Predictive criteria of sustained virological response (more than 60 months) to Nevirapine-based antiretroviral treatment

Background Nevirapine (NVP) was the first non-nucleoside reverse transcriptase inhibitor (NNRTI) to be used for the treatment of HIV infection. NVP is generally a well tollerated drug; early adverse events, such as hypersensitive reactions and hepatic toxicity, are the main limitations. A considerable number of patients obtain a durable virological success for a long time. The aim of this study is to identify predictive criteria for long term NVP virological response (more than 60 months) in a cohort of NNRTIs naive subjects. Patients and methods Clinical records of 137 HIV positive subjects treated with a NVP-including regimen were retrospectively reviewed for age, sex, route of HIV transmission, clinical stage, HCV co-infection, therapeutic regimens, length of treatment, side effects, hepatic and metabolic blood values, reasons for treatment failure. Results 128 patients were included into the study. Twenty eight of them (22%) were still on treatment. Main reasons leading to NVP discontinuation were virological failure (32.8%) after a median of 16.2 months (IQR 8.1-37.9), toxicity (21.9%) (1 month, IQR 0.8-5), patient’s choice (21.1%) (17.6 months, IQR 2.8-39). Hypersensitivity was the more frequent adverse reason leading to interruption (p<0.009). Thirty nine (30.5%) subjects were treated for more than 60 months (long term responders or LTRs), 89 (69.5%) stopped NVP before 60 months (long term not responders or LTNRs). LTRs were older (41.2 years (IQR 36-49.6) vs 36.6 (IQR 32.1-42.7) (p=0.012), with a lower median baseline HIV RNA viral load (2.6 log10 vs 3.7 log10 ) (p=0.01). Conclusions In conclusion, older patients, with lower HIV RNA viral load at baseline have a greater probability to maintain a sustained virological response with a NVP-based treatment over 60 months.