Bimekizumab

Updated October 2024

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What is bimekizumab?

Bimekizumab (brand name: Bimzelx®) is a medicine used to treat adults with psoriatic arthritis, a type of joint inflammation that often occurs with the skin condition called psoriasis. Bimekizumab is also used to treat adults with moderate to severe plaque psoriasis that is chronic (lasts for a long time). 

Bimekizumab may also be used to treat adults with axial spondyloarthritis, including ankylosing spondylitis, a condition which causes inflammation in the spinal joints, resulting in pain and stiffness in the spine. 

Bimekizumab works by targeting proteins in the body called Interleukin 17A (IL-17A) and Interleukin 17F (IL-17F). In people with psoriatic arthritis and axial spondyloarthritis, the body makes too much IL-17A and IL-17F which can lead to stiff and painful joints. By reducing the levels of IL-17A and IL-17F, bimekizumab can reduce the inflammation and symptoms.

Important things to remember

  • You must see your rheumatologist regularly to make sure the treatment is working and check for possible side effects.
  • You should have regular blood tests as suggested by your rheumatologist.
  • It is important to tell your rheumatologist if you have a new serious illness such as a serious infection, cancer or heart failure etc.
  • Remember to change the injection site each time bimekizumab is injected.
  • If you are worried about any side effects, you should contact your rheumatologist as soon as possible.
  • You must tell your rheumatologist if you want to stop bimekizumab. If you don't, your treatment may no longer be funded.
  • Let your rheumatologist know if you plan to become pregnant. 
  • If you need a vaccination, tell your doctor you are being treated with bimekizumab before you have the vaccination. Some vaccines cannot be given while on bimekizumab.

What benefit can you expect from your treatment?

It may take a number of weeks for you to notice some relief of joint swelling, pain and stiffness.

 

Stopping bimekizumab

If you stop or delay your bimekizumab treatment, your condition may get worse. Continue to use your treatment unless your rheumatologist tells you to stop or unless you get side effects (see Side effects).

If you stop bimekizumab for any reason, you must contact your rheumatologist. If you don't, your treatment may no longer be subsidised by Medicare. 
 

How will you be checked while on bimekizumab?

  • Medicines like bimekizumab are very expensive, but Medicare usually helps cover the cost. You can use it if you meet certain conditions. 
  • Bimekizumab can only be given if your disease is active and usual treatments have not worked.
  • The treatment will continue only if it helps you, which is checked between 12 and 16 weeks after starting.
  • You will need blood tests during treatment to check for side effects and see if it’s working.  
  • How often you need blood tests depends on other medicines you take and any other illnesses you have. Your rheumatologist will tell you this.
     

How is bimekizumab given?

Bimekizumab is injected just under the skin of the thigh, belly or upper arms. It is best to avoid (if possible) any areas of skin affected by psoriasis. The prefilled pen or syringe should be taken out of the fridge 30 minutes before injecting so it can reach room temperature. Do not shake or freeze it. It can be injected by your doctor, nurse, carer, or by you. If injecting yourself, be sure to follow the detailed instructions carefully to ensure the best response. It is important to change the injection site each time. 

If you miss an injection

Give the next injection as soon as you remember and continue to use it as you normally would. Do not inject a double dose to make up for a missed dose. If you have missed more than one dose or are not sure what to do, check with your doctor or pharmacist.

What is the dosage?

Bimekizumab comes in a pre-filled syringe or pen which has 160mg of medicine. In psoriatic arthritis and axial spondyloarthritis, the usual dose of bimekizumab is 160mg (one pre-filled syringe or pen) injected every 4 weeks.

Can other medicines be taken with bimekizumab?

This medication may be used alone or with other arthritis medications including:

  • Other disease modifying anti rheumatic drugs (DMARDs) such as methotrexate.
  • Steroid medications such as prednisolone or cortisone injections into the joint. 
  • Anti-inflammatory medications (NSAIDs) such as naproxen (Naprosyn®) or ibuprofen (Brufen®, Nurofen®).
  • Pain medicines such as paracetamol.

Are there any side effects?

You might experience side effects with your treatment. Tell your doctor if you notice side effects that you think are caused by this medication. Many side effects disappear when bimekizumab treatment is stopped.

Most common possible side effects

  • You may have more mild upper respiratory tract infections (common cold, sinus infections), nausea, diarrhoea, cough, and fever.
  • Infections may need treatment and bimekizumab may need to be stopped for a while if you develop infection, so it is important to contact your doctor for advice.
     

Less common or rare side effects

There are some rare but sometimes serious side effects with bimekizumab including:

  • Thrush, athlete's foot and other fungal skin infections, headaches, signs of low white cells (such as fever, sore throat or mouth ulcers due to infections), ear infections, conjunctivitis or discharge from the eye with itching, redness and swelling.
  • Serious allergic reaction: signs of a serious allergic reaction may include a skin rash, a swollen face, lips, mouth or throat, or wheezing, dizziness, trouble swallowing or breathing. 
  • Tell your doctor or go to the hospital immediately if you have an allergic reaction as you need urgent medical attention.
  • Inflammatory bowel disease: new cases of inflammatory bowel disease are rare, but "flare ups" can occur while being treated with bimekizumab. If you have inflammatory bowel disease, tell your doctor if you have worsening symptoms during treatment with bimekizumab, or if you develop stomach pain or diarrhoea. 
  • Other side effects not listed in this leaflet may also occur. Tell your doctor if you notice any other side effects that you think might be caused by bimekizumab. 

 

What precautions are necessary?

Infections  

If you have an active infection of any kind, treatment with bimekizumab will not be started until the infection is gone. Serious infections such as tuberculosis (TB) are seen rarely, and screening for TB may be needed before treatment begins.

Use with other medicines 

Bimekizumab can affect and be affected by other medicines. You should tell all your doctors about all medicines you are taking or plan to take. This includes over-the-counter or herbal/natural medicines. 

Use with phototherapy (light therapy)

Bimekizumab should not be used while receiving light therapy (PUVA) for psoriasis..

Vaccines

  • While being treated with bimekizumab you should not be immunised with ‘live’ vaccines such as: MMR (measles, mumps and rubella), OPV (oral polio virus), BCG (Bacillus Calmette Guerin), Japanese Encephalitis or Yellow Fever. Talk with your rheumatologist before receiving any vaccines.  
  • Pneumococcal vaccines and the yearly seasonal flu vaccinations are safe to receive and encouraged. 
  • For more information on vaccination including the COVID-19 vaccination go to: https://rheumatology.org.au/For-Patients/COVID-Information/COVID-Vaccination-Information.
  • For more information on vaccination including the COVID-19 vaccination click here.  

Surgery

If you need surgery for any reason, you should discuss this with your rheumatologist as some people need to stop taking bimekizumab before surgery.

Alcohol

You may drink alcohol while taking bimekizumab. However, if you are also taking methotrexate, you should be cautious about how much alcohol you drink.

Pregnancy, breastfeeding and fertility

  • We don’t know how bimekizumab can affect an unborn baby. 
  • If you are pregnant or thinking about having a child, you should discuss this with your rheumatologist before beginning this medication. 
  • Women who are able to be pregnant should use effective contraception during treatment 
  • If you have used bimekizumab during your pregnancy, you should check with your doctor before vaccinations are given to your baby. Some vaccines cannot be given to the newborn baby if you were treated with bimekizumab while you were pregnant. 
  • No studies have looked at bimekizumab in breastmilk, but it is unlikely to be harmful to a newborn baby. Women who are breastfeeding should talk to their doctor about whether or not to use bimekizumab. 
     
 
 

Disposal

  • After injecting bimekizumab, the used syringes or pens should be placed in a puncture-resistant container, like a sharps container. Dispose of your sharps container according to your state or local council regulations. If unsure how to dispose of your sharps container, ask your pharmacist. For more information, see the ‘Safe Disposal of Sharps’ guide'. 
  • If your doctor tells you to stop using bimekizumab, or the expiry date has passed, ask your pharmacist what to do with the leftover medicine.
     

How to store bimekizumab

  • Store bimekizumab in the fridge, between 2 and 8°C. Do not freeze. If needed, bimekizumab may be stored out of the fridge once, for up to 30 days at room temperature, not above 25°C. Do not return to the fridge once it has reached room temperature. 
  • Keep the pens or syringes in the original carton to protect them from light until the time of use. 
  • Keep all medicines out of reach of children.