Baxalta Inc. v. Genentech, Inc., 972 F.3d 1341

Baxalta sued Genentech (and initially Chugai) for infringement of claims 1, 4, 17, and 19 of U.S. Patent No. 7,033,590 based on Genentech’s Hemlibra® product.
The asserted claims cover an "isolated antibody or antibody fragment" that binds Factor IX/IXa and increases FIXa procoagulant activity; dependent claims expressly recite embodiments such as bispecific, chimeric, and humanized antibodies and IgG/IgM/IgA/IgE.
The district court construed "antibody" narrowly (as an immunoglobulin that binds only the inducing antigen and consists of two identical heavy and two identical light chains) and construed "antibody fragment" to require partial/complete lack of the constant region and to exclude bispecific antibodies.
Relying on those constructions and a prosecution amendment (substituting "antibody fragment" for "antibody derivative"), the parties stipulated to non-infringement and the district court entered judgment.
On appeal the Federal Circuit held the district court erred: the district court’s constructions conflicted with the claim language, dependent claims, and the specification; prosecution history did not clearly disclaim the broader scope.
The Federal Circuit vacated and remanded, adopting broader constructions for both "antibody" and "antibody fragment."

Issue	Plaintiff's Argument (Baxalta)	Defendant's Argument (Genentech)	Held
Construction of "antibody"	Should mean an immunoglobulin with two heavy chains and two light chains (broad); claims and spec support bispecific/chimeric/humanized embodiments.	Should be limited to immunoglobulins that bind only the inducing antigen (narrow) and consist of two identical H and two identical L chains.	The term is not limited to Genentech's narrow definition; construed as "an immunoglobulin molecule having a specific amino acid sequence comprising two heavy chains (H chains) and two light chains (L chains)."
Construction of "antibody fragment"	Should mean a portion of an immunoglobulin (consistent with claims/spec) and not be limited to fragments lacking constant regions.	Should be limited to fragments that partially/completely lack the constant region and exclude bispecific antibodies.	The district court erred; "antibody fragment" construed as "a portion of an immunoglobulin molecule having a specific amino acid sequence comprising two heavy chains (H chains) and two light chains (L chains)."

Allergan Sales, LLC v. Sandoz, Inc., 935 F.3d 1370 (Fed. Cir. 2019) (review of claim construction where intrinsic evidence controls)
Teva Pharm. USA, Inc. v. Sandoz, Inc., 574 U.S. 318 (U.S. 2015) (deference to subsidiary fact findings from extrinsic evidence when necessary)
Thorner v. Sony Comput. Entm’t Am. LLC, 669 F.3d 1362 (Fed. Cir. 2012) (claims given ordinary meaning to a person of skill in the art)
Intellectual Ventures I LLC v. T-Mobile USA, Inc., 902 F.3d 1372 (Fed. Cir. 2018) (rejecting constructions that render dependent claims meaningless)
Ortho-McNeil Pharm., Inc. v. Mylan Labs., Inc., 520 F.3d 1358 (Fed. Cir. 2008) (same principle on dependent claims)
Budde v. Harley-Davidson, Inc., 250 F.3d 1369 (Fed. Cir. 2001) (read the specification as a whole to preserve internal consistency)
Luminara Worldwide, LLC v. Liown Elecs. Co., 814 F.3d 1343 (Fed. Cir. 2016) (specification language indicative of definitional intent must be clear)
Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) (en banc) (claim construction principles; primacy of intrinsic evidence)
Avid Tech., Inc. v. Harmonic, Inc., 812 F.3d 1040 (Fed. Cir. 2016) (prosecution disclaimer requires clear and unmistakable disavowal)
3M Innovative Properties Co. v. Tredegar Corp., 725 F.3d 1315 (Fed. Cir. 2013) (same on prosecution disclaimer standard)