Background
Pioneer Hi-Bred International owned U.S. Patent No. 11,371,055, which claimed a genus of enzymes capable of degrading both phenoxy auxin and pyridyloxy auxin herbicides. Representative claim 1 required the dual herbicide-degrading function, at least 85% sequence identity with a disclosed sequence, and an AAD-12 motif.
Inari Agriculture challenged claims 1–33 in post-grant review. The claimed genus encompassed approximately 2.14 × 10106 species, while the specification supplied only two examples. Pioneer later tested eight enzymes satisfying the structural limitations; only two displayed the claimed dual function, and those showed just 1% and 2% triclopyr activity. The Patent Trial and Appeal Board found all challenged claims unpatentable for lack of enablement.
The Court’s Holding
The Federal Circuit affirmed. It held that the Board could consider Pioneer’s post-priority-date experimental results because the tested variants could have been made as of the priority date. Post-priority evidence may reveal whether the specification enabled the claims at that time; this case did not involve reliance on later-developed technology or a later-existing state of the art.
The court also found no abuse of discretion in the Board’s reliance on Inari’s expert, who had relevant enzyme-development experience. Substantial evidence supported nonenablement: even after applying the specification’s guidance, the genus remained enormous; the patent disclosed only two examples; and Pioneer’s testing undermined the asserted correlation between the claimed structural features and dual herbicide-degrading function. The specification therefore failed to provide reliable guideposts for practicing the claims across their scope.
Key Takeaways
- Post-priority experimental evidence may be used to assess whether a patent enabled its claims as of the priority date when the tested embodiments could have been made at that time.
- A vast functionally defined genus supported by only a few examples may fail enablement when the disclosed structural features do not reliably predict the claimed function.
- A patent owner’s own later testing can support nonenablement when most tested embodiments satisfying the structural limitations fail to perform the claimed function.
Why It Matters
The nonprecedential decision reinforces the demanding enablement burden for broad biotechnology genus claims: the broader the claimed territory, the more guidance and representative disclosure the specification must provide. Structural similarity alone may not enable a functionally defined genus when experimental evidence shows that the claimed structure does not reliably produce the required function.
The decision also clarifies the distinction between impermissibly judging enablement by later-developed technology and permissibly using later-generated evidence to illuminate what the original disclosure actually enabled.