invalid under 35 USC 101.

The ‘820 patent discloses and claims a method for the diagnosis of a form of myasthenia gravis, a chronic autoimmune disorder. In most patients, diagnosis is achieved through tests that detect the presence of acetylcholine receptor (AChR) autoantibodies. However, about 20% of patients who have myasthenia gravis do not show the presence of AChR autoantibodies. The inventors of the ‘820 patent discovered that, in those patients, IgG antibodies were present, and those antibodies attack muscle specific tyrosine kinase (MuSK). The patent discloses and claims a method for diagnosing myasthenia gravis whereby a radioactive label is attached to MuSK (or a fragment thereof) and is then introduced to a sample of bodily fluid. After the bodily fluid is immunoprecipitated, the presence of the radioactive label on any antibody provides the diagnosis. In one specific claimed example, 125I is used as the radioactive label and the labeled substance is 125I-MuSK. The claimed method provides a way of diagnosing myasthenia gravis in that 20% of patients for whom the previous methods were not useful.

Athena alleged that Mayo Medical Laboratories, having knowledge of the ‘820 patent, designed an alternate test to avoid paying license fees to Athena and, in doing that, infringed the ‘820 patent.

Mayo, as is very usual in today’s patent disputes, moved to dismiss on the grounds that the patent claimed a law of nature or a natural phenomena. The court applied the two-step method presented by the Supreme Court in Mayo Collaborative Servs. v. Prometheus Labs., Inc.1, and later adopted by the Supreme Court in Alice Corp. Pty. Ltd. v. CLS Bank Int’l2. In the first step of the Mayo/Alice test, the court had to “determine whether the claims at issue [were] directed to a patent-ineligible concept.”3 If the claim were directed to a patent-ineligible concept, the court would then have had to “consider the elements of each claim, both individually and 'as an ordered combination,' to determine whether the additional elements ‘transform[ed] the nature of the claim’ into a patent-eligible application.”4

Up to this point, not much is unusual. Over 200 patents have been invalidated due to the Mayo/Alice two-step method. What is of relevance here is, if upheld by the Federal Circuit and the Supreme Court, the impact of this decision would be felt on medical diagnostics and on personalized medicine.

Comparing the claimed invention in the ‘820 patent to the claims considered by the Supreme Court in Mayo, in the claims in the prior Mayo case, a product is administered to a human and metabolized, and a level of the drug in the bloodstream is measured. In contrast, in the method claimed in the ‘820 patent, a non-naturally occurring complex, 125I-MuSK, is used outside of the human body. When modified with Iodine-125, the physical properties of a peptide change drastically (this is described in greater detail here). The Iodine-125-modified MuSK is then introduced to a sample of bodily fluid and immunoprecipitated, all of which occurs outside of the human body and marks an interaction of a nonnaturally occurring complex and bodily fluid. While antibodies are naturally occurring substances, the antibodies in the claimed invention interact with a peptide that has had a man-made drastic modification of the physical properties, but still interacts with the antibodies.

In Enfish, LLC v. Microsoft Corp., the Federal Circuit Court equates the “directed to” inquiry to focusing on the claimed advance over the prior art.5 In the ‘820 patent, the claimed advance over the prior is the method for diagnosis of myasthenia gravis for the 20% of patients who do not show the presence of AChR autoantibodies. However, the U.S. District Court, in this case, finds that the claimed invention in the ‘820 patent is focused on the interaction between Iodine-125-modified MuSK and the bodily fluid, which the court states is a natural occurrence (probably because it is similar to the interaction between MuSK and the bodily fluid).

The U.S. District Court also finds support in Ariosa Diagnostics, Inc. v. Sequenom, Inc., in which the Federal Circuit Court states that, if the claims “are directed to detecting the presence of a naturally occurring thing or natural phenomenon,” the claims fail step one of the Mayo/Alice test.6 Using the Ariosa criterion, rather than the Enfish criterion, it is difficult to see how any medical analytical or detection method would not be found to be directed to one of the court-stated exceptions of 35 USC 101.

Selecting a criterion for determining whether the claims are directed to a law of nature or natural phenomena that results in almost all medical analytical or detection methods being placed in the category of directed to a law of nature or natural phenomena will prevent the fuel of commercial interest to be added the fire of invention (using the language of President Lincoln’s famous quote regarding patents).

If the U.S. District Court decision is appealed, we will see if the Federal Circuit (or the Supreme Court) clarifies the contours of the Mayo test, or whether the U.S. joins a number of other nations in which medical diagnosis tests are not patentable.

1 Mayo, 566 U.S. 66, 71 (2012)
2 Alice, 134 S. Ct. 2347 (2014)
3 Alice, 134 S. Ct. at 2355
4 Mayo, 132 S. Ct. at 1298, 1297
5 Enfish, 822 F.3d 1327, 1335 (Fed. Cir. 2016)
6 Ariosa, 788 F.3d 1372, 1376 (Fed. Cir. 2015)