References Showing Results in One Range Made Investigation into Lower Ranges Obvious; Composition Claim Obvious Where Patentee's Arguments Were Based on Unclaimed Limitation

Senju Pharmaceutical Co. v. Lupin Ltd., ___F.3d ___ (Fed. Cir. Mar. 20 2015) (Newman (dissenting), PLAGER, Moore) (D. Del.: Robinson) (2 of 5 stars)

Federal Circuit affirms bench verdict of invalidity for obviousness. The patent covered an eyedrop composition with a specific range of the drug gatifloxacin with a 0.01% EDTA at a given pH, and a method of increasing the active ingredient's corneal permeability by including that amount of EDTA. As an initial matter, there was no error in the district court relying its own previous findings (in prior litigation on now-canceled claims) that the prior art disclosed certain limitations not contended in this case to be points of novelty.

With respect to the composition claims, the district court thus did not err in rejecting Senju's arguments that the lack of corneal permeability disclosure in the cited art taught away because corneal permeability was not a claim limitation. It also did not err in finding that the proposed combination was motivated by knowledge that gatifloxacin (taught in one reference) is generally an improvement over another drug (taught in the others). Similarly, there was no error in finding that adding EDTA was disclosed in the references, and would have been obvious.

For the method claim, that the district court did not discuss two allegedly-teaching-away references in its opinion was not clear error. Though the references discussed using EDTA concentrations higher than what was claimed, they did not suggest that lower EDTA concentrations would not work. Nor did the district court commit clear error in finding that the prior art's teachings as to EDTA made it obvious to use a specific proportion (0.01% w/v) for the purpose of increasing corneal permeability. A reference's teaching that concentrations lower than 0.5% w/v would increase permeability was sufficient, as it would lead a skilled artisan to consider lower concentrations. The district court's findings as a whole were based on its determination that Lupin's experts were more credible, which was within the court's discretion.

The district court properly considered Senju's proffer concerning unexpected results, and did not clearly err in finding that the results were the product of obvious routine optimization.

Dissent: Judge Newman would have reversed as to the method claim, as none of the cited art teaches improved corneal permeability at such a low EDTA concentration. In Judge Newman's view, the cited references suggest EDTA concentrations higher than 0.01, and the testimony of Lupin's expert witness that lower concentrations would have been obvious was unsupported.