Study to Evaluate Efficacy and Safety of Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide (D/C/F/TAF) Regimen Versus Boosted Protease Inhibitor (bPI) Along With Emtricitabine/Tenofovir Disoproxil Fumarate (FTC/TDF) Regimen in Virologically-Suppressed, HIV-1 Infected Participants

A Phase 3, Randomized, Active-controlled, Open-label Study to Evaluate the Efficacy, Safety and Tolerability of Switching to a Darunavir/ Cobicistat/ Emtricitabine/ Tenofovir Alafenamide (D/C/F/TAF) Once-daily Single-tablet Regimen Versus Continuing the Current Regimen Consisting of a Boosted Protease Inhibitor (bPI) Combined With Emtricitabine/Tenofovir Disoproxil Fumarate (FTC/TDF) in Virologically-suppressed, Human Immunodeficiency Virus Type 1 (HIV-1) Infected Subjects

The purpose of this study is to demonstrate non-inferiority in efficacy while switching to a once-daily single-tablet regimen containing darunavir (DRV)/ cobicistat (COBI)/ emtricitabine (FTC)/ tenofovir alafenamide (TAF) (D/C/F/TAF tablet) relative to continuing the current regimen consisting of a boosted protease inhibitor (bPI) combined with tenofovir disoproxil fumarate (FTC/TDF) in virologically-suppressed (human immunodeficiency virus type 1 ribonucleic acid [HIV-1 RNA] concentrations less than [<] 50 copies per milliliter [copies/mL]) HIV-1 infected participants.

This is a randomized (study medication assigned to participants by chance), active-controlled (study in which the experimental treatment or procedure is compared to a standard treatment or procedure), open-label (participants and researchers are aware about the treatment, participants are receiving), multicenter (when more than 1 hospital or medical school team work on a medical research study), study in virologically-suppressed, HIV-1 infected adult participants. The study will include a Screening Period of approximately 30 days (up to maximum 6 weeks), a controlled Treatment Period of 48 weeks, an Extension Phase of 48 weeks. All eligible participants will be randomly assigned to receive either current treatment regimen - a bPI (limited to DRV with low-dose ritonavir [rtv] or COBI, atazanavir [ATV] with rtv or COBI, or lopinavir [LPV] with rtv) combined with FTC/TDF, or experimental treatment regimen - D/C/F/TAF once-daily single-tablet for 48 weeks. After completion of week 48, participants assigned to the experimental treatment will continue with D/C/F/TAF in the extension phase up to week 96 . Participants who continued their current regimen will receive the experimental treatment (if all criteria are fulfilled) at week 52 up to week 96. As from Week 96, all participants will be given the option to continue D/C/F/TAF treatment, if they wish and if they continue to benefit from it until D/C/F/TAF becomes commercially available and is reimbursed, or can be accessed through another source in the country where he/she is living,or until the sponsor terminates clinical development. A bone investigation substudy will be performed at selected study sites, to assess bone biomarkers and energy x-ray absorptiometry (DXA) scans, in approximately 300 participants (200 in the D/C/F/TAF treatment arm versus 100 in the control arm) who provide informed consent for the substudy.

Inclusion Criteria:

• Currently being treated with a stable antiretroviral (ARV) regimen consisting of a boosted protease inhibitor (limited to darunavir [DRV] or atazanavir with low-dose ritonavir [rtv] or cobicistat [COBI], or lopinavir with rtv) combined with emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) only, for at least 6 consecutive months preceding the Screening visit
• On-treatment plasma human immunodeficiency virus type 1 ribonucleic acid (HIV-1 RNA) concentrations less than (<) 50 copies per milliliter (copies/mL) or HIV-1 RNA undetectable by a local HIV-1 RNA test between 12 and 2 months prior to the Screening visit and have HIV-1 RNA <50 copies/mL at the Screening visit
• A single virologic elevation of greater than or equal to (>=) 50 copies/mL after previously reaching viral suppression between 12 and 2 months prior to Screening is acceptable, provided a subsequent test prior to Screening was <50 copies/mL
• Absence of history of failure on DRV treatment and absence of DRV resistance-associated mutations (RAMs), if documented historical genotypes are available
• Normal electrocardiogram (ECG) at Screening (or if abnormal, determined by the Investigator to be not clinically significant)

Exclusion Criteria:

• A new acquired immunodeficiency syndrome (AIDS) - defining condition diagnosed within the 30 days prior to Screening
• Proven or suspected acute hepatitis within 30 days prior to study entry
• Hepatitis C antibody positive; however, participants previously cured of hepatitis C virus (HCV) infection, with documented sustained virologic response, that is, undetectable HCV RNA 24 weeks after the last dose of HCV treatment, are allowed to participate
• Hepatitis B surface antigen (HBsAg) positive
• Participants with cirrhosis as diagnosed based on local practices