A Switch to Doravirine/Islatravir (DOR/ISL) in Participants With Human Immunodeficiency Virus Type 1 (HIV-1) Who Are Virologically Suppressed on Bictegravir/Emtricitabine/Tenofovir Alafenamide (BIC/FTC/TAF) (MK-8591A-052)

The primary objectives of this study are to evaluate the antiretroviral activity of a switch to DOR/ISL compared with continued BIC/FTC/TAF at Week 48; and to evaluate the safety and tolerability of a switch to DOR/ISL compared with continued BIC/FTC/TAF, through Week 48. The primary hypotheses are that (1) DOR/ISL is non-inferior to continued BIC/FTC/TAF, as assessed by the percentage of participants with HIV-1 ribonucleic acid (RNA) ≥50 copies/mL at Week 48, with a margin of 4 percentage points used to define non-inferiority; and (2) DOR/ISL is superior to BIC/FTC/TAF, as assessed by the percentage of participants with HIV-1 RNA ≥50 copies/mL at Week 48.

The key inclusion and exclusion criteria include but are not limited to the following:Inclusion Criteria:Is HIV-1 positive with plasma HIV-1 RNA <50 copies/mLHas been receiving BIC/FTC/TAF therapy with documented viral suppression (HIV-1 RNA <50 copies/mL) for ≥3 consecutive months prior to providing documented informed consent and has no history of prior virologic treatment failure on any past or current regimenFemale is not a participant of childbearing potential (POCBP); or if a participant of childbearing potential, not pregnant or breastfeeding, and is willing to use an acceptable contraceptive method or abstain from heterosexual intercourse for study durationExclusion Criteria:Has HIV-2 infectionHas a diagnosis of an active acquired immunodeficiency syndrome (AIDS)-defining opportunistic infection within 30 days prior to screeningHas active hepatitis B virus (HBV) infectionHas chronic hepatitis C virus (HCV) infection with laboratory values consistent with cirrhosisHas a history of malignancy ≤5 years prior to providing documented informed consent except for adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, or cutaneous Kaposi's sarcomaIs taking or is anticipated to require systemic immunosuppressive therapy, immune modulators, or strong and moderate cytochrome P450 3A (CYP3A ) inducersHas a documented or known virologic resistance to DORHas taken long-acting HIV therapy at any time (e.g., cabotegravir, lenacapavir)Is currently participating in or has participated in a clinical study and received (or is receiving) an investigational compound or device from 45 days prior to Day 1 through the study treatment period except those currently enrolled in the comparator arm of an ongoing DOR/ISL study