BGB-A445,a novel non-ligand-blocking agonistic anti-OX40 antibody,exhibits superior immune activation and antitumor effects in preclinical models

t OX40 is a costimulatory receptor that is expressed primarily on activated CD4+,CD8+,and regulatory T cells.The ligation of OX40 to its sole ligand OX40L potentiates T cell expansion,differentiation,and activation and also promotes dendritic cells to mature to enhance their cytokine production.Therefore,the use of agonistic anti-Ox40 antibodies for cancer immunotherapy has gained great interest.However,most of the agonistic anti-OX40 antibodies in the clinic are OX40L-competitive and show limited efficacy.Here,we discovered that BGB-A445,a non-ligand-competitive agonistic anti-OX40 antibody currently under clinical investigation,induced optimal T cell activation without impairing dendritic cell function.In addition,BGB-A445 dose-dependently and significantly depleted regulatory T cells in vitro and in vivo via antibody-dependent cellular cytotoxicity.In the MC38 syngeneic model established in humanized OX40 knock-in mice,BGB-A445 demonstrated robust and dose-dependent antitumor efficacy,whereas the ligand-competitive anti-Ox40 antibody showed antitumor efficacy characterized by a hook effect.Furthermore,BGB-A445 demonstrated a strong combination antitumor effect with an anti-PD-1 antibody.Taken together,our findings show that BGB-A445,which does not block OX40-OX40L interaction in contrast to clinical-stage anti-OX40 antibodies,shows superior immune-stimulating effects and antitumor efficacy and thus warrants further clinical investigation.

Harnessing macrophages in thermal and non-thermal ablative therapies for urologic cancers-Potential for immunotherapy

Prostate and bladder cancers are one of the cancers occurring worldwide.In addition to radical surgery,the past decade has also focused on targeted therapy of overexpressed cancer proteins that are lethal and critical for cancer cell survival.However,targeted therapy cannot adapt for changing of cancer molecular characteristics and,ultimately,a clone that bypasses the targeted therapy emerges.This can be overcome by immunotherapy.New studies on ablative therapy of cancers show presence of immunomodulatory effect in these modalities.Tumor ablation prime the immune system for further destruction of persistent primary tumor in addition to destruction of concurrent metastatic disease and also reduce recurrence.Ablative therapies can achieve a state of increased antigenicity.Its combination with a novel macrophage targeted therapy may enhance immune priming,trafficking,and/or effector phases;thereby improving clinical outcomes.Tumor associated macrophages or M2 phenotype are now known to mediate this immunosuppressive pro-tumorigenic effect.Alteration of macrophage differentiation may enhance tumor destruction of ablative therapy.This breakthrough in immunotherapy opens up arenas for further robust clinical trials on combinatorial therapies.In the present review,we aim to elucidate the major aspects of immune stimulatory minimal invasive approaches by combining with macrophage directed pathways.

Immunotherapy with Agonistic Anti-CD137:Two Sides of a Coin

CD137 (4-1BB),a member of the TNF receptor superfamily,is an inducible T cell costimulatory receptor primarily expressed on activated CD4^+ and CD8^+ T cells.Agonistic monoclonal antibodies (mAbs) against CD137 greatly enhance T cell-mediated immune responses against many types of tumors and viruses.Surprisingly,these agonists also showed therapeutic effects in several autoimmune diseases.These findings suggest that in different disease environments,CD137 engagement with agonist mAb in vivo can diametrically modulate immune response outcomes.Therefore,CD137 agonists represent a promising immunotherapeutic approach to a wide array of disparate immune disorders.However,CD137's potency in modulating immune response necessitates caution when targeting CD137 clinically.Cellular & Molecular Immunology.2004;1(1):31-36.