Background: The OCTANE trial reports superior outcomes of lopinavir/ritonavir vs. nevirapine-based antiretroviral therapy (ART) among women previously exposed to single-dose nevirapine to prevent mother-to-child HIV transmission. However, lopinavir/ritonavir is 12 times costlier than nevirapine.
Methods: We used a computer model, with OCTANE and local data, to simulate HIV-infected, single-dose nevirapine-exposed women in South Africa. Outcomes of three alternative ART sequences were projected: no ART (for comparison), first-line nevirapine, and first-line lopinavir/ritonavir. OCTANE data included mean age (31 years) and CD4 cell count (135/μl); median time since single-dose nevirapine (17 months); and 24-week viral suppression efficacy for first-line ART (nevirapine: 85%, lopinavir/ritonavir: 97%). Outcomes included life expectancy, per-person costs (2008 US$), and incremental cost-effectiveness ratios.
Results: With no ART, projected life expectancy was 1.6 years and per-person cost was $2980. First-line nevirapine increased life expectancy (15.2 years) and cost ($13 990; cost-effectiveness ratio: $810/year of life saved versus no ART). First-line lopinavir/ritonavir further increased life expectancy to 16.3 years and cost to $15 630 (cost-effectiveness ratio: $1520/year of life saved versus first-line nevirapine). First-line lopinavir/ritonavir cost-effectiveness was sensitive to prevalence of nevirapine-resistant virus at ART initiation, time from single-dose nevirapine exposure to ART initiation (6-12, 12-24, or >24 months), second-line ART efficacies, and outcomes after 24 weeks on ART.
Conclusions: First-line lopinavir/ritonavir-based ART is very cost-effective in single-dose nevirapine-exposed, South African women similar to OCTANE participants. Lopinavir/ritonavir should be initiated in women with known nevirapine resistance or single-dose nevirapine exposure less than 12 months prior, or in whom such information is unknown.