In UCB, Inc. v. Yeda Research and Development Co., the Federal Circuit affirmed the determination by the District Court for the Eastern District of Virginia that UCB, Inc.’s Cimzia® (certolizumab pegol), a biologic medicine that treats inflammatory conditions such as rheumatoid arthritis and Crohn’s disease, does not infringe a monoclonal antibody patent owned by Yeda Research and Development Co., Ltd.. (Fed. Cir. Appeal No. 2015-1957, September 8, 2016). UCB sued Yeda requesting a declaration that Cimzia did not infringe Yeda’s patent. Yeda counterclaimed for infringement.

Cimzia is a recombinant, humanized antibody fragment that is conjugated to polyethylene glycol (PEG). Cimzia blocks tumor necrosis factor alpha, a protein that participates in inflammatory processes. It is approved for the treatment of rheumatoid arthritis, psoriatic arthritis, active ankylosing spondylitis, and Crohn’s disease.

Yeda’s patent included claims to a “monoclonal antibody” with certain characteristics. Claim 1, which is representative, did not mention any particular antibody and it was not amended or narrowed during prosecution. The specification only described murine (mouse) monoclonal antibodies although humanized and chimeric antibodies were also known at the relevant time. During prosecution, Yeda submitted claims to “rat, hamster and human antibodies and chimeras thereof.” The PTO “rejected the proposed claims on the ground of new matter not supported in the specification” and Yeda withdrew the proposed specific claims in order to obtain allowance of its patent. Claim 1, which generally referred to a “monoclonal antibody,” was not rejected on this ground.

The district court construed “monoclonal antibody” to exclude “chimeric and humanized antibodies” and then granted summary judgment of noninfringement on the basis of its claim construction. The Federal Circuit affirmed, agreeing “that the prosecution history requires this construction, for the scope now sought by Yeda was requested of the [PTO], and refused on the ground of new matter.”

Yeda argued that “monoclonal antibody” was understood to have broader meaning than a murine monoclonal antibody and that the term should not be limited to examples in the specification. It noted that every embodiment did not need to be specifically described to be within the scope of a generic term and that “generic terms in claims are construed in light of that which is already known.” Yeda also argued that without a narrowing amendment to the proposed claim that issued as claim 1, “there can be no prosecution estoppel to the scope of claim 1, merely because some proposed different claims were rejected by the [PTO] and then dropped by the applicant.”

The Federal Circuit rejected Yeda’s arguments. It held that although claim 1 had not been amended, “the general rule is that a patent applicant cannot later obtain scope that was requested during prosecution, rejected by the [PTO], and then withdrawn by the applicant.” On that basis, it agreed with the district court that Yeda could not “obtain a claim construction that recovers claim scope that was yielded in order to obtain issuance of the patent” and held that Yeda was “estopped from including chimeric and humanized antibodies within the scope of the monoclonal antibodies claimed in the [Yeda] patent.” The decision illustrates that an applicant’s actions with respect to narrower claims can impact the meaning of a generic term in a different claim that would otherwise encompass them.