Effect of simplification from protease inhibitors to boosted atazanavir-based regimens in real-life conditions.

Background: Atazanavir (ATV) boosted with ritonavir (ATV/r) is a potent, well-tolerated, once-daily protease inhibitor (PI). Few data are available on this agent as a treatment simplification option for patients taking other PIs.

Objective: The aim of the study was to determine the effectiveness and safety of ATV-containing regimens in patients who have simplified their antiretroviral treatment.

Methods: SIMPATAZ was a multicentre, prospective, noninterventional study in patients who had undetectable HIV RNA on their current PI-containing therapy and who were switched to an ATV/r-based regimen. Patients underwent a routine physical examination, and data were collected on HIV RNA levels, CD4 cell counts, liver function, lipid parameters, adverse reactions, adherence to treatment and patient satisfaction.

Results: A total of 183 patients were enrolled in the study and included in the analysis (80% were male, 29% had AIDS, and 52% were coinfected with HIV and hepatitis B virus or hepatitis C virus). The median baseline CD4 count was 514 cells/μL. Median exposure to previous HIV therapy was 8 years, and 32% of patients had a history of PI failures. Lopinavir boosted with ritonavir was the most frequent PI replaced (62%) and tenofovir+lamivudine /emtricitabine the backbone most used during the study (29%). The study drug was discontinued early by 25 patients (14%), two of whom discontinued as a result of adverse events (Hodgkin lymphoma and vomiting). Two patients died (lung cancer and myocardial infarction). At month 12, 93% of the study population had an undetectable HIV RNA viral load. Hyperbilirubinaemia >3 mg/dL and increased alanine aminotransferase levels>200 IU/L were observed in 38.5% and 4.4% of patients, respectively. Median changes from baseline to month 12 in total cholesterol, triglycerides and low-density lipoprotein cholesterol were -13 mg/dL (-7%; P<0.0001), -19 mg/dL (-13%; P<0.0001) and -7 mg/dL (-6%; P=0.021), respectively.

Conclusions: In a real-world setting, switching from other PIs to ATV/r is a well-tolerated and safe option for improving the lipid profile and for retaining virological response in controlled pretreated patients.