AVXS-101 is the name of an experimental medicine for SMA being developed by a US company Avexis. AVXS-101 belongs to the class of gene therapies, or therapies which permanently modify human DNA. AVXS-101 brings the missing SMN1 DNA sequence (a SMN1 transgene) to the human body by infecting it with a virus that carries the missing sequence.
Because most neuronal cells survive throughout the entire life of the human, it is assumed that a single injection of AVXS-101 will have a lasting effect.
AVXS-101 was also formerly called ChariSMA.
The first clinical trial of AVXS-101 started in May 2015 and included 15 babies with type 1 SMA. The first three babies received a lower dose of the virus; the following 12 received a dose several times higher.
As can be seen on the chart above, the three children on lower dose remained stable since the injection. On the other hand, those who received higher dose witnessed dramatic improvement of muscle function. After 18 months from injection, the strongest two SMA 1 children could walk and run independently and most of the remaining ones were able to sit without support. The video below, published in October 2016, shows the changes after AVXS-101 treatment:
The above clinical trial completed in September 2017, following which Avexis went on to test the treatment in other groups of patients:
- STR1VE – a US trial of AVXS-101 administered intravenously to babies with SMA type 1. As of November 2018, enrolment has been completed.
- STR1VE EU – a similar trial run in the European Union. As of November 2018, the trial is open in Milan and London. 14 more sites in 8 countries – including Newcastle – are scheduled to be activated during autumn of 2018.
- SPR1NT – a clinical trial of AVXS-101 administered intravenously to presymptomatic babies younger than 6 weeks. As of November 2018, the trial is oepn for enrolment in the US and Australia. Plans are there to open the trial also in selected hospitals across the European Union.
- STRONG – a US-based clinical trial for children with SMA type 2 younger than 6 years in whom AVXS-101 is administered intrathecally. As of November 2018, recruitment has been completed. This trial does not currently have a corresponding EU trial.
- REACH – a clinical trial in which AVXS-101 will be administered intrathecally to children and adults with various types of SMA. This trial is planned to be conducted globally in 2019. As of November 2018 it is in planning stage.