Insite Vision Inc. (“Pfizer”) v. Sandoz, Inc.

Docket No. 2014-1065

April 9, 2015

Brief Summary: FC found no clear error or abuse of discretion in its conclusions that the patents-in-suit were not obvious (prior art “discloses a ‘laundry list of active ingredients’” and expert testified “that a researcher would focus on the examples”).

Summary: Sandoz appealed DC decision that US 6,861,411 (owned by Pfizer, Insite is exclusive licensee); 6,239,113 (owned by Insite); 6.569,443 (owned by Insite); and 7,056,893 (owned by Insite) relating to compositions and methods for using azithromycin topically for eye infections (marketed by Insite as Azasite®). Sandoz filed an ANDA with a paragraph IV certification as to the patents-in-suit. After claim construction, Sandoz stipulated as to infringement but contested the validity (obviousness). Before trial, Sandoz attempted to enter the file history of the EP counterpart to the ‘411 patent but was denied (“the late proffer was prejudicial”). The DC found Sandoz had failed to show by clear and convincing evidence that the asserted claims would have been obvious. The FC opinion first notes that it reviews the ultimate legal conclusions of obviousness decisions de novo and the underlying factual findings for clear error (Tyco, FC 2014). Sandoz argued that the DC improperly “framed” the obviousness question as whether “a topical ophthalmic formulation containing azithromycin” when it should have considered “whether it would have been obvious that topical azithromycin could be used to treat conjunctivitis”. This, Sandoz argued, required it “to provide the obviousness of topical treatments of all manner of eye infections and not merely conjunctivitis”. Pfizer argued “that nothing…precluded Sandoz from proving that topical treatment of conjunctivitis would have been obvious, but that Sandoz simply failed to carry its burden-a factual issue not a legal question”. The FC panel found the DC did not err in its framing of the question and that Sandoz’s “proofs simply failed to carry the day”. Sandoz argued that the ‘411 patent was an obvious modification of a topical formulation Illotycin® containing erythromycin and an oral formulation of azithromycin (Zithromax®) for treating conjunctivitis. However, the FC found no clear error with the DC conclusion, based largely on consideration of expert testimony, that Sandoz had not met its clear and convincing burden. The DC also concluded the Insite patents would not have been obvious because “persons of ordinary skill in the art would not have been motivated to use the water-based polymeric solutions of the prior art in an azithromycin formulation because [it] was considered insoluble and instable in water” and “one of skill in the art would not use polycarbophil, a gelling polymer, but would instead use a colloidal system” for a topical, water-based azithromycin formulation. The FC found no clear error with the DC conclusions, including that one prior art patent (US 5,192,535) “discloses a ‘laundry list of active ingredients’” (see col. 8, line 64 to col. 9, line 25), crediting an expert witness’ testimony “that a researcher would focus on the examples, none of which mention erythromycin” (Sandoz had argued it would have been obvious to replace erythromycin with azithromycin). The FC explained that, unlike in Merck (FC 1989) (disclosure of “a multitude of effective combinations does not render any particular formulation less obvious”), “[h]ere…selecting from the laundry list of potential active ingredients listed in the ‘535 patent at best teaches that polycarbophil can be combine with eyrthryomycin” since it “does not mention azithromycin” and “[m]oreover…those of skill in the art would have been concerned about azithromycin’s solubility and stability in water, so the modification from erythromycin to azithromycin would be even less obvious”. Regarding the EPO file history issue, the FC found the DC did not abuse its discretion to exclude it based on FRCP 16(e) and its analysis of the “Pennypack” factors (3rd Cir. 1977) (impact of the evidence).

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