Safety, Tolerability and Immunogenicity Study of 2 Dose Levels of Trimeric Glycoprotein140 (gp140) in Healthy Adult Volunteers

This is a single-center, randomized (the study drug is assigned by chance),
placebo-controlled (study in which the experimental treatment or procedure is compared to a
pretend treatment with no drug in it to test if the drug has a real effect), and
double-blind (neither physician nor participant knows the treatment that the participant
receives) study. The study comprises a Screening Period (up to 4 weeks), a Vaccination
Period (participants will be vaccinated on Days 1 and 29), and a Follow-up Period (up to 48
weeks). All eligible participants will be randomly assigned to 1 of the 2 sequential cohorts
(low dose cohort and high dose cohort). Participants in low dose cohort will receive 1 of
the following treatments: low dose (50 microgram [mcg]) gp140 drug product (DP), low dose
gp140 DP with adjuvant (aluminum phosphate), placebo matched to low dose DP; and
participants in high dose cohort will receive 1 of the following treatments: high dose (250
mcg) gp140 DP, high dose gp140 DP with adjuvant, and placebo matched to high dose DP. There
will be an interim safety review of safety/tolerability from low-dose cohort before the
high-dose cohort receives study treatment. Total study duration will be 56 weeks per
participant. Participants' safety will be monitored throughout the study.

Inclusion Criteria:

- Participant must be healthy on the basis of physical examination, medical history,
electrocardiogram (ECG), laboratory criteria, and vital signs measurement performed
at Screening

- Participants are negative for human immunodeficiency virus (HIV) infection at
Screening (negative United States Food and Drug Administration-approved HIV
diagnostic blood test)

- All female participants of childbearing potential must have a negative serum (beta
human chorionic gonadotropin) at Screening, and a negative urine pregnancy test
pre-dose on Day 1 and Day 29

- A woman must agree not to donate eggs (ova, oocytes) for the purposes of assisted
reproduction until 3 months after receiving the last dose of study vaccine. A man
must agree not to donate sperm until 3 months after receiving the last dose of study
vaccine

- Participants are assessed by the clinic staff as being at low risk for HIV infection

Exclusion Criteria:

- Participant has chronic active hepatitis B or active hepatitis C, active syphilis
infection, chlamydia, gonorrhea, or trichomonas. Active syphilis documented by exam
or serology unless positive serology is due to past treated infection

- In the 12 months prior to enrollment, participant has a history of newly acquired
syphilis, gonorrhea, non-gonococcal urethritis, herpes simplex virus type 2 (HSV2),
chlamydia, pelvic inflammatory disease, trichomonas, mucopurulent cervicitis,
epididymitis, proctitis, lymphogranulomavenereum, chancroid, or hepatitis B

- Participant has any clinically significant acute or chronic medical condition that in
the opinion of the Investigator would preclude participation (for example, history of
seizure disorders, bleeding/clotting disorder, autoimmune disease, active malignancy,
poorly controlled asthma, active tuberculosis or other systemic infections)

- Participant has had major surgery within the 4 weeks prior to study entry or planned
major surgery through the course of the study

- Participant has had a thyroidectomy, or thyroid disease requiring medication during
the last 12 months