An antisense medicine for SOD1-related motor neurone disease
Tofersen
A specialist injection used to treat a rare inherited form of motor neurone disease caused by SOD1 gene changes.
What is Tofersen?
Tofersen is a specialist medicine used to treat a rare, inherited form of motor neurone disease (also called amyotrophic lateral sclerosis, or ALS) caused by changes in a gene called SOD1. It is an antisense medicine that lowers the production of a faulty protein that damages nerve cells. It is given by injection into the fluid around the spinal cord, through a procedure similar to a lumbar puncture, in hospital. Because of how it is given, it can cause back pain, headache and, rarely, more serious problems affecting the spinal cord or nerve roots, so it is used only under a specialist neurology team.
Education and reference only. This is a plain-language guide to Tofersen — 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
Tofersen is a medicine used for a rare, inherited form of motor neurone disease (amyotrophic lateral sclerosis, or ALS) that is caused by changes in the SOD1 gene. It is a type of medicine called an antisense oligonucleotide, which works at the genetic level to reduce the amount of a harmful protein the body makes. It is given by a doctor as an injection into the fluid around the spinal cord, a procedure like a lumbar puncture, in a hospital setting. It is only suitable for people whose motor neurone disease is confirmed to be linked to a SOD1 gene change, and it is started and supervised by a specialist neurology team.
How it works
In SOD1-related motor neurone disease, a faulty version of the SOD1 protein builds up and damages the motor nerves that control movement. Tofersen attaches to the genetic message that tells the body to make this protein, prompting the body to break that message down, so less of the harmful protein is produced. By lowering the amount of the damaging protein, it aims to slow the loss of nerve function. It is given directly into the fluid around the spinal cord so it can reach the nervous system, and it is repeated on a regular schedule to keep the protein levels down.
Company & origin
Originated / developed by: Specialist manufacturer.
A specialist medicine used in the UK for a rare, inherited form of motor neurone disease caused by changes in the SOD1 gene, given by injection into the fluid around the spinal cord.
Practical use
How to take Tofersen
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by a specialist doctor as an injection into the fluid around the spinal cord, in hospital; you do not take it yourself.
- Expect each dose to involve a procedure similar to a lumbar puncture, with a starting series of doses followed by regular maintenance doses.
- Rest as advised after the procedure, as headache and back pain are common afterwards.
- Tell the team straight away about new or worsening weakness, numbness, severe back pain, or problems with your bladder or bowels.
- Keep all your appointments, as treatment is given on a regular schedule and needs close monitoring.
Weighing it up
Advantages & disadvantages of Tofersen
Advantages
- Targets the underlying cause in SOD1-related motor neurone disease by lowering production of the harmful protein.
- Offers a specific treatment for a form of motor neurone disease that previously had none.
- Given on a regular schedule under close specialist supervision.
Disadvantages
- Only suitable for the small number of people with a confirmed SOD1 gene change.
- Each dose is given by a spinal procedure, which commonly causes headache and back pain.
- Can rarely cause serious problems affecting the spinal cord or nerve roots.
Practical use
Good to know
The most important thing to understand is that tofersen is only for the small number of people whose motor neurone disease is caused by a confirmed SOD1 gene change, so genetic testing is needed first. It is given by injection into the fluid around the spinal cord in hospital, so each dose involves a procedure similar to a lumbar puncture, and headache, back pain and pain at the injection site afterwards are common. A key safety point is that, rarely, it can cause more serious problems affecting the spinal cord or the nerve roots, such as inflammation (myelitis or radiculitis) or other serious neurological events, so any new or worsening weakness, numbness, severe pain, or problems with the bladder or bowels should be reported urgently. The specialist team explains what to expect from the procedure and watches closely for these problems.
Who should not take it / use with caution
- People who have had a serious allergic reaction to tofersen should not have it.
- It is only for people whose motor neurone disease is confirmed to be caused by a SOD1 gene change.
- It should only be given under a specialist neurology team able to perform the spinal procedure safely.
Monitoring
- Genetic testing to confirm a SOD1 gene change before starting.
- Close watching after each dose for headache, back pain and any new neurological symptoms.
- Regular review of nerve and muscle function and of spinal-fluid tests over time.
Side effects
- Headache, back pain and pain or discomfort where the injection is given, related to the spinal procedure.
- Tiredness, muscle or joint pain, or fever-like feelings after a dose.
- Rarely but seriously, inflammation of the spinal cord or nerve roots (myelitis or radiculitis) or other serious neurological events, which need urgent attention.
Key interactions
- There are few well-established routine medicine interactions, but tell your team about everything you take.
- Medicines that affect blood clotting may matter around the spinal procedure, so your team will review them.
- It is used as part of overall specialist care for motor neurone disease, alongside other supportive treatments.
Available as: A solution given by injection into the fluid around the spinal cord.
Answers
Tofersen: frequently asked questions
What is tofersen used for?
It is used to treat a rare, inherited form of motor neurone disease (ALS) caused by changes in the SOD1 gene, by lowering the harmful protein that damages the nerves.
How is it given?
It is given by a specialist doctor as an injection into the fluid around the spinal cord, through a procedure similar to a lumbar puncture, in hospital.
Why do I need a genetic test first?
Tofersen only helps people whose motor neurone disease is caused by a SOD1 gene change, so a genetic test is needed to confirm this before treatment.
Why might I get a headache or back pain afterwards?
These are common after the spinal procedure used to give the medicine; rest as advised, and tell your team if symptoms are severe or do not settle.
When should I call the team urgently?
Report new or worsening weakness, numbness, severe back pain, or problems with your bladder or bowels straight away, as these can signal a serious problem affecting the spinal cord or nerves.
Authoritative sources
- BNF
- NICE CKS
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