Factual Findings Support The District Court’s 'Framing' Of Obviousness Question

Insite Vision Inc. and Inspire Pharmaceuticals, Inc. v. Sandoz, Inc., No. 2014-1065, 2015 U.S. App. LEXIS 5717 (Fed. Cir. Apr. 9, 2015) (Linn, J.). Click Here for a copy of the opinion.

Pfizer owns U.S. Pat. No. 6,861,411, which claims a method of treating an ocular infection by administering topical azithromycin. Insite owns three patents (US. Pat. Nos. 6,239,113; 6,569,443 and 7,056,893), which claim a topical ophthalmic composition and a process for treating an eye with an azalide antibiotic. Inspire is licensed under all of these patents, which are listed in the FDA Orange Book as covering Insite's topical azithromycin solution (Azasite). Sandoz sought to market a generic version of Azasite and filed an Abbreviated New Drug Application (ANDA) with a Paragraph IV certification alleging that Orange Book patents for Azasite were invalid and/or not infringed. Plaintiffs in turn sued Sandoz for infringement.

Before trial, the district court denied Sandoz's motion to amend the pre-trial order to include the file history of the '411 patent's European counterpart as evidence. After the trial, the court ruled that Sandoz failed to show "by clear and convincing evidence that the asserted claims would have been obvious to a person of ordinary skill in the art." On appeal, Sandoz argued that the district court "misframed" the inquiry facing a person of ordinary skill in the art at the time of the invention. Sandoz also appealed the court's refusal to admit the European file history into evidence.

The district court framed the obviousness inquiry as "whether it would have been obvious to a person of ordinary skill in the art at the time of the invention to develop a topical ophthalmic formulation containing azithromycin." Sandoz argued for a more specific question: "whether it would have been obvious that topical azithromycin could be used to treat conjunctivitis."

The Federal Circuit found that factual findings support the district court's decision. Azithromycin and its class of molecules were "known to be bacteriostatic, to have a limited spectrum of activity, and to require multiple doses per day to penetrate tissue." Furthermore, "the unique balance of log P, molecular weight, solubility, and charge" made the compound a poor candidate for treating ocular infections. The district court's broader question did not foreclose Sandoz from proving that it would have been obvious to use topical azithromycin to treat one infection. The issue, according...