There has been a lot of activity in the clinical trial space for spinal muscular atrophy in the last 2 years.
Nusinersen is an antisense oligonucleotide, or a short synthetic stretch of nucleic acid, that is designed to specifically bind SMN2 transcripts and “correct” SMN2 gene expression.
Two hospitals in Australia- the Royal Children’s Hospital (RCH) and Sydney Children’s Hospital Network (SCH/CHW) – have been trial sites for the Nusinersen trials, run by Biogen. The Lady Cilento Children’s Hospital (LCCH) was also a potential trial site for one of these studies but did not enrol a patient.
In Australia we had several infants enrolled in several of the Nusinersen trials, one for pre-symptomatic SMA type 1 (a trial called NURTURE) and one for SMA type 1 (a trial called ENDEAR, with roll= over after 12 months into an open-label trial called SHINE).
In the US and Europe there was another trial – in SMA 2 patients- called CHERISH, which no Australasian sites were involved with.
The ENDEAR and CHERISH studies have now been stopped because their interim (half-way) analysis showed that the drug was effective in meeting the studies’ primary endpoints (motor development).
RCH, SCH and LCCH have now been invited to register as sites for Biogen’s Extended Access Program (EAP) for SMA type 1 and are in the process of doing so. Other Australian sites may also enrol in this EAP in the forthcoming months. The EAP means that infants with SMA will be able to access Nusinersen – free of charge to the patient, hospital or state- before it goes through the full process of regulatory approval in Australia. That regulatory process could take months or years.
For each site, registration for an EAP requires detailed applications to the hospital’s research ethics committee and drug usage committee, followed by an application to the Australian government’s regulatory agency, the TGA. This process takes quite some time. Because Nusinersen is not a licensed drug anywhere in the world yet, and it is undergoing regulatory drug approval processes all over the world, the ethics committees have to be comfortable that the medication is likely to be safe in this patient population.
The company that owns the drug has not yet been able to release a whole lot of information about the results of the trials, given that some patients have not yet rolled over onto open-label treatment, and that they have a lot of data to go through.
We don’t yet know when we might be able to set up an EAP for patients with SMA type 2, or who might qualify for treatment under this EAP. We hope to have that information early in 2017.
Nusinersen is given by an intrathecal injection into the spinal fluid via a lumbar puncture. In the ENDEAR and NURTURE studies, children received an initial series of three injections over 6 weeks then a top-up treatment every 4 months. In CHERISH, the maintenance treatment was given every 6 months. In the EAP, treatments will be every 4 months. Some children will need to have the procedure done under sedation or an anaesthetic. Each centre will need to work out individually how best to do this in their hospital.
As each centre gains approval to go ahead with the EAP, the doctors and nurses at that centre will talk to the families of all the children who are known to be potentially eligible. This will involve a detailed discussion of the risk/ benefits of the EAP for their child. We can’t really engage in those discussions yet, until we know exactly when the EAPs can start and how they will work. Those risks/ benefits of the EAP might be dependent on the child’s lung function etc, so that discussion has to be done on a case by case basis once we have permission to proceed.
We are aware of all the children followed at RCH, SCH/CHW and LCCH who might be suitable and plan to contact their families as soon as we have the go-ahead to proceed with the EAP. If there are other families in the community with children with SMA of whom we are unaware we would be happy for them to make contact with us.
In Queensland, families can contact Dr Anita Cairns or Kate Munro, Neuromuscular Clinical Nurse Consultant via CHQ-Neuromuscular@health.qld.gov.au