Therapeutic Activity of Agonistic, Human Anti-CD40 Monoclonal Antibodies Requires Selective FcγR Engagement.
While engagement of the inhibitory Fcγ-receptor (FcγR) IIB is an absolute requirement for in vivo antitumor activity of agonistic mouse anti-CD40 monoclonal antibodies (mAbs), a similar requirement for human mAbs has been disputed. By using a mouse model humanized for its FcγRs and CD40, we revealed that FcγRIIB engagement is essential for the activity of human CD40 mAbs, while engagement of the activating FcγRIIA inhibits this activity. By engineering Fc variants with selective enhanced binding to FcγRIIB, but not to FcγRIIA, significantly improved antitumor immunity was observed. These findings highlight the necessity of optimizing the Fc domain for this class of therapeutic antibodies by using appropriate preclinical models that accurately reflect the unique affinities and cellular expression of human FcγR.
Laboratory of Molecular Genetics and Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10021-6399, USA.
Rony
R
Dahan
Bristol-Myers Squibb, Biologics Discovery California, 700 Bay Road, Redwood City, CA 94063, USA.
Bryan C
BC
Barnhart
Laboratory of Molecular Genetics and Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10021-6399, USA.
Fubin
F
Li
Bristol-Myers Squibb, Department of Molecular Discovery Technologies, Princeton, NJ 08543, USA.
Aaron P
AP
Yamniuk
Bristol-Myers Squibb, Biologics Discovery California, 700 Bay Road, Redwood City, CA 94063, USA.
Alan J
AJ
Korman
Laboratory of Molecular Genetics and Immunology, The Rockefeller University, 1230 York Avenue, New York, NY 10021-6399, USA. Electronic address: ravetch@rockefeller.edu.
Jeffrey V
JV
Ravetch
D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000276:immunology; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage* / Q000276:immunology; D019013:CD40 Antigens / Q000819:agonists*; D045744:Cell Line, Tumor; D006801:Humans; D007167:Immunotherapy; D051379:Mice; D009369:Neoplasms / Q000188:drug therapy* / Q000276:immunology; D017452:Receptors, IgG / Q000276:immunology*; D023041:Xenograft Model Antitumor Assays
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D019013:CD40 Antigens; C080568:Fc gamma receptor IIA; C080571:Fc gamma receptor IIB; D017452:Receptors, IgG