C-021 dihydrochloride is a potent CCR4 antagonist. It potently inhibits functional chemotaxis in human and mouse with IC50s of 140 nM and 39 nM.

C 021 dihydrochloride is a potent CCR4 antagonist. C-021 (4-Quinazolinamine, 2-[1,4'-bipiperidin]-1'-yl-N-cycloheptyl-6,7-dimethoxy-) dihydrochloride potently inhibits functional chemotaxis in humans and mice with IC50s of 140 nM and 39 nM, respectively. It effectively prevents human CCL22-derived [35S]GTPγS from binding to the receptor (IC50: 18 nM).