On June 12, 2015, the Federal Circuit invalidated Sequenom’s patent on fetal DNA testing (U.S. Patent No. 6,258,540; “the ’540 patent”) holding that the subject matter was not eligible for patent protection under 35 U.S.C. § 101. This is the first time that a lower court applied the Supreme Court’s ruling in Mayo Collaborative Services v. Prometheus Laboratories.

The inventors of the ’540 patent discovered that pregnant women’s blood serum and plasma contain a surprisingly large amount of fetal DNA (cffDNA). The cffDNA can be used for non-invasive genetic testing of the fetus in a variety of applications, such as in determining the fetus’s gender or screening hereditary conditions. Noting the high commercial value of this groundbreaking discovery, the inventors obtained the ’540 patent, which claims a method for detecting fetal DNA that comprises the steps of amplifying cffDNA and detecting a nucleic acid.

The Federal Circuit applied a two-step analysis as proposed in Mayo to determine the patent eligibility of the invention. First, the court considered the patent eligibility of the invention’s elements. Here the court found that the existence of cffDNA in maternal bloodstream is a natural phenomenon, and that Sequenom’s method for detecting fetal DNA “starts and ends with a natural phenomenon.” Given the patent ineligibility of the invention’s individual elements, the court next considered if the claimed method contained a sufficiently inventive feature to render the method patent eligible. The court examined the patent’s specification, its prosecution history, and expert testimonies and came to the conclusion that DNA amplification was “well-understood, routine, and conventional” at the time of filing. From the two-step analysis, the court held that the ’540 patent was directed at patent ineligible matter, and thus invalid.

The court also addressed the principle of preemption, which states that a patent should not be allowed to cover all practical uses of a basic building block of technology such as abstract ideas, natural phenomena, or natural laws. While stating that the principle of preemption was already inherent in the Mayo two-step analysis, the court nonetheless refuted Sequenom’s argument for non-preemption by saying that non-preemption was not sufficient for patent eligibility.

Finally, the court agreed with Sequenom that the invention was a brilliant discovery and a significantly valuable contribution to the medical field. However, the court found that it nevertheless fell short of the legal requirement in term of patent eligibility.

In Judge Linn’s concurrence, he found that the court applied the relevant laws correctly, but was critical to the Supreme Court’s ruling in Mayo. Judge Linn distinguished the present case from Mayoin that doctors had already been practicing the claimed method in Mayo, but in the current case the amplification and detection of cffDNA had never been accomplished before. Judge Linn was of the opinion that the invention deserved patent protection in all fairness and noted that this case was an unintended consequence of the overly broad language in Mayo.