Uptake and effectiveness of two-drug compared with three-drug antiretroviral regimens among HIV-positive individuals in Europe. AIDS
Neesgaard et al. on behalf of the EuroSIDA study analysed the uptake of two-drug antiretroviral regimens (2DRs), factors associated with starting or switching to a 2DR in the European-based EuroSIDA cohort, and virologic and immunologic outcomes of using 2DRs compared with three-drug regimens (3DRs) in this large, heterogeneous, population of people living with HIV (PLWHIV) seen in routine clinical care.
Virologic outcomes were assessed on-treatment as the proportion of individuals with controlled viral load (<400 copies/ml), or with a composite modified FDA snapshot endpoint (mFDA), with mFDA success defined as controlled viral load at 6 months or 12 months for individuals with a known viral load, no regimen changes, AIDS or death. Immunologic response was defined as a 100 cells/[mu]l or a 25% increase in CD4+ cell counts from baseline.
Between 1 July 2010 and 31 December 2016, 423 individuals started or switched to a 2DR (eight antiretroviral-naive) and 4’347 started a 3DR (566 naive). Individuals on 2DR tended to have suppressed viral load, higher CD4+ cell counts and more comorbidities at baseline compared with those on 3DR. There were no differences in the proportions of individuals who obtained on-treatment or mFDA success, and no significant differences in the adjusted odds ratios for mFDA success or immunologic responses between the 2DR and 3DR groups at 6 months or 12 months.
In conclusion, the study found that the 2DRs in this analysis were largely used according to the current clinical guidelines. The study-results show that 2DRs in the period were mainly prescribed to antiretroviral-experienced individuals who switched from their previous regimen with virologic suppression, high CD4+ cell counts and preexisting or higher risk of comorbidities. Although the study observed favourable outcomes for antiretroviral-naive individuals starting a 2DR, the numbers were too low to allow meaningful conclusions. Overall, virologic and immunologic outcomes in individuals on 2DRs were similar to individuals on 3DRs in this selected population, in line with results from randomized clinical trials, although confounding by indication cannot be fully excluded.