Experimental Treatments for Cystic Fibrosis


4D-710 is an aerosol gene therapy designed to deliver an artificial version of the CFTR gene, called a transgene, that provides instructions for making a working version of the CFTR protein. The therapy aims to increase CFTR protein function, normalizing mucus production and easing CF symptoms. A Phase 1/2 trial is currently being conducted.

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ARV-1801 is designed to treat pulmonary exacerbations in people with CF. It is not approved in the U.S. but is in clinical use in other countries. ARV-1801 contains sodium fusidate, a potent antibiotic against the bacterium Staphylococcus aureus, which is responsible for about 70% of lung infections in CF patients. A Phase 2 trial in CF is being planned.

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CRISPR/Cas9 is an experimental approach for treating CF. The therapy features a novel protein-RNA complex that is designed to address the genetic mutations that cause the disease by editing a patient’s genetics, correcting the mutations themselves. It is the preclinical stages of development for CF.

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ELX-02 targets a less common mutation known as a nonsense mutation where there is a premature stop signal in the CFTR gene. This premature stop signal causes the cellular machinery to stop making the CFTR protein midway. The resulting incomplete protein is quickly degraded by the cell. ELX-02 is designed to ensure that sufficient quantities of full-length CFTR protein are made to lessen the burden of CF. Phase 2 trials in CF patients are currently recruiting.

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Fosfomycin/tobramycin inhalation solution (FTI) is a combination antibiotic therapy consisting of fosfomycin and tobramycin. FTI has shown improved effectiveness against lung infections caused by bacteria compared with fosfomycin or tobramycin alone. It is being investigated to treat lung infections in patients with CF. A Phase 2 trial in CF is reportedly being planned.

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Gallium has been shown to increase the effectiveness of antibiotics and to have antimicrobial activity itself. The molecule is being studied for its safety and effectiveness in controlling antibiotic-resistant bacterial infections in people with CF. A Phase 1 trial investigating intravenous gallium in CF patients is currently recruiting.

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GLPG1837 is a CFTR potentiator — a type of CFTR modulator that helps keep the gated passageway open for extended periods and facilitate the movement of chloride ions across the cell membrane. Research has shown that GLPG1837 is beneficial in class 3 mutations, e.g., G551D, G178R, and S549N. It was last tested in a Phase 2 trial.

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Inhaled Levofloxacin

Inhaled levofloxacin is being investigated for use as s long-term lung infection treatment caused by Pseudomonas aeruginosa in adults with CF. Levofloxacin is a well-known antibiotic and is approved to treat CF in the EU and Canada but not yet in the U.S. A Phase 3 trial has been completed.

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LAU-7b is an oral form of the retinoid fenretinide. Retinoids are a group of compounds related to vitamin A. Administered once a day, LAU-7b is designed to correct the defective metabolism and modulate chronic inflammation due to the genetic defect that causes CF. It is currently being tested in a Phase 2 trial in CF patients.

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MRT5005 — a messenger RNA molecule, which provides instructions for the production of proteins in the body — is designed to boost the production of the CFTR protein, which is defective or absent in CF. Thus, it has the potential to address the underlying cause of CF and may be a therapy for all CF patients regardless of the type of mutation they carry. It is currently in a Phase 1/2 trial, which is still recruiting.

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Nitric Oxide

Nitric oxide (NO, brand name Thiolanox) is a naturally occurring gas that, when inhaled, may reduce lung infections, leading to improved lung function in people with CF. During an infection, NO may improve oxygenation as well as local blood flow to the respiratory tract due to its vasodilatory effect. It was last tested in a Phase 2 trial, which was terminated due to COVID-19.

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OligoG is an experimental inhaled dry powder that decreases the thickness of mucus in the lungs of people with CF, and may help them clear mucus more easily. It may also help to improve the effectiveness of some antibiotics. It is designed to be used with a dry powder inhaler or a liquid for use with a nebulizer. It is in Phase 2 testing for CF patients.

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POL6014, now known as lonodelestat, is an investigational, highly potent, and reversible inhibitor of human neutrophil elastase. The experimental therapy can be formulated as an aerosol or dry powder formulation as a treatment for lung inflammation in CF patients. It has completed a Phase 1b trial.

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SNSP113 is an inhaled therapy being developed to ease pulmonary infections, airway congestion, and inflammation. It contains an active ingredient called poly N (acetyl, arginyl) glucosamine, which is a type of complex sugar molecule. The treatment has a multifaceted mechanism of action that might protect pulmonary function in CF patients. It has completed a Phase 1 trial.

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SPIRO-2101 is an inhaled gene therapy designed to replace the faulty version of the CFTR gene in the cells lining the inside of the lungs. The therapy uses inactive adeno-associated viruses to deliver the new gene into the cells. It could potentially treat CF patients with class 1 mutations an those patients who do not tolerate treatment with a CFTR modulator. It is currently in preclinical studies.

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VX-561 (formerly CTP-656) is targeted for CF patients with gating mutations, meaning patients have full-length CFTR proteins, but the channel doesn’t open sufficiently to allow the passage of chloride through the cells. The therapy functions as a potentiator for this channel, keeping the channel open for the molecules to pass through. It is being tested in Phase 2 trials. 

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