Assessing Tenapanor as a Treatment of CF-related Constipation.

Phase 3

Not yet recruiting

• Conditions: Cystic Fibrosis; Constipation
• Interventions: Drug: Tenapanor

• Registration Number: NCT06810167
• Lead Sponsor: Massachusetts General Hospital

Brief Summary

Tenapanor is the newest FDA-approved drug for IBS with constipation (IBS-C). This study seeks to understand tenapanor as a treatment for cystic fibrosis-related constipation (CFrC) in CF patients. Participants will ingest one 50 mg tablet of tenapanor, twice daily, for a 4-week treatment period. They will also complete three questionnaires, the PAC-SYM, PAC-QoL, and IBS-SSS, and daily diaries to characterize GI symptom burden and spontaneous bowel movement (SBM) frequency.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2025-01-23
• Study First Submitted QC: 2025-01-31
• Study First Posted: 2025-02-05
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-06
• Last Update Posted: 2025-05-09
• Study Start: 2025-06-01
• Primary Completion: 2026-02-01
• Study Completion: 2027-06-30

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 25

Inclusion Criteria

1. Having confirmed cystic fibrosis (either by sweat chloride or genetic testing)

2. Meeting criteria for CFrC

   Must include 2 of the following, with or without abdominal pain for at least 3 months, with symptom onset at least 6-months prior:

   • Straining in at least 25% of defecations
   • Bristol Stool Scale 1-2 more than 25% of defecations (change in stool form)
   • Sensation of incomplete evacuation more than 25% of defecations
   • Sensation of anorectal obstruction/blockage more than 25% of defecations
   • Manual disimpaction/manipulation of pelvic floor to facilitate more than 25% of defecations
   • Fewer than 3 spontaneous bowel movements weekly (change in stool frequency)
   • Loose stools rarely present without the use of laxatives

3. Willingness to avoid major dietary or lifestyle changes during study.

Exclusion Criteria

1. Use of any antibiotic to treat infection within the 4-weeks prior to study initiation (stable azithromycin dosed 3-times weekly for lung function is to be allowed)
2. Inability to discontinue standing bowel regimen (including fiber, stool softener, as well as either osmotic or stimulant laxative, pro-kinetic serotonergic agents, or other therapy) 2-weeks prior to study drug initiation (with ability to use osmotic laxative therapy as rescue therapy only).
3. Severe CFrC as determined by study team
4. Prior tenapanor usage
5. Hospitalization within 4-weeks prior to study initiation.
6. DIOS within 4-weeks prior to study initiation.
7. Other known/suspected mechanical obstruction

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Cystic fibrosis patients with CF-related constipation	Tenapanor	-

Primary Outcome Measures

Name	Time	Method
Increase in SBM frequency	Patients will record SBM frequency over the 4-week treatment period.	There will be a statistically significant increase in spontaneous bowel movement frequency (SBM) in cystic fibrosis patients with CF-related constipation receiving tenapanor.

Secondary Outcome Measures

Name	Time	Method
Change in PAC-SYM questionnaire score	Patients will complete the PAC-SYM at -2 weeks, 0 weeks, 2 weeks, and 4 weeks.	There will be a change (with use of descriptive statistics) in bowel symptoms characterized by the Patient Assessment of Constipation Symptoms (PAC-SYM) questionnaire with tenapanor administration. PAC-SYM is a PRO previously used to examine constipation in pwCF. A decreased score corresponds to improvement of bowel symptoms.
Change in PAC-QOL questionnaire score	Patients will complete the PAC-QOL at -2 weeks, 0 weeks, 2 weeks, and 4 weeks.	There will be a change (with use of descriptive statistics) in bowel symptoms characterized by the Patient Assessment of Constipation Quality of Life (PAC-QOL) questionnaire with tenapanor administration. PAC-QOL is a PRO previously used to examine constipation in pwCF. A decreased score corresponds to improvement of bowel symptoms.
Change in IBS-SSS questionnaire score	Patients will complete the IBS-SSS at -2 weeks, 0 weeks, 2 weeks, and 4 weeks.	There will be a 50-point change in the Irritable Bowel Syndrome Scoring System - IBS-SSS (in line with recent bowel distress related literature Ford AC, Wright-Hughes A, Alderson SLet al Lancet 2023) in pwCF and CFrC receiving tenapanor.