A Study to Evaluate the Safety and Efficacy of RDX5791 for the Treatment of Constipation Predominant Irritable Bowel Syndrome (IBS-C)

Study Overview
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Brief Summary
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This is a multi-center, Phase 2, randomized, double-blind, placebo controlled study of RDX5791 in subjects with IBS-C. Patients who are 18 to 75 years old, meeting the definition of IBS-C as defined by the Rome III Criteria for the Diagnosis of IBS will undergo a battery of screening procedures to determine eligibility for the trial. The study will consist of a 2-week treatment-free screening period, a 4-week blinded treatment period, and a 2-week treatment-free follow-up period.

Official Title
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A Randomized, Double-Blind, Placebo-Controlled Study to Assess the Safety and Efficacy of RDX5791 for the Treatment of Constipation-Predominant Irritable Bowel Syndrome (IBS-C)

Conditions
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Constipation Predominant Irritable Bowel Syndrome

Intervention / Treatment
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* Drug: RDX5791


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject meets Rome III criteria for IBS-C If > 50 years old, colonoscopy evaluation within 10 years All ages, negative colonoscopy if any warning symptoms Active disease during 2-week screening period Compliant with IVRS Exclusion Criteria: Subjects has IBS-D, IBS-M or un-subtyped IBS according to Rome III criteria Diagnosis or treatment of any clinically symptomatic biochemical or structural abnormality of the GI tract Use of medications that are known to affect stool consistency Subject has any protocol-excluded or clinically significant medical or surgical history that could confound the study assessments or prevent completion of study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>Capsule that is identical in size and color to other treatments | Drug: RDX5791<br>* Capsule, QD<br>|
| Experimental: Low Dose<br>10 mg capsule of tenapanor | Drug: RDX5791<br>* Capsule, QD<br>|
| Experimental: Mid Dose<br>30 mg capsule of tenapanor | Drug: RDX5791<br>* Capsule, QD<br>|
| Experimental: High Dose<br>100 mg capsule of tenapanor | Drug: RDX5791<br>* Capsule, QD<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Complete Spontaneous Bowel Movement (CSBM) Frequency Change From Baseline | Patients complete a phone diary daily. They are asked how many bowel movements have you had today? they are then asked for each spontaneous bowel movement (unaided with laxative use) wether there was its was a complete evacuation. if it was then it is a complete spontaneous bowel movement. All CSBMs are added and adjusted for a mean compete sponteneous bowel movement. | Baseline and Week 4 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Spontaneous Bowel Movement (SBM) Frequency Change From Baseline |  | baseline and week 4 |