In a patent infringement suit related to the generic version of the drug Combigan®, the US Court of Appeals for the Federal Circuit held that claims asserted by Allergan Sales, LLC, were not invalid but not infringed. Allergan Sales, LLC v. Sandoz, Inc., et al., Case Nos. 2017-1499; -1500; -1558; -1559 (Fed. Cir., Dec. 22, 2017) (Hughes, J).
Allergan holds the approved new drug application for Combigan®, an ophthalmic solution used to reduce eye pressure in glaucoma and ocular hypertension patients. Combigan® is a "fixed combination" solution consisting of 0.2 percent brimonidine tartrate and 0.68 percent timolol maleate. Allergan claimed that three of its patents protect the drug and its administration.
Generic drug manufacturers Sandoz, Inc.; Alcon Laboratories, Inc.; and Alcon Research, Ltd., (collectively, Sandoz) filed an abbreviated new drug application (ANDA) seeking approval to market generic versions of Combigan®. Allergan sued Sandoz for infringement of various claims of its patents under the Hatch-Waxman Act. In response, Sandoz argued that all asserted claims were invalid as obvious and that one asserted claim was invalid for lack of written description in the specification. The district court found the asserted claims not invalid and claims from one patent infringed.
On appeal, Sandoz argued that all the asserted claims merely recited the inherent results of administering an obvious combination. The Federal Circuit conceded that the concomitant administration of brimonidine and timolol ophthalmic composition twice daily was obvious in light of the prior art. The court found, however, that each asserted claim recited an additional efficacy limitation that restricted the claimed method and was not disclosed by any prior art reference in the record. The court also noted that these efficacy limitations were not inherent in the administration of the ophthalmic composition, a finding adequately supported by the record.
Sandoz also argued that one asserted claim was invalid for lack of written description because the claim encompassed hundreds of brimonidine and timolol combinations. The Federal Circuit disagreed. First, the court explained that a sufficient description of a genus requires the disclosure of either a representative number of species falling within the scope of the genus or structural features common to members of the genus so that a person of skill in the art could recognize the members. Here, the specification disclosed the sole embodiment of the claimed genus. The Federal Circuit also found that the district court correctly credited testimony from Allergan's expert, who explained that the claim encompassed only six possible combinations of brimonidine and timolol. Therefore, the Federal Circuit affirmed the district court's finding that the asserted claims were not invalid based on obviousness or lack of written description.
Finally, both Allergan and Sandoz appealed the district court's infringement findings. Allergan asserted literal infringement of claims that recited administration of 0.5 percent timolol free base. However, both Combigan® and Sandoz's proposed generic contained 0.68 percent timolol maleate, a compound distinct from 0.5 percent timolol free base. The district court relied on the equivalency of the two compounds in concluding that the proposed generic literally infringed. Because the Court determined that chemical equivalency was not sufficient for finding literal infringement, however, the district court erred.
The Federal Circuit also examined infringement under Section 271(e)(2)(A). The Hatch-Waxman Act provides for a technical infringement upon submission of an ANDA, but only for a drug claimed in a patent. Combigan® contains a solution composed of 0.2 percent brimonidine tartrate and 0.68 percent timolol maleate. The asserted claims expressly recited 0.5 percent timolol free base, however, not 0.68 percent timolol maleate. The Court found that since Combigan® was not the "drug claimed in" the asserted patent, Sandoz's ANDA did not infringe, as a matter of law, under Section 271(e)(2)(A).
On cross-appeal, Allergan argued that the district court erred in finding that Sandoz's proposed generic did not literally infringe Allergan's remaining asserted claims. The claims recited 0.2 percent brimonidine, but Sandoz's proposed generic contained 0.2 percent brimonidine titrate. The Federal Circuit found these two compounds distinct. Therefore, the Court concluded that the district court did not err in finding that Sandoz did not infringe the claims.
Accordingly, the Federal Circuit affirmed in part and reversed in part the district court's infringement findings.
Ophthalmic Solution Claims Not Invalid, Not Infringed
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