A genetic therapy called tofersen has been approved in the UK to treat SOD1-ALS, a rare inherited form of motor neurone disease.
The drug targets amyotrophic lateral sclerosis (ALS) caused by mutations in the SOD1 gene – which produces an enzyme called superoxide dismutase 1 – leading to a toxic protein that damages nerve cells.
Motor neurone disease progressively affects nerve cells in the brain and spinal cord, causing muscle weakness. In SOD1-ALS, symptoms often include difficulty breathing and swallowing.
MND Association Director of Engagement Richard Evans said: “Tofersen has been described as a game changer for the 2 per cent of people whose MND is caused by a variation in the SOD1 gene, so the licensing of the drug is a really important step forward and one which, of course, we welcome.
“However, it is important to stress that just because it has MHRA approval, it does not necessarily mean it will be available on the NHS, as it will be for NICE to decide if it considers it value for money.
“What we need now is for tofersen to be appraised as quickly as possible by NICE and for it to be approved for use on the NHS.
“Only then can we be confident that everyone with SOD1 MND – we think that’s around 60 to 100 people – can access the drug which could save their lives.”
The Medicines and Healthcare products Regulatory Agency (MHRA) approved tofersen – marketed as Qalsody – on 22 July 2025 via the International Recognition Procedure.
The treatment works by lowering levels of the harmful superoxide dismutase 1 protein. It is administered at regular intervals via lumbar puncture – an injection into the lower spine – by a healthcare professional.
Common side effects reported in clinical studies include headache, back pain and tiredness. More rarely, serious effects such as inflammation of the spinal cord or optic nerve and increased pressure around the brain have occurred.
The SOD1 form of ALS is inherited and can be identified through genetic testing. Unlike most cases of motor neurone disease, which occur sporadically, this variant now has a targeted treatment.
The UK approval brings access in line with other countries where the therapy is already available.
The drug will be supplied by Biogen Netherlands B.V. and remains under continued regulatory review to monitor its safety and effectiveness.
