Senju Pharm. Co. Ltd. v. Apotex Inc.

January 03, 2012

GENERICally Speaking: A Hatch Waxman Litigation Bulletin

Case Name:  Senju Pharm. Co. Ltd. v. Apotex Inc., Civ. No. 07-779-SLR, 2011 U.S. Dist. LEXIS 146271 (D. Del. Dec. 20, 2011) (Robinson, J.).

Drug Product and Patent(s)-in-Suit: Zymar® (0.3% gatifloxacin ophthalmic solution); U.S. Patent No. 6,333,045

Nature of the Case and Issue(s) Presented:  Whether the asserted claims of the ‘045 patent were obvious.  In their ANDA, defendants certified that their generic product did not infringe certain claims of the '045 patent and that those claims were invalid.  After a trial, the magistrate judge found infringement, but ruled that the claims were invalid as obvious.  In post-trial briefings, plaintiffs challenged the finding of obviousness on one claim.  The Court was persuaded that the evidence presented at trial before the magistrate judge may not have been sufficient, and therefore conducted a second trial on the obviousness issue for that one particular claim. 

At the second trial, plaintiffs presented expert testimony regarding tests, which plaintiffs claimed were based on the prior art.  Plaintiffs argued that the results of those experiments demonstrated that the claimed results disclosed in the ‘045 patent were unexpected.  Defendants countered, arguing that plaintiffs' experiments were not conducted as described in the prior art references, and that the results were irrelevant because the experiments were not the proper test to determine the presence of the claimed invention.  Further, defendants presented additional scholarly materials to demonstrate that the claimed results would have been routine and expected by one of skill in the art.  The Court ruled in defendants' favor.

Why Apotex Prevailed:  (No unexpected results).  The Court found the claim obvious in light of the prior art because the scholarly material that defendants presented demonstrated that the supposed unexpected results actually would have been expected in view of the combination of certain prior art references.  The Court gave little to no weight to plaintiffs' experiments because they were not the correct experiments to conduct in determining if the claimed results would have occurred when combining the prior art references and, perhaps more importantly, the experiments were not conducted in the manner described in the prior art references.  The Court noted that the plaintiffs' experiments were "irrelevant at best, [and] unreliable at worst."  Based on the evidence, the Court found that the asserted claim of the '045 patent was invalid as obvious.

Oren D. Langer


Managing Partner, New York Office
Member of Executive Board

Ryan M. Schultz


Pronouns: he/him

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