A Fully Human Recombinant IgG-like Bispecific Antibody to Both the Epidermal Growth Factor Receptor and the Insulin-like Growth Factor Receptor for Enhanced Antitumor Activity

Dan Lu,Haifan Zhang,Henry Koo,James Tonra,Paul Balderes,Marie Prewett,Eric Corcoran,Venkata Mangalampalli,Rajiv Bassi,Deborah Anselma,Dipa Patel,Xiaoqiang Kang,Dale L Ludwig,Daniel J Hicklin,Peter Bohlen,Larry Witte,Zhenping Zhu

doi:10.1074/jbc.m500815200

Abstract

Both the epidermal growth factor receptor (EGFR) and the insulin-like growth factor receptor (IGFR) have been implicated in the tumorigenesis of a variety of cancers. Here we propose that simultaneous targeting of both receptors with a bispecific antibody would lead to enhanced antitumor activity. To this end, we produced a recombinant human IgG-like bispecific antibody, a Di-diabody, using the variable regions from two antagonistic antibodies: IMC-11F8 to EGFR and IMC-A12 to IGFR. The Di-diabody binds to both EGFR and IGFR and effectively blocked both EGF- and IGF-stimulated receptor activation and tumor cell proliferation. The Di-diabody also inherited the biological properties from both of its parent antibodies; it triggers rapid and significant IGFR internalization and degradation and mediates effective antibody-dependent cellular cytotoxicity in a variety of tumor cells. Finally, the Di-diabody strongly inhibited the growth of two different human tumor xenografts in vivo. Our results underscore the benefits of simultaneous targeting of two tumor targets with bispecific antibodies.

Highlights

The lack of specificity of currently available chemo- and radiotherapeutic agents constitutes the major obstacle to the effective treatment of cancer
Compelling evidence suggest that both epidermal growth factor receptor (EGFR) and insulin-like growth factor receptor (IGFR) play important roles in the growth and progression of a variety of human cancers; they may represent excellent targets for effective cancer intervention
We hypothesize that a strategy that targets both EGFR and IGFR simultaneously, by using either a combination of two antagonistic antibodies or a bispecific antibodies (BsAb), may yield greater antitumor activity than other approaches that address only a single receptor

Summary

Inhibition of Both EGFR and IGFR with a Bispecific Antibody

Iressa® (ZD1839), has shown great anticancer activity in a number of animal models as well as in various clinical studies (for reviews, see Refs. 16 –20). Iressa® (ZD1839), has shown great anticancer activity in a number of animal models as well as in various clinical studies Significant tumor inhibition has been achieved in animal models with several IGFR targeting strategies including antisense oligonucleotides [21], dominate-negative receptor mutants [22], and neutralizing mAb Using the variable domains of two neutralizing human antibodies as the “building blocks,” one directed against EGFR and the other against IGFR, we constructed and produced an IgG-like tetravalent BsAb, a so-called “Di-diabody.”. The Di-diabody bound to both EGFR and IGFR, blocked the receptors from interacting with their respective ligands, and inhibited both EGF- and IGF-stimulated activation of the receptors as well as the receptor-associated downstream signaling pathways. The Di-diabody strongly inhibited the growth of human tumor xenografts in vivo

EXPERIMENTAL PROCEDURES

RESULTS

DISCUSSION