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Page last checked: 22nd November 2022
Last updated: March 2020


In March 2020, results were reported from this trial of children with a diagnosis of SMA Type 1 with one or two copies of the SMN2 and less than six months of age at the time of treatment.

Children experienced rapid, sustained and clinically meaningful improvements in motor function. Nearly all (91%) patients met the major efficacy endpoint of event-free survival at 14 months, while more than half (59%) met the second main efficacy endpoint of sitting for more than 30 seconds at 18 months of age. This latter milestone is never normally achieved in the natural history of SMA Type 1. Importantly, 9 of 22 patients demonstrated the “ability to thrive” at 18 months of age.

Previous Updates

March: The Cumulative Safety Data across all trials of Zolgensma from 335 patients indicate that it is generally safe and well tolerated. Nearly all patients experienced adverse events, however, most were not serious and unrelated to the treatment.

25th January: This Phase 3 on-going Phase 3 pivotal trial for SMA Type 1 has enrolled three patients to date and aims to include a minimum of 15 infants (<6 months old) with SMA Type 1 and test administration into the bloodstream.

12th October: The Food and Drug Administration (FDA) has granted permission to AveXis to begin their planned US pivotal trial. It will have an open-label, single-arm design, meaning that everyone will receive the drug, and no placebo will be used. As the trial is designed to continue to assess safety, but also to evaluate drug effectiveness, motor milestone achievements of patients on the drug will be compared to natural history information from untreated SMA patients.