Biogen Idec Inc. v. Glaxosmithkline LLC

Prosecution History Disclaimer Can Arise from an Applicant’s Silence in Response to Statements by the Examiner

12-1120

April 16, 2013

Decision

Last Month at the Federal Circuit - May 2013

Judges: Dyk, Plager (dissenting), Reyna (author)

[Appealed from: S.D. Cal., Judge Benitez]

In Biogen Idec, Inc. v. GlaxoSmithKline LLC, No. 12-1120 (Fed. Cir. Apr. 16, 2013), the Federal Circuit affirmed the district court’s claim construction of the claim term “anti-CD20 antibody” in U.S. Patent No. 7,682,612 (“the ’612 patent”), which narrowed the term based on prosecution history disclaimer.

Biogen Idec, Inc. and Genentech, Inc. (collectively “Biogen”) obtained the ’612 patent directed to methods for treating patients with Chronic Lymphocytic Leukemia (CLL) involving administering a therapeutically effective amount of an anti-CD20 antibody. The ’612 patent was not limited to any particular type of anti-CD20 antibody, but stated that a particularly preferred chimeric anti-CD20 antibody is Rituxan® (rituximab) and incorporated by reference U.S. Patent No. 5,736,137 (“the ’137 patent”). The ’137 patent defines an “anti-CD20 antibody” as used therein as “an antibody which specifically recognizes a cell surface . . . typically designated as the human B lymphocyte restricted differentiation antigen Bp35, commonly referred to as CD20.” Slip op. at 4 (alteration in original) (citation omitted).

During prosecution of the ’612 patent, the examiner rejected all the claims for not providing enablement for “any and all anti-CD20 antibodies, no matter the specificity or affinity for the specific epitope on the circulating tumor cells.” Id. at 5 (citation omitted). The examiner acknowledged that the specification was enabling for Rituxan®, but that it was “silent concerning what sort of specificity and affinity would be necessary” for other anti-CD20 antibodies. Id. (citation omitted). In response, Biogen stated that “one of skill in the art could readily identify an antibody that binds to CD20 with similar affinity and specificity as does RITUXAN®.” Id. (citation omitted). The examiner withdrew the enablement rejection and the claims issued.

GlaxoSmithKline LLC and Glaxo Group Ltd. (collectively “GSK”) developed the anti-CD20 antibody Arzerra® (ofatumumab), which is distinctly different from Rituxan® in several respects. Arzerra® is a full human antibody that binds to a different epitope than Rituxan® and has a much greater affinity for the CD20 antigen than Rituxan®. Biogen sued GSK for infringement of the ’612 patent, and GSK counterclaimed, alleging noninfringement, invalidity, and unenforceability of the asserted claims. At a Markman hearing, the district court adopted GSK’s construction of the term “anti-CD20 antibody” as “rituximab and antibodies that bind to the same epitope of the CD20 antigen with similar affinity and specificity as rituximab,” reasoning that prosecution history disclaimer applied because Biogen limited the term to overcome the enablement rejection. Id. at 7 (citation omitted). Biogen stipulated to noninfringement based on this construction and then appealed.

On appeal, the Federal Circuit considered whether statements in the prosecution history were sufficient to overcome the “heavy presumption” that the term carries its full ordinary and customary meaning advanced by Biogen, so as to limit the term “anti-CD20 antibody” in the ’612 patent to those antibodies having similar specificity and affinity for the specific epitope to which Rituxan® binds. The Federal Circuit concluded that they were.

The Court reasoned that in response to an enablement rejection, “rather than challenging the examiner’s understanding of the crucial terms, the applicants argued that the specification was enabling for anti-CD20 antibodies with similar affinity and specificity as Rituxan®.” Id. at 10. “[I]t is clear that [the applicants] were limiting their invention to what the examiner believed they enabled: antibodies that have a similar specificity and affinity for the specific epitope to which Rituxan® binds.” Id.

The Court rejected Biogen’s argument that because it never explicitly referred to any particular “epitope” and because CD20 was only thought to have one epitope at the time of filing, the applicants were merely referring to specificity and affinity in the general sense. The Court reasoned that, read in context, the full prosecution history did not support Biogen’s position, as Biogen adopted the examiner’s characterization of the antibodies when they limited their claims to antibodies similar to Rituxan®. “While disavowing statements must be ‘so clear as to show reasonable clarity and deliberateness,’ this requirement does not require the applicant to parrot back language used by the examiner when clearly and deliberately responding to a particular ground[] for rejection.” Id. at 11 (quoting Omega Eng’g, Inc. v. Raytek Corp., 334 F.3d 1314, 1325 (Fed. Cir. 2003)). “If an applicant chooses, she can challenge an examiner’s characterization in order to avoid any chance for disclaimer, but the applicants in this case did not directly challenge the examiner’s characterization.” Id. (citing TorPharm Inc. v. Ranbaxy Pharm., Inc., 336 F.3d 1322, 1330 (Fed. Cir. 2003)).

The Court also found unpersuasive Biogen’s two arguments for why the claim term’s full plain and ordinary meaning should control. First, the Court rejected Biogen’s claim differentiation argument, stating that, where found, prosecution history can overcome the presumption of claim differentiation. Second, the Court rejected Biogen’s argument that the definition in the ’137 patent, which was incorporated by reference, should control. The Court reasoned that the ’137 patent expressly and uniquely defined the term for use within the ’137 patent, and that the definition thus did not necessarily reflect how a person of ordinary skill in the art would understand the term in the context of the ’612 patent. The Court concluded there was no basis for reversing the district court’s claim construction, and affirmed that the term “anti-CD20 antibody” was limited by prosecution history disclaimer.

Judge Plager dissented, stating he did not “find anywhere in the majority opinion or in the prosecution history that clear and unmistakable evidence of a disclaimer as required by our precedents.” Plager Dissent at 1. Judge Plager opined that “an applicant’s silence regarding statements made by the examiner during prosecution cannot amount to a clear and unmistakable disavowal of claim scope.” Id. at 5 (citing Sorensen v. Int’l Trade Comm’n, 427 F.3d 1375, 1379 (Fed. Cir. 2005); Salazar v. Procter & Gamble Co., 414 F.3d 1342, 1345 (Fed. Cir. 2005)). Judge Plager also disagreed with the majority’s treatment of the ’137 patent, stating that “even assuming that the applicants of the ’137 patent were acting as their own lexicographer when broadly defining the term ‘anti-CD20 antibody,’ the ’612 patent then incorporated this ‘special definition’ into its own disclosure.” Id. at 7.

Summary authored by Ian Y. Liu, Esq.