While couched in terms of being your own lexicographer, this case mainly illustrates the broader point that intrinsic evidence trumps extrinsic evidence in claim construction. Perhaps most importantly, I think the patentee’s use of dependent claims to set up the proper context of the independent claims is what saved them. Otherwise, there is nothing to force the interpretation that the claims were not merely directed to the narrower embodiment of two identical substituents. There are also some good quotes to Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) (en banc) that could be useful during prosecution to emphasize how the Examiner (or more likely, the Board) must give claim terms their full context: (1) at 1312-13, “Importantly, the person of ordinary skill in the art is deemed to read the claim term not only in the context of the particular claim in which the disputed term appears, but in the context of the entire patent, including the specification;” and (2) at 1321: “Properly viewed, the ‘ordinary meaning’ of a claim term is its meaning to the ordinary artisan after reading the entire patent.”
Background / Facts: The patent here is directed to Allergan’s FDA approved drug “Lumigan,” which reduces intraocular pressure (“IOP”) in the eyes of people with ocular hypertension or glaucoma. The claims recite an associated chemical formula having an –N(R4)2 radical “wherein R4 is selected from [a Markush group].”
Issue(s): Whether the –N(R4)2 element requires that the two R4 substituents be identical.
Holding(s): No. Although “the plain and ordinary meaning” of –N(R4)2 suggests that identical R4 substituents are required, Allergan “acted as its own lexicographer by defining –N(R4)2 to permit nonidentical R4 elements.” In particular, the court pointed to several dependent claims that expressly include three compounds with nonidentical R4 elements, and to the specification’s listing of these same compounds. “Barr and Sandoz’s argument regarding the plain meaning of –N(R4)2 is unpersuasive; when properly construed in light of the entire patent, the –N(R4)2 term plainly encompasses nonidentical R4 substituents.”