Phase 3 Cystic Fibrosis Trial, Recruiting
Who may be able to join
AI generated eligibility summary. Written by an AI model from the official source data and checked on a sample basis. It can contain mistakes, so confirm anything important against the original source. How we use AI
Who might be able to join this trial:
- People who have been diagnosed with cystic fibrosis, confirmed either through a sweat chloride test or genetic testing.
- People who have cystic fibrosis-related constipation (CFrC), meaning they have experienced at least 2 of the following symptoms for at least 3 months, with those symptoms starting at least 6 months before joining the trial: needing to strain during more than 1 in 4 bowel movements; passing hard or lumpy stools more than 25% of the time; feeling like the bowel hasn't fully emptied more than 25% of the time; feeling a blockage in the back passage more than 25% of the time; needing to use hands or press on the pelvic floor to help pass a stool more than 25% of the time; having fewer than 3 bowel movements per week; or rarely having soft stools unless laxatives are used.
- People who are willing to avoid making major changes to their diet or lifestyle during the study.
Who may not be able to join:
- People who have taken antibiotics to treat an infection in the 4 weeks before the study starts (note: regular low-dose azithromycin taken 3 times a week for lung health is allowed — confirm with trial site).
- People who are unable to stop their regular bowel treatments — such as fibre supplements, stool softeners, laxatives, or gut-motility medicines — for 2 weeks before starting the study drug (limited use of osmotic laxatives as a rescue option only may be permitted — confirm with trial site).
- People whose cystic fibrosis-related constipation is considered severe by the study team.
- People who have previously used a medicine called tenapanor.
- People who have been hospitalised in the 4 weeks before the study starts.
- People who have had a serious bowel blockage known as distal intestinal obstruction syndrome (DIOS) in the 4 weeks before the study starts.
- People who have another known or suspected physical blockage in the bowel.
Important: Always verify eligibility with the trial site directly before applying.
Based on publicly available eligibility criteria from ClinicalTrials.gov. Verify directly with the trial site before acting. This is not medical advice.
Contact this trial
Principal Investigator: Christoher D Velez, MD, Massachusetts General Hospital
Phone: 6176437088
Contact details sourced from ClinicalTrials.gov. Verify directly with the trial site before attending.
GP referral letter
Print a one-page summary to share with your doctor.
Trial details
Where this trial is recruiting
Primary endpoints
Increase in SBM frequency
Can't join this trial?
Data last synced from ClinicalTrials.gov: 27 July 2026. Trial status can change. Always verify current status directly with the trial site before making any decision.