New genetic therapy approved for SOD1-ALS brings targeted treatment option to patients in the UK
The Medicines and Healthcare products Regulatory Agency (MHRA) approved tofersen (Qalsody) on 22 July 2025 to treat adults with amyotrophic lateral sclerosis (ALS) caused by mutations in the SOD1 (an enzyme called superoxide dismutase 1) gene - a rare, inherited form of motor neurone disease (MND).
ALS is a progressive condition that affects nerve cells in the brain and spinal cord. This leads to muscle weakness, including the muscles needed to breathe and swallow. Tofersen works by reducing levels of the toxic protein produced by the SOD1 gene, which damages nerve cells.
The approval was granted via the International Recognition Procedure (IRP).
Tofersen is given by lumbar puncture (injection into the lower spine) at regular intervals by a healthcare professional.
Common side effects seen in clinical studies include headache, back pain and tiredness. In rare cases, more serious side effects have occurred, including inflammation of the spinal cord or optic nerve, and increased pressure around the brain.
As with any medicine, the MHRA will keep the safety and effectiveness of tofersen under close review.
Anyone who suspects they are having a side effect from this medicine is encouraged to talk to their doctor, pharmacist or nurse and report it directly to the MHRA Yellow Card scheme, either through the website ( https://yellowcard.mhra.gov.uk/ ) or by searching the Google Play or Apple App stores for MHRA Yellow Card.
Notes:
- The approval was granted on 22 July 2025 to Biogen Netherlands B.V.
