CCR5 antagonists have recently entered the HIV armamentarium. This novel class of drugs inhibit viral entry blocking host cellular receptors, and therefore display unique mechanisms of resistance, different from other antiretroviral drugs. Maraviroc only blocks replication of R5 viruses and accordingly patients with X4 or D/M viruses do not or only marginally benefit from maraviroc therapy. Viral tropism has to be tested before considering maraviroc prescription. Phenotypic and more recently genotypic tools have been demonstrated to reliably estimate HIV-1 tropism in most cases and predict viral response. Beyond the initial approval only for antiretroviral-experienced patients, the pharmacokinetic properties and safety profile of maraviroc may support an earlier use of the drug. Studies using maraviroc in drug-naive patients and as part of switch strategies are warranted.
aDepartment of Infectious Diseases, Hospital Carlos III, Madrid, Spain
bDepartment of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
cInstitute of Virology, University of Cologne, Cologne, Germany
dService of Virology, Hospital Pitié-Salpetrière, Paris, France
eInfectious Diseases Unit, Hospital Clinic, Barcelona, Spain
fUniversity of Torino, Torino, Italy
gDepartment of Infection, University College London, and Centre for Infections, Health Protection Agency, London, UK
hDepartment of Medicine, University of Bonn, Bonn, Germany
iDepartment of Virology, Royal Free Hampstead NHS Trust & University College London Medical School, London, UK.
Received 25 May, 2009
Revised 1 September, 2009
Accepted 9 September, 2009
Correspondence to Dr Vincent Soriano, Department of Infectious Diseases, Hospital Carlos III, Calle Sinesio Delgado 10, Madrid 28029, Spain. Tel: +34 91 453 25 00; fax: +34 91 7336614; e-mail: email@example.com