Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371 (Fed. Cir. 2015), was one of the most important Federal Circuit decisions in the field of biotechnology in 2015. It could have far-ranging implications for patents on diagnostic methods. The claims covered methods of genetic testing by detecting and amplifying paternally inherited fetal cell-free DNA (cffDNA) from maternal blood and plasma. Before the inventors’ creation of this non-invasive prenatal diagnostic test, maternal plasma was routinely discarded as waste.

The panel decision, authored by Judge Reyna, applied Mayo Collaborative Services. v. Prometheus Laboratories, Inc., 132 S. Ct. 1289 (2012), and held that the claimed subject matter was not patentable under Section 101. The Court determined that the claims were directed to a natural phenomenon (the presence of paternally inherited cffDNA in maternal blood and plasma), and that the recited steps for detecting that cffDNA were well-understood, routine activities. Therefore, the claims lacked an inventive concept under Mayo and were not patent eligible. Judge Linn concurred in the decision, but characterized the test for patent eligibility under Mayo as overbroad, “excluding a meritorious invention from the patent protection it deserves.” In the Federal Circuit’s order denying rehearing en banc, other judges echoed Judge Linn’s concerns about the Mayo test, but ultimately agreed that the panel’s decision correctly applied that test. Judge Newman dissented from the denial of rehearing en banc.

Ariosa could make natural product and diagnostic method patents more difficult to obtain and enforce. The decision starkly illustrates the severity of the Mayo test. Although several members of the Federal Circuit appear to question the wisdom of Mayo, most of them (other than Judge Newman) found no basis for a narrower reading of the Supreme Court’s Mayo decision. It remains to be seen whether Sequenom will petition for certiorari and, if so, whether the Supreme Court will grant review. Absent Supreme Court review, Ariosa’s interpretation of Mayo could potentially have a chilling effect on innovations in genetic and diagnostic testing. Diagnostic method patents will continue to be scrutinized and frequently invalidated under Section 101 as directed to patent-ineligible natural laws or phenomena.