The purpose of this study is to evaluate the safety and effects of an investigational drug called VX-147 in people who have APOL1-mediated chronic kidney disease (CKD), which occurs more frequently in people of African descent. CKD is a condition in which increased levels of protein are present in urine because the kidneys may not be working properly, possibly caused by changes in a gene called APOL1. CKD can lead to kidney failure which requires dialysis or a kidney transplant. Researchers will conduct blood and urine tests; only individuals with a particular change in the APOL1 gene will be allowed to participate in the study. Participants will be divided into groups. One group will receive VX-147, and the other will receive placebo (inactive substance).