CG1xCD3xCD28

**CG1xCD3xCD28** is a trispecific antibody designed as a T-cell engager for cancer immunotherapy. It simultaneously binds to a tumor-associated antigen (designated CG1, likely a cancer-specific target such as a tumor antigen), CD3 on T cells to recruit and activate them, and CD28 to provide co-stimulatory signaling, enhancing T-cell proliferation, cytokine production, and tumor cell killing beyond standard bispecific T-cell engagers. This modality aims to overcome limitations of CD3-only bispecifics by mimicking natural T-cell activation requiring both TCR signaling (via CD3) and co-stimulation (via CD28), potentially improving efficacy in solid tumors or resistant hematologic malignancies.