Holding: A patent does not satisfy the written description requirement when the specification presents options that, despite appearing limited, still encompass numerous variations for a claimed compound, unless the specification provides clear “blaze marks” that guide a skilled artisan to the specific compounds or subgenus being claimed.
Duke University and Allergan Sales own the rights to US Patent 9,579,270, which is directed to a method of treating hair loss using compositions that include prostaglandin F (PGF) analogs. Allergan markets the drug Latisse®, which treats eyelash hair loss with a composition that consists of a 0.03% bimatoprost ophthalmic solution, a PGF analog. Duke and Allergan sued Sandoz, alleging that Sandoz’s generic version of Latisse® infringes the ’270 Patent.
At trial, Sandoz’s expert alleged that the ‘270 Patent was invalid for lack of written description, testifying that the ‘270 Patent describes over 4,000 compounds that can cause hair growth, but does not identify the specific embodiment disclosed in the asserted claim in the specification and does not disclose common structural features of the compounds encompassed by the asserted claim. The jury found the ‘270 Patent to be valid and awarded Allergan damages of $39 million. The district court denied Sandoz’s motion for a new trial and judgment as a matter of law.
Sufficiency of written description is a question of fact. To satisfy the written description requirement it must be shown that a person of ordinary skill in the art would conclude that the inventors possessed the full scope of the claimed invention when the application was filed. Sandoz argued that the asserted claim of the ‘270 Patent covers a specific subgenus of PGF analogs, but the specification does not show that the inventors were in possession of the full subgenus and the embodiment in the asserted claim at the time the application for the ‘270 Patent was filed. According to Sandoz, the specification of the ‘270 Patent is so broad that it encompasses billions of compounds, but the asserted claim is limited to only 1,620 of those compounds.
Allergan’s expert agreed that the specification of the ‘270 Patent is written to describe a chemical structure that has multiple open positions which may be filled in various ways to encompass billions of compounds. However, in order to have adequate written description, the specification must give a skilled artisan enough specific information regarding how to narrow this large universe of compounds to the smaller subset of compounds actually claimed. This information comes from the description of the outer limits of the genus and a representative number of members of the genus or from a description of the structural features that are common to the members of the genus.
The specification of the ‘270 Patent does not expressly disclose any embodiments of the subgenus of the asserted claim, so Allergan argued that the specification disclosed sufficient structural features that would guide a person of ordinary skill in the art to the claimed compounds. However, the Federal Circuit found that no reasonable juror could conclude that the specification provides sufficient structural details to allow a person skilled in the art to visualize or recognize the members of the subgenus.
Allergan stated that the ‘270 Patent disclosed three features that are common to all members of the claimed subgenus in the asserted claim: (1) prostaglandin hairpin; (2) amides at the C1 position; and (3) an unsubstituted phenyl ring at the omega end. The Federal Circuit found that the ‘270 Patent at best discloses two prostaglandin hairpin structures but then provides a long list of atoms, moieties, and functional groups that may fill the rest of the positions of the claimed structure. This lack of specificity is inadequate because it leaves a skilled artisan with too many possible choices to identify the claimed subgenus. The prostaglandin hairpin structure is shared by all compounds disclosed in the specification, and not unique to the claimed subgenus.
The specification of the ‘270 Patent allows for too much variation for the component at the C1 position. Allergan argued that the ‘270 Patent provides a limited list of 13 different options for the C1 position. However, of these 13 options, 9 of the options are categories of components that require further choices that may have additional alternative choices. This “maze-like” path of multiple alternatives only provides written description for a claimed compound if the specification includes sufficient “blaze marks” to direct a skilled artisan to the claimed compound. In the ‘270 Patent, the only blaze marks lead the skilled artisan away from the claimed compound, as the specification called out five of the 13 options as the preferred embodiments, and these preferred embodiments did not include the option that encompasses the asserted claim.
The ’270 Patent also gives insufficient guidance as to the phenyl ring at the omega end of the claimed compound. Again, the specification gives eight categories of options for the omega end, but each of these eight categories requires further choices. The specification discloses that phenyl is the preferred option if the skilled artisan chooses an aromatic group from the eight options, but nothing in the specification discloses that the aromatic group is the preferred choice. Even though 10 of the example compounds disclosed in the specification include unsubstituted phenyl at the omega end, the specification lists 95 example compounds and does not state that the 10 compounds with unsubstituted phenyl are preferred.
The ’270 Patent does not provide sufficient “blaze marks” to lead the skilled artisan to the claimed PGF analog in the asserted claim. Therefore, the Federal Circuit held that the asserted claim was invalid for lack of written description.
Federal Circuit Precedential 
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