Extavia (interferon beta 1b) is a disease modifying drug (DMD) for relapsing remitting MS.
You self-inject Extavia under the skin every other day to reduce the number and severity of relapses. It reduces the number of relapses by about one third (30%).
Common side effects include flu-like symptoms and injection site reactions.
What is Extavia used for in MS?
Extavia is a disease modifying drug for relapsing MS. You have fewer relapses than you might have had with no treatment and any relapses you do have should be less severe.
Extavia is a moderately effective (category 1.1) DMD; in clinical trials people taking Extavia had about 30% fewer relapses than people taking placebo. In clinical trials, MRI scans showed people taking Extavia had fewer, smaller or no new areas of active MS (lesions). Extavia may also slow down the build-up of disability associated with MS.
Extavia can be prescribed for adults with active relapsing remitting MS.
Extavia has been approved for use on the NHS since 2009. It can only be prescribed by a neurologist.
It's important that you tell your MS team if you have any health problems or are taking other medicines. Extavia may not be suitable if you have severe depression or suicidal thoughts.
The prescribing advice for Extavia during pregnancy and breastfeeding is appropriately cautious. However, pregnancy registers and clinical experience have shown no increased risk to the health of mother or baby with Extavia.
If you are trying for a family, talk to your MS nurse or neurologist about whether you should continue to take Extavia until you are pregnant.
If you become pregnant while on Extavia, your neurologist or MS nurse may recommend you stop taking it, depending on how active your MS has been and the benefits and risks to you and your baby. Women usually experience fewer relapses during pregnancy, so continuing to take Extavia may not be necessary. However, if Extavia is stopped during pregnancy, it will take several months to reach full effectiveness when restarted and may not reduce relapses during the first few months after childbirth.
Pregnancy guidelines consider that it is safe to take Extavia during breastfeeding if required.
You self-inject Extavia under the skin every other day. Extavia is supplied as powder and solution which are combined just before doing an injection.
Your MS nurse will show you how to do the injections, discuss the practicalities and offer advice or training and ongoing support if you should need it.
To give your body a chance to get used to Extavia and reduce the impact of side effects, your doctor or MS nurse may suggest you start on a lower dose and gradually increase to the full dose.
What side effects could I get with Extavia?
The most common side effects include:
- Flu-like symptoms, such as headache, muscle ache and stiffness, chills or fever, following an injection
- Injection site reactions
You are more likely to have these side effects when you first start taking Extavia. Most people have mild to moderate side effects which tend to go away over time.
A neurologist or MS nurse may suggest ways to reduce these side effects including:
- To help with flu-like symptoms, it may be helpful to change the time of day of injection in order to sleep through the worst of the side effects
- To help reduce fever, paracetamol or ibuprofen can be taken before the injection and at four to six hour intervals after the injection, as required
Common side effects (affecting more than 1 person in 100)
- flu-like symptoms
- headache
- injection site reactions
- blood cell abnormalities
- feeling weak or tired
- difficulty sleeping
- diarrhoea, nausea and vomiting
- muscular or joint pain
- infections
Less common side effects (affecting less than 1 person in 100)
- changes in menstruation (periods)
- neurological symptoms, mood changes, depression
- liver abnormalities
- allergic reactions
- heart problems and hypertension
- hair thinning or loss
- damage to small blood vessels leading to kidney problems
A full list of side effects is included in the manufacturer's Patient Information Leaflet.
Assessment before treatment
Before starting Extavia, you should have blood tests to measure blood cell counts and check liver function.
Assessment during treatment
Once you've started treatment, you'll have blood tests to measure blood cell counts and monitor liver function, generally every three months for the first year, then less frequently. Depending on local practice, the tests may be carried out at a local GP surgery or it may be necessary to attend a hospital clinic.
During the coronavirus outbreak, you may find that your regular blood tests happen less frequently, may take place in a different location or may temporarily stop. The Association of British Neurologists has assessed the risks and benefits of blood monitoring for people taking Extavia, and has recommended a safe minimum schedule for all DMDs during this period. The recommendation for Extavia is that the first blood test, 3 months after starting to take the drug, is essential, but that further tests can be halted temporarily. If you notice any new or worsening MS symptoms, you should contact your MS team.
Interferons are proteins that occur naturally in the immune system. It is thought that beta interferon acts by reducing both inflammation and the immune response that is attacking the body's own myelin.
As Extavia is very similar to Betaferon, no additional studies were needed. The following study first demonstrated the effectiveness of Betaferon:
- The IFNB Multiple Sclerosis Study Group - 1993 - Betaferon compared to placebo
This clinical trial compared two doses of Betaferon or placebo in 372 people with relapsing remitting MS. Compared with placebo, the higher dose of Betaferon reduced the relapse rate by 31% over the 2 year study. Disability levels measured by EDSS changed very little in treatment and placebo groups. The higher dose of Betaferon reduced the number of brain lesions on MRI.
- Risk Sharing Scheme - 2018 - long-term effectiveness of beta interferons and Copaxone
This study was set up in 2002 to evaluate the long-term benefits of beta interferons and Copaxone (glatiramer acetate). More than 5000 people taking either Avonex, Betaferon, Copaxone or Rebif were recruited at study centres around the UK and their disability levels (EDSS) monitored for 10 years. At the end of the study, changes in disability levels were compared to those recorded from an untreated group.
The study found that the DMDs delayed the need to use a walking stick (EDSS 6.0) by four years.
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National Institute for Health and Care Excellence (NICE).
Beta interferons and glatiramer acetate for treating multiple sclerosis.
NICE technology appraisal guidance TA527.
Full guideline (link is external)
Interferon beta-1b is effective in relapsing-remitting multiple sclerosis. I. Clinical results of a multicenter, randomized, double-blind, placebo-controlled trial. The IFNB Multiple Sclerosis Study Group.
Neurology 1993;43(4):655-61.
Summary (link is external)