 This is a Phase 1, multicenter, open-label, 2-part study designed to assess the PK, safety, and tolerability of KBP-5074 in patients undergoing HD and non-HD patients with severe CKD defined using the eGFR 15 mLmin1.73 m2 and 29 mLmin1.73 m2 based on the MDRD equation. The study will be conducted at up to 4 clinical research units CRUs in the US. Approximately 12 patients will be enrolled in the study a single cohort of 6 patients in each of Part 1 and Part 2. Parts 1 and 2 of the study will be conducted in parallel. If Part 1 is completed prior to the completion of Part 2, or vice versa, the PK, safety, and tolerability analyses for the completed study part may proceed as planned and will not be delayed based on the timing of the other respective study part. 