 This study aims to evaluate a switch from fixed dose combination FDC treatment with ATRIPLATM for 12 weeks prior to screening to FDC treatment with MK-1439A in virologically-suppressed, human immunodeficiency virus type 1 HIV-1-infected participants. The primary hypothesis is that switching from ATRIPLATM to MK-1439A results in a lower proportion of participants with at least one CNS toxicity of at least Grade 2 intensity at Week 12 than continuation of ATRIPLATM treatment. 