3BNC117 Monoclonal Antibody in HIV-infected Subjects During Treatment Interruption

The proposed study is a Phase II, open label study to evaluate the safety and antiretroviral
activity of two and four infusions of 3BNC117 in HIV-infected subjects on combination ART
during a brief analytical treatment interruption.

After meeting enrollment criteria sixteen subjects with 3BNC117 sensitive virus (<2μg/ml
IC50) will receive two (Group A) or four (Group B) intravenous infusions of 3BNC117,
administered at 30 mg/kg.

In both dosing groups, antiretroviral therapy will be discontinued 2 days after the first
3BNC117 infusion (day 2) until week 12. Combination ART will be resumed at week 12. ART will
be resumed sooner if plasma HIV-1 RNA level is ≥ 200 copies/ml or if CD4+ count drops < 350
cells/μl and either result is confirmed upon repeat measurement. Participants will be
followed weekly until week 12 for safety assessments and for monitoring plasma HIV-1 RNA
levels (viral load). CD4+ T cell counts will be monitored every 2 weeks until week 12.

Participants may remain off antiretroviral therapy after week 12, with weekly viral load
monitoring, if viral rebound does not occur by week 12. Participants will be followed for a
total of 36 weeks.

Inclusion Criteria:

- Age 18 to 65

- HIV-1 infection confirmed by ELISA and immunoblot.

- Plasma HIV-1 RNA < 50 copies/ml for at least 12 months while on combination ART and <
20 copies/ml at the screening visit. [Note: One or two viral blips of < 200 copies/mL
prior to enrollment are permitted if preceded and followed by test results showing VL
less than or equal to 50 copies/mL on the same ARV regimen.]

- 3BNC117 sensitivity (IC50 < 2 μg/ml) of subject derived HIV-1 virus isolates. These
are isolated under protocol MCA-823 by co-culture of subject PBMCs with HIV-uninfected
donor PBMCs followed by in vitro neutralization assays as previously described

- Current CD4 cell count > 500 cells/μl and no prior CD4 cell count < 200 cells/μl.

- Willing to interrupt antiretroviral treatment for 12 weeks, or until viral rebound
occurs.

- If sexually active male or female, and participating in sexual activity that could
lead to pregnancy using an effective method of contraception throughout the study
period. Subjects should also agree to use a male or female condom during the time of
pausing their HIV medication.

- If on an NNRTI-based regimen willing to a switch for 4 weeks to dolutegravir.

Exclusion Criteria:

- Have a history of AIDS-defining illness within 1 year prior to enrollment

- History of systemic corticosteroids, immunosuppressive anti-cancer, or other
medications considered significant by the trial physician within the last 6 months;

- Chronic hepatitis B or hepatitis C;

- Patient report, or chart history, of significant coronary artery disease, myocardial
infarction, percutaneous coronary intervention with placement of cardiac stents;

- Patient report, or chart history, of diabetes type 1 or 2 and/or current use of
insulin or oral hypoglycemic medications;

- Uncontrolled hypertension, as defined by a systolic blood pressure > 180 and/or
diastolic blood pressure > 120, in the presence or absence of anti-hypertensive
medications;

- Any other clinically significant acute or chronic medical condition, such as
autoimmune diseases, that in the opinion of the investigator would preclude
participation;

- Current cigarette use in excess of 1 pack per day;

- Laboratory abnormalities in the parameters listed below:

- Absolute neutrophil count ≤1,000

- Hemoglobin ≤ 10 gm/dL

- Platelet count ≤125,000

- ALT ≥ 2.0 x ULN

- AST ≥ 2.0 x ULN

- Total bilirubin ≥ 1.5 ULN

- Creatinine ≥ 1.1 x ULN

- Coagulation parameters ≥ 1.5 x ULN;

- Current antiretroviral regimen includes either maraviroc or enfuvirtide;

- Pregnancy or lactation;

- Any vaccination within 14 days prior to 3BNC117 administration;

- Receipt of any monoclonal antibody therapy of any kind in the past;

- Participation in another clinical study of an investigational product currently or
within past 12 weeks, or expected participation during this study.

- History of resistance to two or more antiretroviral drug classes