A Phase III, Randomized, Multicenter, Parallel-group, Non-inferiority Study Evaluating the Efficacy, Safety, and Tolerability of Switching to Dolutegravir Plus Lamivudine in HIV-1 Infected Adults Who Are Virologically Suppressed

The aim of the study is to establish if human immunodeficiency virus type 1 (HIV-1) infected
adult participants with current virologic suppression on a >=3-drug tenofovir alafenamide
(TAF) based regimen (TBR) remain suppressed upon switching to a two-drug regimen of
dolutegravir (DTG) 50 milligram (mg) + lamivudine (3TC) 300 mg. This study will also provide
important information regarding the safety and participant satisfaction with this two-drug
regimen. The primary objective of this trial is to demonstrate the non-inferior antiviral
activity of switching to DTG + 3TC once daily compared to continuation of TBR over 48 weeks
in HIV-1 infected, antiretroviral therapy (ART)-experienced, virologically suppressed
participants. This study also will characterize the long-term antiviral activity,
tolerability and safety of DTG + 3TC compared to TBR through Week 144 and characterize the
long-term antiviral activity, tolerability and safety of DTG + 3TC through Week 200.

This will be a 200-week, Phase III, randomized, open-label, active-controlled, multicenter,
parallel- group study. The study will include a screening phase (up to 28 days), a randomized
early switch phase (Day 1 up to Week 148), a randomized late switch phase (Week 148 up to
Week 200), and a continuation phase (post Week 200). HIV-1 infected adults on stable TBR will
be randomized 1:1 to switch to DTG + 3TC once daily for up to 200 weeks, or to continue their
TBR for 148 weeks, at which time and if HIV-1 ribonucleic acid (RNA) <50 copies per
milliliter (c/mL) at Week 144, these participants will switch to DTG + 3TC up to Week 200.