Study to Evaluate Switching From a Regimen Consisting of Efavirenz/Emtricitabine/Tenofovir Disoproxil Fumarate (EFV/FTC/TDF) Fixed Dose Combination (FDC) to Emtricitabine/Rilpivirine/Tenofovir Alafenamide (FTC/RPV/TAF) FDC in Virologically-Suppressed, HIV-1 Infected Adults

A Phase 3b, Randomized, Double-Blind Study to Evaluate Switching From a Regimen Consisting of Efavirenz/Emtricitabine/Tenofovir Disoproxil Fumarate (EFV/FTC/TDF) Fixed Dose Combination (FDC) to Emtricitabine/Rilpivirine/ Tenofovir Alafenamide (FTC/RPV/TAF) FDC in Virologically-Suppressed, HIV-1 Infected Subjects

The primary objective of this study is to evaluate the non-inferiority of switching to emtricitabine/rilpivirine/tenofovir alafenamide (FTC/RPV/TAF) fixed dose combination (FDC) as compared to continuing the non-nucleoside reverse transcriptase inhibitor (NNRTI) regimen of efavirenz /FTC/tenofovir disoproxil fumarate (EFV/FTC/TDF) FDC in virologically-suppressed HIV-1 infected participants.

Key Inclusion Criteria:

• The ability to understand and sign a written informed consent form, which must be obtained prior to initiation of study procedures
• Currently receiving EFV/FTC/TDF FDC for ≥ 6 consecutive months preceding the screening visit
• Documented plasma HIV-1 RNA levels < 50 copies/mL (or undetectable HIV-1 RNA level according to the local assay being used if the limit of detection is > 50 copies/mL) for ≥ 6 months preceding the screening visit. Unconfirmed virologic elevation of ≥ 50 copies/mL after previously reaching viral suppression (transient detectable viremia, or "blip") and prior to screening is acceptable
• Have no documented resistance to any of the study agents at any time in the past
• HIV-1 RNA < 50 copies/mL at the screening visit
• Hepatic transaminases (AST and ALT) ≤ 5 × upper limit of normal (ULN)
• Total bilirubin ≤ 1.5 mg/dL, or normal direct bilirubin
• Adequate hematologic function (absolute neutrophil count ≥ 1,000/mm^3; platelets ≥ 50,000/mm^3; hemoglobin ≥ 8.5 g/dL)
• Serum amylase ≤ 5 × ULN (individuals with serum amylase > 5 × ULN will remain eligible if serum lipase is ≤ 5 × ULN)
• Normal ECG (or if abnormal, determined by the Investigator to be not clinically significant)
• Adequate renal function: Estimated glomerular filtration rate ≥ 50 mL/min according to the Cockcroft-Gault formula

Key Exclusion Criteria:

• Hepatitis B surface antigen (HBsAg) positive
• Hepatitis C antibody positive with detectable hepatitis C virus (HCV) RNA (individuals who have HCV antibody but no detectable HCV RNA are eligible to enroll)
• Individuals experiencing or with a medical history of decompensated cirrhosis (e.g., ascites, encephalopathy, etc.)
• Females who are breastfeeding
• Positive serum pregnancy test
• Current alcohol or substance use judged by the Investigator to potentially interfere with the individual's 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. Individuals with cutaneous KS are eligible, but must not have received any systemic therapy for KS within 30 days of Baseline/Day 1 and must not be anticipated to require systemic therapy during the study
• Active, serious infections (other than HIV-1 infection) requiring parenteral antibiotic or antifungal therapy within 30 days prior to Baseline/Day 1
• Any other clinical condition or prior therapy that, in the opinion of the Investigator, would make the individual unsuitable for the study or unable to comply with dosing requirements
• Participation in any other clinical trial (including observational trials) without prior approval from the sponsor is prohibited while participating in this trial
• Individuals receiving ongoing therapy with any of the disallowed medications listed in the protocol, including drugs not to be used with FTC, RPV and/or TAF; or individuals with any known allergies to the excipients of FTC/RPV/TAF

Note: Other protocol defined inclusion/exclusion criteria may apply.