Questioning Conventionality and Redefining Process in Patent Eligibility Law

by Dennis Crouch

In CareDx v. Natera, an intriguing amicus brief was recently filed by the Honorable Paul Michel (Ret.) and Professor John Duffy in support of the patentee petitioners Stanford and CareDx. The brief advocates for the clarification of patent-eligibility law, and criticizes the Federal Circuit’s handling of the case. The filing of the brief has seemingly prompted the Supreme Court to request a response from the accused infringers, after they initially waived their right to do so. This move reflects some significance of the arguments presented in the brief.  [Read the Brief]

According to Michel and Duffy, the Federal Circuit’s decision in the case overlooked the text of the Patent Act and conflicts with Supreme Court precedent such as Diehr and Cochran v. Deener. They argue that the decision fails to recognize the difference between patent eligibility (under § 101) and patentability (under §§ 102, 103, and 112). They further criticize the decision for an unduly simplified description of the invention that leaves out important details and for improper emphasis on “conventionality.”  The concept of “conventionality” is more appropriately associated with issues of novelty and nonobviousness, as regulated by §§ 102 and 103 respectively, rather than being a key criterion for patent eligibility under § 101.

The brief spends some amount of time focusing on landmark patent cases such as Diehr and Cochrane v. Deener (while rejecting Flook) to illustrate how a process can be patent eligible despite encompassing conventional elements.  And, throughout this argues that the Federal Circuit misunderstood the definition of “process,” which under 35 U.S.C. § 100(b) is defined to include “a new use of a known process.” The brief contends that this definition permits patents on new applications or improvements of known technologies, and that such improvements should be presumed to be patent eligible.  But, the Federal Circuit’s eligibility criteria of “conventionality” prohibits this interpretation even though not rooted in the Patent Act’s text or the Supreme Court’s precedent.

As with other recent eligibility briefs, this one also underscores a need to address confusion and uncertainty surrounding patent eligibility, particularly in relation to biomedical and diagnostic patents.

Now that we’re almost to June, the petition is unlikely to be decided before the recess and instead will be held-over until the fall 2023 before we get a decision on whether the court will grant certiorari.

See, A. Sasha Hoyt, The Impact of Uncertainty Regarding Patent Eligible Subject Matter for Investment in U.S. Medical Diagnostic Technologies, 79 Wash. & L. Rev. 397 (2022)