Natural Products and Diagnostics after Myriad: Patent Eligibility Today

Section 101 of the Patent Act covers any new and useful process, machine, manufacture or composition of matter. The Supreme Court has long recognized implicit exceptions: laws of nature, natural phenomena and abstract ideas are not patentable as such. Between 2012 and 2014, three decisions reshaped how those exceptions apply, with especially strong effects on life-science inventions such as isolated natural products and diagnostic methods.

This page summarizes that framework, how USPTO guidance has developed, and why eligibility matters in post-grant proceedings.

Three Supreme Court decisions

Mayo v. Prometheus (2012)

In Mayo Collaborative Services v. Prometheus Laboratories, Inc. (2012), the claims covered a method of adjusting a drug dosage based on measured metabolite levels. The Court held the claims ineligible because they effectively claimed a natural correlation, adding only well-understood, routine and conventional steps such as administering the drug and measuring the result. Mayo had particular impact on diagnostic claims that tie a measurement to a clinical conclusion.

Association for Molecular Pathology v. Myriad Genetics (2013)

In Association for Molecular Pathology v. Myriad Genetics, Inc. (2013), the Court held that a naturally occurring DNA segment is a product of nature and is not patent-eligible merely because it has been isolated. By contrast, complementary DNA (cDNA), which is synthesized in the laboratory and omits non-coding regions, is not naturally occurring and can be eligible. The Court noted that its decision did not address method claims or applications of knowledge about genes.

Alice Corp. v. CLS Bank International (2014)

Alice Corp. v. CLS Bank International (2014) concerned computer-implemented financial claims, but it confirmed a two-step framework drawn from Mayo that applies to all subject matter:

1. Determine whether the claim is directed to a judicial exception, such as a law of nature, natural phenomenon or abstract idea.
2. If so, determine whether the claim’s elements, individually and as an ordered combination, add an “inventive concept” that amounts to significantly more than the exception itself.

See the Supreme Court decisions reference for summaries and links, and the earlier Alice case page.

How USPTO guidance developed

After Myriad and Mayo, the USPTO issued guidance in 2014 that took a broad view of which nature-based products were ineligible. That guidance drew significant criticism and was replaced later in 2014 by interim eligibility guidance built around the Alice/Mayo framework. The Office continued to revise its approach in later years, and its eligibility guidance is now consolidated in MPEP § 2106.

For nature-based products, the current approach centers on whether the claimed product has markedly different characteristics from its natural counterpart. Examiners compare the claimed product with the closest naturally occurring counterpart and look for differences in structure, function or other properties. A product that is markedly different is not treated as a product-of-nature exception. A product that is not markedly different is analyzed further to see whether the claim as a whole integrates the exception into a practical application or adds significantly more.

Because eligibility guidance has been revised repeatedly, readers should consult the current MPEP and any recent USPTO updates.

Diagnostics in the courts

The Federal Circuit has applied Mayo to many diagnostic claims. In Ariosa Diagnostics, Inc. v. Sequenom, Inc. (Fed. Cir. 2015), claims to methods of detecting cell-free fetal DNA in maternal blood were held ineligible. In Athena Diagnostics, Inc. v. Mayo Collaborative Services, LLC (Fed. Cir. 2019), claims to diagnosing a neurological condition by detecting antibodies were also held ineligible. In contrast, Vanda Pharmaceuticals Inc. v. West-Ward Pharmaceuticals International Ltd. (Fed. Cir. 2018) held a method of treatment claim eligible, because it applied a natural relationship by administering a drug at specified doses.

The pattern is that claims to detecting or correlating natural phenomena are vulnerable, while claims that apply that knowledge in a specific treatment or a non-conventional technique stand on firmer ground.

Why eligibility matters in post-grant proceedings

Section 101 is not available in every USPTO proceeding:

Proceeding	Can § 101 be raised?
Inter partes review	No; limited to §§ 102 and 103 on patents and printed publications
Post-grant review	Yes, within nine months of grant for first-inventor-to-file patents
Covered business method review	Yes, but the program closed to new petitions on September 16, 2020
Ex parte reexamination	No; limited to patents and printed publications

A party concerned about a newly issued nature-based or diagnostic patent may consider whether post-grant review is available, since it is the only current USPTO trial that reaches eligibility. Institution requires showing that it is more likely than not that at least one claim is unpatentable; see the different threshold standards. For the former CBM program, see the covered business method guide.

Drafting and prosecution considerations

At a general level, practitioners working with nature-based inventions often consider:

• Describing structural and functional differences. Where a product differs from its natural counterpart, documenting those differences in the specification supports a markedly-different analysis.
• Including application claims. Claims to methods of treatment, manufacture or use that apply a natural principle in a specific way may fare better than pure detection or correlation claims.
• Avoiding reliance on conventional steps alone. Claims whose only additions are routine measurement or data-gathering steps are vulnerable under Mayo.
• Building a varied claim set. Product, method-of-use and composition claims of different scope reduce the risk that a single eligibility ruling disposes of the whole patent.

Key takeaways

• Mayo (2012), Myriad (2013) and Alice (2014) define today’s eligibility framework for natural products and diagnostics.
• Isolated naturally occurring DNA is ineligible; cDNA can be eligible.
• USPTO guidance is consolidated in MPEP § 2106 and focuses on markedly different characteristics for nature-based products.
• § 101 can be raised in post-grant review, and formerly in CBM review, but not in inter partes review.