Richards Layton & Finger
 

Magistrate Judge Burke Permits Deposition of Claim Construction Declarant

May 9, 2018

In Astellas Pharma Inc. v. Actavis Elizabeth LLC, No. 16-905-JFB-CJB (D. Del. Feb. 27, 2018), Magistrate Judge Burke granted the defendants’ request to depose an expert who submitted a declaration regarding indefiniteness (among other issues) in support of the plaintiffs’ opening claim construction brief. The defendants sought to depose the expert before submitting their sur-reply claim construction brief.

In allowing the deposition, Judge Burke noted that the parties were briefing indefiniteness during claim construction proceedings (as opposed to during summary judgment) at the plaintiffs’ insistence, and that the defendants should accordingly have the opportunity to make a complete record on the issue. Judge Burke granted the plaintiffs leave to respond to anything regarding the deposition testimony addressed by the defendants in their sur-reply brief.

Analysis: The use of expert testimony during Markman proceedings may result in the deposition of the expert, but Magistrate Judge Burke noted that parties should seek such a deposition early in the proceedings.