In defending a patent infringement claim, an accused infringer will often locate additional prior art in the course of its case investigation.  When the prior art is located after the accused infringer has already disclosed its invalidity contentions, a question often arises under the local patent rules as to whether the accused infringer is permitted to include the new prior art in revised contentions.  Recently, the District Court of New Jersey analyzed this question and provided some additional guidance regarding the relevant factors of good cause and timeliness in seeking to amend the invalidity contentions.

In  Jazz Pharmaceuticals v. Roxane Laboratories (.pdf), Case No. 2:10-cv-6108 (D.N.J. Feb. 28, 2013), the Court ruled that the accused infringer was not allowed to amend its invalidity contentions with additional prior art from the FDA.  On the issue of good cause for the requested amendment, the Court stated that “the Federal Circuit has stated that parties must ‘proceed with diligence in amending when new information comes to light in the course of discovery.’ O2 Micro, 467 F.3d at 1366-68.  Thus, to illustrate good cause, the moving party must demonstrate its diligence. (Id at 1366).”   The Court rejected the accused infringer’s argument that it was diligent in a five month delay in finding the FDA prior art because FDA materials are not the type of materials that is customarily searched for in an initial prior art search.  On the issues of timeliness, the court rejected the accused infringer’s argument that a delay in amending its contentions was justified because it needed to confirm that the prior art-at-issue was not cumulative of the art already disclosed in its initial contentions, as well as to confirm that the prior art was publicly available.

Key Takeaways:

At least one court has determined that the unique type of prior art located does not excuse its late disclosure.  Moreover, taking additional time to confirm that new prior art is not cumulative of other prior art or to confirm the new prior art is public may not justify an otherwise untimely disclosure.