A Phase 3b, Randomized, Open-Label Study to Evaluate the Safety and Efficacy of Switching from Regimens Consisting of Abacavir/Lamivudine (ABC/3TC) plus a Third Antiretroviral Agent to the Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Alafenamide (E/C/F/TAF) Fixed-Dose Combination (FDC) in Virologically-Suppressed HIV-1 Infected Adult Subjects

INTERVENTION:

Trade Name: Genvoya Product Code: E/C/F/TAF 150mg/150mg/200mg/10mg Pharmaceutical Form: Film‐coated tablet INN or Proposed

INN:

Elvitegravir CAS Number: 697761‐98‐1 Other descriptive name: ELVITEGRAVIR Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 150‐ INN or Proposed

INN:

COBICISTAT CAS Number: 1004316‐88‐4 Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 150‐ INN or Proposed

INN:

EMTRICITABINE CAS Number: 143491‐57‐0 Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 200‐ INN or Proposed

INN:

Tenofovir alafenamide CAS Number: 379270‐37‐8 Other descriptive name: TENOFOVIR ALAFENAMIDE Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 10‐

CONDITION:

Human Immunodeficiency Virus (HIV‐1) Infection ; MedDRA version: 19.0 Level: LLT Classification code 10068341 Term: HIV‐1 infection System Organ Class: 100000004862 Therapeutic area: Diseases [C] ‐ Virus Diseases [C02]

PRIMARY OUTCOME:

Main Objective: To evaluate the efficacy of switching to E/C/F/TAF FDC relative to continuing on a baseline regimen consisting of ABC/3TC plus a third antiretroviral agent in maintaining HIV‐1 RNA < 50 copies/mL at Week 24 (using FDA snapshot algorithm) in virologically suppressed, HIV‐1 infected adult subjects Primary end point(s): Proportion of subjects with HIV‐1 RNA <50 copies/mL at Week 24 as defined by the FDA snapshot algorithm Secondary Objective: ‐ To evaluate the proportion of subjects maintaining virological response (defined as HIV‐1 RNA < 50 copies/mL, FDA snapshot analysis) at Weeks 12 and 48; ‐ To evaluate changes from baseline in CD4+ cell counts at Weeks 24 and 48; ‐ To evaluate the safety and tolerability of the two treatment groups over 24 and 48 weeks Timepoint(s) of evaluation of this end point: Week 24

SECONDARY OUTCOME:

Secondary end point(s): 1) Proportion of subjects with HIV‐1 RNA <50 copies/mL at Weeks 12 and 48 as defined by the FDA snapshot algorithm ; 2) The change from baseline in CD4+ cell counts at Weeks 24 and 48 Timepoint(s) of evaluation of this end point: 1) Weeks 12 and 48 ; 2) Weeks 24 and 48

INCLUSION CRITERIA:

1) The ability to understand and sign a written informed consent form, which must be obtained prior to initiation of study procedures 2) Age = 18 years 3) Currently receiving ABC/3TC plus a third antiretroviral (ARV) agent for = 6 consecutive months prior to the screening visit. For subjects with 3 or more ART regimens, a regimen history must be provided to the Sponsor for approval. 4) Documented plasma HIV‐1 RNA levels < 50 copies/mL for = 6 months preceding the screening visit (measured at least twice using the same assay). 5) Plasma HIV‐1 RNA level < 50 copies/mL at screening visit 6) All documented historical plasma genotype(s) must not show resistance to TDF or FTC, including, but not limited to the presence of reverse transcriptase resistance mutants K65R, K70E, M184V/I, or thymidine analog‐associated mutations (TAMs) (TAMs are: M41L, D67N, K70R, L210W, T215Y/F, K219Q/E/N/R). If historical plasma genotype prior to first ART is not avai