Judge Andrews recently issued a memorandum order denying plaintiff’s motion for partial summary judgment of no inequitable conduct. Bristol-Myers Squibb Co. v. Teva Pharmaceuticals USA, Inc., C.A. No. 10-805-RGA (D. Del. July 19, 2012). Defendant’s inequitable conduct defense was premised on the failure of the inventor of the patent-in-suit and two prosecuting attorneys to disclose to the PTO prior art relating to “the compound 2’-CDG.” Id. at 1. Judge Andrews explained the applicable law set forth by the Federal Circuit in Therasense, Inc. v. Becton, Dickinson & Co., 649 F.3d 1276, 1290-91 (Fed. Cir. 2011) (see write up at Patently-O) and noted that it “was intended to cut back on inequitable conduct as a defense.” Id. at 3. At the Summary Judgment stage, Judge Andrews stated that the only issue was “whether at least one of the three accused individuals knew the withheld information was material and made a deliberate decision to withhold it.” Id. Despite plaintiff’s evidence that the inventor and two attorneys did not make an intentional decision to withhold the prior art and did not consider the prior art material, Judge Andrews decided that summary judgment would be inappropriate because “the ‘materiality’ question [was] one on which two experts differ, and [he did] not know which one [he was] going to accept.” Id. at 4. Judge Andrews concluded by noting that “[i]t is often difficult to prove someone’s state of mind about something the person did yesterday. To prove by clear and convincing evidence that a person intended to deceive the PTO twenty years ago in the absence of any direct evidence that he did so, is about as difficult as climbing Mt. Everest. I cannot say, however, as a matter of law that it cannot be done.” Id.