Long-acting Injectable Antiretroviral Therapy in South African Adolescents and Young Adults – Week 48 results from the AFINAty Study

Background: Long-acting injectable antiretroviral therapy (LAI-ART) with cabotegravir and rilpivirine offers a promising alternative to daily oral ART, particularly for young people living with HIV (YLHIV). However, there are limited data on the feasibility, acceptability and efficacy of LAI-ART delivery in lower- and middle-income countries. Methods: We conducted a 48-week, community-based study of cabotegravir and rilpivirine LAI-ART among YLHIV aged 12-24 years in Cape Town, South Africa. Participants (virally suppressed, struggling with adherence or ART naïve) were required to be virally suppressed (<50 copies/ml) on first-line ART at the end of the screening phase before switching to cabotegravir and rilpivirine LAI-ART every 8 weeks for 48 weeks. Feasibility, retention, adherence to injection schedules, viral suppression and safety were assessed. Virological failure was defined as two consecutive viral loads ≥200 copies/ml. Results: Between December 2022 and December 2023, 172 participants were screened and 134 (77·9%) switched to LAI-ART. The median age was 20 years and 62·7% were assigned female at birth. Nearly one quarter (23·1%) were under 18 years of age. Overall, 47% had prior NNRTI exposure. Retention at week 48 was 98·5% with 97·5% of all injections given on schedule. Viral suppression, as indicated by VL <50 copies/ml, at week 48 was achieved by 95·5% with no confirmed virological failures. All participants who completed week 48 opted to remain on LAI-ART. Interpretation: LAI-ART was safe, highly acceptable and effective among YLHIV. These findings support the feasibility of implementing LAI-ART through community-based models in sub-Saharan Africa.