This is an open-label phase 1b clinical trial enrolling people living with HIV (PLWH) who are antiretroviral therapy (ART)-naïve or have not been on ART for > 24 weeks. This study will enroll PLWH to assess the safety, tolerability, and antiviral effect of bispecific and long-acting bNAbs, alone and in combination. The study will be conducted as a single center study at National Institute for Medical Research-Mbeya Medical Research Center (NIMR-MMRC) in Mbeya, Tanzania.

20 PLWH will be sequentially enrolled into one of 5 arms, each arm comprised of 4 participants. Sequential enrollment will occur in the following order:

• Arm 1 will receive standard daily oral ART.
• Arm 2 will receive a single dose of 10E8.4/iMab 600mg intravenous injection (IV).
• Arm 3 will receive a single dose of 10E8.4/iMab 600mg intramuscular injection (IM).
• Arm 4 will receive a single dose of 10E8.4/iMab 1800mg IV.
• Arm 5 will receive a single dose of combination therapy with both 10E8.4/iMab 1800mg IV and VRC07-523LS 1200mg IV.

Although global initiatives have made great strides in controlling the human immunodeficiency virus (HIV) pandemic, HIV and acquired immune deficiency syndrome (AIDS) continue to impact the lives and livelihoods of a significant portion of the population. In 2019, 38 million individuals were living with HIV and 690,000 died of AIDS-related causes. Despite extensive global efforts for disease control over the last 20 years, 1.7 million individuals contract HIV annually. Antiretroviral therapy (ART) reduces morbidity and mortality associated with HIV by suppressing viral replication but does not eradicate infection. There are barriers to universal ART use that include toxicities, costs, drug resistance, and the need for lifelong adherence. To overcome these barriers, HIV broadly neutralizing antibodies (bNAbs) represent a novel approach to HIV prevention and treatment.

The primary endpoint of change in viral load will be assessed at day 14. Participants will then transition to Step 2, during which all participants will take standard daily oral ART and have viral load monitored through Step 2 week 48.

Inclusion Criteria:

1. Able to read and write in Kiswahili and/or English

2. Able and willing to provide written informed consent

3. Passes Test of Understanding (TOU)

4. Aged 18-50 years, inclusive

5. Antiretroviral Therapy (ART)-naïve or no ART for > 24 weeks at the time of screening

6. HIV RNA 1,000-100,000 copies/mL

7. CD4 ≥ 500 cells/mm3

8. Laboratory criteria at screening within protocol-specified limits for blood, chemistry and urinalysis

9. Willing and able to participate in study visits and procedures for up to 50 weeks

10. Willing and able to begin ART as directed during the study

11. Willing and able to use barrier protection during sex with partners without HIV or partners with unknown HIV status throughout Step 1 and until viral suppression <200 copies/mL is confirmed in Step 2

12. Willing and able to adhere to the following contraception requirements:

    1. Participants who are able to become pregnant must agree to use at least one method of highly effective contraception if participating in sexual activity that could lead to pregnancy. This must begin at least 14 days prior to study enrollment.
    2. Participants who engage in sexual activity that could lead to their partner becoming pregnant and who are of reproductive potential must agree to use a barrier method of contraception to avoid pregnancy in a sexual partner of reproductive potential. The barrier method must be used for the duration of the study.

Exclusion Criteria:

1. Weight >100 kg
2. Previous receipt of humanized or human monoclonal antibody whether licensed or investigational (other than for the prevention and/or treatment of SARS-CoV2/COVID-19)
3. History of viral failure on two or more ART regimens
4. Planned or anticipated need for enfuvirtide, maraviroc, fostemsavir, or ibalizumab for antiretroviral therapy.
5. AIDS-defining illness, as enumerated by the WHO Stage 3 or 4, within the six months prior to enrollment
6. Ongoing oral thrush
7. Active injection or other recreational drug use within the previous 12 months that, in the opinion of the investigator, would impede the participant's ability to safely and consistently adhere to the study protocol
8. History of a severe allergic reaction with generalized urticaria, angioedema or anaphylaxis in the 2 years prior to enrollment.
9. History of chronic urticaria requiring daily treatment
10. Known active hepatitis B virus infection or positive hepatitis B surface antigen at any time in the past
11. Known active hepatitis C virus infection or positive hepatitis C antibody at any time in the past
12. Untreated syphilis
13. Estimated GFR < 50 mL/min within the past 90 days
14. Pregnant or breast-feeding
15. Receipt of licensed vaccine or other investigational study agent within 28 days prior to enrollment or any past participation in an investigational HIV vaccine study with receipt of active product
16. Current or planned participation in another interventional clinical trial during the study period, including clinical trials of investigational new drugs or investigating a new application for an approved medication
17. Chronic or recurrent use of medications that modify host immune response, such as oral steroids, parenteral steroids, or cancer chemotherapy (note: locally-acting medications-such as inhaled, topical, or intra-articular steroids-are allowed)
18. Any other chronic or clinically significant medical condition that in the opinion of the investigator would jeopardize the safety or rights of the participant including, but not limited to: diabetes mellitus type I, chronic hepatitis, renal failure; OR clinically significant forms of: drug or alcohol abuse, mental illness, severe asthma, autoimmune disease, decompensated psychiatric disorders, hypertension, heart disease, or cancer
19. Any medications that, in the opinion of the investigator, would preclude intramuscular injections
20. Study site employee

Individual participant data that underlie results published in any manuscript or otherwise disseminated will be shared. Sharing would occur only after deidentification and with researchers who provide a methodologically sound proposal to analyze the data and secure required regulatory and ethical approvals through appropriate institutions. Deidentified data may also be made available through public data repositories.

After completion of the study.

Data will only be shared with proper approvals in place to entities that are approved to access the data according to the sponsor.