Design of a Trispecific Checkpoint Inhibitor and Natural Killer Cell Engager Based on a 2 + 1 Common Light Chain Antibody Architecture

• Published in: Frontiers in immunology Vol. 12; p. 669496
• Main Authors: Bogen, Jan P, Carrara, Stefania C, Fiebig, David, Grzeschik, Julius, Hock, Björn, Kolmar, Harald
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 10.05.2021
• Subjects: Animals; Antibodies, Bispecific - immunology; Antibodies, Bispecific - pharmacology; Antibodies, Monoclonal, Humanized - immunology; Antibodies, Monoclonal, Humanized - pharmacology; Antibody Specificity; B7-H1 Antigen - antagonists & inhibitors; B7-H1 Antigen - immunology; B7-H1 Antigen - metabolism; bispecific antibody; Cell Line, Tumor; checkpoint inhibitor; Chickens; common light chain; Cytotoxicity, Immunologic - drug effects; Drug Design; Epitopes; ErbB Receptors - antagonists & inhibitors; ErbB Receptors - immunology; ErbB Receptors - metabolism; Immune Checkpoint Inhibitors - immunology; Immune Checkpoint Inhibitors - pharmacology; Immunization; Immunoglobulin Light Chains - immunology; Immunoglobulin Light Chains - pharmacology; Immunology; Killer Cells, Natural - drug effects; Killer Cells, Natural - immunology; Killer Cells, Natural - metabolism; NK cell engager; Receptors, IgG - antagonists & inhibitors; Receptors, IgG - immunology; Receptors, IgG - metabolism; Skin Neoplasms - drug therapy; Skin Neoplasms - immunology; Skin Neoplasms - metabolism; Skin Neoplasms - pathology; trispecific antibody; NK cell engager; bispecific antibody; trispecific antibody; common light chain; checkpoint inhibitor
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2021.669496

Natural killer cell engagers gained enormous interest in recent years due to their potent anti-tumor activity and favorable safety profile. Simultaneously, chicken-derived antibodies entered clinical studies paving the way for avian-derived therapeutics. In this study, we describe the affinity maturation of a common light chain (cLC)-based, chicken-derived antibody targeting EGFR, followed by utilization of the same light chain for the isolation of CD16a- and PD-L1-specific monoclonal antibodies. The resulting binders target their respective antigen with single-digit nanomolar affinity while blocking the ligand binding of all three respective receptors. Following library-based humanization, bispecific and trispecific variants in a standard 1 + 1 or a 2 + 1 common light chain format were generated, simultaneously targeting EGFR, CD16a, and PD-L1. The trispecific antibody mediated an elevated antibody-dependent cellular cytotoxicity (ADCC) in comparison to the EGFR×CD16a bispecific variant by effectively bridging EGFR/PD-L1 double-positive cancer cells with CD16a-positive effector cells. These findings represent, to our knowledge, the first detailed report on the generation of a trispecific 2 + 1 antibodies exhibiting a common light chain and illustrate synergistic effects of trispecific antigen binding. Overall, this generic procedure paves the way for the engineering of tri- and oligospecific therapeutic antibodies derived from avian immunizations.