A Study to Evaluate the Safety and Antiviral Activity of Two Human Monoclonal Antibodies (VRC07-523LS and PGT121.414.LS) During Analytic Treatment Interruption in Participants Living With HIV Who Initiated ART During Acute/Early HIV-1 Infection

This study is an open-label, two-arm, multi-step phase I study evaluating a combination of two broadly neutralizing antibodies (bNAbs), VRC07-523LS and PGT121.414.LS, in people living with HIV (PWH) who started antiretroviral therapy (ART) during acute/early infection. Participants will receive PGT121.414.LS and VRC07-523LS prior to undergoing an analytical treatment interruption (ATI). Participants will restart ART and continue follow-up after ATI to confirm viral suppression. Participants will be screened for eligibility and have a pre-entry visit. After determination of eligibility, participants will be enrolled sequentially into Arm A (n=20) and then Arm B (n=20). The study consists of three steps including an analytic treatment interruption. Arm A: * Step 1: Participants remain on ART and will receive an infusion of VRC07-523LS and PGT121.414.LS at study entry. * Step 2: Participants will interrupt their ART and receive a second infusion of VRC07-523LS 12 weeks after the initial infusion. Participants will be monitored closely for indications to resume ART. * Step 3: Upon meeting ART restart criteria in Step 2; participants will resume ART and be followed for up to 24 weeks. Arm B: * Step 1: Participants remain on ART and will receive an infusion of VRC07-523LS and PGT121.414.LS at study entry and a second infusion of VRC07-523LS 12 weeks later. * Step 2: Participants will interrupt their ART. Participants will be monitored closely for indications to resume ART. * Step 3: Upon meeting ART restart criteria in Step 2; participants will resume ART and be followed for up to 24 weeks. Participation in both arms will last up to 98 weeks.