General FAQs on genetic therapies

A gene is a specific piece, or sequence, of DNA that contains instructions on how to make a particular protein. For example, the CFTR gene that is faulty in CF contains instructions for how to make the CFTR protein. Cystic fibrosis is caused by mutations in the CFTR gene which changes the instructions for the CFTR protein and causes it not to function correctly (or at all).

Cystic fibrosis is a ‘recessive’ inherited disease, which means that it only occurs when a child has twocopies of the mutated CFTR gene – one copy from each parent.

Genetic therapies are medicines that are designed to make working copies of a protein. They are being developed for conditions where there are faults in a gene such as in cystic fibrosis.

There are many types of genetic therapies, including gene therapy, RNA therapy, anti-sense oligonucleotides (also known as ‘ASOs’) and gene editing. Each type of genetic therapy acts at one of the steps involved in making a protein from a gene.

Genetic therapies are very different to anything that you may have come across before for the treatment of your CF.

CF genetic therapies could help the body to make working copies of the CFTR protein, from the CFTR gene. Different types of genetic therapies do this in different ways. For example CF gene therapy an additional, working copy of the CF gene is delivered. Working copies of the CFTR protein would make the lungs of people with CF much healthier. (The lungs are the first part of the body that CF genetic therapies are being designed for).

Genetic therapies offer the potential of being able to treat everyone with CF, regardless of their mutation. This would include people who, for whatever reason, are not able to take CFTR modulators such as Kaftrio.

In CF, different things go wrong with production of the CFTR protein or how it works, depending on which CFTR mutation (genotype) people have. A mutation in some places within the gene means that no protein is produced. A mutation in other places means that a protein is produced, but it doesn’t form the correct shape or can’t do its job on the surface of the cells.

CFTR modulators such as Kaftrio help some versions of the CF protein work properly. The only people to benefit from these medicines are those people who can make any CFTR protein.

Genetic therapies work by helping cells to make working copies of the CFTR protein. For genetic therapies to work, it doesn’t matter if your CF genotype (your CFTR mutations) mean that your cells don’t make any CFTR protein. 

Genetic therapies have been approved for other conditions such as the genetic, neurological condition Spinal Muscular Atrophy, but so far there have been no genetic therapies approved for use for cystic fibrosis.

Yes, there is lots of research happening looking at CF genetic therapies. RNA therapies are currently being tested in clinical trials in CF, and plans are underway for gene therapy clinical trials towards the end of 2023.

Worldwide, lab-based research is underway to develop other types of genetic therapy, including research into gene editing (using CRISPR-Cas9) and different types of gene therapy and RNA therapy.

Clinical trials of genetic therapies in the UK will all be listed in our Trials Tracker. You can speak to your clinical team and let them know that you would be interested in an opportunity to take part in a trial or contact one of our early phase CF trial co-ordinators. You can also contact Cystic Fibrosis Trust clinical trials team on [email protected] . 

Read more about CF genetic therapy clinical trials

The Trust is supporting research into genetic therapies through our Trials Accelerator programme and through funding early lab-based research into new genetic therapies.

Our Early Phase trials network within the Trials Accelerator programme provides the safe space, care and expertise that is needed for pharma companies to test out new genetic therapies. More nursing care, health monitoring and in-patient stays are likely to be required for the first clinical trials of genetic therapies in comparison to other trials run in the rest of the Trials Accelerator network.

Through our Strategic Research Centre and Venture and Innovation Award research funding schemes, we are funding lab-based research into genetic therapies.

It depends on what you call a cure! Researchers at the Cystic Fibrosis Foundation in USA have called a cure a permanent correction of the CFTR gene in DNA of ‘stem cells’ of someone with CF. Stem cells are basic cells that have the ability to make lots of other types of cells.

Researchers hope that some types of genetic therapy, known as integrating gene therapy, or  gene editing, will permanently correct the CFTR gene in stem cells in the lungs. This means that people would have one course of genetic therapy treatment, and wouldn’t need to receive it on a regular basis.

Unfortunately, if a genetic therapy is able to permanently correct the CFTR gene in stem cells, it wouldn’t reverse the existing damage caused to the body.

We don’t know when genetic therapies are likely to become available for people with CF. We’re at the very first stages of testing whether these therapies are safe in people in clinical trials. If these clinical trials go well, it is likely to be many years before they become available.

We’ve created a genetic therapies glossary that explains some of the words used to explain how genetic therapies work and what they mean.

Look up a word in our genetic therapy glossary