AveXis presents updated STRONG data at WMS demonstrating a higher mean increase in Hammersmith Functional Motor Scale-Expanded (HFMSE) scores among older SMA Type 2 patients following one-time intrathecal administration of AVXS-101

  • Older patients (= 2 years and < 5 years) achieved a mean increase of 5.9 points from baseline in HFMSE scores, nearly double the clinically meaningful threshold (at a mean duration of follow-up time of 9.3 months)
  • Untreated SMA Type 2 patients historically experience declining HFMSE scores over time, will never walk without support and often need a wheelchair. More than 30% of patients with SMA Type 2 will die by age 25

Basel, October 5, 2019 - AveXis, a Novartis company, today announced new interim data from the Phase 1/2 STRONG study for intrathecal (IT) administration of AVXS-101, demonstrating older patients (= 6 months to < 2 years old:

  • The primary efficacy endpoint is the ability to stand without support for = 3 seconds
  • The secondary efficacy endpoint is the ability to walk independently for = 5 steps, according to the Bayley-III Gross Motor Milestone Scale  
  • Since treatment, 18 motor milestones were achieved among the 16 patients who received Dose A or Dose B, including two patients who gained the ability to stand independently, one of whom went on to walk alone

In patients = 2 years to < 5 years old:

  • The primary efficacy endpoint is change in HFMSE score from baseline
  • The secondary efficacy endpoint is the ability to walk independently for = 5 steps according to the Bayley-III Gross Motor Milestone Scale 
  • Patients showed a clinically meaningful improvement in motor function, having a mean 5.9-point increase from baseline in HFMSE scores at their most recent visit, at a mean duration of follow-up time of 9.3 months
    • In a responder analysis, half of patients (6/12) had a = 3-point increase, which was observed starting at one month post-treatment
  • Since treatment, four motor milestones have been achieved among 12 patients in the Dose B group, including one patient who gained the ability to walk with assistance

All patients in STRONG study experienced at least one treatment emergent adverse event (TEAE) and 13 patients (43%) were reported to have a TEAE considered by the investigator to be related to treatment. Serious TEAEs were reported in 13% (n=4) of patients. A total of seven serious TEAEs were reported in four patients (n=1 each): influenza, pneumonia, respiratory syncytial virus infection, elevated ALT, elevated AST, blood alkaline phosphatase increased, and respiratory failure. Elevated ALT and AST (in one patient) were considered probably related to treatment. None of the serious TEAEs resulted in discontinuation from the study and no deaths were reported.

About AVXS-101 Intrathecal Administration
Investigational IT administration of AVXS-101 is currently being evaluated in patients with SMA Type 2 in a Phase 1/2 clinical trial.

About Spinal Muscular Atrophy (SMA)
SMA is a severe neuromuscular disease characterized by the loss of motor neurons leading to progressive muscle weakness and paralysis. SMA is caused by a genetic defect in the SMN1 gene that codes SMN, a protein necessary for survival of motor neurons. , The incidence of SMA is approximately 1 in 10,000 live births and it is the leading genetic cause of infant mortality. , The most severe form of SMA is Type 1, a lethal genetic disorder characterized by rapid motor neuron loss and associated muscle deterioration, resulting in mortality or the need for permanent ventilation support by 24 months of age for more than 90% of patients if left untreated. Patients with SMA Type 2 typically have 3-4 copies of SMN2, will never walk without support and often need a wheelchair.1 More than 30% of patients with SMA Type 2 will die by age 25.