Collects cells from people with rare cystic fibrosis gene changes
Collects blood, nasal and intestinal cells from people with rare CFTR changes.
Plain-language title generated from the registry record
Registry title: Rare CFTR Mutation Cell Collection Protocol (RARE)
Key facts
- Where
- Birmingham, United StatesSee the site
AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults and teens with cystic fibrosis caused by rare CFTR gene changes. Blood, gut cells and nose cells are collected to test future medicines in the lab.
- Age
- 17 years or older
- Sex
- Men and women can join.
- Disease stage
- Cystic fibrosis confirmed by clinical features plus a sweat chloride test of 60 mEq/L or more, two well-characterized CFTR mutations, or an abnormal nasal potential difference test.
- Earlier treatment
- Cannot use oral steroids above 20 mg/day for more than 14 days before the rectal biopsy. Cannot use oral blood thinners within 7 days before or after the biopsy.
- Biomarker or test result
- A confirmed rare CFTR genotype. The first focus is people with two premature stop codon mutations.
Main reasons for not taking part
- Diseased rectal or gut tissue that makes the biopsy risky
- Abnormal blood counts or clotting tests at the study visit
- Positive pregnancy test
- Breastfeeding, if sedation is used
- History of organ transplant
Read by machine on 9 November 2026.
Where in United States
- University of Alabama at BirminghamBirmingham, United StatesTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- George Solomon
- Trial code
- NCT03161808
- Record updated
- 29 May 2026
- Original description
Over 1,900 mutations in the gene for the cystic fibrosis transmembrane conductance regulator (CFTR) protein are implicated in causing Cystic Fibrosis (CF). Potential therapies that directly target defective CFTR are being evaluated in important clinical trials, but most target the most common CFTR mutation F508del. Many patients with rare CF mutations are not able to participate in those studies. The RARE study is specifically designed for people with CF caused by rare mutations. Eligible rare mutations are listed below:Read full original descriptionShow less
Rare CFTR Mutation Cell Collection Protocol (RARE)
Over 1,900 mutations in the gene for the cystic fibrosis transmembrane conductance regulator (CFTR) protein are implicated in causing Cystic Fibrosis (CF). Potential therapies that directly target defective CFTR are being evaluated in important clinical trials, but most target the most common CFTR mutation F508del. Many patients with rare CF mutations are not able to participate in those studies. The RARE study is specifically designed for people with CF caused by rare mutations. Eligible rare mutations are listed below:
• CF patients who are heterozygous for pre-mature stop codons as noted below: i. one allele must be a F508del ii. the other allele must be a pre-mature stop codon mutation
• CF Patients with other genotypes that require Study PI permission: i. CF patients with two mutations that are not eligible for Trikafta ii. CF patients homozygous or heterozygous (other allele must be F508del) for rare mutations of special interest (e.g., 711+3A->G, 2789+5G->A, 3272-26A->G, 3849+10kbC->T). Other rare mutations will be considered on a case by case basis
This is a multi-site, specimen collection study. Investigators will collect blood, intestinal cells and nasal cells from each participant. Cells from these specimens will be used to test future CFTR modulators to see if they might work for people with study eligible rare mutations. Having cells to test in the lab is an important first step in identifying potential new therapies for people with these mutations.
Inclusion: Male or female ≥ 17 years of age at time of consent; Documentation of a CF diagnosis as evidenced by one or more clinical features consistent with CF and one or more of the following criteria (1. Sweat chloride ≥ 60 milliequivalents/Liter (mEq/L) by quantitative pilocarpineiontophoresis test (QPIT) OR upon permission of the RARE Investigator- Sponsors, 2. Two well-characterized mutations in the cystic fibrosis transmembrane conductive regulator (CFTR) gene, 3.Abnormal nasal potential difference (NPD) (change in NPD in response to a low chloride solution and isoproterenol of lessthan -6.6 mV); Confirmed genotype of the current recruitment focus for certain target rare mutations. The initial recruitment focus will be CF patients who are homozygous for pre-mature stop codons. Operations Memos will detail any future current genotype targets; Written informed consent (and assent when applicable) obtained from participant or participant's legal representative and ability to comply with the requirements of the study; Willing to travel (if needed) to a regional study site for cell collection.
Exclusion: Current use of drugs with significant risks of compromising immunity (e.g. oral steroid use >20 mg/day) for >14 days prior to the rectal biopsy; History of organ transplant; Presence of a medical condition, abnormality, or laboratory value(s) that in the opinion of the onsite principal investigator and/or collaborating gastroenterologist may compromise the quality of the data or place the subject at significant risk by undergoing the research related biopsy, including:; Significantly diseased distal rectal/GI tissue that could place the participant at risk by participating in the study (as judged by the collaborating gastroenterologist, such as significant hemorrhoids, vascular abnormalities, colonic infection, radiation injury or history of radiation therapy to the rectum, prostate and/or pelvic area); Any of the following abnormal lab values at the study visit:; Platelets < 50 x 10\^3/µL ii. Hemoglobin < 10 gm/dL iii. Hematocrit < 30% iv. WBC > 20 x 10\^3/µL v. Neutropenia (ANC < 1.5 x 10\^3/µL) vi. Lymphopenia (absolute lymphocyte count < 1.5 x 10\^3/µL) vii. PT/INR > 1.5 viii. Other bleeding diathesis; Use of oral anticoagulant medications (e.g., chronic anticoagulant therapy such as warfarin or platelet inactivators such as aspirin) within seven days prior to rectal biopsy; Unable or unwilling to withhold use of oral anticoagulant medications (e.g., chronic anticoagulant therapy such as warfarin or platelet inactivators such as aspirin) within 7 days after rectal biopsy; Positive pregnancy test (for female of childbearing potential) at the study visit; Breastfeeding (if patient opts to use sedation).