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

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)

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.

Study Overview

• Status: Completed
• Conditions: Constipation Predominant Irritable Bowel Syndrome
• Intervention / Treatment: Drug: RDX5791

• Study Type: Interventional
• Enrollment (Actual): 186
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • California
    • San Diego, California, United States, 92108
      • Ardelyx Investigational Site
  • Florida
    • Jupiter, Florida, United States, 33458
      • Ardelyx Investigational Site
    • Pinellas Park, Florida, United States, 33782
      • Ardelyx Investigational Site
  • Illinois
    • Rockford, Illinois, United States, 61107
      • Ardelyx Investigational Site
  • Kansas
    • Mission, Kansas, United States, 66202
      • Ardelyx Investigational Site
  • Louisiana
    • Monroe, Louisiana, United States, 71201
      • Ardelyx Investigational Site
  • Maryland
    • Annapolis, Maryland, United States, 21401
      • Ardelyx Investigational Site
  • Michigan
    • Chesterfield, Michigan, United States, 48047
      • Ardelyx Investigational Site
  • Missouri
    • Saint Louis, Missouri, United States, 63128
      • Ardelyx Investigational Site
  • New York
    • Brooklyn, New York, United States, 11214
      • Ardelyx Investigational Site
  • North Carolina
    • Greensboro, North Carolina, United States, 27408
      • Ardelyx Investigational Site
  • Oklahoma
    • Oklahoma City, Oklahoma, United States, 73104
      • Ardelyx Investigational Site
  • South Carolina
    • Simpsonville, South Carolina, United States, 29681
      • Ardelyx Investigational Site
  • Tennessee
    • Bristol, Tennessee, United States, 37620
      • Ardelyx Investigational Site
  • Utah
    • Ogden, Utah, United States, 84405
      • Ardelyx Investigational Site
  • Virginia
    • Lynchburg, Virginia, United States, 24502
      • Ardelyx Investigational Site

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

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

What is the study measuring?

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	Time Frame
Spontaneous Bowel Movement (SBM) Frequency Change From Baseline	baseline and week 4

Collaborators and Investigators

• Sponsor: Ardelyx
• Investigators: Study Chair: David P Rosenbaum, Ph.D., Ardelyx

Publications and helpful links

Helpful Links

• Related Info

Study record dates

Study Major Dates

• Study Start: May 1, 2011
• Primary Completion (Actual): December 1, 2011
• Study Completion (Actual): February 1, 2012

Study Registration Dates

• First Submitted: April 20, 2011
• First Submitted That Met QC Criteria: April 20, 2011
• First Posted (Estimate): April 22, 2011

Study Record Updates

• Last Update Posted (Actual): October 15, 2019
• Last Update Submitted That Met QC Criteria: September 25, 2019
• Last Verified: September 1, 2019

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Digestive System Diseases; Pathologic Processes; Disease; Signs and Symptoms, Digestive; Gastrointestinal Diseases; Colonic Diseases, Functional; Colonic Diseases; Intestinal Diseases; Syndrome; Irritable Bowel Syndrome; Constipation
• Other Study ID Numbers: RDX5791-201