Bispecific antibodies targeting CD40 and tumor-associated antigens promote cross-priming of T cells resulting in an antitumor response superior to monospecific antibodies

Abstract

BackgroundIndications with poor T-cell infiltration or deficiencies in T-cell priming and associated unresponsiveness to established immunotherapies represent an unmet medical need in oncology. CD40-targeting therapies designed to enhance antigen presentation, generate new tumor-specific T cells, and activate tumor-infiltrating myeloid cells to remodel the tumor microenvironment, represent a promising opportunity to meet this need. In this study, we present the first in vivo data supporting a role for tumor-associated antigen (TAA)-mediated uptake and cross-presentation of tumor antigens to enhance tumor-specific T-cell priming using CD40×TAA bispecific antibodies, a concept we named Neo-X-Prime.MethodsBispecific antibodies targeting CD40 and either of two cell-surface expressed TAA, carcinoembryonic antigen-related cell adhesion molecule 5 (CEA) or epithelial cell adhesion molecule (EpCAM), were developed in a tetravalent format. TAA-conditional CD40 agonism, activation of tumor-infiltrating immune cells, antitumor efficacy and the role of delivery of tumor-derived material such as extracellular vesicles, tumor debris and exosomes by the CD40×TAA bispecific antibodies were demonstrated in vitro using primary human and murine cells and in vivo using human CD40 transgenic mice with different tumor models.ResultsThe results showed that the CD40×TAA bispecific antibodies induced TAA-conditional CD40 activation both in vitro and in vivo. Further, it was demonstrated in vitro that they induced clustering of tumor debris and CD40-expressing cells in a dose-dependent manner and superior T-cell priming when added to dendritic cells (DC), ovalbumin (OVA)-specific T cells and OVA-containing tumor debris or exosomes. The antitumor activity of the Neo-X-Prime bispecific antibodies was demonstrated to be significantly superior to the monospecific CD40 antibody, and the resulting T-cell dependent antitumor immunity was directed to tumor antigens other than the TAA used for targeting (EpCAM).ConclusionsThe data presented herein support the hypothesis that CD40×TAA bispecific antibodies can engage tumor-derived vesicles containing tumor neoantigens to myeloid cells such as DCs resulting in an improved DC-mediated cross-priming of tumor-specific CD8+T cells. Thus, this principle may offer therapeutics strategies to enhance tumor-specific T-cell immunity and associated clinical benefit in indications characterized by poor T-cell infiltration or deficiencies in T-cell priming.

RUBY® – a tetravalent (2+2) bispecific antibody format with excellent functionality and IgG-like stability, pharmacology and developability properties

“…The functionality of RUBY bsAbs was evaluated in a variety of assays. It was shown that a CD40-EpCAM RUBY bsAb displayed conditional CD40 activation in a reporter assay, similar to what has been shown by Hägerbrand et al 29 The bsAb induced activation of CD40-expressing cells only in the presence of EpCAM expressed on CHO cells whereas no activation was observed in a similar set up with CHO cells lacking EpCAM expression ( Figure 3(b) ). Additionally, a CD137-5T4 RUBY bsAb induced potent T cell activation as measured by a dose-dependent increase in interferon (IFN)-gamma release in the presence of 5T4.…”

“…These results are in line with efficient tumor localization of a RUBY bsAb previously seen in vivo in tumor-bearing mice. 29 …”

“…The safety of RUBY has been partly evaluated in a study by Hägerbrand et al 29 where non-human primates were administered up to 37.5 mg/mL repeated doses of a CEAxCD40 RUBY, which showed no pathological findings related to either format or compound. Additional prerequisites for appropriate safety and immunogenicity profiles are good physiological stress and low presence of product-related impurities, as it is known that these can increase the drug toxicity and patient immunogenic responses.…”

RASGRP2 is a potential immune-related biomarker and regulates mitochondrial-dependent apoptosis in lung adenocarcinoma

“…It has been reported the immunostimulators mainly focus on the tumor necrosis factor receptor (TNFR) family and B7-CD28 family. Currently, a number of agonistic antibodies have entered the clinical stage (44)(45)(46). TNFRSF4, also known as OX40, activates the PI3K/PKB, NF-kB1 and NFAT pathways and enhances T cell-mediated antitumor immunity, thereby improving survival in several preclinical cancer models, including B16 melanoma and lung cancer (47).…”

Controlling Antigen Fate in Therapeutic Cancer Vaccines by Targeting Dendritic Cell Receptors

“…Therefore, it cannot be concluded whether antigen fate or DC maturation induced by CD40 targeting was the main determinant for the enhanced T cell proliferation. Of note, an exciting prospect in the context of CD40 targeting are bispecific antibodies recognizing CD40 and a TAA. , These constructs bring tumor debris in proximity to CD40 + cells, which can take up, process, and present the tumor antigens, while simultaneously being stimulated via CD40. This results in antitumor responses surpassing immune reactivity toward the initial targeted epitope …”