QL615

QL615 is a tetraspecific T-cell engager developed by QLSF Biotherapeutics using its proprietary TECAD (T Cell Engager with Co-Stimulation Avidity Driven) platform. It is designed for the treatment of solid tumors by simultaneously targeting the Hepatocyte Growth Factor Receptor (MET) and the Epidermal Growth Factor Receptor (EGFR). The drug's mechanism involves activating T cells through CD3 engagement and providing conditional co-stimulation via CD2 activation. This activation is 'AND-gated,' meaning it occurs with high avidity only when both MET and EGFR are co-expressed on the tumor cell surface, thereby enhancing tumor selectivity and reducing off-tumor toxicity in tissues where these receptors are expressed individually. Although categorized as an antibody-drug conjugate (ADC) in some pipeline listings, it functions as a multi-specific antibody-based T-cell engager.