A Study Evaluating the Onset-of-Action, Safety, and Efficacy of RDX227675 for the Treatment of Hyperkalemia

Study Overview
=================
Brief Summary
-----------------
This phase 2, single-blind, placebo-controlled study will evaluate the onset-of-action, safety, and efficacy of RDX227675 for the treatment of hyperkalemia. Subjects who qualify are randomized into one of four treatment groups: Group 1 (Placebo qd), Group 2 (RDX227675 10 g qd), Group 3 (RDX227675 20 g qd), Group 4 (RDX227675 30 g qd).

Detailed Description
-----------------
The study consists of a screening visit, a 7-day treatment period, and a 7-day treatment-free follow-up period.

Official Title
-----------------
A Single-Blind, Placebo-Controlled Study Evaluating the Onset-of-Action, Safety, and Efficacy of RDX227675 for the Treatment of Hyperkalemia

Conditions
-----------------
Hyperkalemia

Intervention / Treatment
-----------------
* Drug: RDX227675
* Drug: Placebo


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: 18 to 85 years old, inclusive Two consecutive i-STAT K values ≥ 5.5 to < 6.5 mmol/L, measured a minimum of 60-minutes apart within 1 day of first RDX227675 dose on Day 1 (prior to randomization) i-STAT K value ≥ 5.5 to < 6.5 mmol/L on Day 1 (prior to randomization) Ability to have repeated blood draws or effective venous catheterization Females of child bearing potential must have negative urine pregnancy test on Day 1 (prior to randomization) Females but be non-pregnant, non-lactating, and either be post-menopausal for at least 12 months, have documentation of irreversible surgical sterilization, or confirm the use of one of the acceptable contraceptive methods Males must agree to use an appropriate method of contraception or have documented surgical sterilization Exclusion Criteria: Pseudohyperkalemia signs and symptoms Treatment with K lowering drugs, within 7 days prior to randomization Uncontrolled Type 2 diabetes, as defined as most recent historical HbA1c > 10%, or hospitalization to treat hyper- or hypo-glycemia in the past 3 months Diabetic ketoacidosis Known hypersensitivity to polystyrene sulfonate Significant cardiovascular or cerebrovascular events in the past 2 months Severe heart failure, defined as NYHA (New York Heart Association) class IV or hospitalization to treat heart failure in previous 3 months History of bowel obstruction, swallowing disorders, severe gastrointestinal disorders, or major gastrointestinal surgery Major psychiatric disorder (DSM-III-R or DSM-IV) including major depression or other psychoses that has required hospitalization in the last 3 years. History of attempted suicide or uncontrolled bipolar disorder. Use of an investigational product within 30 days prior to Screening

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>Microcrystalline Cellulose (MCC), 2 g qd. Subjects assigned to the Placebo group will be randomly assigned in a 1:1:1 ratio to receive either one, two, or three bottles of drug per day. | Drug: Placebo<br> <br> |
| Experimental: 10 g qd<br>RDX227675, 10 g qd | Drug: RDX227675<br> <br> |
| Experimental: 20 g qd<br>RDX227675, 20 g qd | Drug: RDX227675<br> <br> |
| Experimental: 30 g qd<br>RDX227675, 30 g qd | Drug: RDX227675<br> <br> |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Exponential Rate of Change in Serum Potassium from Baseline | Onset of Action | 48 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Serum Potassium Levels |  | 7 days | 
| Incidence of Treatment - Emergent Adverse Events [Safety and Tolerability] |  | 7 days |