RDN-CKD Study is a prospective, randomized (1:1, central randomization), double-blind (unblinded interventionalist and blinded study team at each center), sham controlled, multicenter feasibility study. The purpose of the RDN-CKD Study is to demonstrate that renal denervation (RDN) effectively reduces 24-h ambulatory BP in 80 patients with chronic kidney disease (CKD) stage 3a or 3b.

1. Introduction Uncontrolled hypertension is more prevalent in patients with chronic kidney disease (CKD) and the risk of developing end-stage renal disease is increased in patients with uncontrolled hypertension. Clinical and experimental studies have clearly shown that sympathetic nerve activity is increased in CKD and substantially aggravates the progression of CKD. Recent clinical studies have indicated that invasive, catheter-based renal denervation (RDN) decreases the sympathetic nerve activity in the whole body and in particular in the kidneys. In patients with primary hypertension washed off of antihypertensive medications, RDN has been found to significantly decrease blood pressure (BP) in two randomized, double blind, sham-controlled studies.
2. Study Purpose The purpose of the RDN-CKD Study is to demonstrate that RDN effectively reduces 24-h ambulatory BP in patients with CKD stage 3.
3. Study Design RDN-CKD Study is a prospective, randomized (1:1, central randomization), double-blind (unblinded interventionalist and blinded study team at each center), sham controlled, multicenter feasibility study. All centers have participated at least in one of the sham-controlled trials in primary hypertension thereby having established an unblinded and a blinded team.
4. Patient Population

80 patients with CKD stages 3a or 3b (according to the currently used estimation formulas [MDRD, CKD-EPI] and uncontrolled hypertension.

5 Endpoints Primary Efficacy Endpoint The primary efficacy endpoint will be the change in systolic 24-h ambulatory BP at 6 months post-procedure compared between the 2 groups.

6 Visit and Follow-Up Schedule The primary efficacy endpoint will be assessed at 26 weeks (6 months) post-procedure in both cohorts; however, all subjects will be followed for a minimum of 12 months post-procedure. Scheduled in-clinic follow-up (FU) visits will occur at 3, 6, 12 (3 months), 19, 26 (6 months), 39 and 52 (12 months) weeks post procedure.

7 Blinding The subjects and all study personnel taking BP measurements will be blinded to the randomization. Subjects will complete a blinding assessment prior to hospital pre-discharge and at 3 weeks and 6 months FU.

8 Crossover to treatment Crossover of patients allocated to the sham group is allowed after 12 months. At that time, after 12 months of blinded FU, unblinding of the individual patient takes place. To be eligible for crossover treatment, patients have to fulfill the same BP criteria as specified at the inclusion criteria and exclusion criteria within the next 4 weeks after FU.

All randomized patients will be included in a registry after 12 months to capture long-term safety signals.

9 Medication Adherence Adherence to drug therapy will be captured by interviewing patients, checking the patient's BP diary and by urinary toxicological analysis at baseline, 6 months, and 12 months visit.

10 Safety Signals A major combined safety endpoint is the incidence of any major adverse events (MAE) through the 12 months FU.

11 Study Geographies The RDN-CKD Study will be conducted at 4 clinical investigational sites, which are the University Hospitals in Erlangen, Homburg/Saar, Düsseldorf, and Nürnberg.

12 Escape Criteria Enrolled subjects will be excluded if office (attended) BP exceeds ≥170/105 mmHg confirmed by 7-day average of home blood pressure measurements ≥ BP >160/100 mmHg or confirmed by office (attended) BP ≥170/105 mmHg at another study visit.

13 Ethics The study will be conducted in accordance with the declaration of Helsinki, ISO 14155:2011, FDA 21 CFR parts 50, 54, 56, 812 and other applicable local and national regulations.

Inclusion Criteria:

• CKD stage 3 (eGFR 30-59 ml/min/1.73m² [according to the currently used estimation formulas: MDRD, CKD-EPI]) with diabetic or non-diabetic nephropathy
• Uncontrolled hypertension with 1-5 drug classes (renin angiotensin system [RAS] blockade is mandatory, unless intolerance to RAS blockers has been documented) and systolic office (attended) BP ≥140 mmHg confirmed by 24-h ambulatory BP systolic ≥130 mmHg
• Patient is adhering to a stable drug regimen including RAS blockade without changes for a minimum of 4 weeks.
• Individual is ≥ 18 years of age, both genders are included.

Exclusion Criteria:

• Anatomically significant renal artery abnormality in either renal artery which in the eyes of the interventionalist would interfere with safe catheter Placement
• Other cause of Hypertension that can be treated by Intervention/surgery (e.g. hemodynamically relevant renal artery stenosis, functional adrenal adenoma)
• Prior renal denervation procedure
• Office (attended) BP ≥ 180 mmHg systolic and/or ≥ 110 mmHg diastolic
• 24-h ambulatory BP ≥ 160 mmHg systolic
• Anatomic or functional solitary kidney, kidney transplantation
• Lack of capturing serum creatinine levels in the past
• Secondary hypertension other than obstructive sleep apnea
• Type 1 diabetes mellitus
• Nephrotic syndrome
• Contraindication to magnetic resonance imaging (MRI)
• Individual has experienced a myocardial infarction, unstable angina pectoris, or a cerebrovascular accident within 3 months of the screening visit
• Acute episode of renal disease requiring uptitration of any immunosuppressive drug regimen within the last 3 months
• Subject is pregnant, nursing, or intends to become pregnant
• Enrollment in another interventional research protocol.
• Any condition that, at the discretion of the investigator, would preclude participation in the study (e.g. non-adherence)

The subjects and all study personnel taking BP measurements will be blinded to the randomization. Subjects will complete a blinding assessment prior to hospital pre-discharge and at 3 weeks, 6 months and 12 months FU.