AMD 3465 also potently inhibits the replication of X4 HIV strains (IC50: 1-10 nM). However, it has no effect on CCR5-using (R5) viruses. AMD 3465 (GENZ-644494) is a potent antagonist of CXCR4, inhibits binding of 12G5 mAb and CXCL12AF647 to CXCR4, with IC