Joost J. Neijssen

Efficient generation of stable bispecific IgG1 by controlled Fab-arm exchange

The promise of bispecific antibodies (bsAbs) to yield more effective therapeutics is well recognized; however, the generation of bsAbs in a practical and cost-effective manner has been a formidable challenge. Here we present a technology for the efficient generation of bsAbs with normal IgG structures that is amenable to both antibody drug discovery and development. The process involves separate expression of two parental antibodies, each containing single matched point mutations in the CH3 domains. The parental antibodies are mixed and subjected to controlled reducing conditions in vitro that separate the antibodies into HL half-molecules and allow reassembly and reoxidation to form highly pure bsAbs. The technology is compatible with standard large-scale antibody manufacturing and ensures bsAbs with Fc-mediated effector functions and in vivo stability typical of IgG1 antibodies. Proof-of-concept studies with HER2×CD3 (T-cell recruitment) and HER2×HER2 (dual epitope targeting) bsAbs demonstrate superior in vivo activity compared with parental antibody pairs.

Species-Specific Determinants in the IgG CH3 Domain Enable Fab-Arm Exchange by Affecting the Noncovalent CH3–CH3 Interaction Strength

A distinctive feature of human IgG4 is its ability to recombine half molecules (H chain and attached L chain) through a dynamic process termed Fab-arm exchange, which results in bispecific Abs. It is becoming evident that the process of Fab-arm exchange is conserved in several mammalian species, and thereby represents a mechanism that impacts humoral immunity more generally than previously thought. In humans, Fab-arm exchange has been attributed to the IgG4 core-hinge sequence (226-CPSCP-230) in combination with unknown determinants in the third constant H chain domain (CH3). In this study, we investigated the role of the CH3 domain in the mechanism of Fab-arm exchange, and thus identified amino acid position 409 as the critical CH3 determinant in human IgG, with R409 resulting in exchange and K409 resulting in stable IgG. Interestingly, studies with IgG from various species showed that Fab-arm exchange could not be assigned to a common CH3 domain amino acid motif. Accordingly, in rhesus monkeys (Macaca mulatta), aa 405 was identified as the CH3 determinant responsible (in combination with 226-CPACP-230). Using native mass spectrometry, we demonstrated that the ability to exchange Fab-arms correlated with the CH3–CH3 dissociation constant. Species-specific adaptations in the CH3 domain thus enable Fab-arm exchange by affecting the inter-CH3 domain interaction strength. The redistribution of Ag-binding domains between molecules may constitute a general immunological and evolutionary advantage. The current insights impact our view of humoral immunity and should furthermore be considered in the design and evaluation of Ab-based studies and therapeutics.

A Novel Bispecific Antibody Targeting EGFR and cMet Is Effective against EGFR Inhibitor–Resistant Lung Tumors

Non-small cell lung cancers (NSCLC) with activating EGFR mutations become resistant to tyrosine kinase inhibitors (TKI), often through second-site mutations in EGFR (T790M) and/or activation of the cMet pathway. We engineered a bispecific EGFR-cMet antibody (JNJ-61186372) with multiple mechanisms of action to inhibit primary/secondary EGFR mutations and the cMet pathway. JNJ-61186372 blocked ligand-induced phosphorylation of EGFR and cMet and inhibited phospho-ERK and phospho-AKT more potently than the combination of single receptor-binding antibodies. In NSCLC tumor models driven by EGFR and/or cMet, JNJ-61186372 treatment resulted in tumor regression through inhibition of signaling/receptor downmodulation and Fc-driven effector interactions. Complete and durable regression of human lung xenograft tumors was observed with the combination of JNJ-61186372 and a third-generation EGFR TKI. Interestingly, treatment of cynomolgus monkeys with JNJ-61186372 resulted in no major toxicities, including absence of skin rash observed with other EGFR-directed agents. These results highlight the differentiated potential of JNJ-61186372 to inhibit the spectrum of mutations driving EGFR TKI resistance in NSCLC. Cancer Res; 76(13); 3942-53. ©2016 AACR.

Abstract B241: Bispecific antibody targeting EGFR and cMet demonstrates superior activity compared to the combination of single pathway inhibitors.

Many tumors respond initially to targeted therapy, only to develop resistance over time thereby allowing the tumors to progress. In patients treated with EGFR small molecule inhibitors, the cMet pathway is often upregulated, either through MET gene amplification or an increase in the ligand HGF, to compensate and provide resistance to the EGFR monotherapy. Because both EGFR and cMet signal through some of the same survival and growth-promoting pathways, dual inhibition of these receptors may improve efficacy and prevent resistance through these mechanisms. We have designed a bispecific EGFR-cMet antibody (EM1-mAb) with multiple mechanisms of action resulting in superior activity compared to a combination of single EGFR and cMet inhibitors. Fab arm exchange was used to produce EM1-mAb, a technique that allows for efficient large-scale preparation of bispecific antibodies. EM1-mAb prevented binding of the ligands EGF and HGF to their respective receptors, EGFR (IC50 = 10 nM) and cMet (IC50 = 30 nM). Ligand-induced phosphorylation of each receptor was inhibited in cell-based assays. Blocking signaling from both EGFR and cMet with a combination of single monospecific antibodies resulted in an enhanced inhibition of pERK, a downstream effector of both receptors. The bispecific EM1-mAb further increased the potency of inhibition of pERK (55-65-fold) compared to the combination of single monospecific antibodies, suggesting an avidity effect on downstream signaling. EM1-mAb was evaluated in SCID-beige mice implanted with tumor cells engineered to express human HGF. Complete regression of 8/8 tumors was observed upon treatment with EM1-mAb dosed twice a week at 20 mg/kg. After the dosing period of four weeks, mice were monitored for an additional 10 weeks and no tumor regrowth was observed. Our data demonstrate that the bispecific antibody EM1-mAb, generated using Fab arm exchange, inhibited EGFR and cMet pathways simultaneously, resulting in superior activity in cellular downstream signaling compared to the combination of single pathway inhibitors. These attributes allow for a more efficient path toward clinical development. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B241. Citation Format: Sheri Moores, Mark Chiu, Barbara Bushey, Kristen Chevalier, Diana Chin, Susan Chippari, Peter Haytko, Frank McCabe, Joost Neijssen, Paul Parren, Janine Schuurman, Sam Wu, Ricardo Attar, Mark Anderson. Bispecific antibody targeting EGFR and cMet demonstrates superior activity compared to the combination of single pathway inhibitors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B241.

Abstract A11: Activity of a bispecific antibody targeting EGFR and cMet with enhanced Fc effector function in EGFR mutant setting with cMet pathway activation

Non-small cell lung cancers (NSCLCs) with activating mutations in the Epidermal Growth Factor Receptor (EGFR) gene are associated with high response rates (70-80%) to EGFR tyrosine kinase inhibitors (TKIs), such as erlotinib and gefitinib, but most acquire resistance over time through numerous mechanisms. In these patients, the cMet pathway is often activated to compensate and provide resistance to the EGFR targeted monotherapy; this activation can occur by MET gene amplification, overexpression of cMet protein, or an increase in the ligand HGF. We have designed a bispecific EGFR-cMet antibody (JNJ-61186372) with multiple mechanisms of action resulting in anti-tumor activity in the EGFR mutant setting, with or without cMet pathway activation. Controlled Fab-arm exchange was used to produce JNJ-61186372, a technique that allows for efficient large-scale preparation of bispecific antibodies with a regular IgG 1 structure. JNJ-61186372 was shown to bind EGFR and cMet and efficiently inhibited ligand-induced phosphorylation of both receptors. In addition to this important mechanism of action, we have engineered the antibody to contain lower than normal fucose levels to increase Fc-dependent effector mechanisms. JNJ-61186372 exhibited antibody dependent cellular cytotoxicity (ADCC) activity in vitro in a range of NSCLC cell lines with EGFR mutations, KRas mutation, and/or amplified MET gene. Furthermore, the low fucose form of JNJ-61186372 demonstrated more effective ADCC activity compared to its normal fucose counterpart. The bispecific JNJ-61186372 antibody showed increased potency (2-3 fold) compared to the combination of monovalent EGFR and monovalent cMet antibodies, demonstrating the beneficial effects of dual targeting in a single molecule. Antibody dependent cell-mediated phagocytosis (ADCP) activity of JNJ-61186372 was also confirmed in vitro. We have also demonstrated that Fc-dependent effector functions contributed to in vivo anti-tumor growth activity of JNJ-61186372, in a xenograft model with EGFR mutations and cMet activation. Our data demonstrate that the bispecific antibody JNJ-61186372, generated using controlled Fab-arm exchange, has in vitro ADCC and ADCP activity in EGFR mutant settings, either with or without cMet pathway activation, and with KRas mutation. In addition, the Fc-dependent effector mechanisms contributed to in vivo anti-tumor efficacy. The dual signaling inhibition of EGFR and cMet pathways by JNJ-61186372, combined with enhanced Fc effector function, may provide multiple mechanisms to combat resistance in EGFR mutant NSCLC patients. Citation Format: Keri L. Soring, Katharine D. Grugan, Randall J. Breszki, Jose Pardinas, Leopoldo Luistro, Barbara Bushey, Joost Neijssen, Paul Parren, Janine Schuurman, Mark Anderson, Ricardo Attar, Matthew V. Lorenzi, Mark Chiu, Sheri Moores. Activity of a bispecific antibody targeting EGFR and cMet with enhanced Fc effector function in EGFR mutant setting with cMet pathway activation. [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy: A New Chapter; December 1-4, 2014; Orlando, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2015;3(10 Suppl):Abstract nr A11.

Abstract DDT01-03: Discovery and preclinical pharmacology of JNJ-61186372: A novel bispecific antibody targeting EGFR and cMET

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CAnnNSCLC with activating mutations in the EGFR gene are associated with high response rates to EGFR tyrosine kinase inhibitors (TKIs), such as erlotinib and gefitinib, but invariably acquired resistance emerges over time. A primary cause of resistance is the emergence of secondary mutations in EGFR which neutralize the effectiveness of TKIs. In addition, the cMet pathway is often activated, either through MET gene amplification, overexpression of cMet protein, or an increase in the ligand HGF, to provide a compensatory survival pathway conferring resistance to EGFR TKIs.nnWe have designed a bispecific EGFR-cMet antibody (JNJ-61186372) with a unique set of mechanisms of action resulting in anti-tumor activity in the EGFR mutant setting, with or without cMet pathway activation. We have demonstrated three mechanisms of action that contribute to the activity of JNJ-61186372: 1) inhibition of ligand-induced phosphorylation of both EGFR and cMet, 2) receptor degradation in vivo, and 3) enhanced ADCC activity.nnJNJ-61186372 inhibited EGF-induced phosphorylation of EGFR in cell lines with either wild-type (WT) EGFR or activating mutations in EGFR. In the same cell lines, JNJ-61186372 inhibited HGF-induced phosphorylation of cMet. JNJ-61186372 also blocked pERK and pAkt with similar IC50 values in EGFR-WT and EGFR mutant cell lines, indicating that downstream signaling pathways were inhibited. Total protein levels of both EGFR and cMet were decreased in xenograft tumor models following treatment with JNJ-61186372 compared to tumors from mice treated with PBS control suggesting that one mechanism by which JNJ-61186372 suppresses EGFR and cMet activity in vivo is through degradation of both receptors. The third mechanism of action is directing immune cells to kill tumor cells. JNJ-61186372 is produced with low levels of fucosylation, which translates to an enhanced antibody-dependent cellular cytotoxicity (ADCC).nnThese three mechanisms of action of JNJ-61186372 provide a distinct preclinical profile for targeting both EGFR and cMET in a single bispecific antibody. JNJ-61186372 demonstrated efficacy in multiple in vivo tumor models with EGFR mutations, including both cell line and patient-derived xenografts. Importantly, JNJ-61186372 effectively inhibited tumor growth in models with mutant EGFR and cMet activation, whereas single agent EGFR inhibitors were less effective. The preclinical data support the clinical development of JNJ-61186372 in patients with lung cancer and other malignancies associated with aberrant EGFR and cMET signaling.nnCitation Format: Sheri L. Moores, Mark Chiu, Barbara Bushey, Kristen Chevalier, Peter Haytko, Joost Neijssen, Paul Parren, Janine Schuurman, Mark Anderson, Ricardo Attar, Robert Kramer, Matthew V. Lorenzi. Discovery and preclinical pharmacology of JNJ-61186372: A novel bispecific antibody targeting EGFR and cMET. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr DDT01-03. doi:10.1158/1538-7445.AM2014-DDT01-03