The human agonistic CD40 antibody ADC-1013 eradicates bladder tumors and generates T cell dependent tumor immunity.

Purpose: Local administration of immune-activating antibodies may increase the efficacy and reduce the immune-related adverse events associated with systemic immunotherapy of cancer. Here we report the development and affinity maturation of a fully human agonistic CD40 antibody (IgG1), ADC-1013. Experimental Design: We have used molecular engineering to generate an agonistic antibody with high affinity for CD40. The functional activity of ADC-1013 has been investigated in human and murine in vitro models. The in vivo effect has been investigated in two separate bladder cancer models, both using human xenograft tumors in immune deficient NSG mice and using a syngeneic bladder cancer model in a novel human CD40 transgenic mouse. Results: Activation of dendritic cells (DCs) by ADC-1013 results in up-regulation of the co-stimulatory molecules CD80 and CD86, and secretion of IL-12. ADC-1013 also activates dendritic cells from human CD40 transgenic mice, and peptide-pulsed and ADC-1013-stimulated dendritic cells induce antigen-specific T cell proliferation in vitro. In vivo, treatment with ADC-1013 in a syngeneic bladder cancer model, negative for hCD40, induces significant anti-tumor effects and long-term tumor-specific immunity. Further, ADC-1013 demonstrates significant anti-tumor effects in a human bladder cancer transplanted into immunodeficient NSG mice. Conclusions: Our data demonstrate that ADC-1013 induces long-lasting anti-tumor responses and immunological memory mediated by CD40 stimulation. To the best of our knowledge, ADC-1013 represents the first immunomodulatory antibody developed for local immunotherapy of cancer.