A claim on a molecule is not adequately enabled by a specification with only one working example if one of ordinary skill in the art would be required to synthesize and screen each of at least tens of thousands of candidate compounds to practice the full scope of the claim.

Wyeth et al. v. Abbott Laboratories et al., No. 2012-1223, -1224 (Fed. Cir. June 26, 2013).

Wyeth and Cordis Corporation (“Wyeth”) appealed from the U.S. District Court for the District of New Jersey’s grant of summary judgment that claims 1 and 2 of U.S. Patent No. 5,516,781 and claim 1 of U.S. Patent 5,563,146 are invalid for nonenablement. The patents-in-suit relate to the use of rapamycin for the treatment and prevention of restenosis. The claims relate to a method of treating or preventing “restenosis...which comprises administering an antirestenosis effective amount of rapamycin to said mammal.” See, e.g., ‘781 patent at claim 1. In general, “rapamycin” refers to a class of compounds, and the District Court adopted Wyeth’s proposed construction of “rapamycin” as “a compound containing a macrocyclic triene ring structure produced by Streptomyces hygroscopicus, having immune-suppressive and antirestenotic effects.” Based on that construction, the District Court granted defendants’ motions for summary judgment of invalidity for nonenablement.

The Federal Circuit affirmed, holding that there is no genuine issue of material fact that the specification does not enable one of ordinary skill to practice the asserted claims without undue experimentation. Claims are not enabled when, at the effective filing date of the patent, one of ordinary skill in the art could not practice the full scope without undue experimentation. Adopting the District Court’s unchallenged construction of “rapamycin,” the court found the invention to be a new method of use of a known compound (sirlimus) and any other compounds that meet the construction’s structural and functional requirements. The specification only disclosed a single species along with assays that could be used to determine which compounds exhibited the requisite effect. This meant that it would be necessary to synthesize and test each candidate compound using the assays disclosed in the specification to determine whether the potential compound possessed the necessary immunosuppressive and antirestenotic effects. The court found that there was “no genuine dispute that practicing the full scope of the claims would require synthesizing and screening each of at least tens of thousands of compounds” and that effort, which required “a complicated and lengthy series of experiments” represented undue experimentation.

A copy of the opinion can be found here.