Therasense, Inc. v. Becton, Dickinson and Co

Facts

Therasense, Inc.’s (Plaintiff) and its corporate parent, Abbott (Plaintiff), held several patents, including the ‘551 patent, for disposable blood glucose test strips for diabetes management.  Becton, Dickinson and Co. (Becton) (Defendant), a competitor, sued for a declaratory judgment that the patents were invalid.  Therasense (Plaintiff) and Abbott (Plaintiff) sued for a declaratory judgment that the patents were invalid.  Plaintiffs countersued for patent infringement.  The cases were consolidated, and the district court held that all of the litigated patent claims were either invalid or not infringed.  The court also ruled that the ‘551 patent was unenforceable because of Abbott’s (Plaintiff) inequitable conduct.  Specifically, the ‘551 patent claimed a test strip with an electrochemical sensor for testing whole blood without a membrane over the electrode.  For more than thirteen years after Abbott (Plaintiff) filed the original application leading to the ‘551 patent, that original application saw multiple rejections for anticipation and obviousness.  Some of the rejections related to there being a protective membrane over the sensor.  Then, Abbott’s (Plaintiff) patent attorney, Pope, and its director of research and marketing, Sanghera, presented new claims to the examiner based on a new sensor that did not require a protective membrane for whole blood.  Pope asserted that this distinction would overcome the prior art found in another Abbott (Plaintiff) patent (the ‘382 patent).  They submitted an affidavit supporting this assertion, showing that the prior art required a membrane for whole blood at the time of the invention.  However, several years earlier, while prosecuting the European counterpart to the ‘382 patent, Plaintiff made representations to the European Patent Office (EPO) that disclosed sensors in which a protective membrane was optional in all cases except the case of live blood (as distinguished from whole blood), in which case the protective membrane was preferred—but not required.  Abbott (Plaintiff) failed to disclose the briefs it had filed with the EPO to the U.S. Patent and Trademark Office (PTO) when it presented new claims for the ‘551 patent.  Accordingly, the district court found that this failure constituted inequitable conduct.  The court of appeals affirmed all of the district court’s rulings.  However, the court of appeals panel was divided on the inequitable conduct issue.  Plaintiffs petitioned for an en banc rehearing.  The court of appeals granted the petition.