Tenapanor for cystic fibrosis-related constipation

An Open-label, Single Center Study Assessing Tenapanor as a Non-CFTR-mediated Treatment of CF-related Constipation in People With CF.

This study will try tenapanor 50 mg twice daily for four weeks to see if it helps people with cystic fibrosis who have constipation.

Quick facts

• Phase: Phase 3
• Study type: Interventional
• Enrollment: 25 (estimated)
• Ages: 18 Years to 75 Years
• Sex: All
• Sponsor: Massachusetts General Hospital (Academic / other)
• Locations: 1 site (Boston, Massachusetts)
• Trial ID: NCT06810167 on ClinicalTrials.gov

What this trial studies

This Phase 3 interventional trial at Massachusetts General Hospital gives participants oral tenapanor 50 mg twice daily for a four-week treatment period and tracks outcomes. Participants complete validated questionnaires (PAC-SYM, PAC-QoL, IBS-SSS) and daily diaries to record gastrointestinal symptom burden and spontaneous bowel movement frequency. Eligible participants must have confirmed cystic fibrosis and meet criteria for CF-related constipation (two or more specified bowel symptoms for at least three months with onset at least six months prior). The trial focuses on changes in bowel frequency and patient-reported constipation symptoms over the treatment period.

Who should consider this trial

Good fit: People with confirmed cystic fibrosis who meet the defined CFrC symptom criteria and are willing to take an oral medication and avoid major diet or lifestyle changes during the study.

Not a fit: Patients who recently used antibiotics to treat infection within four weeks before enrollment or who are excluded by the protocol, or whose constipation is due to causes other than CFrC, may not receive benefit from this treatment.

Why it matters

Potential benefit: If successful, tenapanor could increase spontaneous bowel movements and reduce constipation symptoms in people with cystic fibrosis.

How similar studies have performed: Tenapanor is FDA-approved and has demonstrated benefit for IBS with constipation, but using it specifically for cystic fibrosis-related constipation is novel and not yet well studied.

Eligibility criteria

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

Where this trial is running

Boston, Massachusetts

• Massachusetts General Hospital — Boston, Massachusetts, United States (Recruiting)

Study contacts

• Principal investigator: Christoher D Velez, MD — Massachusetts General Hospital
• Study coordinator: Chloe Butzel, BA

Conditions Cystic Fibrosis; Constipation; CFrC