ONB-CFTR: Validation of Therapeutic Efficacy Targeting the Splicing Variants in Cystic Fibrosis and CFTR Pathologies

Sponsor

University Hospital, Montpellier (Other)

Overall Status

Recruiting

CT.gov ID

NCT05100823

Collaborator

Foch Hospital, Suresnes, FRANCE (Other), Hôpital Necker-Enfants Malades (Other), Hôpital Cochin (Other)

Enrollment

Location

Arm

Anticipated Duration (Months)

0.6

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Cystic Fibrosis, an inherited autosomal recessive disease, arises from mutations in the CFTR gene. For intronic mutations affecting splicing events, oligonucleotides therapy has the potential to restore the production of the full length CFTR protein. Recent scientific research has demonstrated the potential of this approach to restore full length mRNA CFTR in in vitro human airway cells. The study aims to validate the therapeutic efficacy of oligonucleotide blockers (ONB) that target splicing defects associated to splicing variants in epithelia obtained from patients with Cystic Fibrosis and CFTR-related disorders.

Condition or Disease	Intervention/Treatment	Phase
Cystic Fibrosis CFTR Gene Mutation	Procedure: Nasal cells sampling Procedure: Rectal biopsy sampling	N/A

Detailed Description

The study will include patients with various CFTR genotypes. The assessment of ONB (named ONB-CFTR) will be performed using an air-liquid interface model of airway epithelium, developed from nasal cells of patients, without or with a combination of existing CFTR modulators, depending on the patient' genotype.

This study will also aim to build a local biobank of rectal organoids from patients (only from Montpellier, France) carrying rare CFTR disease-causing variants.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

20 participants

Allocation:

N/A

Intervention Model:

Single Group Assignment

Masking:

None (Open Label)

Primary Purpose:

Basic Science

Official Title:

Validation of Therapeutic Efficacy Targeting the Splicing Variants in Cystic Fibrosis and CFTR Pathologies

Actual Study Start Date :

Mar 30, 2022

Anticipated Primary Completion Date :

Mar 30, 2025

Anticipated Study Completion Date :

Mar 30, 2025

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Nasal cells sampling and/or rectal biospy Depending of the patient' genotype, specific ONB-CFTR (50 nM) will be incubated at the apical face of in vitro epithelium, alone and in combination with CFTR modulators. Efficacy of ONB will be compared to a condition with oligonucleotide control incubation. Rectal biopsies from volunteer patients were stored as a bio-bank of organoids.	Procedure: Nasal cells sampling Nasal epithelium brushing in intermediate turbinate using a specific curette following a local anesthesia with Xylocaine 5% nebulizer. Procedure: Rectal biopsy sampling Forceps Biopsy Procedure (Servidoni et al., 2013) Only for volunteer patients included in the Montpellier center.

Arm

Intervention/Treatment

Experimental: Nasal cells sampling and/or rectal biospy

Depending of the patient' genotype, specific ONB-CFTR (50 nM) will be incubated at the apical face of in vitro epithelium, alone and in combination with CFTR modulators. Efficacy of ONB will be compared to a condition with oligonucleotide control incubation. Rectal biopsies from volunteer patients were stored as a bio-bank of organoids.

Procedure: Nasal cells sampling

Nasal epithelium brushing in intermediate turbinate using a specific curette following a local anesthesia with Xylocaine 5% nebulizer.

Procedure: Rectal biopsy sampling

Forceps Biopsy Procedure (Servidoni et al., 2013) Only for volunteer patients included in the Montpellier center.

Outcome Measures

Primary Outcome Measures

Restoration of the correctly spliced CFTR mRNA (full length) using specific ONB-CFTR (designed for one splicing variant). [21 days after the air-liquid switch of epithelia (i.e. full differentiation)]
The increase will be assessed in comparison to oligonucleotide-control effect by using semi-quantitative fluorescent PCR.
Restoration of the mature CFTR protein using specific ONB-CFTR (designed for one splicing variant). [21 days after the air-liquid switch of epithelia (i.e. full differentiation)]
The increase will be assessed in comparison to oligonucleotide-control effect by using western blot
Restoration of CFTR channel function using specific ONB-CFTR (designed for one splicing variant). [21 days after the air-liquid switch of epithelia (i.e. full differentiation)]
The increase will be assessed in comparison to oligonucleotide-control effect by using electrophysiological assays (Ussing chamber).

Secondary Outcome Measures

Restoration of the correctly spliced CFTR mRNA (full length) and mature CFTR protein and CFTR channel function using a pool of ONB-CFTR (a mix of specific ONB-CFTR). [21 days after the air-liquid switch of epithelia (i.e. full differentiation)]
The increase will be assessed in comparison to oligonucleotide-control effect by using semi-quantitative fluorescent PCR, western blot and electrophysiological assays (Ussing chamber).
Assessment of the amount of CFTR mRNA with normal splicing under the conditions tested. [21 days after the air-liquid switch of epithelia (i.e. full differentiation)]
That parameter will be quantified in comparison to oligonucleotide-control effect by using quantitative PCR assays.
Assessment of the amount of mature CFTR proteins under the conditions tested. [21 days after the air-liquid switch of epithelia (i.e. full differentiation)]
That parameter will be quantified in comparison to oligonucleotide-control effect by using western blot assays.
Assessment of the CFTR channel activity under the conditions tested. [21 days after the air-liquid switch of epithelia (i.e. full differentiation)]
That parameter will be quantified in comparison to oligonucleotide-control effect by using electrophysiological assays (Ussing chamber).
Increase of CFTR channel function using ONB-CFTR and CFTR modulators (correctors and/or potentiators) under the conditions tested. [21 days after the air-liquid switch of epithelia (i.e. full differentiation)]
The increase will be assessed in comparison to oligonucleotide-control effect by using electrophysiological assays (Ussing chamber).

Eligibility Criteria

Criteria

Ages Eligible for Study:

12 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

The subject must have given their free and informed consent and signed the consent
The subject must be affiliated or beneficiary of a health insurance plan Women and men are included
The patient is at least 12 years old.
The patient has cystic fibrosis or a CFTR pathology and therefore carries two mutations (with at least one mutation affecting splicing) in the CFTR gene.
Patients who volunteer for rectal biopsy collection (only from Montpellier University Hospital) must be at least 18 years old.

Exclusion Criteria:

The subject is in a period of exclusion determined by a previous study.
The subject is under judicial protection, under guardianship or under curatorship
The subject does not accept to sign consent
It turns out to be impossible to give informed information to the subject
The subject does not read the French language fluently
The subject is a pregnant or breastfeeding woman
The subject has porphyria, or has hepatic insufficiency, or suffers from epilepsy, or suffers from conduction disorders, or suffers from severe heart failure, has a cons-indication to the use of a local anesthetic spray.