Pilot phase IV, multicenter, randomized, open-label and controlled study to assess the evolution of peripheral body fat distribution after switching from zidovudine-containing backbone to truvada in HIV-1-infected patients on highly active antiretroviral therapy

INTERVENTION: Patients on current HAART regimen containing zidovudine and lamivudine at usual doses for at least six months, will be randomised to switch to truvada (fixed‐dose combination of tenofovir and emtricitabine) or to continue with the same HAART regimen containing zidovudine and lamividine. The other drugs included in the original HAART regimen will not change. CONDITION: Human immunodeficiency virus (HIV) ; Infections and Infestations ; Human immunodeficiency virus PRIMARY OUTCOME: Objective assessment of change from baseline in limb fat at week 48 as measured by DEXA; ; 1. Dual‐energy x‐ray absortiometry (DEXA) scans will be performed at baseline, week 24, week 48 and week 72; 2. Study of mitochondrial toxicity at baseline, week 12, week 24, week 48 and week 72 SECONDARY OUTCOME: 1. Change in the mitochondrial deoxyribonucleic acid (DNA) or nuclear DNA ratio in the different visits compared with baseline; 2. Change in lactate concentration in the different visits compared with baseline; 3. Proportion of patients who maintain confirmed HIV‐1 RNA levels of <50 copies per ml; 4. Proportion of patients with HIV‐1 RNA levels between >50 and <400 copies per ml; 5. Proportion of patients with virologic failure as confirmed by two consecutive HIV‐1 RNA >400 copies/ml; 6. Time to loss of virological response, defined as the time elapsed from the patient’s first dose of study drug to confirmed HIV‐1 RNA levels of >50 and <400 copies/ml, death caused by the disease, medication discontinuation, or addition of a new antiretroviral medication; 7. Time to definite virological failure, defined as the time elapsed from the patient’s first dose of study drug to confirmed HIV‐1 RNA levels of >400 copies/ml; 8. Change in CD4+ cell counts in the different study visits compared with baseline; 9. Change in serum triglycerides, total cholesterol, low‐density lipoprotein (LDL), and high‐density lipoprotein (HDL) fractions in the different study visits compared with baseline; 10. Change in hemoglobin and hematocrit concentrations in the different visits compared with baseline; 11. Proportion of patients with different specific mutations after virological failure; 12. Proportion of patients who show treatment adherence INCLUSION CRITERIA: 1. Human immunodeficiency virus (HIV‐1) infection as documented by positively confirmed HIV‐1 antibody test and/or positive polymerase chain reaction (PCR) for HIV‐1 ribonucleic acid (RNA) 2. Adult patients (over 18 years of age) 3. Currently on highly active antiretroviral therapy (HAART) regimen, containing zidovudine and lamivudine at usual doses for at least six months 4. Viral load <50 copies/ml on the last two consecutive determinations under zidovudine and lamivudine‐containing HAART regimen 5. For women of childbearing potential, negative urine pregnancy test at screening visit 6. Agreement to take part in the study and signed informed consent form 7. Patients on lipid‐lowering treatment will be allowed to participate in the study only if the lipid‐lowering treatment (either statins or fibrates) is stable for at least eight weeks prior to screening and is not expected to change this treatment during the first three months of the trial