Treatment
Tysabri [natalizumab] R1
Tysabri (natalizumab) represents a new class of MS treatments called selective adhesion molecule (SAM) inhibitors.
Tysabri is used to treat highly active relapsing-remitting multiple sclerosis (RRMS). In clinical trials, it has been shown to decrease the number of MS relapses by about two thirds and to approximately halve the progression of the disabling effects of MS.
Tysabri works in a different way to older disease modifying treatments (ie, interferons-beta and glatiramer acetate). Tysabri works by binding to a protein molecule which is present on most white blood cells called a4-integrin, also called an adhesion molecule. These cells play a key role in the inflammatory process of MS. White blood cells use adhesion molecules to cross the barrier between the blood and the brain (the blood-brain barrier). By binding to a4-integrin, Tysabri blocks the action of the adhesion molecules on white blood cells and so should stop them from getting into the brain and causing new MS lesions.
Tysabri is a suitable treatment for people with highly active relapsing remitting multiple sclerosis. This means people who have experienced two or more relapses in a one year period with an MRI scan consistent with a diagnosis of highly active RRMS. Tysabri may also be given to people who have experienced one relapse despite treatment with an interferon-beta.
Tysabri is administered by intravenous infusion, or drip, once every 4 weeks; including tests and checks, this process takes about 2 hours. To give an infusion, a nurse, technician or doctor places a narrow plastic tube into a vein (usually in the arm) using a needle. The needle is then removed and the fluid is infused (dripped) through the tube into the vein.
As Tysabri is a novel treatment, it is important to gather as much information as possible about it in ‘real life’ patients. Therefore, people taking Tysabri beyond two years should be reassessed by their doctor. Individual treatment decisions about longer-term therapy can then be made for each person individually.
Tysabri will not be given if:
- You are allergic (hypersensitive) to any of the ingredients of Tysabri
- You have a serious problem with your immune system (due to a disease, e.g. leukaemia/HIV, or due to a medicine you are taking or have previously taken)
- You are taking medicines that cannot be used with Tysabri
- You have cancer (unless it is a type of skin cancer called basal cell carcinoma)
- You are under 18 years of age
- You are pregnant, considering becoming pregnant or are breastfeeding
- You are over 65 years of age
Take special care with Tysabri if:
You need a blood test. If this is the case, you will need to tell the healthcare professional/doctor that you are receiving Tysabri since Tysabri may affect the results of these tests.
Tysabri is associated with some side effects, those which occur more frequently include urinary tract infection, sore throat, a runny or blocked nose, shivering or fever, itchy rash (hives), headache, dizziness, nausea or vomiting, joint pain or tiredness.
Some people may experience a generalised hypersensitivity (allergic) reaction to Tysabri. If this is the case, your Tysabri treatment will be stopped permanently. In contrast, infusion reactions which include symptoms such as urticaria, dizziness, nausea and shaking are more common and do not require you to stop taking the medicine.
People taking Tysabri may develop neutralising antibodies. This is because Tysabri is a foreign protein and the body's immune system naturally produces antibodies against foreign proteins. Neutralising antibodies may reduce the effectiveness of Tysabri. In trials, 6% of patients developed “persistent antibodies” which means that they had to stop treatment with Tysabri.
There have been very rare reports of a brain infection called PML (progressive multifocal leukoencephalopathy) that has occurred in people who were taking Tysabri. To date, PML has only been reported in patients taking Tysabri together with other drugs which affect the immune system. For this reason, Tysabri is given as a ‘monotherapy’. This means that you should not take medicines like interferon-beta in combination with Tysabri. PML usually leads to severe disability or death. The symptoms of PML may be similar to an MS relapse. So, if you believe your MS is getting worse or if you notice any new symptoms whilst you are taking Tysabri, it is important that you speak to your doctor as soon as possible.
Tysabri received a license for the treatment of highly active relapsing remitting MS in 2006. Tysabri is marketed by Biogen Idec Ltd and Elan in the UK and Ireland. Tysabri was recommended for use on the NHS in England and Wales by NICE in July 2007.
More detailed prescribing information on Tysabri can be found by going to www.medicines.org.uk. Typing Tysabri in the ‘search’ box and pressing ‘go’ will bring you to a patient information leaflet on Tysabri.
Suitability criteria:
Tysabri is an appropriate treatment for people with highly active RRMS provided they fulfil the following criteria:
1.1 Have had two or more disabling relapses in one year and have an MRI scan which shows activity consistent with highly active RRMS.
or
1.2 Have had one disabling relapse while receiving interferon beta and have MRI activity consistent with highly active RRMS.
2. Are aged over 18 years and under 65 years
3. Have no contraindications (i.e. there is no medical reason why the person should not receive Tysabri).
Stopping criteria:
Treatment should be stopped in people taking Tysabri if:
- There are intolerable side effects
- There is a hypersensitivity reaction
- The person develops neutralising antibodies
- If a pregnancy is planned
- If Tysabri does not appear to be effective, e.g. if the person experiences no evidence of therapeutic benefit after 6 months of treatment.
References
1. Tysabri Summary of Product Characteristics November 2007