A plaintiff chooses to file three separate actions in the same district against three separate alleged infringers. The plaintiff asserts the same patents in all three actions. A defendant in one of the matters adds an inequitable conduct defense against the plaintiff. After the cut-off date for amendments to the pleadings, the defendant in another matter moves to amend its answer to add the same claims of inequitable conduct that were pled by the other defendant in the separate pending matter. What is the result? Should the defendant be able to add the same defense asserted by another defendant in a different action but against the same plaintiff? Magistrate Judge Thynge recently answered that question, yes. Parker-Hannifin Corporation v. Zippertubing (Japan), Ltd., C.A. No. 06-751-MPT, Memo. Order (D. Del. Sept. 24, 2008). Under Rule 15(a), the plaintiff could not argue prejudice since they had notice of the allegations from the companion case and the case was early in the discovery process. Id. at 5 n.8.
The plaintiff, in arguing against allowing the amendment, did not in fact argue prejudice, but instead argued that defendant’s one theory of inequitable conduct “is not necessary to practice the patents-in-suit or for the best mode” and that the other theory rests on a patent that is not prior art or material to other patentability requirements. Id. at 3. The Court will not weigh evidence when deciding a motion to amend and therefore the plaintiff’s reliance on factual contentions in opposing the amendment were unsuccessful. Id. at 7. Furthermore, in order to satisfy Federal Rule of Civil Procedure 9(b), the defendant need only allege the relevant material information and the acts of alleged fraud to “permit responsive pleading” and defendant disclosed “at least that much in its twenty-eight paragraph amendment.” Id. at 7-8.