CBOE v. ISE, No. 07 C 623, Slip Op. (N.D. Ill. Mar. 6, 2013) (Lefkow, J.).

Judge Lefkow granted in part plaintiff CBOE’s motion to strike defendant ISE’s expert witness in this patent case, as follows:

  • This case was not governed by the Local Patent Rules (“LPR”) because it was filed before the LPR became effective.
  • Although ISE’s interrogatories did not specifically identify its doctrine of equivalents theory, ISE sufficiently disclosed its theory as to claims 4, 35 and 36 during discovery, including in ISE’s summary judgment motion.
  • ISE did not sufficiently disclose its doctrine of equivalents argument as to claim 56.
  • CBOE was not prejudiced as to claims 4, 35 and 36 because the arguments were disclosed at least at summary judgment.
  • CBOE was prejudiced by ISE’s failure to disclose it argument as to claim 56.  ISE’s doctrine of equivalents argument as to claim 56 was, therefore, struck.
  • ISE had sufficiently disclosed its commercial success arguments by disclosing its product and the nexus between the patent and the product.  ISE identified its argument as early as its initial discovery responses.