Intellectual Property Law

Judge Robinson: Obviousness Found in Zymar case

By Karen E. Keller, Andrew A. Lundgren et al.

Judge Robinson recently issued an opinion in Senju Pharmaceuitical Co. v. Apotex, Inc., C.A. No. 07-779-SLR (D. Del. June 16, 2010), holding that the patent at issue was infringed, but also invalid as obvious.

Senju had asserted several claims of U.S. Patent No. 6,333,045, which covered the use of a "Gatifloxacin ophthalmic solution containing disodium edetate [("EDTA")]," sold as the antibiotic eye-drop "ZYMAR." Apotex filed an abbreviated new drug application ("ANDA") with the FDA, seeking approval to market a generic version of the drug -- Gatifloxacin by itself was covered by a recently expired patent. Id. at 1. The patent at issue in this case, however, was filed later, and claimed the combination of Gatifloxacin and EDTA, as well as the method and uses of combining the two. Id. at 1-2.

The Court found that it would have been obvious to one of ordinary skill in the art to combine Gatifloxacin with EDTA. Id. at 22-33. As described by the Court, both Gatifloxacin and EDTA were known in the prior art, as were the uses and benefits of EDTA combined with compounds similar to Gatifloxacin. Id. at 4-9. The original Gatifloxacin patent recognized the similarity of Gatifloxacin and these other compounds, and also recognized that the "pharmaceutical formulations of Gatifloxacin would follow 'the routes well known ... ' with respect to 'oral[] and parenteral[]' administration.'" Id. At the time, such "routes well known" included combinations with EDTA. Id. Thus, it was obvious to one of ordinary skill to combine the substances.

The Court also evaluated the secondary considerations of non-obviousness, but found that they did not weigh in favor of either party. Id. at 33-37. The Court did not give much weight to the product's commercial success, because the prior Gatifloxacin patent blocked the entry of any generic competitors into the market. Id. Senju also argued that a contemporaneous invention had occurred, but the Court determined that the second inventor "did not recognize or appreciate the invention," and discounted this factor as well. Id. at 33-35. All in all, this was a fairly clear-cut obviousness opinion.

Senju Pharmaceuitical Co. v. Apotex, Inc., C.A. No. 07-779-SLR (D. Del. June 16, 2010)

Full post as published by Delaware IP Law Blog on July 07, 2010 (boomark / email).