Patent Eligibility in Biotechnology: Diagnostic Methods and Natural Phenomena

The United States is not alone in excluding subject matter from patent eligibility, but it is unusual in the breadth and severity of its patent-eligibility doctrine. Although the general principles of patent eligibility apply across all fields of technology in the U.S., they have proven to be particularly challenging in biotechnology. In this area, inventions often arise not from the creation of entirely new structures, but from the discovery of relationships within natural systems. Judicial exceptions to patent eligibility include laws of nature and natural phenomena (including products of nature), and as a result biotechnology inventions involving natural genes, DNA sequences, proteins, antibodies, metabolites, naturally occurring microorganisms, and biological relationships often present eligibility challenges.

This problem is especially difficult with respect to diagnostic assays. A diagnostic test often depends on the discovery that a biological marker, genetic pattern, protein level, or other measurable signal correlates with a disease, prognosis, or treatment response. But diagnostic claims that depend primarily on this relationship are often regarded as patent ineligible, particularly if the laboratory steps are conventional. Claims that combine diagnosis with a specific treatment step may sometimes be treated more favorably, but may create practical enforcement problems if the testing is performed by one party and treatment decisions are made by a separate physician or healthcare provider.

For that reason, patent strategy in this area usually has to be broader than simply trying to patent the diagnostic correlation. Protection is often strongest where the invention includes modified technical implementation, such as improved sample preparation, engineered reagents, a particular assay format, a multi-marker panel, specialized software tied to laboratory processing, or a cartridge or instrument system. In cases where patent protection is likely to be narrow or unattainable, companies may, in some instances, rely on non-patent advantages, including trade secrets, proprietary datasets, clinical validation, regulatory approvals, reimbursement strategies, and manufacturing know-how.

These issues arise far less frequently in chemistry, where inventions are more often directed to new compounds or compositions of matter with defined structures. In such cases, the claimed subject matter is typically understood as a man-made invention rather than a discovery of a natural relationship. The contrast highlights the extent to which patent eligibility, although governed by a single body of law, can depend on the characteristics of the underlying technology.

Understanding the challenges associated with patent eligibility in biotechnology is therefore essential in developing effective strategies for protecting life sciences inventions. In particular, careful attention must be given to how claims are framed, so that they are directed not simply to a natural relationship, but to a patent-eligible application of that relationship.

Disclaimer: This piece is provided for general informational purposes only and does not constitute legal advice. Patent issues are often complex and highly fact-specific, and no one should act on general information of this kind without consulting qualified patent counsel regarding the particular circumstances involved.