Inbrx-105 is a recombinant, humanized bispecific antibody targeting programmed death-ligand 1 (PD-L1) and 4-1BB (CD137), with potential checkpoint inhibitory, immunostimulating, and antineoplastic activities. By binding to 4-1BB on activated T lymphocytes and PD-L1 on tumor cells, INBRX-105 enhances T-cell co-stimulation and inhibits PD-L1-mediated T-cell inhibition, potentially leading to reduced tumor growth. INBRX-105 exhibits antitumor efficacy and increased T-cell frequency in patients with solid tumors and in in-vivo. MW: 101.9 KD.