A Switch to Doravirine/Islatravir (DOR/ISL) in Participants With Human Immunodeficiency Virus Type 1 (HIV-1) Who Are Virologically Suppressed on Antiretroviral Therapy (ART) (MK-8591A-051)

Open to people ages 18 years and up

• Is HIV-1 positive with plasma HIV-1 RNA <50 copies/mL at screening
• Has been receiving continuous, stable oral 2-drug or 3-drug combination (± PK booster) ART 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 regimen
• Female is not a participant of childbearing potential (POCBP); or if a POCBP uses an acceptable contraceptive method or abstains from penile-vaginal intercourse as their preferred and usual lifestyle; has a negative highly sensitive pregnancy test; and whose medical history, menstrual history, and recent sexual activity has been reviewed by the investigator

• 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 acquired immunodeficiency syndrome (AIDS)-defining opportunistic infection within 30 days prior to screening
• Has active hepatitis B virus (HBV) infection
• Has chronic hepatitis C virus (HCV) infection consistent with cirrhosis
• Has a ≤5 years prior history of malignancy
• Is taking or is anticipated to require systemic immunosuppressive therapy, immune modulators, or strong and moderate cytochrome P450 3A (CYP3A ) inducers
• Has taken long-acting HIV therapy at any time
• 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
• Has a documented or known virologic resistance to DOR