A CFTR corrector (combined with ivacaftor)
Lumacaftor
A CFTR corrector combined with ivacaftor for people with two copies of the F508del cystic fibrosis gene change.
What is Lumacaftor?
Lumacaftor is a cystic fibrosis medicine known as a corrector, which helps the faulty CFTR protein form properly and reach the cell surface. It is always combined with ivacaftor (sold as Orkambi) and is for people who have two copies of the F508del gene change, confirmed by a genetic test. Some people get chest tightness or breathlessness when they first start it, which usually settles. It interacts strongly with other medicines, including making hormonal contraception less reliable. It is a specialist medicine taken with fatty food and overseen by a cystic fibrosis team.
Education and reference only. This is a plain-language guide to Lumacaftor — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Lumacaftor is a CFTR modulator used to treat cystic fibrosis, a lifelong inherited condition that causes thick, sticky mucus because of a faulty protein called CFTR. It is a corrector, meaning it helps the misshapen CFTR protein fold and move to the cell surface where it is needed. Lumacaftor is always given together with ivacaftor (a potentiator) in a combined product called Orkambi, and it is for people who have two copies of the most common gene change, F508del. It is taken by mouth with fatty food and started by a specialist cystic fibrosis team.
How it works
In people with two copies of the F508del change, the CFTR protein is made in the wrong shape, so it is broken down inside the cell and little reaches the surface. Lumacaftor acts as a corrector, helping more of this protein fold correctly and travel to the cell surface. Ivacaftor, the potentiator it is combined with, then helps that protein open and let salt and water move. Working together they can thin the mucus, improve lung function and reduce flare-ups in suitable people.
Company & origin
Originated / developed by: Vertex Pharmaceuticals.
A cystic fibrosis medicine used in the UK, combined with ivacaftor (as Orkambi), for people with two copies of the F508del gene change.
Practical use
How to take Lumacaftor
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it by mouth with food that contains fat, such as a meal or snack with butter, cheese, eggs or full-fat milk, to help your body absorb it.
- Take the morning and evening doses as directed, keeping to a regular routine each day.
- If you get chest tightness or breathlessness when starting, tell your cystic fibrosis team rather than stopping on your own, as it usually settles.
- If you use hormonal contraception, arrange an additional or alternative method, as this medicine makes it less reliable.
- Check with your team or pharmacist before starting any new medicine, supplement or herbal product, as interactions are common.
- Continue your other cystic fibrosis treatments, such as physiotherapy and inhaled medicines, alongside it.
Weighing it up
Advantages & disadvantages of Lumacaftor
Advantages
- Targets the underlying protein problem in people with two copies of the F508del gene change.
- Combined with ivacaftor, it can improve lung function and reduce flare-ups in those it suits.
- Taken by mouth, so it fits into a daily cystic fibrosis routine.
Disadvantages
- Only suitable for people with two copies of the F508del change, confirmed by genetic testing.
- Can cause chest tightness and breathlessness when first started, which some people find difficult.
- Interacts strongly with many medicines and makes hormonal contraception less reliable.
Practical use
Good to know
Lumacaftor is only for people with two copies of the F508del gene change, so a genetic test is needed first. When starting, some people feel chest tightness, breathlessness or wheeze, which usually settles after the first weeks; tell your team if it is troubling. It is taken with fatty food to help absorption. A particularly important point is that it interacts strongly with many medicines and makes hormonal contraception (the pill, patch, implant, injection or vaginal ring) less reliable, so an additional or alternative method of contraception is needed — discuss this with your team. The liver may be monitored, and you should keep up the rest of your cystic fibrosis care alongside it.
Who should not take it / use with caution
- People who do not have two copies of the F508del gene change, as it will not help them.
- Anyone who has had a serious allergic reaction to lumacaftor or ivacaftor.
- It is used with extra care and closer monitoring in people with significant liver problems, under specialist guidance.
Monitoring
- Liver blood tests before starting and regularly during treatment.
- Watching breathing, especially in the first weeks of treatment.
- Reviewing lung function, weight, flare-ups and contraception needs with the cystic fibrosis team.
- Eye (cataract) checks in children and young people, as the combination contains ivacaftor.
Side effects
- Breathlessness, chest tightness or wheeze, especially when starting, which usually settles.
- Headache, dizziness, nausea, diarrhoea and a blocked or runny nose.
- Changes in liver blood tests; periods may change, and contraception becomes less reliable.
Key interactions
- Reduces the reliability of hormonal contraception, so an additional or alternative method is needed.
- Strongly affects the liver enzymes that process many medicines, so it can lower or change the levels of other drugs.
- Tell your cystic fibrosis team and pharmacist about every medicine, supplement and herbal product you take.
Available as: Tablets and granules (combined with ivacaftor) taken by mouth with fatty food.
Answers
Lumacaftor: frequently asked questions
Who can take lumacaftor?
It is for people who have two copies of the F508del gene change, confirmed by a genetic test, and it is always combined with ivacaftor as Orkambi.
Why do I feel tight-chested after starting it?
Chest tightness and breathlessness are common in the first weeks and usually settle; tell your team if it is troubling rather than stopping on your own.
Will it affect my contraception?
Yes, it makes hormonal contraception less reliable, so you will need an additional or alternative method — discuss this with your team.
Why take it with fatty food?
Fat helps your body absorb the medicine, so it should be taken with a meal or snack containing fat.
Does it replace my other treatments?
No, you should keep up your usual cystic fibrosis care, such as physiotherapy and inhaled medicines, alongside it.
Authoritative sources
- BNF
- NICE CKS
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