Efavirenz Better than Nevirapine for Most Patients

Most HIV treatment guidelines list nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens among the preferred or recommended options for antiretroviral therapy (ART) in treatment-naive patients. But which NNRTI is generally better for initial treatment: efavirenz or nevirapine? Observational studies and a pooled analysis of clinical-trial data suggest better survival rates with efavirenz, and some studies also show that efavirenz is associated with higher rates of virologic suppression, greater immunologic responses, and lower rates of clinical disease progression. However, these studies were generally not restricted to ART-naive, AIDS-free patients and so were not representative of the current ART-initiating population.

To address this issue, researchers with the HIV-CAUSAL Collaboration evaluated data from 14,857 AIDS-free patients in Europe and the U.S. who initiated ART with efavirenz + ≥2 nucleosides and 7724 who initiated ART with nevirapine + ≥2 nucleosides. All patients were from settings with universal access to care (e.g., the Veterans Affairs system in the U.S.).

Nevirapine was associated with a significantly higher risk of death than efavirenz (hazard ratio, 1.6; 95% confidence interval, 1.3–2.0) and also a higher risk of incident AIDS-defining events or death (HR, 1.3; 95% CI, 1.1–1.5). After 12 months of treatment, nevirapine recipients had significantly smaller CD4 cell–count increases (mean difference, 10.8 cells/mm³) and a greater risk for virologic failure (HR, 1.5; 95% CI, 1.3–1.8). Similar results were seen in subset analyses, including those restricted to men, to more-recent baseline calendar years (2001 forward), to patients with baseline CD4 counts <200 cells/mm³, and to those with higher baseline viral loads (>100,000 copies/mL).