A Phase 1/2a Study of PGT121, VRC07-523LS and PGDM1400 Monoclonal Antibodies in HIV-uninfected and HIV-infected Adults

This is a Phase 1/2a open label study to evaluate the safety, tolerability, pharmacokinetics
and anti-viral efficacy of PGT121, VRC07-523LS and PGDM1400 antibodies for HIV prevention and
therapy. PGT121, VRC07-523LS and PGDM1400 are recombinant human IgG1 monoclonal antibodies
that target a V3 glycan-dependent epitope region of the HIV envelope protein and the CD4
binding site (CD4bs) of the HIV envelope protein. PGT121, VRC07-523LS and PGDM1400 mAbs were
chosen for this study because of their potency, their ability to neutralize a wide array of
cross-clade HIV viruses in a complementary pattern, and their proven antiviral activity in
animal studies, e.g., their capacity to robustly prevent and treat simian-human
immunodeficiency virus (SHIV) in rhesus monkeys.

The potency and breadth of PGT121, VRC07-523LS and PGDM1400 raise the possibility that
monoclonal antibodies may be effective for HIV prophylaxis at low doses and against global
viruses. Neutralization sensitivity profiles are complementary; and the combination of these
mAbs with unique epitope specificities will provide experience assessing the potential
additive, synergistic, or antagonistic properties of two bNAbs given sequentially.

1. Willing to comply with the requirements of the protocol and available for follow-up
for the planned duration of the study.

2. In the opinion of the Principal Investigator or designee and based on Assessment of
Informed Consent Understanding results, has understood the information provided and
potential impact and/or risks linked to IV infusion and participation in the trial;
written informed consent will be obtained from the volunteer before any study-related
procedures are performed.

3. All volunteers born female engaging in sexual activity that could lead to pregnancy
must commit to use an effective method of contraception from the day of the first IV
infusion of investigational product until 6 months following the final investigational
product administration

4. All sexually active volunteers born male, regardless of reproductive potential, must
be willing to consistently use an effective method of contraception from the day of
investigational product administration until at least 6 months following the final
investigational product administration to avoid exposure of partners to
investigational product in ejaculate, and to prevent conception with female partners.

5. All volunteers born female must be willing to undergo urine pregnancy tests at time
points indicated in the Schedule of Procedures and must test negative prior to
investigational product administration.

6. All volunteers born female must agree not to donate eggs (ova, oocytes) for the
purpose of assisted reproduction until 6 months after the final investigational
product administration. Volunteers born male must agree not to donate sperm until 6
months after final investigational product administration.

7. Willing to forgo donations of blood and/or any other tissues, including bone marrow,
during the study and, for those HIV-uninfected volunteers who test HIV-positive due to
investigational product administration, until the anti-HIV antibody titers become
undetectable.

Specific inclusion criteria for HIV-uninfected volunteers (Group 1):

1. Healthy male or female, including transgender, volunteers, as assessed by a medical
history, physical exam, and laboratory test

2. At least 18 years of age on the day of screening and has not reached his or her 51st
birthday on the day of signing the Informed Consent Document

3. Willing to undergo HIV testing, risk reduction counseling and receive HIV test results

4. Low risk for HIV infection for 12 months prior to study participation and willing to
maintain low-risk behavior for the duration of the trial

Specific inclusion criteria for HIV-infected volunteers (Group 2):

1. At least 18 years of age on the day of screening and has not reached his or her 66th
birthday on the day of signing the Informed Consent Document

2. Confirmed HIV-1 infection (HIV Ab+ or HIV RNA+) by documentation in the medical
records or in-clinic HIV testing

3. CD4 ≥ 400 cells/µl

4. On antiretroviral therapy for a minimum of 24 months, with plasma HIV-1 RNA levels of
< 50 copies/ml for at least 12 months as documented in the medical records, and with a
viral load < 50 copies / ml at time of screening (within 56 days prior to IP
administration). ART must not have been initiated during the acute phase of the
infection as suggested by the available medical history and laboratory data from the
time of the diagnosis. Note: ART is defined as a regimen including > 2 compounds,
e.g., 2x nucleoside reverse transcriptase inhibitors plus either non-nucleoside
reverse transcriptase inhibitor or protease inhibitor or integrase inhibitor.

5. If on an NNRTI-based regimen, willing to switch to an integrase inhibitor containing
regimen for 4 weeks prior to discontinuing ART

6. No history of AIDS-defining illness within the past 5 years

7. No history of CD4 nadir <200 cells/ul

8. Under care of an HIV healthcare provider 5.6 Exclusion Criteria

Exclusion criteria for all volunteers:

1. Any clinically significant acute or chronic medical condition, other than HIV
infection, that is considered progressive or in the opinion of the investigator makes
the volunteer unsuitable for participation in the study.

2. Any clinically relevant abnormality on history or examination including history of
immunodeficiency (other then HIV infection) or autoimmune disease; use of systemic
corticosteroids, immunosuppressive, anticancer, or other medications considered
significant by the investigator within the previous 6 months. The following exceptions
are permitted and will not exclude study participation: use of corticosteroid nasal
spray for rhinitis, topical corticosteroids for an acute uncomplicated dermatitis; or
a short course (duration of 10 days or less, or a single injection) of corticosteroid
for a non-chronic condition (based on investigator clinical judgment) at least 6 weeks
prior to enrollment in this study.

3. If born female, pregnant, lactating or planning a pregnancy during the period of
screening through completion of the study.

4. In the past 6 months a history of alcohol or substance use, including marijuana,
judged by the Investigator to potentially interfere with volunteer study compliance.

5. Bleeding disorder that was diagnosed by a physician. Note: A volunteer who states that
he or she has easy bruising or bleeding, but does not have a formal diagnosis and has
intramuscular injections and blood draws without any adverse experience, is eligible.

6. History of a splenectomy.

7. Receipt of live attenuated vaccine within the previous 30 days or planned receipt
within 30 days after administration of investigational product; or receipt of other
vaccine within the previous 14 days or planned receipt within 14 days after infusion
with investigational product (exception is live attenuated influenza vaccine within 14
days).

8. Receipt of blood transfusion or blood-derived products within the previous 3 months.

9. Participation in another clinical trial of an investigational product currently,
within the previous 3 months or expected participation during this study. Note:
receipt of placebo in a clinical trial in the previous 3 months will not exclude a
volunteer from participation if documentation is available and the Medical Monitor
gives approval.

10. Prior receipt of an investigational HIV vaccine candidate, monoclonal antibody or
polyclonal immunoglobulin. Note: receipt of placebo in a previous HIV vaccine or
monoclonal antibody trial will not exclude a volunteer from participation if
documentation is available and the Medical Monitor gives approval.

11. History of severe local or systemic reactogenicity to injections or IV infusion (e.g.,
anaphylaxis, respiratory difficulties, angioedema).

12. Psychiatric condition that compromises safety of the volunteer and precludes
compliance with the protocol. Specifically excluded are persons with psychoses within
the past 3 years, ongoing risk for suicide, or history of suicide attempt or gesture
within the past 3 years.

13. If, in the opinion of the Principal Investigator, it is not in the best interest of
the volunteer to participate in the trial.

14. Seizure disorder: a volunteer who has had a seizure in the last 3 years is excluded.

15. Body mass index ≥ 35 or ≤ 18.5.

16. Infectious disease: chronic hepatitis B infection (HbsAg), current hepatitis C
infection (HCV Ab positive and HCV RNA positive) or interferon-alfa treatment for
chronic hepatitis C infection in the past year, chlamydia, gonorrhea, or active
syphilis.

17. A history of malignancy within the past 5 years (prior to screening) or ongoing
malignancy (exceptions are squamous and basal cell carcinomas of the skin and
carcinoma in situ of the cervix, or malignancy, which is considered cured with minimal
risk of recurrence)

18. Active, serious infections (other than HIV-1 infection) requiring parenteral
antibiotic, antiviral or antifungal therapy within 30 days prior to enrollment.

19. Any of the following abnormal laboratory parameters listed below:

Hematology

- Hemoglobin < 10.5 g/dL in females; hemoglobin <11.0 g/dL in males

- Absolute Neutrophil Count (ANC): ≤ 1000/mm3

- Platelets: < 100,000 mm3 or ≥ 550,000/mm3 Chemistry

- AST ≥ 1.5 x ULN

- ALT ≥ 1.5 x ULN

- Total bilirubin ≥ 1.1 x ULN

- Alkaline phosphatase ≥ 1.5 x ULN

- Albumin ≤ 3.0 g/dL (equivalent to ≤ 30 g/L)

- Estimated Glomerular filtration rate (GFR) < 60 ml/min according to the Cockcroft
Gault formula for creatinine clearance

- Male: (140 - age in years) x (wt in kg) = CLcr (ml/min) / 72 x (serum creatinine
in mg/dL)

- Female: (140 - age in years) x (wt in kg) x 0.85 = CLcr (mL/min) / 72 x (serum
creatinine in mg/dL)

Urinalysis: Any of the following abnormal findings if consistent with clinically
significant disease:

- Protein = 2+ or more

- Blood = 2+ or more (not due to menses)

Specific exclusion criteria for HIV-uninfected volunteers (Group 1):

1. Confirmed HIV-1 infection