Efficacy and Safety of Ocedurenone: Subgroup Analysis of the BLOCK-CKD Study.

BACKGROUND: Ocedurenone (KBP-5074), a nonsteroidal mineralocorticoid receptor antagonist, is documented to lower blood pressure in patients with stage 3b/4 chronic kidney disease (CKD) with uncontrolled or resistant hypertension (BLOCK-CKD study). However, the efficacy and safety of Ocedurenone in subgroups such as Hispanic patients or those with stage 4 CKD, diabetes, or very high albuminuria have not been reported. METHODS: A total of 162 patients were enrolled in the BLOCK-CKD study. The primary endpoint of these analyses was change in systolic blood pressure (SBP) from baseline to day 84. Prespecified subgroup analysis of SBP focused on demographic (e.g., ethnicity, age) and medical (e.g., CKD stage, diabetes, albuminuria, baseline estimated glomerular filtration rate [eGFR]). The safety analysis focused on changes in serum potassium levels from baseline. RESULTS: SBP reductions were consistent across subgroups compared with the overall study cohort. Placebo-adjusted SBP reductions were observed in Hispanic patients (-8.1 and -9.9 mm Hg for 0.25 and 0.5 mg, respectively, total n = 35) and patients with CKD stage 4 (-9.3 and -10.4 mm Hg for 0.25 and 0.5 mg, respectively, total n = 64), diabetes (-6.9 and -11.6 mm Hg for 0.25 and 0.5 mg, respectively, total n = 51), and very high albuminuria (-13.1 and -12.3 mm Hg for 0.25 and 0.5 mg, respectively, total n = 85). Changes in serum potassium were similar across all patient subgroups regardless of baseline eGFR, diabetes status, or degree of proteinuria. No cases of hyperkalemia required intervention or resulted in study discontinuation. CONCLUSIONS: Ocedurenone consistently reduced in SBP in all patient subgroups. Moreover, while small elevations in serum potassium occurred, they were not associated with Ocedurenone or study discontinuation.

The Non-Steroidal Mineralocorticoid Receptor Antagonist KBP-5074 Limits Albuminuria and has Improved Therapeutic Index Compared With Eplerenone in a Rat Model With Mineralocorticoid-Induced Renal Injury.

The therapeutic indices (TIs) and efficacy of the non-steroidal mineralocorticoid receptor antagonist (MRA) KBP-5074 and steroidal MRA eplerenone were evaluated in a uninephrectomized Sprague Dawley rat model of aldosterone-mediated renal disease. In two parallel studies, rats were placed on a high-salt diet and received aldosterone by osmotic mini-pump infusion over the course of 27 days. The urinary albumin-to-creatinine ratio (UACR) was evaluated after 7, 14, and 26 days of treatment. Serum K+ was evaluated after 14 and 27 days of treatment. Urinary Na+, urinary K+, and urinary Na+/K+ ratio were evaluated after 7, 14, and 26 days of treatment. The TI was calculated for each drug as the ratio of the concentration of drug producing 50% of maximum effect (EC50) for increasing serum K+ to the EC50 for lowering UACR. The TIs were 24.5 for KBP-5074 and 0.620 for eplerenone, resulting in a 39-fold improved TI for KBP-5074 compared with eplerenone. Aldosterone treatment increased UACR, decreased serum K+, and decreased urinary Na+ relative to sham-operated controls that did not receive aldosterone infusion in both studies, validating the aldosterone/salt renal injury model. KBP-5074 prevented the increase in UACR at 0.5, 1.5, and 5 mg/kg BID while eplerenone did so only at the two highest doses of 50 and 450 mg/kg BID. Both KBP-5074 and eplerenone blunted the reduction in serum K+ seen in the aldosterone treatment group, with significant increases in serum K+ at the high doses only (5 mg/kg and 450 mg/kg BID, respectively). Additionally, the urinary Na+ and Na+/K+ ratio significantly increased at the middle and high doses of KBP-5074, but only at the highest dose of eplerenone. These results showed increased TI and efficacy for KBP-5074 compared with eplerenone over a wider therapeutic window.

Effect of KBP-5074 on Blood Pressure in Advanced Chronic Kidney Disease: Results of the BLOCK-CKD Study.

[Figure: see text].

Mineralocorticoid Receptor Antagonists for Hypertension Management in Advanced Chronic Kidney Disease: BLOCK-CKD Trial.

Spironolactone, a steroidal mineralocorticoid receptor antagonist, is recommended as add-on therapy for treatment-resistant/uncontrolled hypertension. However, caution is advised in patients with advanced chronic kidney disease (CKD) due to an increased risk for hyperkalemia. KBP-5074 is a nonsteroidal mineralocorticoid receptor antagonist under investigation for the treatment of treatment-resistant and uncontrolled hypertension in patients with moderate-to-severe CKD. BLOCK-CKD is a phase 2, international, multicenter, randomized, double-blind, placebo-controlled, parallel-group study to evaluate the efficacy and safety of KBP-5074, on top of current therapy, in patients with stage 3B/4 CKD (estimated glomerular filtration rate ≥15 and ≤44 mL/[min·1.73 m2]) and resistant hypertension (trough cuff seated systolic blood pressure ≥140 mm Hg, despite treatment with maximally tolerated doses of 2 or more antihypertensive medicines with complementary mechanisms). Patients (n=240) will be randomized 1:1:1 to once-daily treatment with KBP-5074 0.25 mg, KBP-5074 0.5 mg, or placebo, stratified by estimated glomerular filtration rate (≥30 versus <30 mL/[min·1.73 m2]) and systolic blood pressure (≥160 versus <160 mm Hg). Approximately 30% of enrolled patients should have an estimated glomerular filtration rate of 15 to 29 mL/(min·1.73 m2). The primary efficacy analysis is the change in trough cuff seated systolic blood pressure from baseline to day 84 for the KBP-5074 doses compared with placebo. Changes in urinary albumin-creatinine ratio will be assessed along with changes in serum potassium/incidence of hyperkalemia and changes in estimated glomerular filtration rate and serum creatinine. BLOCK-CKD will determine whether the addition of KBP-5074 will effectively lower blood pressure without an increased risk of hyperkalemia in patients who are not candidates for steroidal mineralocorticoid receptor antagonists due to advanced CKD. Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT03574363.