An interleukin (IL-17) inhibitor biologic
Ixekizumab
An injected biologic that blocks the IL-17 immune signal, used for psoriasis, psoriatic arthritis and axial spondyloarthritis.
What is Ixekizumab?
Ixekizumab is a biologic medicine that calms an overactive immune system by blocking interleukin-17 (IL-17), a messenger protein that drives inflammation. It is used for moderate to severe plaque psoriasis, psoriatic arthritis and axial spondyloarthritis affecting the spine. It is given by injection under the skin, which many people learn to do themselves. Because it dampens part of the immune system, infection is the main caution, so you are usually screened for tuberculosis and hepatitis first and should avoid live vaccines. Like other IL-17 blockers it can bring on thrush and may worsen inflammatory bowel disease.
Education and reference only. This is a plain-language guide to Ixekizumab — 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
Ixekizumab is a biologic medicine, made from living cells, that targets a specific immune signal called interleukin-17. IL-17 is one of the messengers that drives the inflammation behind psoriasis and several related conditions. Ixekizumab is used for moderate to severe plaque psoriasis, psoriatic arthritis and axial spondyloarthritis, a form of inflammatory arthritis affecting the spine, usually when other treatments have not worked well enough. It is given by injection under the skin, and many people are trained to give it themselves at home using a pre-filled pen.
How it works
In psoriasis and similar conditions, the immune system produces too many inflammatory signals. Ixekizumab attaches to interleukin-17, blocking this signal so the immune system stops driving the thickened, scaly skin or the joint and spine inflammation. Because it targets one specific signal rather than the whole immune system, it is a focused treatment. As IL-17 also helps defend against fungal infections and plays a part in the gut, blocking it can lead to thrush and may worsen inflammatory bowel disease.
Company & origin
Originated / developed by: Eli Lilly.
A biologic medicine developed to treat moderate to severe plaque psoriasis and related conditions by blocking the immune signal IL-17.
Practical use
How to take Ixekizumab
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by injection under the skin, often with a pre-filled pen that many people learn to use themselves at home.
- Before starting, expect screening for tuberculosis and hepatitis so a hidden infection does not flare during treatment.
- Avoid live vaccines while being treated, and try to be up to date with recommended non-live vaccinations beforehand.
- Tell your team if you develop thrush or fungal infections, which can happen with this medicine and are usually easy to treat.
- Let your team know if you have inflammatory bowel disease or develop new tummy pain or diarrhoea, as it can worsen these conditions.
Weighing it up
Advantages & disadvantages of Ixekizumab
Advantages
- Often very effective at clearing moderate to severe plaque psoriasis and easing psoriatic arthritis and spinal arthritis.
- Targets one specific immune signal, so it is more focused than older, broad immunosuppressants.
- Can usually be self-injected at home after training, with doses spaced weeks apart once established.
Disadvantages
- It dampens part of the immune system, so it can make infections more likely and may let a hidden tuberculosis or hepatitis infection flare.
- Blocking IL-17 can bring on thrush or other fungal infections and may worsen inflammatory bowel disease.
- Live vaccines must be avoided, and screening and ongoing monitoring are needed.
Practical use
Good to know
The most important point is that ixekizumab calms part of the immune system, so infection is the key caution, although it is more focused than older broad immunosuppressants. Before starting, you are usually screened for tuberculosis and hepatitis so a hidden infection does not flare, and you should avoid live vaccines during treatment. As an IL-17 blocker, it shares two particular cautions: it can bring on thrush or other candida (fungal) infections, usually easily treated, and it can worsen inflammatory bowel disease such as Crohn's or ulcerative colitis, so tell your team about any bowel problems or new tummy symptoms. After training, most people inject it themselves at home, and once established the injections are spaced weeks apart.
Who should not take it / use with caution
- People with a serious active infection should not start it until that infection is treated.
- It is generally avoided or used very cautiously in people with active inflammatory bowel disease, which it can worsen.
- It is used only after assessment in those with untreated tuberculosis or active hepatitis, and live vaccines must be avoided.
Monitoring
- Screening for tuberculosis and hepatitis before starting, and watching for infection throughout treatment.
- Watching for thrush and for any new or worsening bowel symptoms.
- Reviewing how well the skin, joints or spine are responding so treatment can be adjusted.
Side effects
- More frequent infections, including colds and chest infections, are the most important effect to watch for.
- Thrush and other fungal (candida) infections, which are usually mild and easily treated.
- Injection-site redness or soreness, and rarely worsening of bowel disease or serious allergic reactions.
Key interactions
- Combining it with other medicines that suppress the immune system adds to the infection risk and is done only with specialist advice.
- Live vaccines should not be given during treatment.
- Tell your team if you take medicines for inflammatory bowel disease, as the conditions interact with how this medicine is used.
Available as: Injection under the skin, often with a pre-filled pen for self-injection after training.
Answers
Ixekizumab: frequently asked questions
How does ixekizumab work?
It blocks interleukin-17 (IL-17), an immune signal that drives the inflammation behind psoriasis and related conditions, calming the overactivity that causes the symptoms.
Could it cause thrush?
Yes, IL-17 normally helps protect against fungal infections, so blocking it can make thrush or other candida infections more likely; these are usually mild and easily treated.
Is it safe if I have bowel disease?
It can worsen inflammatory bowel disease such as Crohn's or ulcerative colitis, so tell your team if you have a bowel condition or develop new tummy symptoms.
Why are tests done before I start?
You are usually screened for tuberculosis and hepatitis, because calming part of the immune system can let a hidden infection flare.
Can I have vaccinations while on it?
You should avoid live vaccines during treatment; it is best to be up to date with recommended non-live vaccines beforehand, and your team can advise.
The wider class
About Interleukin (IL-17) inhibitor biologic
Ixekizumab belongs to the interleukin (il-17) inhibitor biologic class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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