In a short opinion dated February 24, 2014 (App. Nos. 2013-1593, -94, -95, -98), a Fed. Cir. panel made short work of the defendants’ attempt to invalidate a Glaxo claim in U.S. Pat. No. 5,565,467, to dutasteride “or a pharmaceutically acceptable solvate thereof” on the basis that the term “[dutasteride] solvate” failed to meet the written description requirement (“WDR”). The district court construed a “solvate” of this steroidal drug to mean “a complex formed by dutasteride in which dutasteride is reacted or from which it is precipitated or crystallized.”
While the parties agreed that dutasteride “is the molecule identified before ‘or a pharmaceutically acceptable solvate thereof’,” the panel noted that the defendants failed to argue that there was an inadequate description of “pharmaceutically acceptable” – this term had been construed to mean “suitable for use when administered to the recipient thereof as a pharmaceutical”- and hinted that its ruling might have been different had the defendants adopted this approach, rather than arguing simple lack of an adequate disclosure of enough species to support the genus of dutasteride solvates.
While the specification only contained a general disclosure defining solvates and how to make them, and only one example, the district court and the panel gave weight to the fact that solvate formation is [very] old in the art, steroids are known to readily form solvates and that the universe of useful solvates is relatively small. The district court found that methods to confirm the bioavailability of a given solvate were well known to the art, but the panel could not give weight to that fact.
The panel distinguished language in earlier decisions that a specification that only describes what activity a hypothetical drug must possess coupled with a screening method for that activity fails the written description requirement. Again, this is because a priori predictability of function was not on the table: “the description remains entirely based on structure of the compound and its process of creation.” Citing UC v. Lilly, the panel explained: “Describing a complex of dutasteride and solvent molecules is an identification of ‘structural features commonly possessed by members of the genus that distinguish them from others,’ allowing one of skill in the art to ‘visualize or recognize the identity of the members of the genus’”. Slip. Op. at 10. The panel reached back to Amgen v. Chugai and Fiers v. Revel to remind us that conception can be established when a compound is identified ‘by its method of preparation.’
The panel spent a page distinguishing decisions invalidating claims “that seek to distinguish members of the claimed genus by the shared performance property of encoding a particular enzyme or other product… [or inhibiting] the action of a particular protein… [or inhibiting] a particular medical complication… or [a antibody’s] ability to bind to a particular antigen.” The court went on to contrast the dutasteride solvates, that are at least 50% structurally defined: “’[Solvates] of dutasteride are not distinguished by a particular performance property. The claim term does not assert coverage of yet-unidentified ways of achieving a desired result; it does not ‘attempt to preempt the future before it has arrived.’” Slip op. at 12. Although it sounds like an analysis of teamwork in a sport, watch out for that catchphrase “shared performance property”. I think we will be seeing more of it in the future.