DOR/ISL in HIV-1 Antiretroviral Treatment-naïve Participants (MK-8591A-053)

This is a randomized, active-controlled, double-blind clinical study designed to evaluate the antiretroviral activity, safety, and tolerability of doravirine/islatravir (DOR/ISL \[MK-8591A\]) in treatment-naïve participants with human immunodeficiency virus type 1 (HIV-1) infection. It is hypothesized that DOR/ISL is non-inferior to bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) as assessed by the percentage of participants with HIV-1 ribonucleic acid (RNA) \<50 copies/mL at Week 48.

Inclusion Criteria: * Is HIV-1 positive with plasma HIV-1 RNA ≥500 copies/mL at screening * Is naïve to antiretroviral therapy (ART) defined as having received no prior therapy with any antiretroviral agent following a diagnosis of HIV-1 infection * If female, is not a participant of childbearing potential (POCBP); or if a POCBP, is not pregnant or breastfeeding, and is willing to use an acceptable contraceptive method or abstain from heterosexual intercourse for study duration Exclusion Criteria: * Has HIV-2 infection * Has hypersensitivity or other contraindication to any of the components of the study interventions as determined by the investigator * Has a diagnosis of an active AIDS-defining opportunistic infection within 30 days prior to screening * Has active hepatitis B infection (defined as hepatitis B surface antigen \[HBsAg\]-positive or HBV deoxyribonucleic acid \[DNA\]-positive). * Has chronic hepatitis C virus (HCV) infection (detectable HCV ribonucleic acid \[RNA\]) and lab values are consistent with cirrhosis * Has 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 sarcoma * Has a history or current evidence of any condition (including active tuberculosis infection), therapy, laboratory abnormality, or other circumstance (including drug or alcohol use or dependence) that might, in the opinion of the investigator, confound the results of the study or interfere with the participant's participation for the full duration of the study, such that it is not in the best interest of the participant to participate