April 26, 2017

Case Name: AstraZeneca AB v. Aurobindo Pharma Ltd., 14-664-GMS, 2017 U.S. Dist. LEXIS 14647 (D. Del. Feb. 2, 2017) (Sleet, J.) 

Drug Product and Patent(s)-in-Suit: Onglyza® (saxagliptin) and Kombiglyze™ XR (saxaglibtin and metformin); U.S. Reissue Patent No. RE44,186 (“the ’186 patent”)

Nature of the Case and Issue(s) Presented: AstraZeneca marketed a tablet formulation of saxagliptin under the trade name Onglyza® to improve glycemic control in adults with type 2 diabetes. AstraZeneca also marketed a combination of saxagliptin and metformin under the trade name KombiglyzeTM XR for the same purpose. Defendants filed ANDAs seeking to manufacture and market generic versions of AstraZeneca’s products, arguing that the ’186 patent was invalid as obvious in light of the prior art. AstraZeneca brought suit alleging that defendants’ generic formulations infringed the ’186 patent, and defendants countered by challenging the patent’s validity. After a bench trial, the court found in favor of AstraZeneca, concluding that defendants failed to meet their burden of proving invalidity.

Why AstraZeneca Prevailed: The prior art did not support defendants’ arguments that one of ordinary skill would have developed a saxagliptin formulation based on vildagliptin to treat type 2 diabetes. Indeed, at the time of patenting, there were a number of chemical bases that could have been used to fill the role of vildagliptin, and one of ordinary skill would only conclude that vildagliptin was obvious by relying on impermissible hindsight bias. What’s more, there was no evidence that one of ordinary skill would modify vildagliptin to create saxagliptin. Indeed, the prior art taught away from such a modification, suggesting that it would reduce the stability of the chemical compound. Further, there was no evidence that one of ordinary skill would be motivated to make a second modification to the chemical compound, adding a cyclopropyl group to the compound. Without this modification, the compound would be ineffective in treating type 2 diabetes. For these reasons, the court concluded that defendants had failed to provide sufficient evidence to invalidate the claims.

The court did, however, deny AstraZeneca’s request for fees. Though the court upheld the validity of AstraZeneca’s patent, it did so only after analyzing the credibility of expert witnesses. Thus, the court reasoned, the case did not hinge on a substantively weak litigation position, and an award of fees was inappropriate.