Therasense, Inc. v. Becton, Dickinson and Co.

Abbott Laboratories, which came to include Therasense, Inc. (collectively, Abbott) (defendant) held patents for disposable diabetes-test strips. The’551 patent covered a strip for testing whole blood without the use of a protective membrane on the sensor. Another Abbott patent, the ’382 patent, covered a similar test strip and stated that the use of a protective membrane was preferable but optional. The U.S. Patent and Trademark Office (PTO) originally rejected the application for the ’551 patent for anticipation, determining that every element of the claimed invention existed in prior art. To overcome that hurdle, Abbott submitted declarations to the PTO stating that a person skilled in the art would not read the ’382 patent to mean that use of a protective membrane was truly optional if testing whole blood, and the ’551 patent therefore covered a new invention. Abbott did not disclose to the PTO that years earlier, when obtaining the European counterpart to the ’382 patent, Abbott provided briefs to the European Patent Office (EPO) stating that the use of a protective membrane was unequivocally optional. After the PTO issued the ’551 patent, Becton, Dickinson and Co. (Becton) (plaintiff) sued Abbott, challenging the validity of certain patents. Abbott counterclaimed, alleging that Becton infringed the ’551 patent. Regarding that claim, the district court deemed the ’551 patent unenforceable for inequitable conduct because of Abbott’s failure to disclose the EPO briefs to the PTO. The court of appeals originally affirmed but then granted rehearing en banc.