Maraviroc

Maraviroc is an antiretroviral drug in the CCR5 receptor antagonist class used in the treatment of HIV infection. It is also classed as an entry inhibitor. Maraviroc is extensively metabolized by CYP3A4, with renal clearance accounting for approximately 23% of total clearance. Maraviroc is an entry inhibitor. Specifically, maraviroc is a negative allosteric modulator of the CCR5 receptor, which is found on the surface of certain human cells. Maraviroc (UK-427857) inhibits CCL3 (MIP-1α) binding to CCR5, thereby blocking the HIV protein gp120 from associating with the receptor. Maraviroc (brand-named Selzentry, or Celsentri) displays potent anti-HIV-1 activity. UK-427857 prevents the interaction of HIV-1 gp120 and CCR5 (IC50 = 6.4 nM), inhibiting HIV-1 entry. Maraviroc has no detectable in vitro cytotoxicity and is highly selective for CCR5, as confirmed against a wide range of receptors and enzymes, including the hERG ion channel (50% inhibitory concentration, >10 μM), indicating potential for an excellent clinical safety profile. Maraviroc also appeared to reduce graft-versus-host disease in patients treated with allogeneic bone marrow transplantation for leukemia, in a phase 1/2 study. In addition, those who received the entry inhibitor had a mean increase in CD4 cells of 110 cells/µL in the once-daily group, 106 cells/µL in the twice-daily group, and 56 cells/µL in the placebo group.