A Study to Assess the Efficacy and Safety of Nusinersen (ISIS 396443) in Infants With Spinal Muscular Atrophy

A Phase 3, Randomized, Double-Blind, Sham-Procedure Controlled Study to Assess the Clinical Efficacy and Safety of ISIS 396443 Administered Intrathecally in Patients With Infantile-onset Spinal Muscular Atrophy

The primary objective of the study is to examine the clinical efficacy of nusinersen (ISIS 396443) administered intrathecally (IT) to participants with infantile-onset with infantile-onset spinal muscular atrophy (SMA). The secondary objective of the study is to examine the safety and tolerability of nusinersen administered intrathecally to participants with infantile-onset SMA.

This study was conducted and the protocol was registered by Ionis Pharmaceuticals, Inc..

In August 2016, sponsorship of the trial was transferred to Biogen.

Key Inclusion Criteria:

• Be born (gestational age) between 37 and 42 weeks
• Be medically diagnosed with spinal muscular atrophy (SMA)
• Have Survival Motor Neuron2 (SMN2) Copy number = 2
• Body weight equal to or greater than 3rd percentile for age using appropriate country-specific guidelines
• Be able to follow all study procedures
• Reside within approximately 9 hours ground-travel distance from a participating study center, for the duration of the study

Key Exclusion Criteria:

• Hypoxemia (oxygen [O2] saturation awake less than 96% or O2 saturation asleep less than 96%, without ventilation support) during screening evaluation
• Clinically significant abnormalities in hematology or clinical chemistry parameters or Electrocardiogram (ECG), as assessed by the Site Investigator, at the Screening visit that would render the participant unsuitable for participation in the study
• Participant's parent or legal guardian is not willing to meet standard of care guidelines (including vaccinations and respiratory syncytial virus prophylaxis if available), nor provide nutritional and respiratory support throughout the study

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.