Patent Eligible Subject Matter After Mayo: Federal Circuit Invalidates Diagnostic Test Patent

Last week, in Ariosa Diagnostics, Inc. v. Sequenom, Inc., the Federal Circuit affirmed a district court finding that the asserted claims of a prenatal diagnostic testing method patent are not directed to patent eligible subject matter and are therefore invalid under § 101.

The Patent. The patent at issue (the ‘540 patent) involves a technology that is commercially embodied in Sequenom’s MaterniT21 test, which is a prenatal diagnostic test that analyzes cell-free fetal DNA (“cffDNA”). Because cffDNA circulates in the mother’s bloodstream, obtaining cffDNA is easier and associated with fewer risks than obtaining DNA samples from the fetus or placenta. The ‘540 patent claims certain methods of analyzing cffDNA to diagnose fetal abnormalities but does not claim cffDNA itself.

The District Court. The appellees, Ariosa Diagnostics, Inc. and Natera, Inc. (“Ariosa”),[1] make and sell prenatal tests that use maternal plasma or serum. Ariosa filed a declaratory judgment action against Sequenom, seeking a judgment that it did not infringe the ‘540 patent. Sequenom counterclaimed, alleging infringement, and moved for a preliminary injunction.  The district court denied that motion, and Sequenom appealed . The Federal Circuit vacated and remanded the case, instructing the district court to examine subject matter eligibility in light of Ass’n for Molecular Pathology v. Myriad Genetics, IncOn remand, the parties filed cross motions for summary judgment regarding invalidity under § 101. The district court granted Ariosa’s motion, concluding that “the only inventive component of the processes of the ‘540 patent is to apply those well-understood, routine processes to paternally inherited cffDNA, a natural phenomenon.” Sequenom appealed this decision.

The Federal Circuit. After applying the two-step framework articulated by the Supreme Court in Mayo Collaborative Services v. Prometheus Laboratories, Inc., the Federal Circuit affirmed the district court’s decision.  Following Mayo, courts must first determine whether the claims at issue are directed to a patent-ineligible concept; if so, the elements of each claim must be considered both individually and as an ordered combination to determine whether additional elements transform the nature of the claim into a patent-eligible application. Applying the first step, the court concluded that the claims are directed to naturally occurring matter because the method claims start with cffDNA and end with paternally inherited cffDNA, both of which are natural phenomena. Addressing the second step of the Mayo inquiry, the court explained that the process steps of a method must be new and useful. The court acknowledged that the discovery that cffDNA is present in maternal blood was the new and useful subject matter as of the application date.  The claimed method steps, however, were not new and useful, but involved well-understood, routine, and conventional methods—like the use of PCR to amplify and detect cffDNA. While the discovery in this case has revolutionized prenatal care, following Myriad, “[g]roundbreaking, innovative, or even brilliant discovery does not by itself satisfy the § 101 inquiry.”[2]

The Takeaway. Ariosa makes clear that the test for patent eligible subject matter is whether a claim represents an inventive application of an underlying natural phenomenon at the time the invention was made. This interpretation of Mayo casts doubt on the patent eligibility of diagnostic and treatment methods that involve the use of preexisting processes in combination with newly-discovered but naturally-occurring phenomena.  In order to qualify for patent protection, the process used in conjunction with the newly-discovered but naturally-occurring phenomenon must itself be novel.


[1] Diagnostics Center, Inc., a licensee of Natera, is also an appellee.

[2] In his concurrence, Judge Linn states that he joins the court’s opinion only because he is bound by “the sweeping language of the test set out in Mayo . . . .” He notes that this case illustrates the consequence of that broad language by “excluding a meritorious invention from the patent protection it deserves and should have been entitled to retain.”