Project description:CD3-bispecific antibodies represent an important therapeutic strategy in oncology. These molecules work by redirecting cytotoxic T cells to antigen-bearing tumor cells. Although CD3-bispecific antibodies have been developed for several clinical indications, cases of cancer-derived resistance are an emerging limitation to the more generalized application of these molecules. Here, we devised whole-genome CRISPR screens to identify cancer resistance mechanisms to CD3-bispecific antibodies across multiple targets and cancer types. By validating the screen hits, we found that deficiency in IFNγ signaling has a prominent role in cancer resistance. Interestingly, IFNγ functions by stimulating the expression of T cell killing-related molecules in a cell type-specific manner. Additionally, by assessing resistance to the clinical CD3-bispecific antibody flotetuzumab, we identified core fucosylation as a novel and critical pathway to regulate flotetuzumab binding to the CD123 antigen. Disruption of this pathway resulted in significant resistance to flotetuzumab treatment. Moreover, proper fucosylation of CD123 is required for its normal biological functions. In order to treat the resistance associated with fucosylation loss, flotetuzumab in combination with an alternative targeting CD3-bispecific antibody demonstrated superior efficacy. Together, our study reveals multiple mechanisms that can be targeted to enhance the clinical potential of current and future T cell engaging CD3-bispecific antibody therapies.
Project description:This is a phase II Randomized comparison clinical trial of activated CIK armed with anti-CD3-MUC1 bispecific antibody for advanced colorectal cancer. And the aim of this research is to study the clinical efficacy and safety of activated CIK armed with anti-CD3-MUC1 bispecific antibody for colorectal cancer.
Project description:Functional screening on patient-derived organoids identifies a therapeutic bispecific antibody that triggers EGFR degradation in LGR5+ tumor cells
Project description:Tumor-specific cytotoxic T cells are required for effective immunotherapy. Here we introduce a bispecific fusion protein (tebentafusp) designed to target gp100 (a melanoma-associated antigen) through a high affinity T cell receptor binding domain, and through an anti-CD3 effector domain re-directs any cytotoxic T cell, regardless of its intrinsic specificity, to kill gp100-expressing tumor cells. In patients with metastatic melanoma, tebentafusp showed anti-tumor activity and manageable and predictable side effects. Notably, tebentafusp induced an increase in serum CXCL10 (a T cell attractant), and a reduction in circulating CXCR3+ CD8+ T cells together with an increase in cytotoxic T cells in the tumor microenvironment (TME). Furthermore, the appearance of rash, likely due to cytotoxic T cells targeting of gp100-expressing skin melanocytes, or an increase in serum CXCL10 showed a positive association with patient survival. Taken together, these results suggest that re-directing T cells using a gp100-targeting T cell receptor/anti-CD3 bispecific fusion protein may provide benefit to patients with metastatic melanoma.
Project description:The ability to leverage antibodies to agonize disease relevant biological pathways has the potential to unlock new drug targets for clinical investigation. While antibodies have been successful as antagonists, immune mediators, and targeting agents, they are not readily effective at recapitulating the biological activity of natural ligands. Among the important determinants of antibody agonist activity is the geometry of target receptor engagement. Herein, we describe a novel engineering approach inspired by a naturally occurring Fab-Fab homotypic interaction that constrains IgG in a unique i-shaped conformation. i-shaped antibody (iAb) engineering enables potent intrinsic agonism of five tumor necrosis factor receptor superfamily (TNFRSF) targets. When applied to bispecific antibodies against the heterodimeric IL-2 receptor pair, constrained bispecific IgG formats recapitulate IL-2 agonist activity. Thus, iAb engineering represents a new tool to tune agonist antibody function and this work provides a framework for the development of intrinsic antibody agonists with the potential for generalization across broad receptor classes.
Project description:transcriptome analysis of NK cells sorted from PBMCs at baseline and after addition of a CD20 (B cell)-targeted T cell dependent bispecific antibody (TDB)
Project description:A novel affinity-tuned dual-checkpoint bispecific antibody with potent PD-L1 and moderate CD47 affinity was designed to improve the selectivity to TME and thus enhance antitumor immunity and efficacy. The scRNAseq analysis was performed to examine the immune cell modulation in TME following the CD47/PD-L1 bispecific treatment.
Project description:A novel affinity-tuned dual-checkpoint bispecific antibody with potent PD-L1 and moderate CD47 affinity was designed to improve the selectivity to TME and thus enhance antitumor immunity and efficacy. The gene expression analysis using Nanostring platform was performed to examine the immune cell modulation in TME following the CD47/PD-L1 bispecific treatment.
