Tofersen Treatment

Tofersen is a new type of treatment known as an antisense oligonucleotide (ASO). It is designed to treat a specific type of Amyotrophic Lateral Sclerosis (ALS), also known as Motor Neurone Disease (MND), caused by a mutation in the SOD1 gene.

In people with SOD1-ALS, the body produces a faulty version of the SOD1 protein. This faulty protein can build up to toxic levels and damage the nerves (motor neurones) that control muscle movement. Tofersen works by interfering with the genetic instructions for this protein, helping your body produce less of it. This is intended to slow down the damage to your nerve cells.

You have been offered this treatment because genetic testing has confirmed that you have a mutation in the SOD1 gene. Tofersen is not effective for other types of MND that are not caused by this specific genetic mutation.

It is important that you understand that Tofersen is a new treatment. While clinical trials have shown that Tofersen can lower the levels of neurofilament (a marker of nerve damage) in the blood, it is not yet fully proven to stop or reverse the physical symptoms of MND in all patients.  

Clinical Trials: In the main clinical trial (VALOR), patients treated with Tofersen showed a significant reduction in markers of nerve damage compared to placebo. However, the trial did not definitively prove that Tofersen significantly slowed muscle weakness in all patients over the initial 6-month period.  

Longer-term data: Data from longer-term extensions of the trial suggests there may be a stabilisation of symptoms for some patients who stay on the drug for longer periods, but this is still being studied. 

Your medical team has recommended this treatment because they believe the potential benefits outweigh the risks in your specific case, but individual responses to the drug can vary.

Tofersen cannot be taken as a pill or injected into a vein. It must be injected directly into the fluid surrounding your spinal cord to reach the nerves (intrathecal route). This is done via a Lumbar Puncture (also known as a spinal tap).  

The Procedure: You will come to the National Hospital for Neurology and Neurosurgery (usually the Day Care Unit or Ward) either on the day of the procedure or the day before. You will lie on your side, and a doctor will numb the skin on your lower back with local anaesthetic. A thin needle is inserted into the lower back space. The doctor may use image guidance (X-ray or CT scanning) to help with needle insertion. A small amount of cerebrospinal fluid is removed, and following this, Tofersen is injected.  

Duration: The injection process itself takes about 20–30 minutes, but you may need to stay in the hospital for observation for a specific period afterwards (usually 60–90 minutes) to ensure you feel well.

This treatment requires a significant time commitment. You will need to attend the hospital regularly for administration of Tofersen. A blood test will also be taken at each hospital visit.  

The Induction Phase (Loading Doses): To build up the drug in your system, you will receive 3 doses in the first month: 

Dose 1: Day 0  
Dose 2: Day 14  
Dose 3: Day 28  

The Maintenance Phase: After the first month, you will receive one dose every 28 days. This treatment is intended to continue long-term.

Your consultant will regularly review your condition and discuss with you whether continuing treatment remains the best option.

There may be circumstances where it is appropriate to pause or stop treatment, for example, if you experience significant side effects, or if changes in your condition (such as respiratory or spinal changes) make performing the lumbar puncture procedure difficult or unsafe. Your team will always discuss these decisions with you openly to ensure your care plan remains right for you.

Like all medicines, Tofersen can cause side effects, although not everyone gets them. 

Risks related to the Lumbar Puncture

Because the drug is given via spinal injection, procedural side effects can occur:

• Back pain: Pain, redness, or tenderness at the injection site.
• Post-Lumbar Puncture Headache: A specific type of headache that gets worse when sitting or standing and improves when lying down.
• Infection: Very rare, but serious.

Side Effects of the Drug

The following side effects were reported in clinical trials:  

Very Common (may affect more than 1 in 10 people):

• Pain (including back pain, pain in arms or legs).  
• Feeling tired (fatigue).  
• Muscle or joint pain.  
• Fever.  
• Increased white blood cells or protein in the spinal fluid (this is usually found on laboratory tests and may not cause symptoms).  

Common (may affect up to 1 in 10 people):

• Muscle stiffness.
• Nerve pain.  

Serious Side Effects Serious conditions involving inflammation of the nervous system have occurred. These can occur in least 1 in 100 people, but fewer than 1 in 10 people.

• Myelitis or Radiculitis: Inflammation of the spinal cord or nerve roots. Symptoms may include new or worsening weakness, numbness, burning sensations ("pins and needles"), or pain in the legs or arms.  
• Papilledema: Swelling of the optic nerve at the back of the eye. Symptoms may include blurred vision, double vision, or changes in eyesight.  
• Aseptic Meningitis: Inflammation of the lining of the brain. Symptoms include severe headache, stiff neck, nausea, fever, and sensitivity to light.  

If you experience severe headache, neck stiffness, changes in vision, or new numbness/weakness after treatment, you must contact the hospital immediately.

We do not yet know if Tofersen is safe for an unborn baby.

Pregnancy: You should use effective contraception during treatment. If you are pregnant or planning to become pregnant, please discuss this with your consultant immediately.

Breastfeeding: It is not known if Tofersen passes into breast milk. Breastfeeding is generally not recommended during treatment.

If you decide to go ahead with treatment, by law we must ask for your consent and will ask you to sign a consent form.  This confirms that you agree to have the procedure and understand what it involves.  Staff will explain all the risk and  benefits of the treatment before they ask you to sign a consent form.  If you are unsure about any aspect of your proposed treatment, please don’t hesitate to speak with a senior member of staff again.

Tofersen is currently being provided free of charge by the manufacturer, Biogen. You will also be asked to complete a separate Biogen informed consent form, which explains the conditions of this access scheme.

If you have any concerns or experience side effects, please contact the MND Team:  

• MND Clinical Nurse Specialists: 020 3448 3517 / uclh.referrals.mnd.care@nhs.net  
• Hospital Address: National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG.

You can find more information about Tofersen and Motor Neurone Disease from the following organisations: 

Motor Neurone Disease Association (MNDA): The MNDA provides information and support for people living with MND, their families, and carers.
MND Connect Helpline: 0808 802 6262
Email: mndconnect@mndassociation.org 

Biogen (Manufacturer): You can also refer to the manufacturer’s website for specific product information (Qalsody).
(Note: This website may contain information specific to the US healthcare system).

• Qalsody 100 mg Solution for injection. Summary of Product Characteristics. Published 16 Dec 2025 accessed via Qalsody 100 mg Solution for injection - Patient Information Leaflet (PIL) - (emc) | 101725
• Informed consent form Early Access Program for Tofersen. Global Early Access Program to Provide Tofersen to Patients with Amyotrophic Lateral Sclerosis (ALS) Associated with a Mutation in the Superoxide Dismutase 1 (SOD1) Gene. Biogen. Published June 2024.
• Investigator Brochure. Tofersen (QALSODY®, BIIB067). Biogen. Published May 2025.

We are located at the National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG.