Simplification of protease inhibitor-containing regimens with efavirenz, nevirapine or abacavir: safety and efficacy outcomes.
Chiesa E., Bini T., Adorni F., Capetti A., Rizzardini G., Faggion I., Mussini C., Sollima S., Melzi S., Bongiovanni M., Tordato F., Cicconi P., Castelnuovo B., Rusconi S., d'Arminio Monforte A.
OBJECTIVE: To describe the immunological and virological outcome, and the factors associated to discontinuation in patients switching to a regimen containing efavirenz (EFV), nevirapine (NVP) or abacavir (ABC) after long-term viral suppression under protease inhibitor-including HAART. DESIGN: Observational study at three outpatient clinics for HIV care in Italy. METHODS: Patients with HIV RNA <80 copies/ml and CD4 >200 cells/ml for at least 6 months on a protease inhibitor-containing treatment who switched to NVP, EFV or ABC were included in the study. End-points were immunological failure, virological failure and discontinuation due to toxicity. Survival analyses were performed to find out any independent variables predictive of reaching the end-points. RESULTS: 177 patients were enrolled; 85 started EFV, 54 NVP and 38 ABC as part of the simplification regimen. 16/159 patients experienced immunological failure: the variables associated to CD4 count decrease were HIV RNA set point value (HR 2.32 for each log10 copies more, P=0.040) and intolerance/toxicity as reason for simplification (HR 3.96, P=0.05). 13/151 subjects showed virological failure; an AIDS diagnosis (HR 6.04, P=0.021) and the use of NVP (HR 7.98, P=0.027) were associated to a worse virological outcome, while patients naive before HAART showed a lower risk of failure (HR 0.008, P=0.007). 16/177 patients discontinued simplification regimen due to toxicity; longer HAART duration before switch was associated to risk reduction (HR 0.92, P=0.004). CONCLUSIONS: Simplification is safe and effective, but it should be offered to patients with shorter treatment duration, and in good clinical and immunovirological conditions.