By Memorandum Order entered by The Honorable Richard G. Andrews in HSM Portfolio LLC, et al. v. Elpida Memory Inc., et al., Civil Action No. 11-770-RGA (D.Del., February 11, 2016), the Court, among other things, granted Defendant’s motion to strike (D.I. 1049)  with respect to the new infringement theory for the ‘949 patent raised in Plaintiffs Expert’s Reply Infringement Report.

In its motion to strike, Defendant contended that, in Plaintiffs Expert’s Initial Infringement Report, Plaintiffs only “accused Micron’s 6T SRAM memory cells of infringing the ‘949 patent, and not a ‘sense amplifier’ that would sense the output from those memory cells.” Id. at *5.  Defendant then contended that, in Plaintiffs Expert’s Reply Infringement Report, “Plaintiffs accused an entirely new circuit – a ‘sense amplifier.’” Id. Plaintiffs responded by stating that their expert and Defendant’s expert disagreed regarding what constitutes a sense amplifier.  Id.  However, Plaintiffs conceded that the sense amplifier referred to in their Expert’s Reply Infringement Report was not charted in Plaintiffs Expert’s Initial Infringement Report or included in the invalidity contentions. Id.

The Court concluded that Plaintiffs should not be permitted to advance a new infringement theory in their reply report. Id. The court noted that, while it is true that Defendant filed a supplemental non-infringement report that responded to this new infringement theory, it was not convinced that was sufficient to cure the prejudice. Id. at *5-6.

A copy of the Memorandum Order is attached.

The takeaway from the case in general is that counsel and their infringement experts should be working together to make sure that they are identifying and charting all of the accused products during discovery in the action and are updating and supplementing the pleadings and discovery responses as necessary so that there can be no legitimate motions to strike asserting claims of new infringement theories after the close of discovery.