Switch Study to Evaluate F/TAF in HIV-1 Positive Participants Who Are Virologically Suppressed on Regimens Containing FTC/TDF

Key Inclusion Criteria: * Ability to understand and sign a written informed consent form, which must be obtained prior to initiation of study procedures * Currently receiving antiretroviral regimen containing FTC/TDF in combination with one third agent for ≥ 6 consecutive months prior to screening. * Plasma HIV-1 RNA levels \< 50 copies/mL for at least 6 months preceding the screening visit (measured at least twice using the same assay) and not experienced two consecutive HIV-1 RNA above detectable levels after achieving a confirmed (two consecutive) HIV-1 RNA below detectable levels on the current regimen in the past year. * Plasma HIV-1 RNA should be \< 50 copies/mL at the screening visit. * Normal electrocardiogram (ECG) * Estimated glomerular filtration rate (eGFR) ≥ 50 mL/min according to the Cockcroft-Gault formula for creatinine clearance * Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 5 × the upper limit of the normal range (ULN) * Total bilirubin ≤ 1.5 mg/dL, or normal direct bilirubin (individuals with documented Gilbert's syndrome or with Atazanavir-associated hyperbilirubinemia may have total bilirubin up to 5 x ULN) * Adequate hematologic function * Serum amylase ≤ 5 × ULN * Females of childbearing potential must agree to utilize highly effective contraception methods or be non-heterosexually active, or practice abstinence from screening throughout the duration of the study treatment and for 30 days following the last dose of the study drug. * Females who have stopped menstruating for ≥ 12 months but do not have documentation of ovarian hormonal failure must have a serum follicle stimulating hormone (FSH) level at screening within the post-menopausal range based on the Central Laboratory reference range. * Females who utilize hormonal contraceptive as one of their birth control methods must have used the same method for at least three months prior to study dosing. * Males must agree to utilize a highly effective method of contraception during heterosexual intercourse or be non-heterosexually active, or practice sexual abstinence from first dose throughout the study period and for 30 days following the last study drug dose. Key Exclusion Criteria: * A new AIDS-defining condition diagnosed within the 30 days prior to screening * Hepatitis C virus (HCV) antibody positive and HCV RNA detectable * Individuals experiencing decompensated cirrhosis (e.g., ascites, encephalopathy, etc.) * Individuals receiving ongoing treatment with bisphosphonate to treat bone disease (eg, osteoporosis) * Females who are breastfeeding * Positive serum pregnancy test * Have an implanted defibrillator or pacemaker * Current alcohol or substance use judged by the investigator to potentially interfere with study compliance * A history of malignancy within the past 5 years (prior to screening) or ongoing malignancy other than cutaneous Kaposi's sarcoma (KS), basal cell carcinoma, or resected, non-invasive cutaneous squamous carcinoma. * Active, serious infections (other than HIV-1 infection) requiring parenteral antibiotic or antifungal therapy within 30 days prior to Day 1 Visit * Individuals receiving ongoing therapy with any of the medications not to be used with FTC, TAF, TDF or other antiretroviral third agents. Note: Other protocol defined Inclusion/Exclusion criteria may apply.