Summary Diagnostic methods that merely recite the observation of a natural law lack patent eligibility, unless those methods possess some "unconventional" or "non-routine" steps. The amorphous nature of what is unconventional or non-routine has caused uncertainty for patent applicants and litigants.

The U.S. Supreme Court had the opportunity to provide clarity but refused to reconcile a splintered lower court or revisit the patent eligibility of diagnostic methods. Over the course of January 2020 alone, the Supreme Court refused to hear eight appeals of patent eligibility cases. As a result, it remains the law that unconventional and non-routine steps must be highlighted when drafting, prosecuting, or defending diagnostic methods.

Given the continuing lack of clarity from the courts patent applicants and patent owners should pay heightened attention to patent eligibility issues surrounding their diagnostic methods. Some general principles are presented in this article to guide patent strategy in this area.

  • Focus diagnostic method claims on actions instead of correlations between natural products and disease states. The correlation itself, no matter how surprising a discovery, is unlikely to make a diagnostic method patent eligible. The Supreme Court has shown no interest in changing the law here.
  • Describe the diagnostic method with specificity. Diagnostic claims that are overly broad or generically recite detection of a natural product are not patent eligible.
  • Focus claims on technology or systems related to a diagnostic method. Even if a method of detecting a natural product is not patent eligible, compositions, products, or devices tailored for detection of the natural product may be.
  • Avoid statements that a step is conventional or routine. Those statements may be used as an admission, negating patent eligibility even though the claims are novel or nonobviousness.
  • Finally, maintain a global perspective. Although diagnostic method patents can be difficult to obtain or enforce in the U.S., there can be enough incentive to obtain patent coverage elsewhere even when similar coverage in the U.S. is unlikely.

Background to Splintered Court Decision In the appeal from Athena Diagnostics Inc. v. Mayo Collaborative Services, LLC, 915 F.3d 743 (Fed. Cir. 2019), the U.S. Supreme Court was asked to address whether a new and specific method of diagnosing a medical condition is patent-eligible subject matter. Many were hopeful that this case would be the vehicle for the Supreme Court to shed needed light on the contours of medical diagnostic patent eligibility because "never before has the Federal Circuit been so splintered on a fundamental doctrine of patent law." Amicus Brief Honorable Paul R. Michel (ret.) for Petitioner, Athena Diagnostics Inc. v. Mayo Collaborative Services, LLC, 915 F.3d 743 (Fed. Cir. 2019). You need a scorecard to keep track of eight separate opinions provided by the Federal Circuit that resulted in the invalidation of the diagnostic method in Athena. The Supreme Court, however, refused to revisit the patent eligibility of diagnostic methods in the appeal.

At the Federal Circuit, four judges speaking for the majority concluded that their decision was necessitated by the Supreme Court's Mayo framework, but members of the majority also explicitly pleaded for further guidance. Such a blatant ask for more guidance is rare. For example, Judge Hughes "would welcome further explication of eligibility standards in the area of diagnostics patents. Such standards could permit patenting of essential life-saving inventions based on natural laws while providing a reasonable and measured way to differentiate between overly broad patents claiming natural laws and truly worthy specific applications." Athena, 915 F.3d at 1337.

The dissenting opinions at the Federal Circuit, while disagreeing with the majority's analysis, echoed that claims directed to specific diagnostic methods should be patent eligible. Judge Moore explained "that claims to specific, narrow processes, even if those processes involve natural laws, are not directed to the natural laws themselves." Id. at 1359. Mayo should be distinguishable because the "breadth and generality of the Mayo claims led to their demise, as they recited nothing more than the natural law." Id. at 1361.

The Supreme Court, however, denied the petition for certiorari. By doing so, and denying review of seven other appeals relating to patent eligibility, the Court demonstrated that it is not currently interested in drawing a distinguishing line or providing further guidance.

As a result, those seeking to patent diagnostic methods must think critically and focus effort on emphasizing unconventional and non-routine steps when drafting, prosecuting, or defending the patent eligibility of diagnostic methods in the U.S. or employ alternative strategies for protecting their innovations.

Patent Office Steps into the Vacuum Although the Federal Circuit failed to provide contours to the Court's subject-matter eligibility, the Patent Office has attempted to provide needed clarity. The Patent Office's 2019 Revised Patent Subject Matter Eligibility Guidance distinguishes between broad, general claims that recite nothing more than a judicial exception, and those that are narrow or specific. 84 Fed. Reg. 50 (Jan. 7, 2019). The Guidance articulates the need to evaluate whether a judicial exception is integrated into a practical application. Id. at 54. The Office sought to reframe the question of whether a claim is directed to a judicial exception, like a natural law, into two separate and distinct questions: Does the claim recite a judicial exception? And if it does, does the claim recite additional elements that integrate the judicial exception into a practical application? The goal of this approach is to understand whether a judicial exception is applied, relied on, or used in a manner that imposes a meaningful limitation on the judicial exception. This guidance is helpful for those traversing the Patent Office, but the Patent Office's framework should be viewed skeptically in view of the Federal Circuit's interpretation of Supreme Court precedent. And, for litigants, it should be kept in mind that courts do not typically give deference to PTO guidance documents like this.

What Now? The Supreme Court has signaled an unwillingness to revisit the patent eligibility of medical diagnostics and the Federal Circuit has not outlined the contours of diagnostic method patent eligibility. Diagnostic methods that merely recite the observation of a natural law lack patent eligibility in the U.S.

Those seeking to patent diagnostic methods should take care to describe unconventional or non-routine steps. At a minimum, statements in patent applications, during prosecution, or during litigation that may indicate a step is conventional or routine should be avoided as those statements will be used as an admission.

Diagnostic method claims should not be overly broad or at such a high level of generality to recite nothing more than the detection of a natural product. Moreover, independent arguments supporting the patent eligibility of broader, independent claims and narrower, dependent claims may also be presented. Some judges in the Federal Circuit have signaled that narrower, specific claims may be patent eligible. However, it remains to be seen whether such a line is drawn over time.

Patent protection of technology or systems related to a diagnostic method should also be considered. Even if a method of detecting a natural product succumbs to Mayo scrutiny, compositions, products, or devices tailored for detection of the natural product may withstand it.

Finally, consider patent protection outside of the U.S. Although diagnostic method patents may be difficult to obtain or enforce in the U.S., that is not true everywhere. There may be enough incentive to obtain patent coverage elsewhere even if similar coverage in the U.S. is unlikely.