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Page last checked: 28th November 2022
Last updated: 17th March 2023

Your child must have had the genetic test confirming they have 5q SMA with a bi-allelic mutation in the SMN1 gene. This test can take a few weeks.

You child will need to be weighed at your Specialist Centre which will be referring them for treatment. The Centre will also need to complete a range of blood tests to make sure it’s safe for your child to have gene therapy. These tests include:

  • AAV9 antibody testing – results are valid for 30 days
  • liver function tests
  • full blood count
  • kidney function
  • cardiac enzymes

It should be possible to complete these tests and have the results within a few days.

A small number of children may have developed AAV9 antibodies before they are tested. Depending on what is called the antibody titre level, the presence of these antibodies could mean that it’s not possible to administer Zolgensma. Recent evidence suggests that only a small number of children may become ineligible for this reason (around 5 in 100 children tested). If AAV9 antibody titres are reported to be above 1:50, your child may be re-tested. AAV9 antibody results are valid for 30 days.

If the results of the other tests (liver function, full blood count, kidney function, cardiac enzymes) aren’t clear, these may indicate it wouldn’t be safe to administer Zolgensma. Any such results would be discussed fully with you.

These are at:

  • Bristol
  • Evelina
  • GOSH (Great Ormond Street Hospital)
  • Manchester
  • Sheffield
  • Glasgow
  • Belfast

Children must be referred by their Regional Neuromuscular Centre – see a full list of these here.

Overall care of a child is always with their Referring Regional Neuromuscular Centre (RNMC) or Specialist Centre as care needs to be as convenient as possible for the family. Your child’s team at your regional centre will talk with you about caring for your child and keeping them as well as well as possible in preparation for, and after, their infusion

The infusion centres are always responsible for the infusion and care of the child’s needs during the admission and any safety monitoring and management of the steroid dosage before and after treatment (see below).

Care arrangements always take account of each individual child and family’s circumstances. These fictionalised examples from the NMDT may give some idea of how this can vary:

Baby 1, parents had their own transport and were happy to come to the Infusion Centre for blood tests but were seen by their RNMC for feeding and swallowing assessments and other care before and after the infusion.

Baby 2 became ill between referral and planned admission and was admitted to their local hospital & then eventually, when well, was transferred to the Infusion Centre for their infusion. Parents didn’t have their own transport. A week after infusion, when their safety blood tests were all OK, they were discharged home with follow up tests and care by their RNMC. The results were sent across to the Infusion Centre which advised on the appropriate steroid dose

Baby 3 had been well but became feverish when admitted for treatment at the Infusion Centre; the infusion was postponed and Baby 3 was admitted to the Infusion Centre’s Paediatric Intensive Care Unit (PICU). All care including blood tests, feeding and swallowing was managed by the Infusion Centre. Once Baby 3 was well and had been treated, they were discharged home. Follow up blood tests and care were arranged locally with the RNMC with results sent to the Infusion Centre.

Zolgensma is administered at the infusion centre. It’s a one-time intravenous (IV) infusion. It takes over 60 minutes to deliver the treatment.

Novartis Gene Therapies told us in April 2021:

"There is a need to set up a drip (intravenous cannulation) for your child – which usually goes into the arm. This does involve the sensation of a sharp scratch, the infusion itself should not cause any pain. "

In December 2021, the NMDT told us that:

"Centres have found that for most children the infusion has to be administered via a central bigger vein as it has been impossible to access a ‘peripheral’ vein, such as in the hand. In the UK this requires a specialist service from within the hospital and an anaesthetist – a service which isn’t always readily and easily available."

If your child is unwell or there are other issues at the centre it may be necessary to temporarily delay treatment of your child. Your treating clinician will make that decision.

Novartis Gene Therapies and NHS England told us:

"Your child will normally need to be admitted at the infusion centre the day before the infusion to allow sufficient time for pre-infusion tests and to start oral prednisolone (a common steroid treatment) to reduce liver side effects.

After receiving the infusion, your child will need to stay in hospital for monitoring. Depending on blood test results and as long as there are no complications, children may be able to go home within a few days but with supervision from the infusion centre. In some cases, children and families may need to stay in accommodation close to the infusion centre. The oral steroids will continue for at least two months."

Any drug, including ones that are commonly prescribed or sold over the counter, may cause possible side effects. Side effects of medications are reported and recorded during their clinical trials. They’re also picked up through the ongoing systems that are in place to monitor medications and their use in the ‘real world’. All possible side effects are listed in the Patient Information Leaflet that is given with any medication. They are grouped as:

  • very common
  • common
  • uncommon
  • rare.

For Zolgensma, possible side effects listed are:

Very common: may affect more than 1 in 10 people

  • increases in liver enzymes seen in blood tests.

Common: may affect up to 1 in 10 people

  • vomiting
  • fever.

An infection (e.g., cold, flu or bronchiolitis) before or after Zolgensma treatment may lead to more serious complications.

These and any rare or very rare side effects are listed in the Zolgensma Patient Information Leaflet.

Your child’s team will talk with you about possible side effects to look out for and what to do if these occur.

Zolgensma can:

  • lead to an increase in enzymes (proteins found within the body) produced by the liver or injury to the liver – though actual liver failure is very rare.
  • lower blood-platelet counts (thrombocytopenia).
  • raise levels of a heart protein called troponin-I that may indicate injury to the heart.

As part of the Zolgensma treatment, to help manage any increase in liver enzymes that a child could develop they will be given a corticosteroid medicine such as prednisolone 24-hours before and for about 2 months or longer after treatment.

As corticosteroids can affect the body’s immune (defence) system, your child’s doctor may decide to delay giving some vaccinations while your child is receiving corticosteroid treatment.

For more information, please see the Zolgensma Patient Information Leaflet.

Your child’s team will talk with you about how these possibilities are managed and what to look out for and what to do if these occur.

Novartis Gene Therapies have told us,

"The active substance in Zolgensma may temporarily be excreted through your child’s bodily waste. Careful hand hygiene and care with the disposal of any nappies for at least one month after infusion is recommended in their Package Information Leaflet.

Your child will also need to attend for regular periodic blood test results and follow up clinic appointments for some time following their infusion. These may be able to be carried out locally to your home. Your clinical team will advise you on this. How long this will need to carry on for will depend on your individual child’s needs and should be discussed with your treating clinician."

Your clinical team will talk with you about what supportive care your individual child will continue to need when they go home with you. They may refer to The International Standards of Care for SMA (SoC), the 2017 guidelines for care for all children with SMA – whatever drug treatment they are receiving.

The clinicians at the Infusion Centre will go through all this information with you.

In England, the four centres have arrangements they will put in place for parents / carers to stay close to their child. Centres in the devolved countries will be able to advise what help they can provide.

Travel costs will be met in line with standard NHS Healthcare Travel Costs Scheme. You will be responsible for arranging any time off work or childcare arrangements for other children. The cost of food won’t usually be reimbursed. If you need help with organising or funding arrangements, please talk to the referring or treatment centre and / or the One Gene Therapy Family Liaison Nurse if they are involved.

All the gene therapy centres have facilities in place to support families holistically throughout the treatment period.

NHS England’s advice is here – this is only possible if Zolgensma treatment is not successful.

Data on your child’s developmental milestones, any need for support with feeding and breathing, quality of life measures and need for additional treatments are all part of the data collection. This data will be collected as part of the routine follow up of your child and will link into existing data collection processes with SMA REACH, the national SMA registry (so that doctors can gain the best understanding of how the therapy is being used and how children are benefitting. Information on behalf of all the infusion centres is also being collected by Evelina Hospital for audit and monitoring purposes.