Federal Circuit Affirms Decision Finding Organ Transplant Diagnosis Claims Unpatentable
On July 18, 2022, the United States Court of Appeals for the Federal Circuit (“CAFC”) issued a precedential opinion affirming a judgment by the United States District Court for the Eastern District of Delaware (Chief Judge Colm F. Connolly) that plaintiff's organ transplant diagnosis patents encompassed unpatentable subject matter. CareDx, Inc. v. Natera, Inc., __ F.3d __ (Fed. Cir. July 18, 2022). In its decision, the CAFC held that the district court correctly found the asserted claims to be directed to a natural phenomenon and that the claimed combination of steps is not inventive.
Plaintiff patentee asserted three patents in its district court complaints against two defendants. Each is directed to using measurements of a donor’s cell-free DNA (“cfDNA”) in an organ transplant recipient for non-invasive diagnosis of transplant rejection. As acknowledged in the patents, when an organ transplant is rejected, the recipient’s body, through its natural immune response, destroys the donor cells, thus releasing cfDNA from the donated organ’s dying cells into the blood. These increased levels of donor cfDNA—which occur naturally as the organ’s condition deteriorates—can be detected and then used to diagnose the likelihood of an organ transplant rejection.
The methods disclosed in the representative asserted claims are specifically directed to detecting a donor’s cfDNA in a transplant recipient and have four steps: (1) “obtaining” or “providing” a “sample” from the recipient that contains cfDNA; (2) “genotyping” the transplant donor and/or recipient to develop “polymorphism” or “SNP” “profiles”; (3) “sequencing” the cfDNA from the sample using “multiplex” or “high-throughput” sequencing, or performing “digital PCR”; and (4) “determining” or “quantifying” the amount of donor cfDNA.
Defendants moved to dismiss the complaints for failure to state a claim due to lack of patent-eligible subject matter under § 101. The district court denied these motions as premature but noted that language in the written descriptions of the asserted patents suggested that the patented steps were neither new nor unconventional. After expert discovery, the district court ultimately granted defendants’ motions for summary judgment of ineligibility upon findings that the asserted claims were directed to the detection of natural phenomena, specifically the presence of donor cfDNA in a transplant recipient, and recited only conventional techniques for measuring cfDNA. Plaintiff appealed.
In its decision, the CAFC first cited Mayo Collaborative Servs. v. Prometheus Lab’ys, Inc., 566 U.S. 66, 82 (2012) for the proposition that adding conventional steps, specified at a high level of generality, to a law of nature or natural phenomenon does not make a claim to the law or phenomenon patentable. The CAFC then addressed plaintiff’s arguments and applied the two-step Alice/Mayo test for patentable subject matter.
For Alice step one, plaintiff had argued its claims were directed to improved measurement methods spelled out in the claims as superior to the inadequate prior art measurement techniques and not to the natural correlation between organ rejection and the donor’s cfDNA levels. Plaintiff also faulted the district court for allegedly failing to perform the step one analysis. For Alice step two, plaintiff argued that its claimed measurement claims constituted an inventive breakthrough. Plaintiffs also criticized the district court opinion for making credibility determinations on a summary judgment motion.
The CAFC rejected plaintiffs’ arguments.
First the CAFC noted that the written descriptions of the asserted patents expressly state that the techniques referred to in the claimed steps are conventional techniques of immunology, biochemistry, recombinant DNA, and the like, which are well within the skill of art. Thus, reasoned the CAFC, the patents admittedly apply conventional measurement techniques to detect a natural phenomenon—the level of donor cfDNA in a transplant recipient. The CAFC then cited as instructive its prior Ariosa decision in which it held analogous claims to be unpatentable.
The CAFC next rejected plaintiff’s argument that the district court failed to conduct a distinct Alice step-one analysis. The CAFC found this argument contradicted by the fact that the district court reviewed the claim language and concluded that the claims recite methods for detecting natural phenomena. Based on CAFC precedent, the court noted that claims applying conventional methods “directed to” natural phenomena satisfy Alice/Mayo step one.
The CAFC also noted that it has repeatedly analyzed conventionality at Alice step one and rejected plaintiff’s assertion that the conventionality inquiry is limited to step two.
Regarding Alice step two, the CAFC agreed with the district court and held that the asserted claims add nothing inventive because they merely recite admittedly standard and well-known techniques in a logical combination to detect natural phenomena.
That the court initially denied an earlier summary judgment motion because of warring extrinsic evidence was immaterial according to the CAFC, because the court later found this fact issue non-genuine due to the explicit contradiction between plaintiff’s extrinsic evidence and the numerous admissions of conventionality in the patent specifications.