Abacavir/lamivudine plus darunavir/ritonavir in routine clinical practice: a multicentre experience in antiretroviral therapy-naive and -experienced patients.

OBJECTIVES To present clinical experience with a regimen including abacavir/lamivudine + darunavir/ritonavir in a cohort of HIV-1-infected patients. METHODS A retrospective, multicentre cohort study, including all consecutive adult HIV-1-infected patients who started abacavir/lamivudine + darunavir/ritonavir from April 2008 to December 2010 and had at least one follow-up visit. The primary endpoint was HIV-1 viral load (VL) <40 copies/mL at week 48. RESULTS One hundred and eighty-three patients (42 naive and 141 experienced) from 19 hospitals in Spain were studied. The median follow-up was 26.7 (0.5-58.6) months, 79.8% were men, the median age was 47.1 (21.4-80.5) years, 26.2% had AIDS and 38.8% were positive for hepatitis C virus. At baseline, the median CD4 count was 246 cells/mm(3) in naive patients and 393 cells/mm(3) in experienced patients and the median VL was 4.80 and <1.59 log copies/mL, respectively. At week 48, 81.8% of naive patients and 84.2% of experienced patients receiving the regimen reached a VL <40 copies/mL, whereas at 96 weeks this occurred in 90.5% and 92.8%, respectively. CD4 cell count increases at 48 and 96 weeks were +176.5 and +283.5 cells/mm(3) in naive patients and +74.9 and +93 cells/mm(3) in experienced patients, respectively. Overall, 86 (47%) patients discontinued the study regimen, in many cases possibly related to non-medical reasons, such as drug switches to reduce cost or changes in address due to economic constraints. Three patients died of causes unrelated to therapy and 19 (10.4%) discontinued the regimen due to adverse events. CONCLUSIONS In our cohort, abacavir/lamivudine + darunavir/ritonavir was safe, well tolerated and achieved high rates of virological suppression. In a proportion of patients, discontinuation of this effective regimen was possibly due to non-medical reasons.