G Model MIMM-4561; No. of Pages 12 ARTICLE IN PRESS Molecular Immunology xxx (2015) xxx–xxx Contents lists available at ScienceDirect Molecular Immunology j ournal homepage: www.elsevier.com/locate/molimm Review Alternative molecular formats and therapeutic applications for ଝ bispecific antibodies ∗ Christoph Spiess, Qianting Zhai, Paul J. Carter Department of Antibody Engineering, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA a r t i c l e i n f o a b s t r a c t Article history: Bispecific antibodies are on the cusp of coming of age as therapeutics more than half a century after they Received 28 November 2014 ® were first described. Two bispecific antibodies, catumaxomab (Removab , anti-EpCAM × anti-CD3) and Received in revised form ® blinatumomab (Blincyto , anti-CD19 × anti-CD3) are approved for therapy, and >30 additional bispecific 30 December 2014 antibodies are currently in clinical development. Many of these investigational bispecific antibody drugs Accepted 2 January 2015 are designed to retarget T cells to kill tumor cells, whereas most others are intended to interact with two Available online xxx different disease mediators such as cell surface receptors, soluble ligands and other proteins. The modular architecture of antibodies has been exploited to create more than 60 different bispecific antibody formats. Keywords: These formats vary in many ways including their molecular weight, number of antigen-binding sites, Bispecific antibodies spatial relationship between different binding sites, valency for each antigen, ability to support secondary Antibody engineering Antibody therapeutics immune functions and pharmacokinetic half-life. These diverse formats provide great opportunity to tailor the design of bispecific antibodies to match the proposed mechanisms of action and the intended clinical application. © 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). 1. Introduction first demonstrated more than 50 years ago (Nisonoff and Rivers, 1961). Engineering monospecific antibodies for bispecificity opens Antibodies are a well established and rapidly growing drug class up many new potential therapeutic applications as evidenced by with at least 45 antibody-based products currently marketed for >30 BsAb in clinical development (Table 1). Here we review the ∼ imaging or therapy in the USA and/or Europe with 63 billion USD rationale for making BsAb, criteria for selection of molecular format in total worldwide sales in 2013 (Ecker et al., 2014; Walsh, 2014) from a plethora of alternatives and potential therapeutic applica- (antibodysociety.org). This major clinical and commercial success tions. with antibody therapeutics has fueled much interest in develop- ing next generation antibody drugs including bispecific antibodies 2. Alternative formats for BsAb (Chan and Carter, 2010; Kontermann, 2012; Byrne et al., 2013). As their name implies, bispecific antibodies (BsAb) bind to two dif- The modular architecture of immunoglobulins has been ferent antigens, or two different epitopes on the same antigen, as exploited to create a growing number (>60) of alternative BsAb for- mats (Chan and Carter, 2010; Kontermann, 2012; Byrne et al., 2013; Jost and Plückthun, 2014). BsAb are classified here into five dis- tinct structural groups: (i) bispecific IgG (BsIgG) (ii) IgG appended Abbreviations: ADCC, antibody-dependent cellular cytotoxicity; ADCP, with an additional antigen-binding moiety (iii) BsAb fragments (iv) antibody-dependent cellular phagocytosis; ALL, acute lymphoblastic leukemia; AMD, age-related macular degeneration; AML, acute myeloid leukemia; BsAb, bispe- bispecific fusion proteins and (v) BsAb conjugates (Fig. 1). Each of cific antibody; BsIgG, bispecific IgG; CDC, complement-dependent cytotoxicity; CEA, these different BsAb formats brings different properties in bind- carcinoembryonic antigen; CLL, chronic lymphocytic leukemia; DAF, dual action ing valency for each antigen, geometry of antigen-binding sites, Fab; DART, dual-affinity retargeting; DLBCL, diffuse large B-cell lymphoma; FDA, pharmacokinetic half-life and in some cases effector functions. Food and Drug Administration; ImmTACs, immune-mobilizing monoclonal T cell receptors against cancer; MAPG, melanoma-associated proteoglycan; NHL, non- Hodgkin’s lymphoma. ଝ 2.1. Bispecific antibodies with IgG-like structure This article belongs to Special Issue on Therapeutic Antibodies. ∗ Corresponding author. Tel.: +1 650 467 4371. Bispecific IgG (BsIgG) is a commonly used BsAb format that E-mail addresses: [email protected] (C. Spiess), [email protected] (Q. Zhai), [email protected] (P.J. Carter). is monovalent for each antigen (1 + 1 antigen-binding valency). http://dx.doi.org/10.1016/j.molimm.2015.01.003 0161-5890/© 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Please cite this article in press as: Spiess, C., et al., Alternative molecular formats and therapeutic applications for bispecific antibodies. Mol. Immunol. (2015), http://dx.doi.org/10.1016/j.molimm.2015.01.003 MIMM-4561; 2 G Model Please Mol. Table 1 Bispecific antibodies and other bispecific immunotherapeutics in clinical development. Immunol. cite BsAb (other names, sponsoring organizations) BsAb format Targets Proposed mechanisms of action Development Diseases (or healthy volunteers) stages No. this ® of Catumaxomab (Removab , Fresenius Biotech, BsIgG: Triomab CD3, EpCAM Retargeting of T cells to tumor, Fc Approved in EU Malignant ascites in EpCAM positive (2015), article Pages Trion Pharma, Neopharm) mediated effector functions tumors Ertumaxomab (Neovii Biotech, Fresenius Biotech) BsIgG: Triomab CD3, HER2 Retargeting of T cells to tumor Phase I/II Advanced solid tumors 12 in ® http://dx.doi.org/10.1016/j.molimm.2015.01.003 Blinatumomab (Blincyto , AMG 103, MT 103, BiTE CD3, CD19 Retargeting of T cells to tumor Approved in USA Precursor B-cell ALL press MEDI 538, Amgen) Phase II and III ALL Phase II DLBCL Phase I NHL as: Solitomab (AMG 110, MT110, Amgen) BiTE CD3, EpCAM Retargeting of T cells to tumor Phase I Solid tumors Spiess, MEDI 565 (AMG 211, MedImmune, Amgen) BiTE CD3, CEA Retargeting of T cells to tumor Phase I Gastrointestinal adenocancinoma BAY2010112 (AMG 212, Bayer; Amgen) BiTE CD3, PSMA Retargeting of T cells to tumor Phase I Prostate cancer C., ARTICLE INPRESS ARTICLE et MGD006 (Macrogenics) DART CD3, CD123 Retargeting of T cells to tumor Phase I AML C. Spiess al., MGD007 (Macrogenics) DART CD3, gpA33 Retargeting of T cells to tumor Phase I Colorectal cancer Alternative et AFM11 (Affimed Therapeutics) TandAb CD3, CD19 Retargeting of T cells to tumor Phase I NHL and ALL al. AFM13 (Affimed Therapeutics) TandAb CD30, CD16A Retargeting of NK cells to tumor cells Phase II Hodgkin’s Lymphoma / Molecular GD2 (Barbara Ann Karmanos Cancer Institute) T cells preloaded with CD3, GD2 Retargeting of T cells to tumor Phase I/II Neuroblastoma and osteosarcoma BsAb molecular pGD2 (Barbara Ann Karmanos Cancer Institute) T cells preloaded with CD3, Her2 Retargeting of T cells to tumor Phase II Metastatic breast cancer Immunology BsAb EGFRBi-armed autologous activated T cells (Roger T cells preloaded with CD3, EGFR Autologous activated T cells to Phase I Lung and other solid tumors formats Williams Medical Center) BsAb EGFR-positive tumor xxx Anti-EGFR-armed activated T-cells (Barbara Ann T cells preloaded with CD3, EGFR Autologous activated T cells to Phase I Colon and pancreatic cancers (2015) Karmanos Cancer Institute) BsAb EGFR-positive tumor and rM28 (University Hospital Tübingen) Tandem scFv CD28, MAPG Retargeting of T cells to tumor Phase II Metastatic melanoma xxx–xxx therapeutic IMCgp100 (Immunocore) ImmTAC CD3, peptide MHC Retargeting of T cells to tumor Phase I/II Metastatic melanoma DT2219ARL (NCI, University of Minnesota) 2 scFv linked to CD19, CD22 Targeting of protein toxin to tumor Phase IBcell leukemia diphtheria toxin or lymphoma Duligotuzumab (MEHD7945A, Genentech, Roche) DAF EGFR, HER3 Blockade of 2 receptors, ADCC Phase I and II Head and neck cancer applications Phase II Colorectal cancer LY3164530 (Eli Lily) Not disclosed EGFR, MET Blockade of 2 receptors Phase I Advanced or metastatic cancer MM-111 (Merrimack Pharmaceuticals) HSA body HER2, HER3 Blockade of 2 receptors Phase II Gastric and esophageal cancers Phase I Breast cancer for MM-141, (Merrimack Pharmaceuticals) IgG-scFv IGF-1R, HER3 Blockade of 2 receptors Phase I Advanced solid tumors bispecific RG7221 (RO5520985, Roche) CrossMab Ang2, VEGF A Blockade of 2 proangiogenics Phase I Solid tumors RG7716 (Roche) CrossMab Ang2, VEGF A Blockade of 2 proangiogenics Phase I Wet AMD TF2 (Immunomedics) Dock and lock CEA, HSG Pretargeting tumor for PET or radioimaging Phase II Colorectal, breast and lung cancers antibodies. ABT-981 (AbbVie) DVD-Ig IL-1␣, IL-1␤ Blockade of 2 proinflammatory cytokines Phase II Osteoarthritis ABT-122 (AbbVie) DVD-Ig TNF, IL-17A Blockade of 2 proinflammatory cytokines Phase II Rheumatoid arthritis COVA322 IgG-fynomer TNF, IL17A Blockade of 2 proinflammatory cytokines Phase I/II Plaque psoriasis G Model MIMM-4561; No. of Pages 12 ARTICLE IN PRESS C. Spiess et al. / Molecular Immunology xxx (2015) xxx–xxx 3 Production of BsIgG by co-expression of the two light and two action heavy chains in a single host cell can be highly challenging because of the low yield of desired BsIgG and the difficulty in removing dual