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Page last updated: 9th November 2022

Children who have had a diagnosis of SMA Type 1 and could be eligible for treatment under the terms of the agreements in place and who are not newly diagnosed are referred by their clinical team to the National Multidisciplinary Team (NMDT). This includes representatives from all four infusion centres.

The NMDT’s approach has been to look at a smaller group of children first, prioritising those for whom these is greater evidence for both safety of the treatment and its benefits. These smaller groups have been defined by weight and age limits – see Q3. Each child has been discussed carefully by the NMDT. Once the discussion had taken place, the referring Centre was contacted, the family informed and, if appropriate, treatment has gone ahead.

This approach has been taken as the NMDT considered there was more time to safely plan the possibility of Zolgensma treatment for children already receiving nusinersen treatment. Families have understood that a newly diagnosed child would always be treated first, which may sometimes mean a delay for a child waiting for an agreed infusion. The NMDT has been grateful to families for the patience and understanding they have been showing as this service has continued to develop.

The NMDT has now invited referrals from specialist centres of children who weigh up to 20.5 kgs. This upper limit is for practical reasons as a child’s weight may increase while arrangements for treatment are made. The May 2020 European Commission approved dosing guidance is up to 21 kg.

As there is very limited experience globally of treatment of children in this weight group, the particular circumstance of each child needs to be considered very carefully. The assessment process includes:

  • An initial referral from the Specialist Centre Consultant to the NMDT​
  • A full discussion by the NMDT at one of their weekly meetings to assess if the balance of risks and benefits suggest it may be appropriate to consider gene therapy for this child
  • If treatment is potentially appropriate, the family is invited to attend one of the infusion centres with their child for a full assessment and discussion
  • Following this, there is a further discussion by the NMDT to finally decide if treatment should be offered.

To date, the NMDT has invited referring Centres to refer, and has discussed children in the following order. Note ‘treated’ refers to children who at the time are receiving either nusinersen, including any loading doses, or risdiplam.

For an explanation of age bands and any other criteria for these groups, please see Q 4. below.

  • treated children aged between 6 – 7 months
  • treated children aged between 12 – 13 months
  • treated children who are 6 months and under
  • treated children who are aged 7 – 12 months
  • children who are 13 months of age or over, weigh less than 13.5kgs and are not having non-invasive ventilation​​
  • children who are 13 months or older and under 18 months (have not yet turned 18 months) and weigh less than 13.5kgs​
  • children who are aged 18 months or more but under 24 months (have not yet turned 24 months) and weigh less than 13.5kgs
  • children who are aged under 30 months and weigh less than 13.5kgs
  • children who weigh less than 13.5kgs
  • children who weigh under 15 kgs
  • children who are 15 kgs and over and below 18 kgs​

Age is taken to be:

  • the child’s actual birth date if they were born at term or overdue, or
  • their expected birth date if they were premature.

A child’s age is their age on the date when:

  • they are referred to the infusion centre by a Specialist Centre, or
  • when they are referred internally for Zolgensma treatment if they are already cared for by one of the infusion centres.

Aged six months and younger refers to calendar months and includes children below 7 months of age (e.g. if a child is born on the 1st January 2021, they will be 7 months old on the 1st August).

NICE’s Final Determination Document states that for this group:

"Children who are having more than 16 hours per day of non-invasive ventilation, or who have a tracheostomy, are not eligible."


Age 7 – 12 months refers to calendar months and includes children who are 7 months old up to when they turn 13 months (e.g. if a child is born on the 1st January 2021, they are 7 months old on 1st August and turn 13 months old on the 1st February 2022).

NICE’s Final Determination Document states that for this group:

"Children who are having more than 16 hours per day of non-invasive ventilation, or who have a tracheostomy, are not eligible.

The NMDT should develop auditable criteria to enable onasemnogene abeparvovec to be allocated to babies in whom treatment will give them at least a 70% chance of being able to sit independently."


Age 13 months and over refers to calendar months and includes children who have turned 13 months (e.g. if a child is born on the 1st January 2021, they are 13 months old on the 1st February 2022).

NICE’s Final Determination Document states that for this group:

"Children who are having more than 16 hours per day of non-invasive ventilation, or who have a tracheostomy, are not eligible."