Following a series of U.S. Supreme Court cases from 2012 to 2014 (Mayo Collaborative Services v. Prometheus Laboratories, Inc., Ass'n for Molecular Pathology v. Myriad Genetics, Inc., Alice Corp. Pty. Ltd. v. CLS Bank Intern.), diagnostic method claims have essentially become unwelcome at the US Patent and Trademark Office (USPTO); i.e., the USPTO considers diagnostic method claims patent ineligible and won't allow them. Many patent practitioners in the U.S. have been converting these claims into method-of-treatment style claims, especially following Vanda Pharms. Inc. v. W.-Ward Pharms. Int'l Ltd. in 2018.
This trend began in 2012, when the Supreme Court, in Mayo Collaborative Services v. Prometheus Laboratories, Inc., held that a diagnostic method claim was patent ineligible under 35 U.S.C. § 101. The reason was that this type of claim was directed to a judicial exception to patent eligibility—namely, a law of nature—and when considered as a whole, it did not claim anything that amounted to significantly more than the law of nature itself.
Fast forward to 2022, where the U.S. Court of Appeals for the Federal Circuit applied Mayo in affirming the decision in CareDx, Inc. v. Natera, Inc., ruling the claims of the "Stanford patents" patent ineligible, and the Supreme Court denied hearing the case. The patents are for organ transplant diagnostics that claim an improved method for measuring a previously known natural phenomenon for a useful purpose.
This brings us to 2023 and the introduction of the Patent Eligibility Restoration Act of 2023 (PERA 2023) by Senators Chris Coons (D-DE) and Thom Tillis (R-NC). PERA 2023 is the legislature's attempt to rein in the judiciary's expanding exceptions to patent eligibility or at least clarify what is and is not patent eligible. PERA 2023 eliminates the three judicial exceptions of patent eligibility—abstract ideas, laws of nature and natural phenomena (including products of nature)—and states that any useful process, machine, manufacture, or composition of matter, or useful improvement thereof, is patent eligible. The bill lists only a handful of exclusions:
- Mathematical formulas.
- Mental processes performed solely in the mind of a human being.
- Unmodified human genes as they exist in the human body.
- Unmodified natural materials as they exist in nature.
- Processes that are substantially economic, financial, business, social, cultural, or artistic.
Notably, the bill indicates that one may not obtain a patent for "a process that occurs in nature wholly independent of, and prior to, any human activity" if claimed as such. This presumably means patent practitioners could draft diagnostic patent claims to not read on "a process that occurs in nature, wholly independent of, and prior to, any human activity," making diagnostic methods patent eligible under PERA 2023.
For example, claim 1 of U.S. Patent No. 10,329,607 is exemplary of the Stanford patents, which claims a method of measuring donor and recipient cell-free DNA in a recipient's bloodstream, including:
- Providing a plasma sample from the recipient.
- Extracting cell-free DNA from the sample.
- Performing "selective amplification" of target DNA sequences that "amplifies a plurality of genomic regions comprising at least 1,000 [SNPs]" using PCR.
- Performing "high throughput sequencing" comprising a "sequencing-by-synthesis reaction" with an error rate of less than 1.5%.
- Providing sequences comprising "at least 1,000 [SNPs]."
- Quantifying the proportion of donor-derived DNA using distinguishing biomarkers drawn from those at least 1,000 SNPs and where the donor's cell-free DNA comprises at least 0.03% of the total in the sample.
On its face, claim 1 of the '607 patent would appear to be patent eligible under PERA 2023, as it is dependent on human activity. Although the correlation between increased donor cell-free DNA and organ rejection occurs in nature, human activity is necessary to perform each of the process steps.
Additionally, consider claim 1 of U.S. Patent No. 6,355,623 from the Mayo U.S. Supreme Court case that started the expansion of the judicial exceptions:
A method of optimizing therapeutic efficacy for treatment of an immune-mediated gastrointestinal disorder, comprising:
(a) administering a drug providing 6-thioguanine to a subject having said immune-mediated gastrointestinal disorder; and
(b) determining the level of 6-thioguanine in said subject having said immune-mediated gastrointestinal disorder,
wherein the level of 6-thioguanine less than about 230 pmol per 8×108 red blood cells indicates a need to increase the amount of said drug subsequently administered to said subject and
wherein the level of 6-thioguanine greater than about 400 pmol per 8×108 red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject.
Claim 1 of the '623 patent should also be patent eligible under PERA 2023 because step (a), administering a drug, and step (b), determining the level of 6-thioguanine in a subject, require human activity. As such, the claim is not directed to "a process that occurs in nature, wholly independent of, and prior to, any human activity." If claims of the '607 and '623 patents would now be patent eligible, many other diagnostic method patents could be eligible, or their claims could be rewritten to be patent eligible following PERA 2023.
PERA 2023 is still in the early stage of the legislative process as it was introduced in the Senate in June 2023. The chances of it becoming law without revision through the Senate and the House are low. Thus, it remains to be seen how expansive the effects of PERA 2023 will be. However, if PERA 2023 passes with the patent eligibility exclusion language of "a process that occurs in nature wholly independent of, and prior to, any human activity," then it stands to reason that it should be fairly easy (if all other patentability requirements are met) to obtain pure diagnostic method claims in the U.S. (i.e. without requiring a treatment step) by including any step that requires human activity. Diagnostic companies can benefit from this proposed legislation by having better patent protection and licensing opportunities for their diagnostic technologies.
Originally Published by Bloomberg Law
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.