24-month Treatment Outcomes Amongst HIV-Positive Children and Adolescent Patients Prescribed Stavudine vs. Abacavir

Abstract

Background: In April 2010 the South African government replaced stavudine with abacavir in first-line antiretroviral therapy (ART) for children and young adolescents 5-14 years of age. It was hoped that this change would improve treatment outcomes, partly through reduced toxicity and improved adherence. We examined treatment outcomes among HIV-positive children and adolescents initiated on abacavir-based versus stavudine-based standard first-line regimens. Methods: We conducted a prospective cohort analysis among HIV-positive children (5-9.9 years of age) and adolescents (10-13.9 years of age) initiating lamivudine/efavirenz with either stavudine (between April 2009 and March 2010) or abacavir (between April 2010 and March 2011) at one of eight HIV clinics in Gauteng and Mpumalanga provinces in South Africa. Modified Poisson regression was used to evaluate the association of regimen with all-cause mortality, loss to follow-up and having a detectable viral load over 24-months on ART. Linear regression was used to evaluate the relationship between regimen and immunologic response. Results: 371 (56.9%) patients initiating stavudine and 240 (43.1%) initiating abacavir were included in our analysis. A total of 12 (3.8%) stavudine and 5 (2.1%) abacavir patients died, while 43 (13.6%) stavudine and 34 (14.2%) abacavir patients were lost to follow-up over the first 24-months on ART. A total of 97 (30.6%) stavudine and 72 (30.0%) abacavir had a detectable viral load at 24-months on treatment. While estimates lacked precision, our regression analysis showed that patients on stavudine may have an increase in the risk of death (RR 2.0; 95% CI: 0.6-6.3) compared to abacavir. However, results showed that regimens were comparable
in regards to loss to follow-up (RR 0.8; 95% CI: 0.5-1.4), viral load status (RR 1.1; 95% CI: 0.8-1.7) and mean change in CD4 count from ART initiation (-22 cells/mm3; 95% CI: -94.5-50.6 cells/mm3). Adjusted models also showed that adolescents (10-13.9 years of age) compared to children (5-9.9 years of age) and those with CD4 count <200 vs. >200 cell/smm3 were also at increased risk of death and loss from care. Conclusions: Although comparable in regards to loss to follow-up, viral load status and immunological response by 24-months on treatment, patients initiated onto stavudine may have a higher risk of death versus those initiated onto abacavir. The use of abacavir could help improve long-term treatment outcomes in HIV-positive children and adolescents.

Conference: IWHOD 2014, Sitges, Spain