AXC-715 (T785) trihydrochloride is a TLR7/TLR8 dual agonist, extracted from patent WO2020168017 A1 AXC-715 trihydrochloride, compound D from WO2020190734A1, can be used for synthesis of antibody-adjuvant immunoconjugates, comprising an antibody construct that binds programmed death-ligand 1 (PD-L1) linked to one or more adjuvants .