Effect of transitioning virally suppressed children and adolescents with HIV to dolutegravir-based antiretroviral therapy: emulated target trials in a large cohort in South Africa

Background: Global HIV programmes are transitioning virally suppressed children and adolescents with HIV (CAWH) from prior regimens to dolutegravir-based antiretroviral therapy (ART). However, the supporting evidence largely stems from randomised trials in viraemic CAWH. The effect of transition for virally suppressed CAWH is unknown. Methods: We used observational, de-identified data from 724 clinics in KwaZulu-Natal, South Africa. We sequentially emulated three distinct target trials to estimate the effect of transitioning to dolutegravir-based ART in three paediatric populations: i) ages 8-17 years taking efavirenz-based ART, ii) 8-17 years taking ritonavir-boosted lopinavir (LPV/r)-based ART, and iii) 0-7 years taking LPV/r-based ART, all with a last viral load <1,000 copies/mL. The risk difference (RD) of death or viraemia >1,000 copies/mL through 12 and 24 months was estimated using an inverse probability weighting approach. Findings: From January 2020 to August 2024, 37,145 CAWH contributed 454,081 person-trials. In CAWH initially taking efavirenz, the standardised 12-month risk of death or viraemia was 11.9% with continued efavirenz and 6.7% with transition to dolutegravir (RD -5.2 [95% CI -5.8 to -4.6]). In older CAWH initially taking LPV/r, these risks were 17.8% and 9.5%, respectively (RD -8.3 [-10.0 to -6.8]). In younger children, the respective risks were 15.8% and 6.7% (RD -9.0% [-12.7 to -5.4]). Where available, 24-month endpoints showed slightly greater RDs. Interpretation: This large-scale, causal analysis highlights improvements in viral suppression and strongly supports ongoing transition to dolutegravir-based ART for virally suppressed CAWH. Funding: Gates Foundation, National Institute for Health and Care Research, Swiss National Science Foundation