Rare CFTR Mutation Cell Collection Protocol (RARE)

  • End date
    Dec 1, 2023
  • participants needed
  • sponsor
    George Solomon
Updated on 8 December 2021
cystic fibrosis transmembrane conductance regulator
cftr gene
sweat test
nasal potential difference
cftr modulators


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 homozygous for pre-mature stop codons
  • CF patients with two mutations in the CFTR gene: i. One allele must be a F508del ii. The other allele must be a pre-mature stop codon mutation
  • CF patients with two mutations in the CFTR gene: i. At least one allele must be a pre-mature stop codon mutation ii. The second allele can be any of the following: G85E, N1303K, R334W, 3849+10kb C->T, 621+1G->T
  • CF patients who are homozygous for: G85E, N1303K, R334W, 3849+10kb C->T, or 621+1G->T

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.


This is a multi-site, specimen collection study for people with Cystic Fibrosis who have rare mutations. This study is non-interventional so there is no study drug or investigational treatment involved.

  • Once a potentially eligible participant is identified (either self-identified or by their CF care center), and the person has expressed interest in participating in the study, the participant will be referred to a participating study site to receive additional information about the study and about travel arrangements (if needed).
  • The eligibility criteria are broad and inclusive: Often studies have restrictions around lung function that limit who can participate. The only real restriction for this study rare mutations as defined on the RARE study eligible mutations list.
  • Blood, intestinal cells, nasal cells will be collected from all participants.
  • Participants will be compensated for the time of the visit and travel expenses will be pre-paid by the study. The study site research coordinator can provide more detail on how much participants will be paid.
  • This study is being conducted at six regional sites. Participants may travel to any of the regional study sites to participate, but the participant will need to talk with the research coordinator at the site of their choice to get all of the study details before making a decision to participate. The study site research coordinator will put participants in contact with the travel agency to arrange and pre-pay for travel (including hotel, airline/train arrangements as needed).

Visit Schedule:

Two day study visit

Condition Pulmonary Disease, Cystic Fibrosis, Pancreatic Disorders, Pancreatic disorder, Lung Disease
Clinical Study IdentifierNCT03161808
SponsorGeorge Solomon
Last Modified on8 December 2021


Yes No Not Sure

Inclusion Criteria

Male or female 12 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 Criteria

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
i. Platelets < 50 x 103/L ii. Hemoglobin < 10 gm/dL iii. Hematocrit < 30% iv
WBC > 20 x 103/L v. Neutropenia (ANC < 1.5 x 103/L) vi. Lymphopenia (absolute
lymphocyte count < 1.5 x 103/L) vii. PT/INR > 1.5 viii. Other bleeding
\. Positive pregnancy test (for female of childbearing potential) at the
study visit
\. Breastfeeding (if patient opts to use sedation)
\. 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
\. 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
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How to participate?

Step 1 Connect with a study center
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer to help accelerate the development of new treatments and to get notified about similar trials.

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Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

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If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

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Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

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