Maraviroc (MVC) is the first CCR5 inhibitor licensed for clinical use. A pre-treatment test is mandatory to identify the viral tropism of HIV+ patients. Different phenotypic and genotypic methods have been used to identify viral tropism. The aim of this observational retrospective study is to categorize the reasons and the results of tropism test and to evaluate efficacy and tolerability of MVC based regimens in a group of multi-experienced patients.

The clinical records of 213 HIV+ subjects from 15 Infectious Diseases Units in Sicily that were screened for tropism test were reviewed for age, sex, risk, clinical stage (CDC, CD4 cell count, HIV RNA viral load), therapeutic line, indication and result of test for viral tropism. Within subjects treated with MVC, HIV RNA, CD4 cell count and metabolic parameters trend (measured at time 0 and then at month 4, 8, 12, 16, 20, 24), and adverse event were analyzed. Between January 2008 e December 2011, 213 subjects were screened with Trofile™ or genotypic tropism tests. 200 (92.6%) subjects were on HAART. The others were naive or on treatment interruption. 119 (56%) of screened subjects were CCR5 tropic. We observed a lower number of undetermined test with genotypic test vs. Trofile (2.7% vs. 15.9%). To be R5, D/M or X4 tropic wasn’t associated with motivation to perform the test, therapeutic line, CD4 cell count, HIV RNA and CDC stage. 76 subjects (35.7%) were treated with MVC, 72 out of 115 CCR5+(62.6%). After 12 months of treatment with a MVC based regimen, 56.8% (ITT analysis) and 61.7% (AT analysis) of patients had HIV RNA <50 copies/ml. Median CD4 cell count was 387 (IQR 218-455) cells/µl. After 24 months of treatment with a MVC based regimen, 64.8% (ITT analysis) and 80% (AT analysis) of patients had HIV RNA <50 copies/ml. Median CD4 cell count was 381 (IQR 222-515) cells/µl with a median increase of 168 (IQR 54-274) cells/µl. Seven subjects stopped the treatment: two patients died, one had an adverse event, four had virological failure, three of them with low adherence. New drugs used in MVC based regimen were mainly darunavir and raltegravir. 42% of new combinations were NUCs sparing. An high number of multi-experienced subjects treated with a MVC based regimen obtained HIV RNA <50 copies/ml and a satisfactory increase of CD4 cell count. MVC was generally well tolerated with a good metabolic profile.