OBJECTIVES: To assess the cost-effectiveness of the four comparators examined in the ACTG 5202 clinical trial, tenofovir/emtricitabine (TDF/FTC) or abacavir/ lamivudine (ABC/3TC) in combination with efavirenz (EFV) or atazanavir/ritonavir (ATV/r), for treatment-naïve adults with HIV-1 infection in the United Kingdom (UK).
METHODS: A Markov model with six health states based on CD4+ cell-count ranges was developed to estimate costs and health outcomes for individuals on firstline therapy. Head-to-head efficacy data (lack of regimen failure and mean CD4+ cellcount changes) up to 192 weeks for TDF/FTC+EFV, TDF/FTC+ATV/r, ABC/3TC+EFV, and ABC/3TC+ATV/r were obtained from the ACTG 5202 clinical trial. Antiretroviral drug costs were based on current list prices. Utility values, mortality, and other direct medical costs (2012 UK pounds) were stratified by CD4+ cell-count range and obtained from published sources. All outcomes were discounted at 3.5% per year. Sensitivity and subgroup analyses were conducted, including analysis of low (< 100,000 copies/mL) and high (≥ 100,000 copies/mL) baseline viral load.
RESULTS: Individuals using TDF/FTC-based regimens were predicted to remain on first-line therapy longer and accrue more QALYs than individuals using ABC/3TC-based regimens (QALYs: 6.30 for TDF/FTC+EFV, 6.45 for TDF/FTC+ATV/r, 5.02 for ABC/3TC+EFV, and 5.26 for ABC/3TC+ATV/r). Costs were £111,882 for TDF/FTC+EFV, £124,302 for TDF/FTC+ATV/r, £85,477 for ABC/3TC+EFV, and £99,609 for ABC/3TC+ATV/r. At a willingness- to-pay threshold of £30,000 per QALY gained, TDF/FTC-based regimens were predicted to be cost-effective compared with ABC/3TC-based regimens, with incremental cost-effectiveness ratios of £20,545 for TDF/FTC+EFV versus ABC/3TC+EFV and £20,652 for TDF/FTC+ATV/r versus ABC/3TC+ATV/r. In subgroup analyses, TDF/ FTC-based regimens were predicted to yield more QALYs and to remain cost-effective compared with ABC/3TC-based regimens.
CONCLUSIONS: In an analysis of the regimens examined in the ACTG 5202 clinical trial for treatment-naïve adults with HIV-1 infection, regimens containing TDF/FTC yielded more favorable health outcomes and were predicted to be cost-effective compared with regimens containing ABC/3TC.
