Insite Vision Inc. v. Sandoz, Inc.

Reviewing the district court’s framing of the obviousness inquiry and determination of no motivation to combine for clear error, the U.S. Court of Appeals for the Federal Circuit affirmed the district court’s determination upholding the patents-in-suit against an obviousness challenge. Insite Vision Inc. v. Sandoz, Inc., Case No. 14-1065 (Fed. Cir., Apr. 9, 2015) (Linn, J.)

Plaintiffs market an aqueous ophthalmic solution of the antibiotic azithromycin, which is useful in treating conjunctivitis and other bacterial infections of the eye, and which is covered by several U.S. patents. Sandoz filed an Abbreviated New Drug Application (ANDA) on a generic form of the solution, and plaintiffs brought suit for infringement. After claim construction, Sandoz stipulated to infringement but challenged the validity of the patents-in-suit on obviousness grounds. In the prior art, azithromycin was administered orally instead of topically, and it was thought that azithromycin was a poor candidate for use in aqueous solutions because of its poor solubility in water. However, ophthalmic solutions of other antibiotics structurally related to azithromycin were known. The parties disputed the proper framing of the obviousness question; plaintiffs argued that the proper inquiry was whether it would have been obvious to develop a topical ophthalmic formulation containing azithromycin, and Sandoz argued for the narrower question of whether it would have been obvious that topical azithromycin could be used to treat conjunctivitis. 

The district court agreed with plaintiffs, finding no reason to limit the question to conjunctivitis, reasoning in part that persons of ordinary skill would have sought treatments effective against both conjunctival and corneal infections because conjunctival infections frequently spread to the cornea. Although the district court recognized that the prior art taught aqueous solutions of related antibiotics, such as erythromycin, it concluded that Sandoz had not carried its burden to show that the patents-in-suit were obvious, because Sandoz had not shown that the one of ordinary skill would have been motivated to substitute azithromycin into prior art solutions. Sandoz appealed.

On appeal, Sandoz argued that the district court had erred as a matter of law in improperly framing the question of obviousness and had further erred in failing to find a motivation to combine. Plaintiffs countered that the identification of the problem faced by persons of ordinary skill is a factual determination reviewable for clear error. The Federal Circuit, implicitly adopting the plaintiffs’ view, found that the district court had not clearly erred in its framing of the obviousness inquiry and further that the issue of motivation to combine is a question of fact. Finding no clear error in the district court’s analysis, the Federal Circuit affirmed the district court’s decision upholding the patents’ validity.

Practice Note: At the Federal Circuit, determinations underlying the legal determination of obviousness are factual and therefore reviewable for clear error. The Court appears increasingly reluctant to disturb obviousness determinations of the district courts. SeeSenju Pharm. Co v. Lupin Ltd. (IP Update, Vol. 18, No. 4) (deferentially reviewing a determination of obviousness in another case about ophthalmic antibiotic solutions).