Safety population included all patients who received at least one dose of study medication.

The MFM scale evaluated motor function in three dimensions. D1 evaluates functions related to standing and transfer, D2 evaluates axial and proximal function in supine and sitting position on mat and chair and D3 evaluates distal motor function. The scoring of each task uses a 4-point Likert scale based on the participant's maximal abilities without assistance: 0, cannot initiate the task or maintain the starting position; 1, performs the task partially; 2, performs the task incompletely or imperfectly (with compensatory/uncontrolled movements or slowness); and 3, performs the task fully and "normally". The scores are summed to yield a total score expressed as the percentage of the maximum possible score (the one obtained with no physical impairment); the lower the total score, the more severe the impairment.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM.

The MFM scale evaluated motor function in three dimensions. D1 evaluates functions related to standing and transfer, D2 evaluates axial and proximal function in supine and sitting position on mat and chair and D3 evaluates distal motor function. The scoring of each task uses a 4-point Likert scale based on the participant's maximal abilities without assistance: 0, cannot initiate the task or maintain the starting position; 1, performs the task partially; 2, performs the task incompletely or imperfectly (with compensatory/uncontrolled movements or slowness); and 3, performs the task fully and "normally". The scores are summed to yield a total score expressed as the percentage of the maximum possible score (the one obtained with no physical impairment); the lower the total score, the more severe the impairment.

ITT population includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM

Values are reported separately for QD and BID doses. Dose increase occurred after Week 104.

Included participants in the safety population that received at least one dose of the study drug and had measurable concentration values.

The PedsQL Generic Core Scale includes 23 items using self-report and/or parent report (ages 5+). The instrument covers physical, emotional, social and school functioning. Scale items are linearly transformed to a 0-100 scale (0 = 100, 1 = 75, 2 = 50, 3 = 25, and 4 = 0) so that higher scores indicate better health related quality of life.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM.

The PedsQL Generic Core Scale includes 23 items. The instrument covers physical, emotional, social and school functioning. Scale items are linearly transformed to a 0-100 scale (0 = 100, 1 = 75, 2 = 50, 3 = 25, and 4 = 0) so that higher scores indicate better health related quality of life. Questionnaire was completed by the caregiver.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. Scale scores were not computed if more than 50% of items in the scale were missing.

The PedsQL Neuromuscular Module (Version 3.0) includes 25 items using self-report (ages 5 - 18) and/or parent report (ages 5 -18). The instrument covers problems related to neuromuscular disease, communication and family resources. Scale items are linearly transformed to a 0-100 scale (0 = 100, 1 = 75, 2 = 50, 3 = 25, and 4 = 0) so that higher scores indicate better health related quality of life.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. Scale scores were not computed if more than 50% of items in the scale were missing.

The PedsQL Neuromuscular Module (Version 3.0) includes 25 items using self-report (ages 5 - 18) and/or parent report (ages 5 -18). The instrument covers problems related to neuromuscular disease, communication and family resources. Scale items are linearly transformed to a 0-100 scale (0 = 100, 1 = 75, 2 = 50, 3 = 25, and 4 = 0) so that higher scores indicate better health related quality of life. Questionnaire was completed by the caregiver.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. Scale scores were not computed if more than 50% of items in the scale were missing.

The EQ-5D-5L is a self-reported health status questionnaire that consists of six questions used to calculate a health utility score for use in health economic analysis. There are two components to the EQ-5D-5L: a five-item health state profile that assesses mobility, self-care, usual activities, pain/discomfort, and anxiety/depression used to obtain an Index Utility Score, as well as a visual analogue scale (VAS) that measures health state. Overall scores range from 0 to 1, with low scores representing a higher level of dysfunction.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.

The EQ-5D-5L is a self-reported health status questionnaire that consists of six questions used to calculate a health utility score for use in health economic analysis. There are two components to the EQ-5D-5L: a five-item health state profile that assesses mobility, self-care, usual activities, pain/discomfort, and anxiety/depression used to obtain an Index Utility Score, as well as a visual analogue scale (VAS) that measures health state. Overall scores range from 0 to 1, with low scores representing a higher level of dysfunction. The questionnaire was completed by the caregiver.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.

The EQ-5D-5L is a self-reported health status questionnaire that consists of six questions used to calculate a health utility score for use in health economic analysis. There are two components to the EQ-5D-5L: a five-item health state profile that assesses mobility, self-care, usual activities, pain/discomfort, and anxiety/depression used to obtain an Index Utility Score, as well as a visual analogue scale (VAS) that measures health state. The VAS is designed to rate the participant's current health state on a scale from 0 to 100, where 0 represents the worst imaginable health state and 100 represents the best imaginable health state.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.

The EQ-5D-5L is a self-reported health status questionnaire that consists of six questions used to calculate a health utility score for use in health economic analysis. There are two components to the EQ-5D-5L: a five-item health state profile that assesses mobility, self-care, usual activities, pain/discomfort, and anxiety/depression used to obtain an Index Utility Score, as well as a visual analogue scale (VAS) that measures health state. The VAS is designed to rate the participant's current health state on a scale from 0 to 100, where 0 represents the worst imaginable health state and 100 represents the best imaginable health state. Questionnaire was completed by the caregiver.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.

The WPAI:CG consists of four questions about the effects of Spinal Muscular Atrophy (SMA) on the following: employment status, hours missed due to patient caregiving, hours missed due to other reasons, hours actually worked and two questions that measure the degree to which patient caregiving affected productivity and regular daily activities.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.

The WPAI:CG consists of four questions about the effects of SMA on the following: employment status, hours missed due to patient caregiving (HMC), hours missed due to other reasons (HMO), hours actually worked (HAW) and two questions that measure the degree to which patient caregiving affected productivity and regular daily activities.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.

The WPAI:CG consists of four questions about the effects of Spinal Muscular Atrophy (SMA) on the following: employment status, hours missed due to patient caregiving, hours missed due to other reasons, hours actually worked and two questions that measure the degree to which patient caregiving affected productivity and regular daily activities. WPAI:CG outcomes are expressed as impairment percentages, with higher numbers indicating greater impairment and less productivity. The outcomes are presented for Percent work time missed (WTM), Percent impairment (IMP), Percent overall work impairment (OWI) and Percent activity impairment (AIM).

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.

The WPAI:CG consists of four questions about the effects of Spinal Muscular Atrophy (SMA) on the following: employment status, hours missed due to patient caregiving, hours missed due to other reasons, hours actually worked and two questions that measure the degree to which patient caregiving affected productivity and regular daily activities. WPAI:CG outcomes are expressed as impairment percentages, with higher numbers indicating greater impairment and less productivity.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.

The SF-36 was used to assess health-related quality of life at baseline and at on-treatment visits. The SF-36 consisted of 36 questions covering 8 domains (physical functioning, role-functioning physical, bodily pain, general health, vitality, social functioning, role-functioning emotional and mental health), with each domain scoring on a scale 0-100 (a score of 0 = maximum disability and a score of 100 = no disability). The 8 domains are further summarized to 2 distinct higher-ordered clusters: the physical and mental composite t-scores (PCS and MCS). The range for all 8 domains as well as for the composite norm-based t-scores is from 0 to 100 with 100 as best possible health status and 0 as worst health status. Reported here are the Physical Composite Scores (PCS) and Mental Composite Scores (MCS).

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.

The SF-36 was used to assess health-related quality of life at baseline and at on-treatment visits. The SF-36 consisted of 36 questions covering 8 domains (physical functioning, role-functioning physical, bodily pain, general health, vitality, social functioning, role-functioning emotional and mental health), with each domain scoring on a scale 0-100 (a score of 0 = maximum disability and a score of 100 = no disability). The range for all 8 norm-based domains was from 0 to 100 with 100 as best possible health status and 0 as worst health status.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.

The SF-6D focuses on seven of the eight health domains covered by the SF-36: physical functioning, role participation (combined role-physical and role-emotional), social functioning, bodily pain, mental health, and vitality. SF-6D Health Utility Index (HUI) Score = 0 (worst measured health state) to 1 (best measured health state).

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.

The SMAIS was developed specifically for SMA in order to assess function-related independence. The SMAIS contains 29 items, assessing the amount of assistance required from another individual to perform daily activities, such as eating or transferring to/from a wheelchair. Each item is scored on a zero to four scale (with an additional option to indicate that an item is non-applicable). Item scores are summed to create the total score. The range of total score is between 0 and 116. Lower scores indicate greater dependence on another individual.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.

The SMAIS was developed specifically for SMA in order to assess function-related independence. The SMAIS contains 29 items, assessing the amount of assistance required from another individual to perform daily activities, such as eating or transferring to/from a wheelchair. Each item is scored on a zero to four scale (with an additional option to indicate that an item is non-applicable). Item scores are summed to create the total score. The range of total score is between 0 and 116. Lower scores indicate greater dependence on another individual.

Intent-to-Treat Population (ITT) includes all participants who received at least one dose of study medication and have at least one post-baseline assessment of MFM. The number analyzed represents participants who completed the questionnaire.