July 28, 2022Client Alert

CareDx v. Natera: Further Illustration of Considerations for Patent Eligibility in Molecular Diagnostics

Effective this month, the Federal Circuit’s eligibility decision in CareDx, Inc. v. Natera, Inc. imposes new considerations regarding depictions of a technology as “conventional” or “known in the art.”  CareDX, Inc. v. Natera, Inc., No. 2022-1027 (Fed. Cir., Jul. 18, 2022).  In the case, Stanford and its licensee, CareDx, sued Natera and Eurofins for patent infringement with respect to biotech patents claiming methods of diagnosing organ transplant rejection.  The claims are directed to a method for detecting cell free DNA (cfDNA) in a transplant patient which includes obtaining a sample, genotyping to develop polymorphism or SNP profiles, sequencing the cfDNA from the sample using multiplex or high-throughput sequencing or digital PCR, and quantifying the amount of donor cfDNA.

Ultimately, the court concluded ineligibility under 35 U.S.C. § 101.  Specifically, they believed the patent claims described conventional techniques for obtaining and analyzing cfDNA, therefore, nothing in the claims transformed them into a patent-eligible invention.  The court stated the case involves no new improvements to methods of preparation or measurement techniques analogous to the ineligible method claims in Mayo.  CareDx argued the technological approach was novel because of previous failed attempts of quantifying donor cfDNA as a measure of tissue failure and that the utilization of digital PCR and NGS, included in the claim set, advanced the technology.  However, the court viewed the several boilerplate statements found within the patent document as admissions that the technology was wholly conventional.

The decision raises concerns for drafting patent applications for molecular diagnostics moving forward.  To prevent subject matter ineligibility, specifications should include robust descriptions of any novel or non-standard methods for preparation, detection, or analysis.  Statements regarding the conventional nature of techniques should be avoided.  In the situation where the order of conventional steps is unconventional, the order should be specified in the claims and emphasized as important in the specification.  As the standard for patent eligibility becomes more definite, it may be helpful to file claims of varying scopes to address possible future standards.

The authors would like to recognize Kaila Smith, Michael Best EDGE Intern, for her contribution to this work.

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