“Method of preparation” claims survive §101 challenge at the Federal Circuit

Illumina v Ariosa Diagnostics C.A. No. 2019-1419 (Fed. Cir. 2020)

In Illumina, the Federal Circuit reversed the District Court of Northern District of California, and held two patents directed to methods of preparing samples for use in diagnostic methods are patent eligible under 35 USC §101.  In doing so, the Court differentiated its decision in Ariosa v. Sequenom, 788 F.3d 1371, (Fed. Cir. 2015).   The inventors in Ariosa had discovered that maternal plasma and serum contains some amount of cell-free fetal DNA that is useful for diagnostic purposes, and had obtained a patent for detecting paternally inherited cell-free DNA, which the Federal Circuit invalidated in 2015. In Illumina, the Court was quick to differentiate Ariosa, stating:

This is not a diagnostic case.  And it is not a method of treatment case.  It is a method of preparation case.

Slip Opinion, page 8.  The Court elaborated:

The claims in this case are directed to methods for preparing a fraction of cell-free DNA that is enriched in fetal DNA.  The methods include specific process steps – size discriminating and selectively removing DNA fragments that are above a specified size threshold – to increase the relative amount of fetal DAN as compared to material DNA in the sample.  Those process steps change the composition of the mixture, resulting in a DNA fraction that is different from the naturally-occurring fraction in the mother’s blood.

Slip opinion, page 10, citations omitted.  And rejected challenger Roche’s argument as follows:

Roche insists that the claims in this case are no more eligible than the claims at issue in Ariosa.  We disagree.  In Ariosa, the relevant independent claims were directed to a method “for detecting a paternally inherited nucleic acid” (claims 1 and 24) or a method “for performing a prenatal diagnosis” (claim 25).  The only operative steps in the claim were “amplifying” (i.e., making more of) the cell-free fetal DNA and then “detecting[it],” “subjecting [it]…to a test,” or “performing nucleic acid analysis on [it] to detect [it].”  We found those claims inelegible because, like the invalid diagnostic claims at issue in Mayo, Athena and Cleveland Clinic, they were directed to detecting a natural phenomenon.  In essence, the inventors in Ariosa discovered that cell-free fetal DNA exists, and then obtained patent claims that covered only the knowledge that it exists and a method to see that it exists.

Slip opinion, page 11.

This opinion thus supplies an argument for companies that develop diagnostic tests to apply for and obtain patent protection, if not on the test itself, on methods of preparing samples for use in the test.