A Study Evaluating the Safety and Efficacy of RDX013 for the Treatment of Hyperkalemia (Redukx)

A Two-Part Proof-of-Concept Study: An Open-Label Dose-Ranging Phase (Part A) Followed by a Randomized, Single-Blind, Placebo-Controlled Phase (Part B) Evaluating the Safety and Efficacy of RDX013 for the Treatment of Hyperkalemia

The purpose of this study is to evaluate the ability of RDX013 to lower serum potassium in patients with chronic kidney disease with elevated serum potassium levels

Study Overview

• Status: Completed
• Conditions: Hyperkalemia
• Intervention / Treatment: Drug: RDX013; Drug: Placebo

• Study Type: Interventional
• Enrollment (Actual): 109
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Florida
    • Coral Gables, Florida, United States, 33134
      • Horizon Research Group LLC
    • Miami Lakes, Florida, United States, 33014
      • Panax Clinical Research LLC
    • Miami Springs, Florida, United States, 33166
      • South Florida Research Phase I-IV; Inc.
  • Louisiana
    • Shreveport, Louisiana, United States, 71101
      • NW Louisiana Nephrology Assoc
  • Missouri
    • Kansas City, Missouri, United States, 64111
      • Clinical Research Consultants
  • North Carolina
    • Asheville, North Carolina, United States, 28801
      • Mountain Kidney & Hypertension Associates

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 81 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Males or females aged 18 to 85 years, inclusive
2. Serum potassium value 5.1 to <6.5 mmol/L
3. Chronic kidney disease with eGFR ≥20 to <60 mL/min/1.73m2
4. Able to understand and comply with the protocol
5. Willing and able to sign informed consent

Exclusion Criteria:

1. Pseudo-hyperkalemia signs and symptoms
2. Treatment with potassium-lowering drugs within 7 days prior to enrollment/randomization
3. Treatment with glucocorticoids
4. Uncontrolled Type 2 diabetes, defined as most recent historical HbA1c > 10%, or hospitalization to treat hyper- or hypo-glycemia in the past 3 months
5. Diabetic ketoacidosis
6. Severe heart failure, defined as NYHA (New York Heart Association) Class IV or hospitalization to treat heart failure in previous 3 months
7. History of bowel obstruction, severe gastrointestinal disorders, or major gastrointestinal surgery (e.g., large bowel resection)
8. Females who are pregnant, lactating, or not willing to use appropriate contraception

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: Single

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: RDX013 Cohort 1; RDX013 low dose oral dosage, twice daily	Drug: RDX013; RDX013 is an experimental drug that is a potassium secretagogue
Experimental: RDX013 Cohort 2; RDX013 low, mid dose oral dosage, twice daily	Drug: RDX013; RDX013 is an experimental drug that is a potassium secretagogue
Experimental: RDX013 Cohort 3; RDX013 high, mid dose oral dosage, twice daily	Drug: RDX013; RDX013 is an experimental drug that is a potassium secretagogue
Experimental: RDX013 Cohort 4; RDX013 high dose oral dosage, twice daily	Drug: RDX013; RDX013 is an experimental drug that is a potassium secretagogue
Experimental: RDX013 Part B; RDX013 dose from Part A oral dosage, twice daily	Drug: RDX013; RDX013 is an experimental drug that is a potassium secretagogue
Placebo Comparator: Placebo Part B; oral dosage, twice daily	Drug: Placebo; Placebo treatment that looks identical to experimental treatment

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in serum potassium; Part A	To evaluate the change of serum potassium from baseline to the end of treatment with different doses of RDX013 to identify the optimal dose for further evaluation in Part B of the study.	1 week
Change in serum potassium; Part B	To evaluate the difference between RDX013 and placebo in the change of serum potassium from baseline to the end of treatment.	4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Exporatory Objective; time to serum potassium normalization	To evaluate the time to initial normalization of serum potassium level (≥3.5 to ≤5.0 mmol/L) during the initial 24 hours of treatment.	4 weeks

Collaborators and Investigators

• Sponsor: Ardelyx

Study record dates

Study Major Dates

• Study Start (Actual): January 11, 2021
• Primary Completion (Actual): December 28, 2021
• Study Completion (Actual): March 3, 2022

Study Registration Dates

• First Submitted: January 26, 2021
• First Submitted That Met QC Criteria: March 2, 2021
• First Posted (Actual): March 4, 2021

Study Record Updates

• Last Update Posted (Actual): May 4, 2022
• Last Update Submitted That Met QC Criteria: May 3, 2022
• Last Verified: May 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Metabolic Diseases; Water-Electrolyte Imbalance; Hyperkalemia
• Other Study ID Numbers: RDX013-201

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No