NCT06810167 · Massachusetts General Hospital
Assessing Tenapanor as a Treatment of CF-related Constipation.
What this study is about
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.
View original scientific description
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.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Having confirmed cystic fibrosis (either by sweat chloride or genetic testing)
- 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
- Willingness to avoid major dietary or lifestyle changes during study.
Exclusion criteria
- 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)
- 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).
- Severe CFrC as determined by study team
- Prior tenapanor usage
- Hospitalization within 4-weeks prior to study initiation.
- DIOS within 4-weeks prior to study initiation.
- Other known/suspected mechanical obstruction
Where
- Boston, Massachusetts
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Mar 18, 2026 · Source of record for eligibility and locations