Introduction: BLOCK-CKD is a Phase 2b, multicenter, randomized, double-blind, placebo-controlled study evaluating the safety, efficacy, and pharmacokinetics of the nonsteroidal MRA Ocedurenone (KBP-5074) in patients with stage 3b/4 CKD and uncontrolled hypertension while taking 2 or more antihypertensive medications. Hypothesis: Although the study is not powered for subgroup analysis, it is of interest to examine the consistency of results across various subgroups. Methods: Of 162 patients randomized, 138 (85.2%) completed the study. Effect of Ocedurenone on SBP reduction and serum potassium levels by baseline eGFR < 30, eGFR ≥ 30, and diabetic status was explored. Results: Consistent and clinically meaningful SBP reduction at Day 84 was observed in the subgroups analyzed. SBP mean (SE) change from baseline to day 84 in the eGFR < 30 group were 0.2 (3.03), -12.7 (5.45), and -15.4 (5.01) for placebo, 0.25mg, and 0.5mg doses respectively. In the ≥ 30 group, the changes were -9.7 (3.38), -10.8 (3.29), and -16.1 (4.08), respectively. In the diabetic patient group, the changes were -4.2 (4.22), -11.8 (5.91), and -13.0 (6.5) respectively. In the non-diabetic patient group, the changes were -6.0 (2.93), -11.4 (3.34), and -17.1 (3.51) respectively. Similar small dose-dependent increases in serum potassium were observed in nearly all subpopulations. Changes from baseline to day 84 in SBP by baseline eGFR and diabetic status and the corresponding changes in serum potassium and eGFR by baseline eGFR and diabetic status are shown in Figure 1. Conclusions: In this Phase 2 trial, the effect of Ocedurenone on SBP reduction and serum potassium levels was consistent among clinically important subgroups. Due to the relatively small number of patients these conclusions need to be confirmed in the larger ongoing Phase 3 trial.