Preparation, Diagnostics, Treatment… and Eligibility

In a recent subject matter eligibility case, the Federal Circuit reversed a district court decision finding that claims covering prenatal DNA testing were patent-ineligible.

The Sequenom patents at issue, U.S. 9,580,751 (“the ‘751 patent”) and U.S. 9,738,931 (“the ‘931 patent”), are directed to a method for preparing a DNA fraction from a pregnant human female based on the discovery that cell-free fetal DNA is typically less than 500 base pairs (bp), while maternal DNA is typically greater than 500 bp. Claim 1 of the ‘751 patent is representative:

1. A method for preparing a deoxyribonucleic acid (DNA) fraction from a pregnant human female useful for analyzing a genetic locus involved in a fetal chromosomal aberration, comprising:
(a) extracting DNA from a substantially cell-free sample of blood plasma or blood serum of a pregnant human female to obtain extracellular circulatory fetal and maternal DNA fragments;
(b) producing a fraction of the DNA extracted in (a) by:
(i) size discrimination of extracellular circulatory DNA fragments, and
(ii) selectively removing the DNA fragments greater than approximately 500 base pairs, wherein the DNA fraction after (b) comprises a plurality of genetic loci of the extracellular circulatory fetal and maternal DNA; and
(c) analyzing a genetic locus in the fraction of DNA produced in (b).1

The Federal Circuit stated “[t]his is not a diagnostics case. And it is not a method of treatment case. It is a method of preparation case… The claims in this case do not fall into either bucket, and we consider the claims under the Alice/Mayo test.”²

In its analysis, the Federal Circuit determined that the inventors of the ‘751 and the ‘931 patents discovered the size difference between fetal DNA and maternal DNA, and the inventors then used this information to “develop a solution to the identified problem of distinguishing fetal DNA from maternal DNA in the mother’s bloodstream.”³ The Federal Circuit acknowledged “it is undisputed that the inventors…discovered a natural phenomenon.”⁴ The Federal Circuit then noted that it is not enough to identify a patent-ineligible concept underlying the claims; the claims must be examined to determine whether they are directed to the patent-ineligible concept.

According to the Federal Circuit, the claims are “directed to methods for preparing a fraction of cell-free DNA that is enriched in fetal DNA,” which involve specific process steps such as size discrimination and selective removal of DNA fragments above a certain size.⁵ Based on this analysis, the Federal Circuit concluded that “the claims are not directed to [a] natural phenomenon but rather to a patent-eligible method that utilizes it.”⁶ While the Federal Circuit acknowledged that the techniques recited in the ‘751 and ‘931 patents (e.g., centrifugation, chromatography, electrophoresis, and nanotechnology) were not new, the Federal Circuit stated that such considerations “do not impact the Alice/Mayo step one question whether the claims themselves are directed to a natural phenomenon.”⁷

The Federal Circuit distinguished this case from Ariosa⁸ by noting that the claims in Ariosa were directed to a “method for detecting a paternally inherited nucleic acid” or a “method for performing a prenatal diagnosis,”⁹ while the claims of the ‘751 and ‘931 patents are directed to more than just correlating or detecting a DNA fragment as fetal or maternal. The Federal Circuit also highlighted the differences between Myriad,¹⁰ which covered a gene, and the claims at issue, which do not cover fetal DNA itself but a process to selectively remove non-fetal DNA.

Analogizing to Cellzdirect,¹¹ the Federal Circuit determined “the inventors used their discovery to invent a method of preparing a fraction of DNA that includes physical process steps to selectively remove some maternal DNA in blood to produce a mixture enriched in fetal DNA.”¹² Thus, the district court’s decision was reversed and remanded.

In a dissent, Judge Reyna stated that “[t]he claims are directed to a natural phenomenon because the patent’s claimed advance is the discovery of that natural phenomenon.”¹³ He also stated that the “[m]ajority sidesteps well-established precedent by reasoning that the claims in this case belong in a unique ‘bucket’ reserved for patents that claim ‘a method of preparation.’… By placing this case in that bucket and not in a ‘diagnostic case’ bucket, the Majority summarily dismisses precedent like Athena, Roche Molecular, Cleveland Clinic, Genetic Techs., Ariosa, and others.”¹⁴ According to Judge Reyna’s analysis, the claims of the ‘751 and ‘931 are not patent eligible under the Alice/Mayo test.

Thus, while obtaining “diagnostics” or “method of detecting” claims remain difficult, claims directed to “methods of preparing” that recite a newly discovered natural phenomenon can still be patent eligible.