A 12-Week Study With a 4-Week Randomized Withdrawal Period to Evaluate the Efficacy and Safety of Tenapanor for the Treatment of IBS-C

Phase 3

Completed

• Conditions: Constipation Predominant Irritable Bowel Syndrome
• Interventions: Drug: Placebo; Drug: Tenapanor

• Registration Number: NCT02621892
• Lead Sponsor: Ardelyx

Brief Summary

This phase 3, 12-week, randomized, double-blind, placebo-controlled, multi-center study will evaluate the safety and efficacy of tenapanor in subjects with constipation-predominant irritable bowel syndrome (IBS-C) as defined by the ROME III criteria and who have active disease as determined after a two-week screening period. Subjects who qualify and are randomized into the study will either receive 50mg BID of tenapanor or placebo BID for 12 week treatment period and then undergo a 4 week placebo controlled randomized withdrawal.

Detailed Description

During the 12-week treatment period, subjects will record daily assessments including: frequency and timing of bowel movements; sensation and complete bowel emptying; consistency of bowel movements; degree of straining, worst abdominal pain, abdominal discomfort, abdominal bloating, abdominal fullness and abdominal cramping. Subjects will also record weekly assessments including: adequate relief of IBS severity, and constipation severity.

At the end of the 12-week treatment period, there will be a 4-week randomized withdrawal period in which subjects who complete the study in Tenapanor group will be randomized to either Tenapanor 50mg BID or placebo BID (1:1) and subjects who complete the study in the placebo group will be assigned to receive Tenapanor 50mg BID.

Study Timeline

• Study Start: 2015-10
• Study First Submitted: 2015-12-02
• Study First Submitted QC: 2015-12-02
• Study First Posted: 2015-12-04
• Primary Completion: 2017-03
• Study Completion: 2017-04
• Disposition First Submitted: 2019-03-12
• Disposition First Submitted QC: 2019-03-12
• Disposition First Posted: 2019-03-15
• Results First Submitted: 2020-03-30
• Status Verified: 2020-04
• Results First Submitted QC: 2020-04-10
• Last Update Submitted: 2020-04-10
• Results First Posted: 2020-04-21
• Last Update Posted: 2020-04-21

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 606

Inclusion Criteria

• 18 to 75 years old
• Females must be of non-childbearing potential; If of child-bearing potential, must have negative pregnancy test and confirm the use of one of the appropriate means of contraception.
• Males must agree to use an appropriate method of barrier contraception or have documented surgical sterilization
• Subject meets definition of IBS-C using Rome III Criteria for the Diagnosis of IBS
• A colonoscopy based on AGA guidelines; every 10 years at ≥ 50 years old, or the occurrence of any warning signs

Exclusion Criteria

• Functional diarrhea as defined by Rome III criteria
• IBS with diarrhea (IBS-D), mixed IBS (IBS-M), or unsubtyped IBS as defined by Rome III criteria
• Diagnosis or treatment of any clinically symptomatic biochemical or structural abnormality of the GI tract within 6 months prior to screening, or active disease within 6 months prior to screening; including but not limited to cancer, inflammatory bowel disease, diverticulitis, duodenal ulcer, erosive esophagitis, gastric ulcer, pancreatitis (within 12 months of screening), cholelithiasis, amyloidosis, ileus, non-controlled GERD, gastrointestinal obstruction, ischemic colitis or carcinoid syndrome.
• Subject has a history or current evidence of laxative abuse (in the clinical judgment of the physician)
• Hepatic dysfunction (ALT [SGPT] or AST [SGOT] >2.5 times the upper limit of normal) or renal impairment (serum creatinine > 2mg/dL)
• Any evidence of or treatment of malignancy (other than localized basal cell, squamous cell skin cancer or cancer in situ that has been resected) within the previous year
• Any surgery on the stomach, small intestine or colon, excluding appendectomy or cholecystectomy (unless within 60 days of screening visit)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Placebo
50mg BID	Tenapanor	Tenapanor

Primary Outcome Measures

Name	Time	Method
6 of 12 Week Overall Responder Rate	12 weeks	An overall responder is defined as a weekly responder for the first 6/12 weeks where both CSBM and abdominal pain response criteria were met for the week. The CSBM response criteria are defined as an increase of one or more change in average weekly CSBMs from baseline. The definition of a CSBM is as follows: A CSBM is a spontaneous bowel movement (SBM) for which the subject responds "yes" to the following question; "Did you feel like you completely emptied your bowels?" The abdominal pain response criterion is defined as a decrease of 30% or more of percent change in average weekly worst abdominal pain from baseline.

Secondary Outcome Measures

Name	Time	Method
6 of 12 Week Overall Complete Spontaneous Bowel Movement (CSBM)Responder Rate	12 weeks	An overall CSBM responder is defined as a weekly responder for the first 6/12 weeks. The CSBM response criteria are defined as an increase of one or more change in average weekly CSBMs from baseline. The definition of a CSBM is as follows: A CSBM is a spontaneous bowel movement (SBM) for which the subject responds "yes" to the following question; "Did you feel like you completely emptied your bowels?"
9 of 12 Week Overall Responder Rate	12 weeks	An overall responder is defined as a weekly responder for the first 9/12 weeks where both CSBM and abdominal pain response criteria were met for the week. The CSBM response criteria are defined as an increase of one or more change in average weekly CSBMs from baseline and a minimum of at least 3 CSBMs that same week. The definition of a CSBM is as follows: A CSBM is a spontaneous bowel movement (SBM) for which the subject responds "yes" to the following question; "Did you feel like you completely emptied your bowels?" The abdominal pain response criterion is defined as a decrease of 30% or more of percent change in average weekly worst abdominal pain from baseline.
6 of 12 Week Overall Abdominal Pain Responder Rate	12 weeks	An overall abdominal pain responder is defined as a weekly responder for the first 6/12. The abdominal pain response criterion is defined as a decrease of 30% or more of percent change in average weekly worst abdominal pain from baseline.
9 of 12 Week Overall CSBM Responder Rate	12 weeks	An overall CSBM responder is defined as a weekly responder for the first 9/12 weeks. The CSBM response criteria are defined as an increase of one or more change in average weekly CSBMs from baseline and a minimum of at least 3 CSBMs that same week. The definition of a CSBM is as follows: A CSBM is a spontaneous bowel movement (SBM) for which the subject responds "yes" to the following question; "Did you feel like you completely emptied your bowels?"
9 of 12 Week Overall Abdominal Pain Responder Rate	12 weeks	An overall abdominal pain responder is defined as a weekly responder for the first 9/12 weeks. The abdominal pain response criterion is defined as a decrease of 30% or more of percent change in average weekly worst abdominal pain from baseline.

Trial Locations

Locations (111)

Ardelyx Investigative Site 149; 🇺🇸 Birmingham, Alabama, United States

Ardelyx Investigative Site 114; 🇺🇸 Birmingham, Alabama, United States

Ardelyx Investigative Site 103; 🇺🇸 Huntsville, Alabama, United States

Ardelyx Investigative Site 100; 🇺🇸 Huntsville, Alabama, United States

Ardelyx Investigative Site 145; 🇺🇸 Chandler, Arizona, United States

Ardelyx Investigative Site 210; 🇺🇸 Phoenix, Arizona, United States

Ardelyx Investigative Site 296; 🇺🇸 Phoenix, Arizona, United States

Ardelyx Investigative Site 277; 🇺🇸 Tempe, Arizona, United States

Ardelyx Investigative Site 269; 🇺🇸 Tucson, Arizona, United States

Ardelyx Investigative Site 187; 🇺🇸 Tucson, Arizona, United States

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