Argumentation Cannot Transplant Improvements in Place of "Conventional Techniques"

Earlier this week, in CareDx v. Natera, the Federal Circuit affirmed a district court finding that three patents drawn to diagnosing or predicting organ transplant status by using methods to detect a donor’s cell-free DNA (“cfDNA”), were directed to patent ineligible subject matter under 35 U.S.C. § 101.

CareDx, Inc. is the exclusive licensee of U.S. Patents 8,703,652, 9,845,497, and 10,329,607, (the ’652, ’497, and ’607 patents, respectively). The three patents discussed methods of detecting an amount of a donor’s cfDNA in an organ transplant recipient and diagnosing the likelihood of transplant rejection, where an increase in levels of donor cfDNA over time is indicative of transplant rejection.

CareDx sued Natera, Inc. for infringement of the ’652, ’497, and ’607 patents, and also sued Eurofins Viracor, Inc. for infringement of the ’652 patent. In the district court proceedings, Natera and Eurofins both moved for summary judgment of patent ineligibility, which the district court granted upon reconsideration. The district court found that the claims of the three patents were directed to the detection of natural phenomena using only conventional steps and techniques, and was therefore directed to patent ineligible subject matter, based on the Alice/Mayo test for determining § 101 eligibility.

The U.S. Supreme Court laid out the Alice/Mayo test in two steps. The first step involves determining whether a claim is directed to an abstract idea, a law of nature, or a natural phenomenon. If so, the second step then involves determining whether the claim recites additional inventive elements that transform the nature of the claim to be directed to patent-eligible subject matter.

The Federal Circuit affirmed the district court’s application of the Alice/Mayo test, first finding that the claims of the ’652, ’497, and ’607 patents were drawn to natural phenomenon, specifically the presence of an organ donor’s cfDNA in the blood of a transplant recipient and the correlation between elevated levels of that cfDNA and organ transplant rejection. The Federal Circuit also affirmed the district court’s finding that the recitation of known and conventional techniques in the claims for sample collection and measurement did not provide additional inventive elements to transform the claims into a patent eligible invention. Notably, while CareDx argued that the patents’ claims were directed to improved laboratory techniques, the specifications for the ’652, ’497, and ’607 patents described the claimed methods to involve conventional techniques and existing technology.

This week’s CareDx v. Natera may provide some clarity to at least one aspect of the uncertain § 101 eligibility landscape. Life science patent applicants may want to pause before characterizing described technologies in their patent specifications as conventional or well-known.