XGFR*, a novel affinity-matured bispecific antibody targeting IGF-1R and EGFR with combined signaling inhibition and enhanced immune activation for the treatment of pancreatic cancer

Abstract

The epidermal growth factor receptor (EGFR) and the insulin-like growth factor-1 receptor (IGF-1R) play critical roles in tumor growth, providing a strong rationale for the combined inhibition of IGF-1R and EGFR signaling in cancer therapy. We describe the design, affinity maturation, in vitro and in vivo characterization of the bispecific anti-IGF-1R/EGFR antibody XGFR*. XGFR* is based on the bispecific IgG antibody XGFR, which enabled heterodimerization of an IGF-1R binding scFab heavy chain with an EGFR-binding light and heavy chain by the “knobs-into-holes” technology. XGFR* is optimized for monovalent binding of human EGFR and IGF-1R with increased binding affinity for IGF-1R due to affinity maturation and highly improved protein stability to oxidative and thermal stress. It bears an afucosylated Fc-portion for optimal induction of antibody-dependent cell-mediated cytotoxicity (ADCC). Stable Chinese hamster ovary cell clones with production yields of 2–3 g/L were generated, allowing for large scale production of the bispecific antibody. XGFR* potently inhibits EGFR- and IGF-1R-dependent receptor phosphorylation, reduces tumor cell proliferation in cells with heterogeneous levels of IGF-1R and EGFR receptor expression and induces strong ADCC in vitro. A comparison of pancreatic and colorectal cancer lines demonstrated superior responsiveness to XGFR*-mediated signaling and tumor growth inhibition in pancreatic cancers that frequently show a high degree of IGF-1R/EGFR co-expression. XGFR* showed potent anti-tumoral efficacy in the orthotopic MiaPaCa-2 pancreatic xenograft model, resulting in nearly complete tumor growth inhibition with significant number of tumor remissions. In summary, the bispecific anti-IGF-1R/EGFR antibody XGFR* combines potent signaling and tumor growth inhibition with enhanced ADCC induction and represents a clinical development candidate for the treatment of pancreatic cancer.

The “less-is-more” in therapeutic antibodies: Afucosylated anti-cancer antibodies with enhanced antibody-dependent cellular cytotoxicity

“… 110 Bispecific antibody with EGFR (GA201) and IGF-1R (R1507) specificities     XGFR*IGF-1R and EGFRReducedCoexpression with GnT III and α-ManII in CHO cells (GlycoMAb Technology)Enhanced tumor inhibition over fucosylated bispecific orthotopic Mia-PaCa2 pancreatic cancer xenograft model in SCID miceSchanzer et al. 130 Bispecific antibody with EGFR (GA201) and affinity-matured IGF-1R (R1507) – F13B5 specificities     JNJ-61186372EGFR and c-MetReduced (<10%)CHO cells with low level of fucoseEnhanced xenograft tumor inhibition in nude mouse over control and afucosylated IgG2 isotypeGrugan et al. 109 Bispecific human IgG1     Ifabotuzumab/KB004/IIIA4EPHA3afucosylatedFUT8 −/− CHO cells (Potelligent® Technology)Enhanced tumor growth inhibition over control antibody in DU145 or 22Rv1 xenograft miceVail et al.…”

A ligand-based and enediyne-energized bispecific fusion protein targeting epidermal growth factor receptor and insulin-like growth factor-1 receptor shows potent antitumor efficacy against esophageal cancer

“…Dual targeting strategies with bispecific agents have been classified into two types: i) those that directly act on target molecules, such as bispecific antibodies and ii) those that depend on targets for delivering an active moiety to killing tumor cells, such as bispecific immunotoxins or fusion proteins. A number of bispecific antibodies targeting both EGFR and IGF-1R (EI-04 and XGFR) have demonstrated superior antitumor activity in preclinical models (33,34), and bispecific immunotoxins/fusion proteins developed by Vallera et al also demonstrated either enhanced antitumor activity or broader spectrum of reactivity than the mono-specific molecules (35)(36)(37). EGF-LDP-IGF-AE is a bispecific enediyne-energized fusion protein that was constructed by fusing the natural ligands of EGFR and IGF-1R (EGF and IGF-1) to an enediyne antibiotic lidamycin (LDM; C1027) with potent antitumor activity.…”

Oxidation in the complementarity-determining regions differentially influences the properties of therapeutic antibodies

“…In this work, we present a case study on the bispecific XGFR antibody 46 comprising a Fab for monovalent binding of epidermal growth factor receptor (EGFR) and a single chain Fab specific for human insulin-like growth factor 1 receptor (IGF-1R) (Fig. 1).…”