Early Neutralizing Antibodies in Infants Living With HIV to Enhance Their Life

Overview

The goal of this clinical trial is to learn if subcutaneous ePGT121v1-LS added to standard antiretroviral therapy (ART) is safe and helps improve HIV viral suppression in infants living with HIV in South Africa. The study will also learn how the body processes ePGT121v1-LS and whether caregivers and health workers find this treatment approach acceptable. The main questions it aims to answer are: * Is ePGT121v1-LS safe and well tolerated in infants living with HIV? * Does adding ePGT121v1-LS to standard ART increase the number of infants who achieve HIV viral suppression by week 48? * How long does it take participants receiving ePGT121v1-LS to achieve viral suppression compared with standard treatment alone? * How does ePGT121v1-LS behave in the body after repeated subcutaneous injections? Researchers will compare infants receiving ePGT121v1-LS plus ART to infants receiving standard ART plus placebo (saline) to see if ePGT121v1-LS improves HIV viral suppression. Participants will: * Continue taking standard oral ART. * Receive 4 subcutaneous injections of ePGT121v1-LS or placebo every 12 weeks. * Attend regular clinic visits for safety checks, blood tests, and HIV viral load monitoring. * Have follow-up visits for 48 weeks. * Participate in evaluations of treatment adherence and acceptability from the perspective of caregivers and health workers.

This Phase 1/2 clinical trial is designed to evaluate the safety, tolerability, pharmacokinetics, and antiviral activity of subcutaneous (SC) ePGT121v1-LS administered as adjunctive therapy to standard antiretroviral therapy (ART) in infants living with HIV (ILHIV) in South Africa. Although early ART initiation has significantly improved survival among infants with HIV, achieving sustained virological suppression during infancy remains challenging because of factors including limited pediatric formulations, adherence difficulties, high baseline viral loads, and treatment interruptions. Novel long-acting therapeutic strategies that simplify treatment delivery and enhance antiviral activity may improve outcomes in this vulnerable population. Broadly neutralizing antibodies (bNAbs) have shown antiviral activity in adults and children living with HIV and may provide additional benefits through prolonged antiviral coverage and immunomodulatory effects. ePGT121v1-LS is a long-acting bNAb directed against the V3 glycan supersite of the HIV-1 envelope. The LS mutation extends antibody half-life and supports infrequent dosing schedules using SC administration. This study includes an initial safety lead-in phase followed by a randomized placebo-controlled phase evaluating ePGT121v1-LS in combination with standard ART. The trial will assess the safety profile and tolerability of repeated SC administrations and will characterize pharmacokinetic parameters following serial dosing in infants. In addition, the study will evaluate the antiviral effect of ePGT121v1-LS intensification therapy on HIV viral suppression during the first 48 weeks of follow-up. Exploratory analyses will further assess virological, immunological, and reservoir-related outcomes, including HIV-1 DNA dynamics, viral diversity, neutralization sensitivity, anti-drug antibodies, and immune responses associated with bNAb exposure. Qualitative assessments will also evaluate the acceptability and feasibility of SC bNAb administration from the perspective of caregivers, healthcare workers, and stakeholders. The results of this study are intended to inform the development of future pediatric trials evaluating long-acting bNAb-based therapeutic strategies for infants living with HIV.