A 26-Wk Study to Assess Safety & Efficacy of Tenapanor for T/t of Chronic Idiopathic Constipation in Adults

March 13, 2026 updated by: Ardelyx

A 26-Week, Multi-Center, Randomized, Double-Blind, Placebo-Controlled Study to Assess the Safety and Efficacy of Tenapanor for the Treatment of Chronic Idiopathic Constipation (CIC) in Adults

This is a 26-week, multi-center, randomized, double-blind, placebo-controlled study with a 4-week treatment-free Safety Follow-up period to assess the safety and efficacy of tenapanor (5 mg, 25mg, and 50 mg) in adult patients with Chronic Idiopathic Constipation (CIC) when administered twice daily for 26 consecutive weeks.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This study consists of a 2-week Screening period, followed by a 26-week randomized treatment period (RTP), and a 4-week treatment-free Safety Follow-up period.

After obtaining study informed consent from patients, the 2-week Screening period starts. Patients will be fully assessed for eligibility into the study. The assessments will include evaluation of inclusion/exclusion criteria, including medical histories, physical examination, vital signs, 12-lead electrocardiogram (ECG), and clinical laboratory tests.

Patients will also self-report, on information about the status of their constipation symptoms and severity via an electronic diary (eDiary). Patient compliance with the eDiary will be monitored to determine eligibility at the end of screening.

Eligible patients will be randomized (Visit 2) to receive tenapanor 5 mg BID (twice a day), 25 mg BID, 50 mg BID, or placebo for 26 consecutive weeks as the double-blind RTP. During this period, patients will continue recording daily assessments of constipation symptoms and weekly assessments of constipation severity in the eDiary. Patients will have return visits every two to six weeks at Weeks 2, 4, 8, 12, 16, 20 and 26(Visit 3-9) to undergo safety assessments.

Upon completion of the 26-week RTP, patients will be monitored for AEs (adverse events) during the 4-week treatment-free Safety Follow-up period and complete the Follow-up visit (Visit 10) at the end of this period to undergo safety assessments.

Study Type

Interventional

Enrollment (Estimated)

692

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Arizona
      • Chandler, Arizona, United States, 85225
        • Recruiting
        • Arizona Liver Health - Chandler
        • Principal Investigator:
          • Anita Kohli, MD
        • Contact:
      • Phoenix, Arizona, United States, 85018
        • Recruiting
        • Elite Clinical Studies
        • Principal Investigator:
          • Joseph Lillo, MD
        • Contact:
    • Arkansas
      • North Little Rock, Arkansas, United States, 72117
        • Recruiting
        • Arkansas Gastroenterology - North Little Rock
        • Contact:
        • Principal Investigator:
          • Johnathan Goodwin, MD
    • California
      • Canoga Park, California, United States, 91303
        • Recruiting
        • Hope Clinical Research - Canoga Park
        • Principal Investigator:
          • Hessam Aazami, MD
        • Contact:
      • Chula Vista, California, United States, 91910
        • Recruiting
        • Erick H. Alayo Medical Corporation
        • Principal Investigator:
          • Erick Alayo, MD
        • Contact:
      • Chula Vista, California, United States, 91010
        • Recruiting
        • GW Research Inc.
        • Contact:
        • Principal Investigator:
          • Patrick H Sweet, MD
      • Inglewood, California, United States, 90301
      • Lancaster, California, United States, 93534
      • Lincoln, California, United States, 95648
        • Recruiting
        • Clinical Trials Research
        • Contact:
        • Principal Investigator:
          • Jeffrey D Wayne, MD
      • Santa Ana, California, United States, 92703
        • Recruiting
        • Paragon Rx Clinical, Inc. - Santa Ana
        • Contact:
        • Principal Investigator:
          • Long Dang, MD
    • Colorado
      • Lakewood, Colorado, United States, 80228
        • Recruiting
        • Rocky Mountain Gastroenterology (RMG) - Littleton
        • Contact:
        • Principal Investigator:
          • Andrew Korson, MD
    • Florida
      • Fort Lauderdale, Florida, United States, 33308
        • Recruiting
        • Proactive Clinical Research
        • Contact:
        • Principal Investigator:
          • David Mishkin, MD
      • Miami, Florida, United States, 33174
      • Miami, Florida, United States, 33176
        • Recruiting
        • IMIC, Inc
        • Contact:
        • Principal Investigator:
          • Miguel Rodriguez, MD
      • New Port Richey, Florida, United States, 34652
        • Recruiting
        • Suncoast Clinical Research, Inc. - New Port Richey
        • Principal Investigator:
          • Cathy Barnes, MD
        • Contact:
      • Ocoee, Florida, United States, 34761
        • Recruiting
        • Sensible HealthCare, LLC
        • Contact:
        • Principal Investigator:
          • William (Kelly) Bowman, MD
      • Orange City, Florida, United States, 32763
        • Recruiting
        • Harmony Clinical Research - Orlando
        • Contact:
        • Principal Investigator:
          • Glenda Rosa Gonzalez, MD
      • Palm Harbor, Florida, United States, 34684
        • Recruiting
        • Suncoast Clinical Research, Inc. - Palm Harbor
        • Principal Investigator:
          • Gary Goldstein, MD
        • Contact:
      • Pompano Beach, Florida, United States, 33060
        • Recruiting
        • Clinical Research Center of Florida
        • Principal Investigator:
          • Howard Koch, MD
        • Contact:
    • Georgia
      • Atlanta, Georgia, United States, 30328
        • Recruiting
        • Agile Clinical Research Trials, LLC
        • Principal Investigator:
          • Vasundhara Cheekati, MD
        • Contact:
      • Atlanta, Georgia, United States, 30329
        • Recruiting
        • DelRicht Clinical Research - Atlanta
        • Contact:
        • Principal Investigator:
          • Robert Springer, MD
      • Marietta, Georgia, United States, 30060
        • Recruiting
        • Gastrointestinal Specialists of Georgia PC
        • Principal Investigator:
          • Aasim Sheikh, MD
        • Contact:
      • Woodstock, Georgia, United States, 30189
    • Idaho
      • Blackfoot, Idaho, United States, 83221
        • Recruiting
        • Elite Clinical Trials-Idaho
        • Principal Investigator:
          • Paul Beckett, MD
        • Contact:
    • Illinois
      • Gurnee, Illinois, United States, 60031
        • Recruiting
        • Clinical Investigation Specialists, Inc
        • Contact:
        • Principal Investigator:
          • John Agaiby, MD
    • Indiana
      • Indianapolis, Indiana, United States, 46202
        • Recruiting
        • DelRicht Clinical Research - Indianapolis
        • Contact:
        • Principal Investigator:
          • Rachael Holliday, MD
    • Kansas
      • Overland Park, Kansas, United States, 66209
        • Recruiting
        • DelRicht Clinical Research - Overland Park
        • Contact:
        • Principal Investigator:
          • Jonathan Jacobs
    • Kentucky
      • Louisville, Kentucky, United States, 40205
        • Recruiting
        • DelRicht Clinical Research - Louisville
        • Principal Investigator:
          • Michael Lovelace, MD
        • Contact:
    • Louisiana
      • Houma, Louisiana, United States, 70363
        • Recruiting
        • Tandem Clinical Research GI - Houma
        • Contact:
        • Principal Investigator:
          • Conar Fitton, MD
      • Mandeville, Louisiana, United States, 70471
        • Recruiting
        • DelRicht Clinical Research - Covington
        • Contact:
        • Principal Investigator:
          • Rachael Murphy, MD
      • Marrero, Louisiana, United States, 70072
        • Recruiting
        • Tandem Clinical Research
        • Principal Investigator:
          • Gary Reiss, MD
        • Contact:
      • New Orleans, Louisiana, United States, 70115
        • Recruiting
        • DelRicht Clinical Research - New Orleans
        • Principal Investigator:
          • Patrick Dennis, MD
        • Contact:
      • Prairieville, Louisiana, United States, 70769
        • Recruiting
        • DelRicht Clinical Research - Prairieville
        • Principal Investigator:
          • Taylor Sanders, MD
        • Contact:
      • West Monroe, Louisiana, United States, 71291
        • Recruiting
        • Delta Research Partners of West Monroe, LLC
        • Contact:
        • Principal Investigator:
          • Clarence Dunn, MD
    • Maryland
      • Glen Burnie, Maryland, United States, 21061
        • Recruiting
        • Woodholme Gastroenterology
        • Contact:
        • Principal Investigator:
          • Kenolisa Onwueme, MD
    • Massachusetts
      • Springfield, Massachusetts, United States, 01103
        • Recruiting
        • Elixia SISU BHR - Sprinfield
        • Contact:
        • Principal Investigator:
          • Brittany Perreault, MD
      • Watertown, Massachusetts, United States, 02472
        • Recruiting
        • Bay State Clinical Trials
        • Principal Investigator:
          • Henry David Mitcheson, MD
        • Contact:
    • Mississippi
      • Gulfport, Mississippi, United States, 39503
        • Recruiting
        • DelRicht Clinical Research - Gulfport
        • Contact:
        • Principal Investigator:
          • Sean Kerby, MD
    • Missouri
      • Kansas City, Missouri, United States, 64131
        • Recruiting
        • Kansas City Research Institute
        • Contact:
        • Principal Investigator:
          • Paresh Patel, MD
      • Springfield, Missouri, United States, 65807
        • Recruiting
        • DelRicht Clinical Research - Springfield
        • Contact:
        • Principal Investigator:
          • Luke Van Kirk, MD
      • St Louis, Missouri, United States, 63141
      • Town and Country, Missouri, United States, 63017
        • Recruiting
        • DelRicht Clinical Research - Town and Country
        • Principal Investigator:
          • Amy Roberts, MD
        • Contact:
    • Montana
      • Columbia Falls, Montana, United States, 65201
        • Recruiting
        • Gastrointestinal Associates LLP
        • Principal Investigator:
          • Michael Williams, MD
        • Contact:
    • Nevada
      • Las Vegas, Nevada, United States, 89109
      • Las Vegas, Nevada, United States, 89128
        • Recruiting
        • Digestive Disease Specialists
        • Principal Investigator:
          • Michael Zimmerman, MD
        • Contact:
      • Reno, Nevada, United States, 89511
        • Recruiting
        • Advanced Research Institute - Reno
        • Principal Investigator:
          • George Vagujhelyi, MD
        • Contact:
    • New Jersey
      • Jackson, New Jersey, United States, 08724
        • Recruiting
        • Allied Health Clinical Research Organization, LLC (AHCRO) - Jackson
        • Principal Investigator:
          • William Basri, MD
        • Contact:
      • Somers Point, New Jersey, United States, 08244
        • Recruiting
        • Allied Digestive Health - Jersey Shore Gastroenterology - Point Commons
        • Contact:
        • Principal Investigator:
          • Paul Ljubich, MD
    • New Mexico
      • Albuquerque, New Mexico, United States, 87102
        • Recruiting
        • Albuquerque Clinical Trials (ACT)
        • Principal Investigator:
          • Satkirin Khalsa, MD
        • Contact:
    • New York
      • Brooklyn, New York, United States, 11235
        • Recruiting
        • NY Scientific
        • Principal Investigator:
          • Alexander Brun, MD
        • Contact:
      • Hartsdale, New York, United States, 10530
        • Recruiting
        • Drug Trials America
        • Contact:
        • Principal Investigator:
          • Michael Gerdis, MD
    • North Carolina
      • Charlotte, North Carolina, United States, 28210
        • Recruiting
        • Delricht Clinical Research - Badmus
        • Contact:
          • Keith Logan
        • Principal Investigator:
          • Olabisi Badmus, MD
      • High Point, North Carolina, United States, 27260
      • Morehead City, North Carolina, United States, 28557
        • Recruiting
        • Lucas Research - Diabetes & Endocrinology Consultants, PC
        • Contact:
        • Principal Investigator:
          • Kathryn Jean Locus, MD
    • Ohio
      • Columbus, Ohio, United States, 43215
        • Recruiting
        • Remington Davis, Inc.
        • Contact:
        • Principal Investigator:
          • Roy St. John, MD
      • Columbus, Ohio, United States, 43213
        • Recruiting
        • Centricity Research Columbus Ohio Multispecialty
        • Principal Investigator:
          • Sridhar Guduri, MD
        • Contact:
      • Huber Heights, Ohio, United States, 45424
        • Recruiting
        • Hometown Urgent Care and Research - Huber Heights
        • Principal Investigator:
          • Steve Choi, MD
        • Contact:
      • Mentor, Ohio, United States, 44060
        • Recruiting
        • Great Lakes Gastroenterology Research
        • Principal Investigator:
          • Keith Friedenberg, MD
        • Contact:
    • Oklahoma
      • Tulsa, Oklahoma, United States, 74133
        • Recruiting
        • DelRicht Clinical Research - Tulsa
        • Principal Investigator:
          • Melita Tate, MD
        • Contact:
      • Yukon, Oklahoma, United States, 73099
        • Recruiting
        • Tekton Research - Yukon, OK
        • Principal Investigator:
          • Robert Lockwood, MD
        • Contact:
    • Oregon
      • Tigard, Oregon, United States, 97223
        • Recruiting
        • Advanced Research Institute - Portland
        • Contact:
        • Principal Investigator:
          • James Bergthold, MD
    • South Carolina
      • Charleston, South Carolina, United States, 29407
        • Recruiting
        • DelRicht Clinical Research - Charleston
        • Contact:
        • Principal Investigator:
          • E. Marshall Newton, MD
      • North Charleston, South Carolina, United States, 29405
    • Tennessee
      • Bristol, Tennessee, United States, 37620
        • Recruiting
        • Accellacare of Bristol
        • Contact:
        • Principal Investigator:
          • Bernard Grunstra, MD
      • Hendersonville, Tennessee, United States, 37075
        • Recruiting
        • DelRicht Clinical Research - Nashville
        • Contact:
        • Principal Investigator:
          • Kymberly Moyer, MD
      • Knoxville, Tennessee, United States, 37909
        • Recruiting
        • New Phase Research & Development - Knoxville
        • Contact:
        • Principal Investigator:
          • Amanda Miller, MD
      • Nashville, Tennessee, United States, 37211
        • Recruiting
        • Quality Medical Research, PLLC
        • Contact:
        • Principal Investigator:
          • Saras Sharma, MD
    • Texas
      • Dallas, Texas, United States, 75230
      • DeSoto, Texas, United States, 75115
        • Recruiting
        • Epic Medical Research
        • Principal Investigator:
          • Haresh Boghara, MD
        • Contact:
      • El Paso, Texas, United States, 79925
        • Recruiting
        • 3A Research
        • Principal Investigator:
          • Aldo Maspons, MD
        • Contact:
      • North Richland Hills, Texas, United States, 76180
        • Recruiting
        • North Hills Medical Research Inc. (North Hills Family Medicine)
        • Contact:
        • Principal Investigator:
          • John Gabriel, MD
      • Pearland, Texas, United States, 77584
        • Recruiting
        • LinQ Research, LLC
        • Contact:
        • Principal Investigator:
          • Jignesh Shah, MD
      • Prosper, Texas, United States, 75078
        • Recruiting
        • DelRicht Clinical Research - McKinney
        • Contact:
        • Principal Investigator:
          • Jennifer Zomnir, MD
      • San Antonio, Texas, United States, 78215
        • Recruiting
        • Sun Research Institute
        • Principal Investigator:
          • Leonel Reyes, MD
        • Contact:
    • Utah
      • Ogden, Utah, United States, 84405
        • Recruiting
        • Advanced Research Institute - Ogden
        • Principal Investigator:
          • John Lowe, MD
        • Contact:
      • Sandy City, Utah, United States, 84092
        • Recruiting
        • Advanced Research Institute - Sandy
        • Principal Investigator:
          • Robert Barnett, MD
        • Contact:
    • Virginia
      • Charlottesville, Virginia, United States, 22911
        • Recruiting
        • Charlottesville Medical Research Center, LLC
        • Contact:
        • Principal Investigator:
          • Kristen Holtz, MD
      • Newport News, Virginia, United States, 23606
        • Recruiting
        • Health Research of Hampton Roads, Inc. - Newport News
        • Principal Investigator:
          • George Freeman, MD
        • Contact:
      • Vienna, Virginia, United States, 22182
        • Recruiting
        • DelRicht Clinical Research - Vienn
        • Contact:
        • Principal Investigator:
          • Vijayendra Jaligam, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Patients ≥18 to ≤80 years old at the Screening visit (Visit 1).
  2. Meet the Rome IV Diagnostic Criteria for functional constipation.
  3. Females of non-childbearing potential, or agree to the use of an acceptable means of contraception for up to 30 days following the last dose of study medication.
  4. Males must agree to use an appropriate method of barrier contraception or have documented surgical sterilization.
  5. Meets the entry criteria assessed during the Screening period.
  6. Ability to understand and provide input on the assessments in the eDiary.
  7. Provide written informed consent before the initiation of any study-specific procedures.
  8. Must agree to have daily access to eDiary via a computer, tablet or smart phone

Exclusion Criteria:

  1. Loose or watery stool in the absence of any medication that is known to affect stool consistency for >25% of bowel movements (BMs) during the 3 months prior to the Screening visit
  2. Fecal impaction within 6 months prior to the Screening visit
  3. Unexplained and clinically significant alarm symptoms.
  4. Functional diarrhea as defined by Rome IV criteria
  5. IBS with constipation (IBS-C), IBS with diarrhea (IBS-D), mixed IBS (IBS-M), or unsubtyped IBS as defined by Rome IV criteria
  6. Diagnosis or treatment of any clinically symptomatic abnormality of the GI tract or active disease within 6 months prior to the Screening visit
  7. Patient with central nervous system disorder
  8. Use of prohibited medications defined by protocol
  9. Patient has a history or current evidence of laxative abuse
  10. Hepatic dysfunction
  11. Positive HIV, hepatitis B or hepatitis C test at screening
  12. Positive urinary drug test at Screening, with the exception of cannabis and cannabidiol (CBD)
  13. Any evidence of or treatment of malignancy within 1 year prior to the Screening visit
  14. Any surgery on the stomach, small intestine or colon; appendectomy or cholecystectomy are not excluded unless within 60 days prior to the Screening visit
  15. Pregnant women or women planning to become pregnant during trial participation
  16. A major psychiatric disorder that has required hospitalization in the last year prior to the Screening visit.
  17. Alcohol or substance abuse within 1 year prior to the Screening visit
  18. Participation in other clinical trials within 1 month prior to the Screening visit
  19. Clinical evidence of significant disease that may interfere with the patient's successful completion of the trial

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Tenapanor 5 mg BID
Patients will be randomized to receive 5 mg tenapanor twice daily.
Drug: Tenapanor 5 mg BID
Patients will receive tenapanor 5 mg BID (total of 10 mg daily)
Experimental: Tenapanor 25 mg BID
Patients will be randomized to receive 25 mg tenapanor twice daily.
Drug: Tenapanor 25 mg BID
Patients will receive tenapanor 25 mg BID (total of 50 mg daily)
Experimental: Tenapanor 50 mg BID
Patients will be randomized to receive 50 mg tenapanor twice daily.
Drug: Tenapanor 50 mg BID
Patients will receive tenapanor 50 mg BID (total of 100 mg daily)
Placebo Comparator: Placebo Comparator
Patients will be randomized to receive matching placebo twice daily.
Drug: Placebo
Patients will receive matching placebo BID

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Durable complete spontaneous bowel movements (CSBM) response
Time Frame: 12 Weeks
Durable complete spontaneous bowel movements (CSBM) response is defined as achieving the weekly CSBM response for ≥9 out of the first 12 weeks of the randomized treatment period and and for ≥3 of the last 4 weeks of the first 12 weeks of randomized treatment period
12 Weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
9/12 week complete spontaneous bowel movements (CSBM) response
Time Frame: 12 Weeks
9/12 week complete spontaneous bowel movements (CSBM) response defined as achieving the weekly CSBM response for ≥9 out of the first 12 weeks of the randomized treatment period.
12 Weeks
Change from baseline in complete spontaneous bowel movements (CSBM) frequency
Time Frame: 12 Weeks
Change from baseline over the first 12 weeks of the randomized treatment period in complete spontaneous bowel movements (CSBM) frequency
12 Weeks
Change from baseline in spontaneous bowel movement (SBM) frequency
Time Frame: 12 Weeks
Change from baseline over the first 12 weeks of the randomized treatment period in spontaneous bowel movement (SBM) frequency
12 Weeks
Change from baseline in stool consistency
Time Frame: 12 Weeks
Change from baseline over the first 12 weeks of the randomized treatment period in stool consistency
12 Weeks
Change from baseline in stool straining
Time Frame: 12 Weeks
Change from baseline over the first 12 weeks of the randomized treatment period in straining
12 Weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Ardelyx

Investigators

  • Study Director: Susan Edelstein, PhD, Ardelyx Inc

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 13, 2026

Primary Completion (Estimated)

February 26, 2027

Study Completion (Estimated)

June 4, 2027

Study Registration Dates

First Submitted

January 26, 2026

First Submitted That Met QC Criteria

January 26, 2026

First Posted (Actual)

February 2, 2026

Study Record Updates

Last Update Posted (Actual)

March 17, 2026

Last Update Submitted That Met QC Criteria

March 13, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • TEN-03-301

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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