On June 12, 2015, in Ariosa Diagnostics, Inc. v. Sequenom, Inc., the Federal Circuit affirmed the Northern District of California’s finding that the method claims in U.S. Patent 6,258,540 (‘540 patent) for detecting paternally-inherited cell-free fetal DNA (“cffDNA”) in maternal plasma or serum were invalid because these claims were not directed to patent eligible subject matter (Ariosa Diagnostics, Inc. v. Sequenom, Inc., No. 2014-1139, 2014-1144 (Fed. Cir., June 12, 2015)). The inventors of the ‘540 patent established methods for detecting paternally inherited cffDNA in maternal plasma or serum to determine fetal characteristics, such as gender. The Court applied a 2 part test as set forth in Mayo (Mayo Collaborative Servs. v. Prometheus Labs., Inc., 132 S. Ct. 1289 (U.S. 2012)) and held that “[w]here claims of a method patent are directed to an application that starts and ends with a naturally occurring phenomenon, the patent fails to disclose patent eligible subject matter if the methods themselves are conventional, routine, and well understood applications in the art.”

The Mayo framework provides that first whether the claims at issue are directed to a patent-ineligible concept is determined. If the answer is yes, then the elements of each claim both individually and “as an ordered combination” are considered to determine whether additional elements “transform the nature of the claim” into a patent-eligible application. Here, the natural phenomenon was the existence of cffDNA in maternal blood. cffDNA is found in the portion of the maternal blood samples that previously researchers discarded as medical waste. The Court stated that Sequenom’s method claim “begins and ends with a natural phenomenon” because it was undisputed that cffDNA is a natural phenomenon. Importantly, the inventors did not create or alter any genetic information in the cffDNA.

This second step—known as the “inventive concept”—requires that claims include elements which would render the method both new and useful. The Court stated that the method steps involving standard PCR amplification and gel electrophoresis are “not new and useful.” Accordingly, the claims of the ‘540 patent were found to be invalid for being subject matter ineligible.

The Federal Circuit also addressed preemption and found that because these method claims were deemed subject matter ineligible, the concern of preemption, i.e., whether the methods preclude alternative methods in the same field but outside the scope of the claims, was moot. The Court rejected Sequenom’s arguments that the claimed methods would not preclude alternative methods, and, therefore, would not preempt the field. The Court explained that the questions of preemption are inherent in subject matter eligibility analysis, and when the claims fail the Mayo test, the question of preemption would not arise. Although the Court invalided the method claims, the Court acknowledged that Sequenom’s claimed methods involved “a new way that revolutionized prenatal care” and, therefore, a “positive and valuable contribution to science”.