Treatment Outcomes After Switching to Second-Line Anti-Retroviral Therapy: Results From the Thai National Treatment Program

This study aimed to assess second-line antiretroviral therapy (ART) outcomes in a National HIV Treatment program. People living with HIV aged >= 18 years initiating first-line ART who switched to second-line protease inhibitor-based regimens from January 2008 to May 2019, with a minimum of 1-year follow-up were studied. The primary outcome was second-line treatment failure (two consecutive virological failure episodes (viral load >= 1000 copies/mL)). Of 318,506 PLH initiating ART, 29,015 (9.1%) switched to second-line regimens after a median (IQR) ART duration of 1.63 (0.60-3.59) years. Lost to follow-up (LTFU) occurred in 5316 (18.3%) of whom 1376 (5%) remained LTFU and alive; 4606 (15.9%) died. Cumulative second-line failure incidence was 9.8% at 6 years, more common in females, younger PLH those with lower switch CD4 cell counts. Multidisciplinary, innovative support systems are needed to improve second-line treatment outcomes, particularly those relating to modifiable risk factors. Outcomes after switching to second line antiretroviral regimens in the Thai National Treatment programWe assessed the rates of virological failure, losses to follow-up and death in 29,015 people who switched to second line antiretroviral therapy in Thailand. The cumulative rate of virological failure was a 9.8% at 6 years, loss to follow-up occurred in 18.3% (5% who remained alive) and 15.9% died. Women and those with lower CD4 counts at switch had the highest risk of virological failure.