Overcoming the challenges of US patent eligibility for nature-based elements

Applicants face tough scrutiny for claims around the laws of nature, but details of new processes, steps or guidance can help patents pass the courts’ two-step test, says Michael Taylor of Harness IP.

In the US, the legal framework concerning the granting of a US patent essentially starts with 35 USC §101. This statute outlines patentable subject matter and states, “whoever invents or discovers any new and useful process, machine, manufacture or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor…”

In the not-too-distant past, many patents did not seem to be impeded by this hurdle. For example, according to analytics firm Lex Machina, in the 12 years from January 2000 through December 2011, there were 61 cases in the federal district courts that found patents invalid for §101 subject matter reasons.

More recently, this hurdle seems to have been raised and appears to have become less likely to be overcome. While litigation in federal courts has many individual and unique aspects, in the 12 years from January 2012 to December 2023, there have been 551 cases that found patents invalid for 35 §101 subject matter reasons in federal district courts. This indicates a ninefold increase in cases between two adjacent periods.

Patent-eligible claims around laws of nature

One difference between the two noted periods was the holding by the US Supreme Court in March 2012 in Mayo Collaborative Servs v Prometheus Labs(2012). In this case, the courtheld that the asserted claims were invalid because “the patent claims at issue here effectively claim the underlying laws of nature themselves”. The court’s opinion seems to have opened the door to invalidate patents for reasons that were not previously well established. While this article is not intended to explore every case in detail, a noticeable shift suggests that achieving subject matter eligibility under §101 is a greater burden.

In addition to the statutory requirements of patent-eligible subject matter, Mayo reiterated that judicial exceptions that are also not patentable exist that are “long held” and include laws of nature, natural phenomena and abstract ideas.

And while the court allowed that an application of a law of nature may be patentable, it must be new and useful. However, “[T]he court has also made clear, to transform an unpatentable law of nature into a patent-eligible application of such a law, one must do more than simply state the law of nature while adding the words ‘apply it’.” Thus, the court has also found these exceptions to patent-eligible subject matter, often called judicial exceptions.

Alice looks deeper into patent-ineligible concepts

To assist in the determination process, the court subsequently applied a two-part test in Alice v CLS Bank (2014). It stated: “In Mayo, we set forth a framework for distinguishing patents that claim laws of nature, natural phenomena and abstract ideas from those that claim patent-eligible applications of those concepts.”

In the test, first the court determines whether the claims at issue are directed to a patent-ineligible concept. If so, the court then asks, “[w]hat else is there in the claims before us?” In answering the second question the court reviews the additional elements in the claims and whether they ‘transform the nature of the claim’ into a patent-eligible application.

We have described step two of this analysis as a search for an ‘inventive concept’—ie, an element or combination of elements that is ‘sufficient to ensure that the patent in practice amounts to significantly more than a patent upon the [ineligible concept] itself’.

The fine line between ‘new and useful’ and ineligible

Several recent cases may shed light on whether any progress has been made in meeting the standards set by §101 to obtain a valid patent for ‘new and useful’ invention or discovery.

In Caredx v Natera, the Federal Circuit held that claims in several asserted patents are directed to a natural law together with conventional steps to detect or quantify the manifestation of that law and thus are ineligible under §101. CareDx is the exclusive licensee of several granted patents with claims regarding detecting a donor’s cell-free DNA (cfDNA) relating to donor organ status in a patient.

The court summarised representative claims as four steps for detecting a donor’s cfDNA in a transplant recipient “1) ‘obtaining’ or ‘providing’ a ‘sample’ from the recipient that contains cfDNA; 2) ‘genotyping’ the transplant donor and/or recipient to develop ‘polymorphism’ or ‘SNP’ ‘profiles;’ 3) ‘sequencing’ the cfDNA from the sample using ‘multiplex’ or ‘high-throughput’ sequencing; or performing ‘digital PCR;’ and 4) ‘determining’ or ‘quantifying’ the amount of donor cfDNA”.

In the opinion, the court made note that, “CareDx also concedes that it did not invent or discover the relationship between donor cfDNA and the likelihood of organ transplant rejection…” The court noted that the written description had several characterisations of the “claimed techniques in terms that confirm their conventionality”.

The court goes on to note, “CareDx does not actually claim any improvements in laboratory techniques—rather, as previously discussed, the actual claims of the patent merely recite the conventional use of existing techniques to detect naturally occurring cfDNA. Furthermore, the specification admits that the laboratory techniques disclosed in the claims require only conventional techniques and off-the-shelf technology.” Based on these findings, it seems the court concludes that the claims are “directed to natural phenomena under Alice/Mayo step one”.

The court then proceeded to step two and found that applying standard techniques does not add a sufficient inventive concept. “Each of the methods in the recited steps was already being performed by those in the art. Furthermore, the claimed combination of steps adds nothing inventive.”

Altered or enhanced conventional steps

A brief review of Caredxilluminates that an inventor and/or patent drafter should describe an apparatus or method that does not include a judicial exception to patent eligibility, such as including only a natural phenomenon. However, the court in Caredxtook note that several steps claimed in the CareDx licensed patents were described as being previously used by others or were considered conventional.

Therefore, while the steps used for testing may have connections to previous methods, discussing how these conventional steps were modified or improved could pave the way for patent eligibility, even if they involve a natural phenomenon. Perhaps the altered or enhanced steps could constitute the new and useful process and/or provide the additional inventive concept to qualify as eligible subject matter.

Care is required when claiming eligibility for naturally occurring products

The Federal Circuit held in ChromaDex v Elysium Health, (2023), “[b]ecause the claims are broad enough to encompass a product of nature, it is invalid under §101”. In ChromaDexthe patent is “directed to dietary supplements containing isolated nicotinamide riboside (NR)”, which is a form of vitamin B3 naturally present in many products, such as cow’s milk.

Claim 1 was deemed representative by the court and recited, in part, “A composition comprising isolated nicotinamide riboside. . .wherein said composition is formulated for oral administration and increased NAD+ biosynthesis upon oral administration.” The court found, “the parties agree that NR is naturally present in milk. It is undisputed that milk is a naturally occurring product that is not patent eligible…the only difference between at least one embodiment within the scope of the claims and natural milk is that the NR in the former is isolated.”

Further, the court found that, “As in Myriad, under the circumstances presented here, the act of isolating the NR compared to how NR naturally exists in milk is not sufficient, on its own, to confer patent eligibility. The claimed compositions do not exhibit markedly different characteristics from natural milk and are, therefore, invalid for claiming a patent-ineligible product of nature.” The court does reference that “markedly different characteristics” may distinguish a claimed compound from a naturally occurring form.

However, the court also found that the claims do not include certain specifics regarding NR, such as requiring any minimum quantity. “Nor do these claims attribute the claimed increase in NAD+ biosynthesis to the isolated NR, requiring only that the composition increase NAD+ production.”

The court held that the claims are directed to a product of nature. The court, however, also performed the analysis under step two and found, “the claims lack an inventive step because they are directed to nothing more than compositions that increase NAD+ biosynthesis”. Further, the court held, “the act of isolating the NR by itself. . .similarly does not turn an otherwise patent-ineligible product of nature into a patentable invention.” Despite the potential difficulty or brilliance of the process, the court acknowledged that the specification indicated it was conventional.

In this case, the court again finds that a compound, even when isolated, that occurs naturally without alteration is not patent eligible. Thus, even though the appellant argued that differences existed that should rise to the required “markedly different” characteristics, the courtfound that these differences were not in the claims. Thus, the inventor should take care to not only describe any differences between a naturally occurring compound in the specification of a patent application, but to include them in a claim.

Again, the court also states that the processes to isolate the naturally occurring compound alone are not enough to pass step two of the patent eligibility framework, especially if the processes are disclosed to be conventional. Thus, as noted above, disclosing any altered or enhanced steps may be the new and useful process and/or provide the additional inventive concept to leap into eligible subject matter.

Natural processes that relate to innovative results may not make a claim eligible

Finally, a brief review of a non-precedential opinion of the Federal Circuit from January 2024 may at least provide an appraisal of the court’s mindset to start 2024. In PureCircle USA v Sweegen (2024) , the court upheld a circuit court holding that a claim “is unpatentable under §101”.

In this case, two claims were argued. The first claim—claim 1—recites, in part, “a method for making Rebaudioside X comprising a step of converting Rebaudioside D to Rebaudioside X using a UDP-glucosyltransferase. . . ” The second claim—claim 14—recites, “the method of claim 1, wherein the UDP-glucosyltransferase comprises UGT76G1”. In light of this, the court found that the “enzyme in claim 14, UGT76G1, is naturally found in stevia plants and naturally converts Reb D to Reb X.” PureCircle argued, however, that claim 14 should be read in light of claim 1 that also recites, “conversion of Rebaudioside D to Rebaudioside X is at least about 50% complete”. The court found, “[t]he problem with PureCircle’s argument is that the 50% completion is itself an abstract idea”. In particular, “[t]he claim does not provide any steps or give guidance as to how to achieve a 50% conversion other than the direction to use a natural enzyme.”

Again, this decision reiterates that a claim, when referring to a naturally occurring product or phenomenon, will not be made patent eligible by only claiming a result.

A claim primarily centred around a naturally occurring compound or element, even if processed, may face challenges in meeting the eligibility criteria. But, if the inventor and patent drafter can provide details of a new process, steps or guidance to achieve or obtain a natural product and include it in a claim, the claim may more readily find patent eligibility success.

Michael Taylor is an attorney and principal at Harness IP in the Detroit area. He can be contacted at: mtaylor@harnessip.com