Study to Compare an Oral Weekly Islatravir/Lenacapavir Regimen With Bictegravir/Emtricitabine/Tenofovir Alafenamide in Virologically Suppressed People With HIV-1

Key Inclusion Criteria:

• HIV-1 RNA < 50 copies/mL for ≥ 6 months before screening, as documented by:

1. One HIV-1 RNA < 50 copies/mL immediately preceding the 24 week period prior toscreening.

2. Within 24 weeks prior to screening, if HIV-1 RNA results are available, alllevels must be < 50 copies/mL.

3. During the 6 to 12 months period prior to screening, transient detectableviremia ≥ 50 copies/mL is acceptable ("blip"), as long as it is not confirmedon 2 consecutive visits.

• Plasma HIV-1 RNA levels < 50 copies/mL at screening.

• Individuals are receiving B/F/TAF for ≥ 6 months prior to screening and willing tocontinue until Day 1.

• Individuals assigned female at birth and of childbearing potential who engage inheterosexual intercourse must agree to use protocol-specified methods ofcontraception.

Key Exclusion Criteria:

• Prior virologic failure.

• Prior use of, or exposure to ISL or LEN.

• Active, serious infections requiring parenteral therapy within 30 days beforerandomization.

• Active tuberculosis infection.

• Acute hepatitis within 30 days before randomization.

• Hepatitis B virus (HBV) infection as determined below at the screening visit:

1. Positive HBV surface antigen OR

2. Positive HBV core antibody and negative HBV surface antibody. Note: individualsfound to be susceptible to HBV infection (eg negative hepatitis B surfaceantibody at the screening visit, regardless of prior HBV vaccination history)should be recommended to receive HBV vaccination.

• Active hepatitis C virus (HCV) coinfection, defined as detectable HCV RNA. Note:individuals with prior/inactive HCV infection (defined as undetectable HCV RNA) maybe enrolled.

• Any of the following laboratory values at screening:

1. Creatinine clearance (CLcr) ≤ 30 mL/min according to the Cockcroft-Gaultformula

2. Alanine aminotransferase > 5 x upper limit of normal (ULN)

3. Direct bilirubin > 1.5 x ULN

4. Platelets < 50,000/μL

5. Hemoglobin < 8.0 g/dL

Note: Other protocol defined Inclusion/Exclusion criteria may apply.