The court also rejected defendant’s argument that Cimzia® infringes under the doctrine of equivalents (DOE) because a humanized antibody is equivalent to an antibody made via hybridoma. In rejecting that argument, the court noted that during prosecution the defendant cancelled claims directed to humanized or chimeric antibodies and, therefore, were estopped from trying to recapture that subject matter. The court explained that “[w]hen the USPTO rejected [defendant’s] efforts to claim chimeric and humanized antibodies and [defendant] acquiesced to those rejections, [defendant’s] competitors and interested members of the public were entitled to rely on [defendant’s] actions. Having conceded the correctness of the rejections made by the USPTO, [defendant] cannot now complain that it is estopped from recapturing that subject matter as an equivalent.”
UCB, Inc. v. Yeda Research and Development Co. Ltd., 114cv01038, E.D. Va. (Brinkema).