Study to Assess Safety and Efficacy of Tenapanor for Treatment of IBS-C in Pediatric Patients 12 to Less Than 18 Years

Recruitment Status
RECRUITING
(See Contacts and Locations)Verified December 2025 by Ardelyx
Sponsor
Ardelyx
Information Provided by (Responsible Party)
Ardelyx
Clinicaltrials.gov Identifier
NCT05643534
Other Study ID Numbers:
TEN-01-304
First Submitted
November 29, 2022
First Posted
December 7, 2022
Last Update Posted
January 11, 2026
Last Verified
December 2025

ClinicalTrials.gov processed this data on January 2026. Link to the current ClinicalTrials.gov record .

History of Changes

Study Details

Study Description

This study consists of 2-week screening period followed by 12 week randomized treatment period (RTP) and a 2-week treatment-free Follow-Up period (only for patients who will not enter the 40-week Long Term Safety Extension Study \[TEN-01-306\]). At the beginning of the 2-week Screening period, patients who provide written assent will be fully assessed for eligibility into the study and will be asked to self-report daily information about the status of their IBS symptoms via an electronic diary (eDiary) device. Patient compliance with the eDiary will be monitored actively by the site staff and will be reviewed to determine eligibility at the end of screening. Eligible patients will be randomized to receive one of the study medications: tenapanor 25 mg BID, tenapanor 50 mg BID, or placebo.

During the 12-week double-blind RTP, patients will continue recording daily assessments via the eDiary system as instructed and compliance with eDiary entries will be monitored on an ongoing basis. Patients will return for study visit every two or four weeks (Visits 3-6) and will undergo safety assessments at these visits.

Patients who do not enter the 40-week Long Term Safety Extension Study \[TEN-01-306\] including those who complete the RTP but do not enter study TEN-01-306 and those who prematurely discontinue from the RTP, a Follow-Up Visit will be scheduled approximately 2 weeks after the completion of the RTP (Visit 6) or the Early Termination Visit at which safety assessments will be performed

Condition or DiseaseIntervention/Treatment
Irritable Bowel Syndrome With Constipation (IBS-C)
Drug: Tenapanor 50 MGDrug: Tenapanor 25 mg bidDrug: Placebo

Study Design

Study TypeInterventional
Actual Enrollment180 participants
Design AllocationRandomized
Interventional ModelParallel Assignment
MaskingDouble
Primary PurposeTreatment
Official TitleA 12-Week, Randomized, Double-Blind, Placebo-Controlled, Phase 3 Study to Assess the Safety and Efficacy of Tenapanor for the Treatment of Irritable Bowel Syndrome With Constipation (IBS-C) in Pediatric Patients 12 to Less Than 18 Years Old
Study Start DateNovember 14, 2022
Actual Primary Completion Date2w 2d from now
Actual Study Completion Date2w 2d from now

Groups and Cohorts

Group/CohortIntervention/Treatment
Tenpanor 50 mg BID
Patients will be randomized to receive 50 mg tenapanor twice daily
Drug: Tenapanor 50 MG
Participants will receive tenapanor 50 mg BID (total of 100 mg daily)
Tenpanor 25 mg BID
Patients will be randomized to receive 25 mg tenapanor twice daily
Drug: Tenapanor 25 mg bid
Participants will receive tenapanor 25 mg BID (total of 50 mg daily)
Placebo Comparator
Patients will be randomized to receive matching placebo twice daily
Drug: Placebo
Participants will be randomized to receive matching placebo

Outcome Measures

Primary Outcome Measures
  1. 6/12-week APS (abdominal pain and SBM) +2 response
    6/12-week APS (abdominal pain and SBM (spontaneous bowel movement)) +2 response, defined as achieving the weekly APS +2 response criteria (i.e., achieving both weekly SBM +2 response and weekly abdominal pain response during the same week) for ≥6 out of the 12 weeks of the RTP. * The weekly SBM +2 response is defined as having an increase of ≥2 from baseline in the average weekly SBM frequency for a given week * The weekly abdominal pain response is defined as having ≥30% reduction from baseline in the average weekly abdominal pain score for a given week
Secondary Outcome Measures
  1. 6/12-week SBM +2 response
    6/12-week SBM +2 response: defined as achieving the weekly SBM +2 response for ≥6 out of the 12 weeks of the RTP
  2. 6/12-week abdominal pain response
    6/12-week abdominal pain response: defined as achieving the weekly abdominal pain response for ≥6 out of the 12 weeks of the RTP
  3. Change from baseline in average weekly SBM frequency
    Change from baseline in average weekly SBM frequency
  4. Change from baseline in average weekly stool consistency score
    Change from baseline in average weekly stool consistency score
  5. Change from baseline in average weekly abdominal pain score
    Change from baseline in average weekly abdominal pain score
  6. Overall use of rescue medication
    Overall use of rescue medication

Eligibility Criteria

Ages Eligible for Study(Child)
Sexes Eligible for StudyAll
Accepts Healthy VolunteersNo
Inclusion Criteria
≥12 and \<18 years old
Patient weighs ≥18 kg at the time the patient provides written assent
Females of child-bearing potential must have negative pregnancy test at Visit 1 (serum) and Visit 2 (urine) and confirm the use of appropriate contraception (including abstinence).
Patient meets the Rome IV criteria for child/adolescent diagnosis of IBS-C
Patient is willing to discontinue any laxatives used in favor of the protocol-permitted rescue medicine (which will only be allowed after 72 hours with no bowel movement)
Patient meets the entry criteria assessed during the 2-week Screening period.
Ability of both the patient and parent/guardian/LAR to communicate with the Investigator and to comply with the requirements of the entire study, including an understanding of the assessments in the eDiary and how to use the eDiary device
Patient must provide written assent and the parent/guardian/LAR must provide written informed consent before the initiation of any study-specific procedures
Exclusion Criteria
Functional diarrhea as defined by Rome IV child/adolescent criteria
IBS with diarrhea (IBS-D), mixed IBS (IBS-M), or unsubtyped IBS as defined by Rome IV child/adolescent criteria
History of non-retentive fecal incontinence.
Required manual disimpaction any time prior to randomization (after consent);
Has both unexplained and clinically significant alarm symptoms (lower gastrointestinal \[GI\] bleeding \[rectal bleeding or heme-positive stool\], iron-deficiency anemia, or any unexplained anemia, or weight loss) and systemic signs of infection or colitis, or any neoplastic process
Patient has any of the following conditions:
Celiac disease, or positive serological test for celiac disease
Cystic fibrosis
Hypothyroidism that is untreated or treated with thyroid hormone
Down's syndrome or any other chromosomal disorder
Active anal fissure
Anatomic malformations (eg, imperforate anus)
Intestinal nerve or muscle disorders (eg, Hirschprung disease)
Neuropathic conditions (eg, spinal cord abnormalities)
Lead toxicity, hypercalcemia
Neurodevelopmental disabilities producing a cognitive delay that precludes comprehension and completion of the daily eDiary (Electronic handheld device)
Inflammatory bowel disease
Childhood functional abdominal pain syndrome
Childhood functional abdominal pain;
Poorly treated or poorly controlled psychiatric disorders that might influence his or her ability to participate in the study;
Lactose intolerance that is associated with abdominal pain or discomfort
History of cancer other than treated basal cell carcinoma of the skin; (Note: Patients with a history of cancer are allowed provided that the malignancy has been in a complete remission for at least 5 years before the Randomization Visit.)
History of diabetic neuropathy.
Use of medications that are known to affect stool consistency (Prohibited Medications), including fiber supplements, anti-diarrheals, cathartics, antacids, opiates, prokinetic drugs, laxatives, enemas, antibiotics during the Screening period; unless specified as rescue medication, and used accordingly as directed by the Investigator.
Patient has had surgery that meets any of the following criteria:
Bariatric surgery for treatment of obesity, or surgery to remove a segment of the GI tract at any time before the Screening Visit;
Surgery of the abdomen, pelvis, or retroperitoneal structures during the 6 months before the Screening Visit;
An appendectomy or cholecystectomy during the 60 days before the Screening Visit;
Other major surgery during the 30 days before the Screening Visit
History of alcohol or substance abuse
Participation in other clinical trials within 1 month prior to Screening
Patient and/or parent/guardian/LAR is involved in the conduct and/or administration of this trial as an investigator, sub-investigator, trial coordinator, or other staff member, or the patient is a first-degree family member, significant other, or relative residing with one of the above persons involved in the trial
If, in the opinion of the Investigator, the patient is unable or unwilling to fulfill the requirements of the protocol or has a condition, which would render the results uninterpretable

Contacts and Locations

Sponsors and CollaboratorsArdelyx
Locations
G & L Research, LLC | Foley Alabama, United States, 36535Eclipse Clinical Research | Tucson Arizona, United States, 85745Advanced Research Center, Inc. | Anaheim California, United States, 92805Connecticut Children's Medical Center | Hartford Connecticut, United States, 06106Prohealth Research Center | Doral Florida, United States, 33166I.H.S. Health, LLC | Kissimmee Florida, United States, 34741Waterway Research & Associates Corp | Miami Florida, United States, 33155Valencia Medical and Research Center | Miami Florida, United States, 33165Orlando Health, Inc.- APH Center for Digestive Health and Nutrition | Orlando Florida, United States, 32806Florida Pharmaceutical Research and Associates, Inc. | South Miami Florida, United States, 33143Clinical Research Institute | Stockbridge Georgia, United States, 30281OSF Saint Francis Medical Center | Peoria Illinois, United States, 61637Riley Children's Health IUH | Indianapolis Indiana, United States, 46202Maine Health | Portland Maine, United States, 04102Boston Children's Hospital | Boston Massachusetts, United States, 02115Mankato Clinic/ Javara Research Ltd | Mankato Minnesota, United States, 56001Children's Mercy Hospital | Kansas City Missouri, United States, 64108Boys Town National Research Hospital | Boys Town Nebraska, United States, 68010Med Clinical Research Partners, LLC | Irvington New Jersey, United States, 07111University of New Mexico Health Sciences Center | Albuquerque New Mexico, United States, 87131SUNY Downstate Medical Center | Brooklyn New York, United States, 11203University of Rochester | Rochester New York, United States, 14642Advantage Clinical Trials | The Bronx New York, United States, 10467Atrium Health | Charlotte North Carolina, United States, 28203Duke University School of Medicine | Durham North Carolina, United States, 27705M3 Wake Research, Inc | Raleigh North Carolina, United States, 27612Wilmington Health | Wilmington North Carolina, United States, 28401Frontier Clinical Research, LLC | Scottdale Pennsylvania, United States, 15683Frontier Clinical Research, LLC | Smithfield Pennsylvania, United States, 15478Velocity Clinical Research, Providence | East Greenwich Rhode Island, United States, 02818Prisma Health Children's Hospital | Greenville South Carolina, United States, 29615Advance Clinical Trial PLLC | Abilene Texas, United States, 79606Maspons Pediatric Gastro | El Paso Texas, United States, 79902Proactive El Paso, LLC | El Paso Texas, United States, 79902Texas Digestive Specialists | Harlingen Texas, United States, 78550AIM Trials, LLC | Plano Texas, United States, 75093Sun Research Institute | San Antonio Texas, United States, 78215Pioneer Research Solutions Inc | Sugar Land Texas, United States, 77479ClinPoint Trials | Waxahachie Texas, United States, 75165University Physicians and Surgeons, Inc. | Huntington West Virginia, United States, 25701Frontier Clinical Research | Kingwood West Virginia, United States, 26537
Investigators
Study Director: Susan Edelstein, PhD, Ardelyx