The Local Patent Rules have been designed to require parties to solidify their theories in the early stages of litigation and adhere to them as the case progresses. Yet, the rules are not an entirely rigid structure. They retain some flexibility by providing a non-exhaustive list of circumstances that may warrant an amendment to parties’ original contentions. However, this flexibility decreases the predictability of which amendments will be successful under the rules. 

In Depomed Inc. v. Actavis Elizabeth LLC (.pdf), 2014 WL 1877613 (D.N.J. May 8, 2014), Judge Pisano ruled that a defendant, after unreasonable delay, could not amend its Invalidity Contentions without a good cause to permit the amendment. On August 24, 2012, defendant stated in its Invalidity Contentions that the disputed patent was invalid due to an indefinite size claim, which read “is of a size exceeding the pyloric diameter in the fed mode.” On April 11, 2014, the last day of expert discovery, during defendant’s deposition of plaintiff’s expert, the expert admitted that he could not determine what size would satisfy the claim. On April 14, 2014, defendant informed the plaintiff and the court that it would like to amend its invalidity contention by including the expert’s admission. On April 15, 2014, defendant served its amended invalidity contentions on the plaintiff. On April 17, 2014 the plaintiff notified the defendant that it intended to object to the amendment and filed its objection on April 22, 2014. In its reasoning, the Court applied Local Patent Rule 3.7 and denied defendant’s motion to amend its contentions. The Court found that even though defendant had asserted a general indefiniteness in its 2012 contention, it had not raised this specific issue until the eve of trial, which created an unreasonable delay and unduly prejudiced the plaintiff. Additionally, the Court found no good cause to permit the amendment because defendant was aware of the issue of indefiniteness but failed to assert it during either expert discovery or claim construction. Key takeaway: The Local Patent Rules are flexible when it comes to amending invalidity contentions, but contenders should present new issues at the earliest possible time and should continuously maintain important issues in order to preserve their relevance. Otherwise, a court may prevent a party from supplementing its invalidity contention for lack of good cause and unreasonable delay even if the issue has been previously raised. The author thanks Josh Nosal, a student at the University of Texas School of Law, for his assistance in writing this post.