By Memorandum Opinion entered by the Honorable Sue L. Robinson in Ashai Glass Co., Ltd., et al. v. Guardian Industries Corp., Civil Action No. 09-515-SLR (D.Del., August 12, 2011), the Court denied the motion of defendant, Guardian Industries Corp., seeking to amend its affirmative defenses and counterclaims to assert new allegations of inequitable conduct against plaintiffs relating to concealing or misrepresenting the true inventorship of pending claims to the USPTO during the prosecution of the patents-in-suit.

A complete copy of the Court’s Memorandum Opinion is attached hereto.

By way of background, the Scheduling Order entered by the Court in March 2010 provided that amended pleadings were due by August 15, 2010. Id. at 1. Defendant did not file its motion to amend its affirmative defenses and counterclaims to add the new allegations of inequitable conduct until March 4, 2011. Id.

In denying defendant’s motion to amend, the Court recognized that “leave to amend shall be freely given when justice so requires.” Id. at 3. However, the Court also recognized that “[t]he court may exercise its discretion to deny leave to amend in situations in which the moving party has delayed seeking leave and the delay is ‘undue, motivated by bad faith, or prejudicial to the opposing party.’” Id. The Court noted that “[d]elay is ‘undue’ when an unwarranted burden is placed on the court or when the requesting party has had previous opportunities to amend.” Id. at 4.

After analyzing the particular facts with respect to defendant’s motion to amend, the Court determined that the critical documents to defendant’s new inequitable conduct allegations were publicly available prior to close of discovery, defendant’s delay in waiting to move to amend until March 4, 2011 was largely unexplained, and allowing defendant to amend at such a late stage would place an unwarranted burden on the Court and prejudice plaintiffs in several respects. Id. at 4-6. Thus, defendant’s motion to amend was denied. Id. at 6.