Pharmacokinetics of SAR441236

This study will evaluate the safety, tolerability, pharmacokinetics, and antiviral activity
of SAR441236, a tri-specific broadly neutralizing antibody against HIV.

The study includes two arms. In Arm A, three cohorts of antiretroviral-treated, virologically
suppressed participants will be randomized to receive a single intravenous (IV) dose of
SAR441236 or placebo on Day 0. After Cohort 1, each subsequent cohort will open for
enrollment only after an evaluation of safety outcomes for all participants in the previous
cohort indicates that it is safe to increase the dose of SAR441236. All participants in
Cohorts 1-3 will be followed for 24 weeks.

In Arm A, Cohort 4, participants will be randomized to receive an IV infusion of SAR441236 or
placebo once every 12 weeks beginning at entry, for a total of 4 infusions. Participants in
this cohort will be followed for 72 weeks.

Participants in Arm A will continue taking non-study-provided antiretroviral treatment
throughout the study.

In Arm B, four cohorts of ART naïve, viremic participants will each receive a single IV dose
of SAR441236 on Day 0. After Cohort 5, each subsequent cohort will be opened for enrollment
after an evaluation of safety outcomes for all participants in the previous cohort indicates
that it is safe to increase the dose of SAR441236.

Based on an evaluation of virologic study data, an additional Arm B cohort of antiretroviral
naïve, viremic participants, Cohort 9, may open at a lower dose. Participants in Cohort 9
will receive a single IV dose of SAR441236. All Arm B participants will be followed for 24
weeks.

Participants in Arm B will initiate non-study-provided combination antiretroviral therapy
(selected by their primary HIV clinician) on Day 28.

Inclusion Criteria, Arms A and B

- HIV-1 infection, documented by any licensed rapid HIV-1 test or HIV-1 enzyme or
chemiluminescence immunoassay (E/CIA) test kit at any time prior to study entry and
confirmed by a licensed Western blot, Geenius assay, or a second antibody test by a
method other than the initial rapid HIV-1 and/or E/CIA, or by HIV-1 antigen, plasma
HIV-1 RNA viral load.

- NOTE: The term "licensed" refers to a US Food and Drug Administration
(FDA)-approved kit.

- WHO (World Health Organization) and CDC (Centers for Disease Control and
Prevention) guidelines mandate that confirmation of the initial test result must
use a test that is different from the one used for the initial assessment. A
reactive initial rapid test should be confirmed by either another type of rapid
assay or an E/CIA that is based on a different antigen preparation and/or
different test principle (e.g., indirect versus competitive), or a Western blot,
Geenius assay, or a plasma HIV-1 RNA viral load.

- The following laboratory values obtained within 45 days prior to entry by any US
laboratory that has a Clinical Laboratory Improvement Amendments (CLIA) certification
or its equivalent.

- Absolute neutrophil count (ANC) greater than or equal to 1500 cells/mm^3

- Hemoglobin greater than or equal to 12.0 g/dL for men and greater than or equal
to 11.0 g/dL for women

- Platelet count greater than or equal to 120,000/mm^3

- Creatinine clearance (CrCl) greater than 80 mL/min

- Refer to the calculator located on the FSTRF website (at
https://www.frontierscience.org/): Calculated Creatinine Clearance -
Cockcroft-Gault Equation (Adult).

- Aspartate aminotransferase (AST) (SGOT) less than 1.25 x upper limit of normal
(ULN)

- Alanine aminotransferase (ALT) (SGPT) less than 1.25 x ULN

- Alkaline phosphatase less than 2.0 x ULN

- Total bilirubin less than 1.1 x ULN

- Hepatitis C virus (HCV) antibody negative result within 45 days prior to study entry
or, for study candidates who are HCV antibody positive (based on testing performed at
any time prior to study entry), a negative HCV RNA result obtained within 45 days
prior to study entry.

- NOTE: A negative HCV RNA level may result from either spontaneous clearance or
from HCV therapy. Participants must have completed any HCV therapy at least 6
months prior to enrollment.

- Negative HBsAg result obtained within 45 days prior to study entry, or documented
hepatitis B immunity, defined as positive hepatitis B surface antibody testing, at any
time.

- Female study candidates of reproductive potential must have a negative serum or urine
pregnancy test with a sensitivity of at least 25 mIU/mL performed at screening and
again within 24 hours before study entry by any US clinic or laboratory that has a
CLIA certification or its equivalent, or is using a point of care (POC)/CLIA-waived
test.

- NOTE: Reproductive potential is defined as girls who have reached menarche, and
women who have not been post-menopausal for at least 24 consecutive months, i.e.,
who have had menses within the preceding 24 months, and women who have not
undergone surgical sterilization, specifically hysterectomy and/or bilateral
oophorectomy.

- All study candidates must agree not to participate in an assisted conception process
(e.g., sperm donation, intrauterine insemination, in vitro fertilization) from
screening until 12 weeks after the final study visit.

- If participating in sexual activity that could lead to pregnancy, all study candidates
must agree to use at least one reliable method of contraception from study entry until
12 weeks after the final study visit. At least one of the following methods must be
used appropriately:

- Condoms (male or female) with or without a spermicidal agent. Condoms are
recommended because their appropriate use is the only contraception method
effective for preventing HIV transmission.

- Diaphragm or cervical cap with spermicide.

- Intrauterine device.

- Hormone-based contraceptive.

- Study candidates who are not of reproductive potential are eligible without requiring
the use of a contraceptive method. Acceptable documentation of sterilization,
menopause, and reproductive potential is specified below.

- Written documentation or oral communication from a clinician or clinician's staff
documented in source documents of one of the following:

- Physician report/letter

- Operative report or other source documentation in the patient record

- Discharge summary

- Laboratory report of azoospermia (is required to document successful
vasectomy)

- Follicle-stimulating hormone (FSH) measurement elevated into the menopausal
range as established by the reporting laboratory.

- NOTE A: Female reproductive potential is defined in the criteria above.

- NOTE B: Male candidates who are not of reproductive potential are defined as
having documented azoospermia.

- NOTE C: A female study candidate's oral report of her male partner's lack of
reproductive potential should be recorded in the source documents if written
proof is not available.

- Individuals age greater than or equal to 18 years and less than or equal to 70 years
at study entry.

- Ability and willingness of participant to provide informed consent.

Inclusion Criteria, Arm A only

- Receiving combination ART for at least 12 months prior to study entry with no changes
in ART regimen within the 12 weeks prior to entry.

- NOTE A: Use of a two-drug ART regimen within the 12 months prior to entry is
exclusionary.

- NOTE B: Although ritonavir or cobicistat may be included in a combination ART
regimen, neither of these "counts" in a tally of antiretroviral agents.

- CD4+ cell count of greater than or equal to 200 cells/mm^3 obtained within 45 days
prior to study entry at any US laboratory that has a CLIA certification or its
equivalent.

- Within 45 days prior to study entry, plasma HIV-1 RNA below the limit of
quantification by any FDA-approved assay on a licensed kit with a limit of
quantification less than or equal to 50 copies/mL of plasma by a US laboratory that
has a CLIA certification or its equivalent.

- Within 12 months prior to study entry and before screening, at least one documented
plasma HIV-1 RNA below the limit of quantification by any FDA-approved assay on a
licensed kit with a limit of quantification less than or equal to 50 copies/mL of
plasma by a US laboratory that has a CLIA certification or its equivalent.

Inclusion Criteria, Arm B only

- Plasma HIV-1 RNA greater than 5000 and less than 100,000 copies/mL within 45 days
prior to study entry.

- CD4+ cell count of greater than or equal to 350 cells/mm^3 obtained within 45 days
prior to study entry at any US laboratory that has a CLIA certification or its
equivalent.

- Willingness and ability to start combination ART by or on Day 28 of the study.

Exclusion Criteria, Arms A and B

- Breastfeeding or plans to become pregnant.

- Receipt of chimeric, humanized or human long-acting mAbs, whether licensed or
investigational, within 12 months prior to entry, or receipt of chimeric, humanized or
human regular mAbs, whether licensed or investigational, within 6 months prior to
entry, unless reviewed and approved by the study's core team.

- Known allergy/sensitivity or any hypersensitivity to components of study treatment or
its formulation (refer to the product's Investigator's Brochure).

- Vaccination within 30 days prior to entry or intent to receive an elective vaccination
(e.g., hepatitis A vaccine, travel-related) during the course of the study except as
noted in the study protocol.

- Active drug or alcohol use or dependence that, in the opinion of the site
investigator, would interfere with adherence to study requirements.

- Acute or serious illness requiring systemic treatment and/or hospitalization within 45
days prior to entry.

- Diagnosis of AIDS-defining illness using the current list on the US Centers for
Disease Control and Prevention (CDC) website within 1 year prior to entry.

- Weight greater than 115 kg within 45 days prior to study entry.

Exclusion Criteria, Arm A

- Within 12 months prior to study entry, any plasma HIV-1 RNA above the limit of
quantification by any FDA-approved assay on a licensed kit with a limit of
quantification less than or equal to 50 copies/mL of plasma performed by a US
laboratory that has a CLIA certification or its equivalent.

- Any current or prior use of maraviroc, ibalizumab, or enfuvirtide.

Exclusion Criterion, Arm B

- Any prior use of ART, including pre-exposure prophylaxis (PrEP) at any time.