Study to Compare Bictegravir/Lenacapavir Versus Current Therapy in People With HIV-1 Who Are Successfully Treated With a Complicated Regimen

Key Inclusion Criteria:

• If plasma HIV-1 RNA measurements in the 6 months prior to screening are available,all levels must be < 50 copies/mL.

• At least one documented plasma HIV-1 RNA level measured between 6 and 12 months (± 2months) prior to screening. This and any other HIV-1 RNA measurements documented inthis period must be < 50 copies/mL

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

• Currently receiving a complex antiretroviral (ARV) regimen due to previous viralresistance, or intolerance, or contraindication to existing single-tablet regimens (STR), and on this regimen for at least 6 months prior to the screening visit. Thecriteria to define a complex regimen in this study are as follows:

• A regimen containing a boosted protease inhibitor or a nonnucleos(t)ide reversetranscriptase inhibitor (NRTI) plus at least 1 other third agent (ie, an agentfrom a class other than NRTIs) (eg, bictegravir/emtricitabine/tenofoviralafenamide (coformulated; Biktarvy®)(BVY) + darunavir/cobicistat, BVY +etravirine), or

• A regimen of ≥ 2 pills/day, or a regimen requiring dosing more than once daily,or

• A regimen containing parenteral agent(s) (excluding a complete long-actinginjectable regimen, such as intramuscular cabotegravir plus rilpivirine) aswell as oral agents.

• No documented or suspected resistance to bictegravir (BIC).

• Estimated glomerular filtration rate ≥ 15 mL/min according to the Cockcroft-Gaultformula for creatinine clearance (CLcr) who are not on renal replacement therapy.

Key Exclusion Criteria:

• Prior use of, or exposure to, lenacapavir (LEN)

• Active tuberculosis infection

• Chronic hepatitis B virus (HBV) infection

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