Background
The Regents of the University of California held a patent derived from foundational recombinant DNA research on insulin. The patent claims included narrow claims covering rat insulin cDNA (which the specification fully described) and broad claims covering “vertebrate insulin cDNA” and “mammalian insulin cDNA” — broad genus claims covering all vertebrate or mammalian species’ insulin cDNA sequences. Eli Lilly and Company, which made recombinant human insulin (Humulin), challenged the broad claims as failing the written description requirement of § 112.
The UC specification disclosed the rat insulin cDNA sequence in detail but did not disclose human insulin cDNA or the cDNA sequences for any other vertebrate or mammalian species. UC argued that knowing the rat sequence enabled one to isolate any vertebrate insulin cDNA, and that this was sufficient to support the broader genus claims.
The Court’s Holding
The Federal Circuit held the broad vertebrate and mammalian insulin cDNA claims invalid for lack of written description. The court held that a specification must disclose a representative number of species within the claimed genus — it is not sufficient to disclose a single species (rat insulin cDNA) and claim the entire genus. The fact that one of ordinary skill could isolate other species’ insulin cDNA using techniques derived from the rat sequence disclosure is an enablement argument, not a written description argument: the written description requirement asks whether the inventor had possession of the full scope of the claimed genus, not merely whether the genus could be made from the disclosed species.
The court found that the disclosure of rat insulin cDNA did not demonstrate possession of the full vertebrate or mammalian insulin cDNA genus, since the sequences of those genes across species could be substantially different and the mere ability to isolate them using known techniques did not mean the inventor had described them.
Key Takeaways
- Broad genus claims in biotechnology require written description support by disclosure of a representative number of species within the genus — disclosing a single species and claiming the entire genus is insufficient to establish inventor possession of the full genus.
- The written description requirement is distinct from the enablement requirement: enablement asks whether a skilled artisan could make the full scope of the claimed invention; written description asks whether the specification shows the inventor actually possessed the full scope of the claimed invention.
- For cDNA, protein sequence, and other biotechnology genus claims, the specification must describe structural features or representative species sufficiently diverse to demonstrate that the inventor actually possessed the broad genus being claimed — not merely the technique for generating additional species members.
- Regents v. Eli Lilly is the foundational case for the written description doctrine as applied to biotechnology genus claims — establishing the representative species standard that was later applied in Enzo Biochem, Ariad Pharmaceuticals, and Amgen v. Sanofi.
Why It Matters
Regents of the University of California v. Eli Lilly established the modern written description doctrine for biotechnology genus claims — a doctrine that has significantly constrained the scope of broad patent claims in the life sciences. By holding that a single disclosed species cannot support a broad genus claim, the Federal Circuit set a foundational precedent that was later elaborated in Enzo Biochem v. Gen-Probe (2002), Ariad Pharmaceuticals v. Eli Lilly (2010), and ultimately applied by the Supreme Court in Amgen v. Sanofi (2023).
The decision also established an important boundary between the written description requirement and the enablement requirement in biotechnology — a distinction that has practical significance for how patent specifications must be drafted to support broad genus claims. For life science companies and academic institutions building biotechnology patent portfolios, Regents v. Eli Lilly is a foundational case establishing that genus scope must be commensurate with actual disclosure, not just with what a skilled artisan could do using the disclosed techniques.