Treatment Outcomes of Third-line Antiretroviral Regimens in HIV-infected Thai Adolescents

Background: Efficacy and safety data of third-line antiretroviral (ARV) regimens in adolescents are limited. Methodology: This study enrolled HIV-infected Thais who were treated with third-line regimens consisting of darunavir/ritonavir (DRV/r), etravirine (ETR), tipranavir/ritonavir or raltegravir. Results: Fifty-four adolescents 2–17 years of age were enrolled from 8 sites and followed for 48 weeks. Reasons for switch were second-line failure (n = 44) and toxicity to second-line regimens (n = 10). At switching to third-line ARV, the median age (interquartile range) was 14.3 (12.4–15.4) years. Genotypes at time of second-line failure (n = 44) were M184V (77%), ≥4 thymidine analogue mutations (25%), non-nucleoside reverse transcriptase inhibitor–resistant associated mutation (RAM) (80%), ETR-RAM score ≥4 (14%), any lopinavir-RAM (59%) and ≥1 major DRV-RAM (41%). The third-line regimens had a median of 4 (min–max, 4–6) drugs and included ETR/DRV/r (43%), DRV/r (33%), ETR (17%), tipranavir/ritonavir (2%) or raltegravir/DRV/r/ (4%). The median CD4 (interquartile range) increased from 16% (12–21) at third-line switch to 21% (18–25) and 410 (172–682) to 607 (428–742) cells/mm3 at 48 weeks (P < 0.001). HIV RNA declined from 3.9 (2.9–4.9) to 1.6 (1.6–3.0) log10 copies/mL (P < 0.001) and 33/50 (66%) had levels <50 copies/mL at 48 weeks. Seventeen (31%) had HIV-RNA ≥1000 copies/mL; about half due to poor adherence; genotyping in 13 of these adolescents revealed ETR-RAM score ≥4 in 2 (15%) and ≥1 major DRV-RAM in 7 (54%). Conclusions: Third-line ARV therapy was well tolerated and resulted in virologic suppression in 70% of adolescents at 1 year. Poor adherence and limited ARV options are major problems in the long-term management of adolescents with HIV.