Nusinersen

How it works

It modifies splicing of the SMN2 gene to increase production of functional survival motor neuron protein, partially compensating for the deficient SMN1 gene and supporting motor neuron survival.

Prescribing in practice

• Because it is administered intrathecally by lumbar puncture, it should be given by clinicians experienced in the procedure with appropriate precautions for bleeding and infection.
• Coagulation abnormalities and thrombocytopenia have been reported, so check platelets and clotting before dosing as advised in the SPC.
• Renal toxicity has been reported with antisense oligonucleotides, so urine protein should be monitored.

Monitoring

Monitor platelet count, coagulation parameters and urine protein before each dose, alongside motor function over time.

Counselling the patient

• Treatment requires repeated lumbar punctures, with maintenance doses at intervals after the initial loading phase.
• Some children experience headache or back pain related to the procedure.
• Attend all scheduled doses, as regular administration underpins the benefit.

Evidence & guidelines

Nusinersen improved motor function and survival in spinal muscular atrophy in pivotal trials and is recommended by NICE within a managed access framework.