An anti-CD20 MS monoclonal antibody
Ocrelizumab
An infusion treatment for relapsing and primary-progressive MS that targets B cells, with infusion reactions, infection risk and a need for screening before starting.
What is Ocrelizumab?
Ocrelizumab is a treatment for multiple sclerosis given as a drip into a vein, usually every six months. It targets a type of immune cell called B cells (carrying a marker called CD20) that helps drive the disease, and it is one of the few treatments used for primary-progressive MS as well as relapsing MS. Infusion reactions are common, so doses are given slowly with observation and pre-medication. It raises the risk of infections, so screening for hepatitis B is done and vaccinations are brought up to date before starting.
Education and reference only. This is a plain-language guide to Ocrelizumab — 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
Ocrelizumab is a monoclonal antibody used as a disease-modifying treatment for multiple sclerosis. It is given as an infusion into a vein, typically every six months after the first couple of doses are split to be given more cautiously. It is used for relapsing MS and is also one of the limited options licensed for early primary-progressive MS. By reducing relapses and slowing progression it helps keep the disease quieter, but it does not cure MS or reverse existing damage.
How it works
Ocrelizumab attaches to a marker called CD20 on certain immune cells known as B cells and removes them from the circulation. B cells play an important part in the immune attack on the nerves in multiple sclerosis, so reducing them lowers inflammation, relapses and, in progressive disease, the rate of worsening. Because B cells also help fight infection and produce antibodies, the treatment increases the risk of infections, which is why screening and vaccination beforehand matter. The effect is long-lasting, allowing infusions to be spaced months apart.
Company & origin
Originated / developed by: Roche.
A monoclonal antibody given by infusion in the UK for relapsing and primary-progressive multiple sclerosis.
Practical use
How to take Ocrelizumab
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by a healthcare professional as a slow drip into a vein, usually every six months after the first doses.
- Expect pre-medication and close observation during and after the infusion to manage infusion reactions.
- Make sure hepatitis B screening and any needed vaccinations, including live vaccines, are completed before you start.
- Report any fever, cough, urinary symptoms or other signs of infection promptly.
- Tell your team if you are planning a pregnancy or think you may be pregnant.
- Keep to your infusion schedule and monitoring appointments.
Weighing it up
Advantages & disadvantages of Ocrelizumab
Advantages
- Effective for relapsing MS and one of the few options for early primary-progressive MS.
- Given as an infusion only about twice a year, which is convenient once established.
- Has a strong effect on the immune cells that drive the disease.
Disadvantages
- Infusion reactions are common and require slow administration with observation.
- Raises the risk of infections and can lower protective antibody levels over time.
- Needs hepatitis B screening and up-to-date vaccinations before starting, and is given in hospital.
Practical use
Good to know
Two practical points stand out. First, infusion reactions are common, especially with the first doses, and can include itching, rash, throat irritation, flushing and changes in blood pressure; to reduce this, doses are given slowly with pre-medication and close observation, and the first dose is usually split. Second, because the treatment lowers infection defences, screening for hepatitis B is carried out before starting (as it can reactivate), other infections are checked for, and vaccinations are brought up to date in advance, since live vaccines cannot be given once treatment has started. Over the longer term, antibody levels in the blood can fall, which may increase infection risk, and a rare brain infection (PML) has been reported. Report any signs of infection, and discuss any planned pregnancy with your team.
Who should not take it / use with caution
- People with an active serious infection, including active hepatitis B, should not start it until treated.
- It is avoided in those with a severely weakened immune system.
- It is generally avoided in pregnancy and breastfeeding unless a specialist judges it necessary.
Monitoring
- Hepatitis B screening and a vaccination review before starting.
- Watching for infusion reactions during and after each dose.
- Checking for infections and, over time, blood antibody levels.
Side effects
- Infusion reactions such as itching, rash, flushing, throat irritation and changes in blood pressure.
- A higher chance of infections, including chest and urinary infections, and cold sores.
- Rarely, reactivation of hepatitis B, a fall in protective antibodies, or the brain infection PML.
Key interactions
- Combining it with other immune-suppressing treatments increases the risk of infection and needs specialist guidance.
- Live vaccines must not be given during treatment and should be completed beforehand.
- Recent or planned use of other MS disease-modifying treatments is taken into account when switching.
Available as: A solution given as an infusion into a vein.
Answers
Ocrelizumab: frequently asked questions
How often will I need the infusion?
After the first doses, it is usually given as an infusion roughly every six months, which most people find convenient.
Why do I need screening before I start?
Because the treatment lowers your infection defences, hepatitis B is screened for (as it can reactivate) and vaccinations, including live ones, are brought up to date before you begin.
What is an infusion reaction?
It is a reaction during or after the drip, such as itching, rash, flushing or throat irritation; doses are given slowly with pre-medication and observation to manage it.
Can it be used for progressive MS?
Yes; it is one of the few treatments licensed for early primary-progressive MS, as well as for relapsing MS.
Will it cure my MS?
No. It reduces relapses and can slow progression, but it does not cure MS or reverse existing damage.
Authoritative sources
- BNF
- NICE CKS
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