Anti‐CD3 × anti‐GD2 bispecific antibody redirects T‐cell cytolytic activity to neuroblastoma targets

Abstract

Background The ganglioside GD2 is an attractive target for immunotherapy of neuroectodermal tumors. We tested a unique bispecific antibody anti-CD3 × anti-GD2 (3F8BiAb) for its ability to redirect activated T cells (ATC) to target GD2-positive neuroblastomas. Procedure ATC were generated from normal human peripheral blood mononuclear cells (PBMC) by stimulating the PBMC with OKT3 and expanding the T cells in the presence of interleukin 2 (IL-2) for 14 days. ATC were armed with 3F8BiAb (100 ng/106 cells) or Her2BiAb (50 ng/106 cells) prior to use. 3F8 BiAb were tested for its dual-binding specificity to GD2 expressed on cancer cell lines and CD3 expressed on ATC. 3F8BiAb-armed ATC were further tested ex vivo for their cytotoxicity against GD2 positive tumor targets and its ability to induce cytokine response upon binding to targets. Results GD2 expression in neuroblastoma cells was confirmed by FACS analysis. Specific binding of 3F8BiAb to the tumor targets as well as to ATC was confirmed by FACS analysis. 3F8BiAb-armed ATC exhibited specific killing of GD2 positive neuroblastoma cell lines significantly above unarmed ATC (P < 0.001). GD2BiAb-armed ATC secreted significantly higher levels of Th1 cytokines and chemokines compared to unarmed ATC (P < 0.001). Conclusions These preclinical findings support the potential of a novel immunotherapeutic approach to target T cells to neuroblastoma.

Anti-GD2 MABS and Next-Generation mAb-Based Agents for Cancer Therapy

“…This strategy bridges uncommitted T cells with tumor targets, forming effective immune synapses and redirecting the cytotoxic potential of T cells in order to kill cancer cells in a non-MHC-restricted manner [130]. Preclinical data with biAbs produced by fusing anti-CD3 scFvs to anti-GD2 IgG mAbs [131] or heteroconjugating full anti-CD3 and anti-GD2 mAbs [109,132] have demonstrated their ability to cross-link GD2+ tumors to CD3+ CTLs in the absence of MHC expression by the tumor cell, leading to specific cytolysis of tumor cells via perforin and granzyme B injection.…”

Bispecific antibodies in cancer immunotherapy

“…Chemical conjugation of 2 different purified monoclonal antibodies was used to make bispecific antibodies by oxidative recombination more than 50 y ago 11 and yielded 2 bispecific antibodies that are currently in clinical development. 12,13 More recently, genetic engineering has been used with increasing frequency to create various types of bispecific antibodies. During the past 2 decades, more than 50 formats have been proposed, and some are in different clinical trials phases for the treatment of cancer or autoimmune diseases.…”

Considerations for the Development of Innovative Therapies Against Aggressive Neuroblastoma: Immunotherapy and Twist1 Targeting

“…The idea to bridge activated T cells (ATC) to GD2-positive neuroblastomas provides preclinical rationale for immunotherapy using this bispecific antibody in children with neuroblastoma [12].…”