Cited prior art was a due diligence factor in denying invalidity contention supplement

In Nomadix, Inc. v. Hewlett-Packard Company et al. (March 22, 2012), Judge Pregerson (Central District of California) denied defendants' request to supplement their invalidity contentions.  The Court noted that for amending prior art disclosures, good cause determination factors include:

the relevance of the newly-discovered prior art, whether the request to amend is motivated by gamesmanship, the difficulty of locating the prior art, and whether the opposing party will be prejudiced by the amendment.

(quoting Acco Brands, 2008 WL 2168379, at *1 (N.D. Cal. May 22, 2008)).

The decision appears to suggest that the new prior art (the Vos article) is relevant and that the amendment request is not motivated by gamesmanship.  Although these factors may have favored the defendants, the Court seemed troubled that the defendants did not identify the Vos article sooner, noting that:

Defendants fail to adequately explain their delay in discovering the Vos article, when it was one of only eleven references cited in the 1997 SPINACH paper upon which they based their initial invalidity contentions. (p. 7).

As for prejudice to Plaintiff Nomadix, the supplemental contentions extend beyond the Vos article.

Defendants argue that there is no prejudice here, because they are not shifting or adding theories, but simply developing "the same theory set forth in the preliminary invalidity contentions in July 2010 and first supplemental invalidity contentions in July 2011."  (Reply at 8.)  Specifically, those contentions alleged that the '118 Patent and the SPINACH system rendered invalid Novadix's '894 and '716 Patents, respectively.  As Nomadix explains, however, Defendants seek to go well beyond developing these prior art theories.  Defendants now contend that the '118 Patent and SPINACH system invalidate several additional Nomadix patents.  Likewise, Defendants contend that three other patents are invalidated by a new reference - the Vos article.  In short, Defendants now theorize that prior art invalidates seven Nomadix patents, instead of only two.  Nomadix therefore reasonably argues that responding to these new contentions would require additional fact discovery, which is now closed.

Takeaways - allege invalidity against all asserted patents for each of your prior art references in your preliminary invalidity contentions, and, be sure to consider references to other prior art in your main prior documents because that may be a factor against you when requesting an invalidity contention supplement.