This randomized, double-blind, placebo-controlled Phase 2/3 adaptive study involves an initial investigational blood test to determine if you have a specific variation related to kidney disease. The investigational blood test is to see if you have changes in your DNA of a gene called APOL1. People who have this gene variation may be at risk of losing their kidney function faster than others. If you have the variants (changes in DNA) you may be eligible to continue participation in the study. If you do not have the variants, you will not be eligible, and the study doctor will discuss your other options with you. If you decide to participate, there will be no cost to you and you will be compensated. This study will start by comparing two doses of VX-147 against placebo in subjects with APOL1-mediated kidney disease for 12 weeks. Subjects in Phase 2 will continue to Phase 3 once a dose for Phase 3 is selected. Then the Phase 3 dose of VX-147 will be evaluated for safety and effectiveness. If you meet the requirements and choose to take part in the study, you will be randomly assigned to a treatment group. You will not know which study treatment group you are assigned to and it is possible that you will receive placebo instead of VX-147. The study includes a screening, treatment, and follow-up period. The study will end after the last patient enrolled has completed 2 years in the study. This means some patients enrolling earlier could be in the study for up to 4 years.