title: Maraviroc, risks and benefits: a review of the clinical literature.
abstract: BACKGROUND
  Maraviroc represents the first licensed CCR5 co-receptor antagonist from the new antiretroviral (ARV) drug-class of entry inhibitors.
  
  
  RESULTS
  Results of Phase III clinical trials in three-drug-class experienced patients have presented maraviroc as a promising new agent for treatment of HIV-1-infection. Maraviroc (b.i.d./q.d.) + optimised background therapy (OBT) provided significantly superior virological control and CD4+ increases compared with placebo + OBT at 48 weeks, with no clinically relevant differences in the safety profile between the maraviroc and the placebo groups.
  
  
  CONCLUSIONS
  Its proven efficacy in cases of virological failure and three-class ARV-drug resistance is a major benefit of maraviroc compared to the so far commercially available drugs from existing (non-) nucleoside reverse transcriptase inhibitors ([N]NRTI) and protease inhibitors drug-classes, particularly in times of increasing ARV drug resistance. Moreover, the tolerability profile of the drug makes maraviroc particularly appealing as a combination partner in ARV therapy. As maraviroc however is only effective against CCR5-tropic HIV-1, tropism testing is required before initiation of treatment. Tropism-testing possibilities are still limited, and presently only possible at high costs. The main constraints to be considered in the clinical use of maraviroc are the declining number of CCR5-tropic patients with advanced HIV-1 disease owing to tropism-shifting and the occurrence of drug-drug interactions, requiring regular dose adaptations. The true clinical value of this new substance and its future role in the treatment of HIV-1-infection remains to be defined by further data from clinical studies and by future experiences of practitioners.
authors.affiliation: University Clinic Bonn, Department of Medicine I, Sigmund-Freud-Str. 25, 53105 Bonn, Germany.
authors.forename: Jetske M
authors.initials: JM
authors.lastname: Emmelkamp
authors.forename: Jürgen K
authors.initials: JK
authors.lastname: Rockstroh