When multiple defendants are sued in a single lawsuit, it is common for those joint defendants to share legal positions. For example, when asserting invalidity contentions, the defendants will sometimes disclose a single set of invalidity contentions applicable to all joint defendants. Alternatively, a second defendant may serve invalidity contentions disclosing that, in addition to its own stated contentions, the second defendant also incorporates the invalidity contentions of one or more other first defendants. Whether that type of incorporation by reference is allowed is not expressly addressed by the local patent rules.

In Warner Chilcott Company, LLC v. Lupin Ltd. (.pdf), 2013 WL 4084237, *1 (D.N.J. August 13, 2013), one defendant, Lupin, sought to amend its invalidity contentions one year after the preliminary contentions were due and even after the close of fact discovery. Specifically, Lupin sought to add an “Ovcon” product to its invalidity contentions because the product was (i) produced by Plaintiff during the fact discovery phase of this case, (ii) referenced by the co-defendant in its invalidity contentions, and (iii) well-known to Plaintiff. Plaintiff opposed the amendment arguing that “Lupin’s new theories would inject multiple new issues into the case that would inevitably require additional discovery….”  Id. at *1. When examining the possible prejudice to the Plaintiff caused by the proposed amendment, the Court noted that a different defendant disclosed the Ovcon product in its own invalidity contentions which were then incorporated by reference into Lupin’s preliminary contentions.  Therefore, the Court found that Plaintiff “had more than adequate notice of the invalidity defenses Lupin proposes to add and/or expand upon and will not be prejudiced if Lupin is permitted to do so.”  Id. at *3.

Key Takeaway: When asserting preliminary invalidity contentions, one defendant may be able to rely upon another defendant’s preliminary contentions if those other preliminary contentions are incorporated by reference.