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August 29, 2023 - Intellectual Property, Medical Devices + Diagnostics, United States

A Glimmer of Hope for Simplified Patenting of Medical Diagnostics in the United States

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Should the recent bill entitled the Patent Eligibility Restoration Act of 2023 (PERA) become law, it would override the existing jurisprudence and redefine which inventions are eligible for patenting under 35 U.S.C. § 101.

By way of the Patent Act of 1952, the United States Congress established four statutory categories defining limits on inventions eligible for patent protection that are still in use today: process, machine, manufacture, and composition of matter.[1] On its face, this framework would appear to allow for the patenting of medical diagnostics, which often revolve around a process and/or machine (e.g., a diagnostic device). However, the current patent-eligibility environment in the United States surrounding medical diagnostics is unforgiving and those seeking to patent such inventions face significant challenges in trying to protect their innovations. This is largely due to courts having created, in their established role of interpreting and applying laws, judicially recognized exceptions to the four broad categories of patent-eligible subject matter that bar the patenting of abstract ideas, laws of nature, and natural phenomena.[2]

Foundational to a medical diagnostics invention is the underlying correlation of a result to a condition (e.g., the level of a protein correlating with presence of a human disease). Mayo, an opinion handed down by the Supreme Court in 2012, cemented the basic idea that, for medical diagnostics, such underlying correlations are laws of nature and are not patent-eligible without claiming significantly more than the natural law itself. Mayo Collaborative Services v. Prometheus Laboratories, Inc., 566 U.S. 66 (2012). A patchwork of additional jurisprudence has built up over the decade since Mayo, establishing additional patent-eligibility roadblocks for the patenting of medical diagnostics. Recently, U.S. Senators Tillis and Coons introduced legislation aiming to provide clarity to patent eligibility in a bill titled the Patent Eligibility Restoration Act of 2023 (PERA).[3] Should this bill become law, it would override the existing jurisprudence and redefine which inventions are eligible for patenting under 35 U.S.C. § 101. There is currently no language in PERA expressly stating that medical diagnostics inventions are per se patent-eligible. However, as both senators have singled out the field of medical diagnostics in public statements regarding the bill, it is readily apparent that a driving purpose of PERA is to foster innovation in this space by eliminating the current hurdles to patent eligibility (e.g., Senator Coons is quoted as stating “[c]ritical technologies like medical diagnostics and artificial intelligence can be protected with patents in Europe and China, but not in the United States”). Here, we discuss select aspects of the bill that would change the current legal landscape in this field to allow for the direct patenting of medical diagnostics in the United States (e.g., a method of diagnosing a disease in an individual).

Restarting the clock on statutorily defined patent subject-matter eligibility

As noted above, judicially recognized exceptions to the four categories of patent-eligible subject matter are significant obstacles when pursuing patent protection of medical diagnostics. PERA would expressly eliminate all current judicial exceptions to patent subject-matter eligibility. This does not mean that exceptions will not exist. Rather, PERA will establish new exceptions (many of which are based on currently practiced and accepted exceptions). Specifically, PERA provides that “[w]hoever invents or discovers any useful process, machine, manufacture, or composition of matter, or any useful improvement thereof, may obtain a patent therefor, subject only to the exclusions in subsection (b) and to the further conditions and requirements of this title” (emphasis added).

Hope for broader subject-matter eligibility of medical diagnostics

With relevance to medical diagnostics, under the Eligibility Exclusions detailed in PERA (subsection (b)), it is stated that “a person may not obtain a patent for any of the following, if claimed as such; . . . (C) A process that (i) is a mental process performed solely in the human mind; or (ii) occurs in nature wholly independent of, and prior to, any human activity.” This language would appear to stop exceptions to patent eligibility short of the current reach of judicially recognized exceptions. For example, one could apply the language of PERA to claims in question in Mayo and reasonably conclude that the active steps therein (e.g., administering a drug and determining the level of an analyte) are human activities that do not occur in nature wholly independent of, and prior to, any human activity.[4] This aspect of PERA signals that medical diagnostics will be patent-eligible should they be carefully drafted to include features readily distinguishable from capabilities of the human mind and/or features demonstrating human activity related to performance of such medical diagnostics.

We find additional confirmation that PERA will allow for medical diagnostics to be generally subject-matter-eligible under subsection (c). Subsection (c) states that “eligibility shall be determined . . . (B) without regarding to . . . (ii) whether a claim element is known, conventional, routine, or naturally occurring.” There are two aspects worthy of discussion here as they represent a distinct departure from current patent subject-matter eligibility law. Firstly, under current law, having a claim element that is directed to the naturally occurring (such as the underlying correlation of a medical diagnostics) results in an analysis of the claimed invention where one is forced to establish why the subject matter is in fact patent-eligible. Alice Corp. v. CLS Bank International, 573 U.S. 208 (2014). The language in subsection (c) flips this current notion on its head and in some regards preserves more of a presumption of patent eligibility, whether or not there is a claimed feature that can be attributed to a naturally occurring phenomenon. Under PERA, it seems likely that one will then need to establish why a claimed invention, when viewed as a whole, is not eligible for patent protection for reasons other than containing a naturally occurring phenomenon, as one element.

Secondly, subsection (c) expressly prohibits assessing, for purposes of subject-matter eligibility, whether a claimed element is “conventional” or “routine.” Current subject-matter eligibility law is becoming increasingly entangled with assessing conventionality.  Such language could change how court cases are being decided today. In CareDx, for example, a Federal Circuit court held that claims to noninvasive detection of graft rejection in transplant patients were unpatentable subject matter under 35 U.S.C. § 101 because they involved detection of a natural phenomenon using only conventional techniques. CareDx, Inc. v. Natera, Inc., 40 F.4th 1371, 1381 (Fed. Cir. 2022). In a similar fashion, in Ariosa Diagnostics, a Federal Circuit court held that claims to detecting paternally inherited nucleic acid of fetal origin performed on material serum or plasma were also not subject-matter-eligible as they only recited known methods of analyzing fetal DNA. Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371 (Fed. Cir. 2015). Under PERA, subject-matter eligibility determinations may avoid such a reliance on conventionality of techniques. This would be a significant change in patenting medical diagnostics as there is a commercial drive for developing medical diagnostics that can be performed using “conventional” or “routine” techniques (e.g., conventional PCR or mass spectrometry) to enable widespread adoption.

Next steps

PERA is still in its infancy as a bill. We are continuing to monitor developments related to PERA and will provide relevant updates. If you have any questions about this topic or would like to discuss patenting your own medical diagnostics inventions, please reach out to MoFo’s Patent Strategy + Prosecution team.

Special thanks to Janet Xiao, Meghan Poon, and Laura Ray for the development of this article.

[1] Title 35, United States Code, section 101.

[2] E.g., Diamond v. Diehr, 450 U.S. 175, 185 (1981).

[3] Patent Eligibility Restoration Act of 2023, S.2140, June 22, 2023.

[4] U.S. Patent Nos. 6,355,623 and 6,680,302.