Antiviral Chemistry & Chemotherapy 2010 20:179–192 (doi: 10.3851/IMP1507) Review CCR5 antagonists: host-targeted antiviral agents for the treatment of HIV infection, 4 years on Mike Westby1* and Elna van der Ryst1 1Pfizer Global Research and Development, Sandwich, Kent, UK *Corresponding author: e-mail:
[email protected] The chemokine coreceptor 5 (CCR5) antagonists are anti- are in various stages of clinical development. In 2005, we retroviral agents with an extracellular, host-targeted reviewed the limited clinical data then available on CCR5 mechanism of action against HIV. Maraviroc, the first- antagonists. In this follow-up review, we revisit the field and in-class CCR5 antagonist, received regulatory approval in assess the clinical and virological data that have emerged 2007, becoming the first oral antiretroviral from a new in the 4 years since, with particular reference to maraviroc class in more than 10 years. Other compounds in this class for which the most comprehensive data currently exist. Introduction Chemokine coreceptor 5 (CCR5) antagonists are a new supporting the current and future role of small-molecule class of antiretroviral agents that inhibit HIV replica- CCR5 antagonists in the treatment of HIV infection. tion by binding to CCR5 on the surface of host target cells and preventing entry of viral strains reliant on this Status of CCR5 antagonists in clinical coreceptor for infection. The first and only currently development in 2005 approved agent within this class, maraviroc, received marketing authorisation in the USA, Europe and other Of the three small-molecule CCR5 antagonists in regions of the world in 2007, with an indication for clinical development in 2005, only maraviroc (Figure treatment-experienced adult patients with only CCR5- 1A) is currently approved for clinical use.