Inter partes reviews (IPRs) held in the Patent Trial and Appeal Board (PTAB) of the U.S. Patent and Trademark Office are frequently associated with contemporaneous patent infringement litigations in district courts. The case, Akorn, Inc. v. Senju Pharmaceutical Co., Ltd., discussed in the current post is an example of such a scenario. After Akorn, Inc. ("Akorn") was sued for infringement of U.S. Patent No. 6,114,319 ("the '319 patent") owned by Senju Pharmaceutical Co., Ltd., and Mitsubishi Chemical Corporation, Akorn petitioned for IPR of the '319 patent in the PTAB on the grounds that some of the claims of the patent were unpatentable for obviousness over the prior art, U.S. Patent 5,556,848 ("the '848 patent") and international patent application publication WO 95/31211 ("Ding"). The PTAB issued a Final Written Decision in the IPR on November 22, 2016, (Case IPR2015-01205) holding that Akorn had shown that the challenged claims were unpatentable under 35 USC §103(a) as obvious over the prior art.
The challenged claims of the '319 patent were directed toward an emulsion of difluprednate, which is a steroid. Claim 1 and 18 are representative and are summarized below. For the sake of brevity, the claim elements are not reproduced in their entirety.
For more information on this blog, click the link below.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.