The goal of this clinical study is to learn more about the experimental drugs GS-1720 and GS-4182; to compare the combination of GS-1720 and GS-4182 with the current standard-of-care treatment bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF, BVY), to see if the combination of GS-1720 and GS-4182 is safe and if it works for treating human immunodeficiency virus type 1 (HIV-1) infection. This study has two phases: Phase 2 and Phase 3. The primary objectives of this study are: Phase 2: To evaluate the efficacy of switching to oral weekly GS-1720 in combination with GS-4182 versus continuing BVY in virologically suppressed people with HIV-1 (PWH) at Week 24. Phase 3: To evaluate the efficacy of switching to oral weekly GS-1720/GS-4182 Fixed-dose combination (FDC) tablet regimen versus continuing BVY in virologically suppressed PWH at Week 48.