D18 is an immune modulator that acts as a dual agonist for TLR7/8 (with EC50 values of 24 nM for hTLR7 and 10 nM for hTLR8, respectively). It enhances the expression of PD-L1 through epigenetic regulation, thereby increasing the sensitivity of tumors to PD-1/PD-L1 blockade. Additionally, D18 functions as a cytotoxin for ADC synthesis, specifically for the ADC HE-S2 [1].
Motixafortide (BKT140 4-fluorobenzoyl) is an antagonist of CXCR4 (IC50: 1 nM). BMS-1166 hydrochloride is an inhibitor of PD-1/PD-L1 interaction (IC50: 1.4 nM). BMS-1166 rivalries the inhibitory effect of PD-1/PD-L1 immune checkpoint on T cell activation.