A Study to Investigate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics and Efficacy of Risdiplam (RO7034067) in Type 2 and 3 Spinal Muscular Atrophy (SMA) Participants

Study Overview
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Brief Summary
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Multi-center, randomized, double-blind, placebo-controlled study to assess the safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of Risdiplam in adult and pediatric participants with Type 2 and Type 3 SMA. The study consists of two parts, an exploratory dose finding part (Part 1) of Risdiplam for 12 weeks and a confirmatory part (Part 2) of Risdiplam for 24 months.

Official Title
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A Two Part Seamless, Multi-Center Randomized, Placebo-Controlled, Double-Blind Study to Investigate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics and Efficacy of Risdiplam (RO7034067) in Type 2 and 3 Spinal Muscular Atrophy Patients

Conditions
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Muscular Atrophy, Spinal

Intervention / Treatment
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* Drug: Placebo
* Drug: Risdiplam


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Confirmed diagnosis of 5q-autosomal recessive SMA Negative blood pregnancy test at screening and agreement to comply with measures to prevent pregnancy and restrictions on sperm donation For Part 1: Type 2 or 3 SMA ambulant or non-ambulant For Part 2: 1) Type 2 or 3 SMA non-ambulant; 2) RULM entry item A greater than or equal to 2; 3) ability to sit independently as assessed by item 9 of the MFM Exclusion Criteria: Concomitant or previous participation in any investigational drug or device study within 90 days prior to screening, or 5 half-lives of the drug, whichever is longer Concomitant or previous administration of a SMN2-targeting antisense oligonucleotide, SMN2 splicing modifier or gene therapy either in a clinical study or as part of medical care Any history of cell therapy Hospitalization for a pulmonary event within the last 2 months or planned at time of screening Surgery for scoliosis or hip fixation in the one year preceding screening or planned within the next 18 months Unstable gastrointestinal, renal, hepatic, endocrine, or cardiovascular system diseases as considered to be clinically significant by the Investigator Presence of clinically significant electrocardiogram abnormalities before study drug administration from average of triplicate measurement or cardiovascular disease indicating a safety risk for participants as determined by the Investigator Any major illness within one month before the screening examination or any febrile illness within one week prior to screening and up to first dose administration Recently initiated treatment (within less than [<] 6 months prior to randomization) with oral salbutamol or another beta 2-adrenergic agonist taken orally Any prior use of chloroquine, hydroxychloroquine, retigabin, vigabatrin or thioridazine, is not allowed Ascertained or presumptive hypersensitivity (e.g., anaphylactic reaction) to Risdiplam or to the constituents of its formulation Recent history (less than one year) of ophthalmological diseases Participants requiring invasive ventilation or tracheostomy

Ages Eligible for Study
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Minimum Age: 2 Years
Maximum Age: 25 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Sequential Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Part 1 Group A: Adolescents and Adults (Risdiplam)<br>Adolescent and adult participants aged 12-25 years will receive risdiplam for at least 12 weeks. Once the placebo-controlled period is completed and Part 2 dose is selected, participants will be switched to Part 2 dose and will be treated in an open-label phase. | Drug: Risdiplam<br>* Risdiplam will be administered orally (via mouth) or through a feeding tube (naso-gastric or gastrostomy tube).<br>* Other names: RO7034067;|
| Placebo Comparator: Part 1 Group A: Adolescents and Adults (Placebo)<br>Adolescent and adult participants aged 12-25 years will receive placebo matching to risdiplam for at least 12 weeks. Once placebo-controlled period is completed, participants will be first switched to their cohort risdiplam dose. After the Part 2 dose is selected, participants will be switched to Part 2 dose and will be treated in an open-label phase. | Drug: Placebo<br>* Placebo will be administered orally (via mouth) or through a feeding tube (naso-gastric or gastrostomy tube).<br>Drug: Risdiplam<br>* Risdiplam will be administered orally (via mouth) or through a feeding tube (naso-gastric or gastrostomy tube).<br>* Other names: RO7034067;|
| Placebo Comparator: Part 1 Group B: Children (Placebo)<br>Children aged 2-11 years will receive placebo matching to risdiplam for at least 12 weeks. Once placebo-controlled period is completed, participants will be first switched to their cohort risdiplam dose. After the Part 2 dose is selected, participants will be switched to Part 2 dose and will be treated in an open-label phase. | Drug: Placebo<br>* Placebo will be administered orally (via mouth) or through a feeding tube (naso-gastric or gastrostomy tube).<br>Drug: Risdiplam<br>* Risdiplam will be administered orally (via mouth) or through a feeding tube (naso-gastric or gastrostomy tube).<br>* Other names: RO7034067;|
| Experimental: Part 1 Group B: Children (Risdiplam)<br>Children aged 2-11 years will receive risdiplam for at least 12 weeks. Once the placebo-controlled period is completed and Part 2 dose is selected, participants will be switched to Part 2 dose and will be treated in an open-label phase. | Drug: Risdiplam<br>* Risdiplam will be administered orally (via mouth) or through a feeding tube (naso-gastric or gastrostomy tube).<br>* Other names: RO7034067;|
| Placebo Comparator: Part 2: Placebo<br>Participants aged 2-25 years will receive placebo matching to risdiplam for 12 months. After 12 months of treatment with placebo, participants will be switched to risdiplam (5 mg once daily for participants with a body weight (BW) >/=20kg or 0.25 mg/kg for participants with a BW <20) in a blinded manner and participants will continue with treatment until Month 24. After Month 24, participants will be offered the opportunity to enter the open-label phase. | Drug: Placebo<br>* Placebo will be administered orally (via mouth) or through a feeding tube (naso-gastric or gastrostomy tube).<br>Drug: Risdiplam<br>* Risdiplam will be administered orally (via mouth) or through a feeding tube (naso-gastric or gastrostomy tube).<br>* Other names: RO7034067;|
| Experimental: Part 2: Risdiplam<br>Participants aged 2-25 years will receive risdiplam at the dose selected based on the results from Part 1 of the study (5 mg once daily for participants with a body weight (BW) >/=20kg or 0.25 mg/kg for participants with a BW <20 kg), for 24 months. After 24-month treatment, participants will be offered the opportunity to enter the open-label phase. | Drug: Risdiplam<br>* Risdiplam will be administered orally (via mouth) or through a feeding tube (naso-gastric or gastrostomy tube).<br>* Other names: RO7034067;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Part 1: Selected Part 2 Dose of Risdiplam for Participants With a Body Weight (BW) of >/=20kg | The Internal Monitoring Committee (IMC) was responsible for selecting the dose for Part 2 of the study (pivotal dose). An external Independent Data Monitoring Committee (iDMC) reviewed data from Part 1 and confirmed the dose-selection decision of the IMC. The dose for Part 2 selected by the IMC was a dose that: 1.Was judged to be safe and well-tolerated, based on all available safety data from Part 1 and as confirmed by the iDMC; 2. Resulted in an exposure at steady-state below the exposure cap (mean value) of AUC0-24h,ss 2000 ng*h/mL (adjusted for free-fraction, if required); 3. Resulted in an SMN protein increase that was expected to be clinically relevant. | Day 1 up to at least 4 weeks on study (Up to CCOD of 25 July 2017) | 
| Part 1: Selected Part 2 Dose of Risdiplam for Participants With BW of <20kg | The Internal Monitoring Committee (IMC) was responsible for selecting the dose for Part 2 of the study (pivotal dose). An external Independent Data Monitoring Committee (iDMC) reviewed data from Part 1 and confirmed the dose-selection decision of the IMC. The dose for Part 2 selected by the IMC was a dose that: 1.Was judged to be safe and well-tolerated, based on all available safety data from Part 1 and as confirmed by the iDMC; 2. Resulted in an exposure at steady-state below the exposure cap (mean value) of AUC0-24h,ss 2000 ng*h/mL (adjusted for free-fraction, if required); 3. Resulted in an SMN protein increase that was expected to be clinically relevant. | Day 1 up to at least 4 weeks on study (Up to CCOD of 25 July 2017) | 
| Part 2: Change From Baseline in the Total Motor Function Measure 32 (MFM-32) Total Score at Month 12 | The Motor Function Measure 32 (MFM32) is a scale constructed for use in neuromuscular disorders. It comprises 32 items that evaluate physical function in three dimensions: D1 function related to standing and transfer; D2 axial and proximal function; D3 distal motor function. Tasks are scored with a 4-point Likert scale: 0 - cannot initiate the task or maintain the starting position; 1 - performs the task partially; 2 - performs the task incompletely or imperfectly; 3 - performs the task fully and normally. The 32 scores are summed and expressed on a 0-100 scale for the MFM32 total score. Higher scores indicate increased motor function. A positive change from Baseline indicates improvement. MMRM analysis was performed based on primary efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Part 2: Percentage of Participants With Marked Improvement (Defined as >= 3) in the Total Motor Function Measure (MFM32) Score at Month 12 | The MFM32 comprises 32 items that evaluate physical function. The scoring of each task uses a 4-point Likert scale: 0 - cannot initiate the task or maintain the starting position; 1 - performs the task partially; 2 - performs the task incompletely or imperfectly; 3 - performs the task fully and normally. The 32 scores are summed and expressed on a 0-100 scale for the MFM32 total score. A change in MFM32 total score of threshold >/=3 represents marked improvement in this measure. Logistic regression analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | At Month 12 | 
| Part 2: Change From Baseline in the Total Score of the Revised Upper Limb Module (RULM) at Month 12 | The RULM is a 20 items scale that assesses the proximal and distal motor functions of the arm. There is an entry item and the remaining 18 items are scored on the 3 point scale of: 0: cannot complete task independently; 1: modified method but can complete task independently; 2: completes task without any assistance, and with 1 item scored on a 2 point scale of as a can/cannot score with 1 as the highest score. The RULM total score is the sum of 19 items scores with range of 0-37, and the entry item does not contribute to the total score. Higher scores indicate greater upper limb function. A positive change from Baseline indicates improvement. MMRM analysis was performed based on the efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in Total Score of Hammersmith Functional Motor Scale Expanded (HFMSE) at Month 12 | The HFMSE scale contains 33 items, which are scored on a 3-point Likert-type scale (0-2) and summed to derive the total score, with lower scores indicating greater impairment. The HFMSE contains a series of assessments designed to assess important functional abilities, including standing, transfers, ambulation, and proximal and axial function. The overall score is the sum of the scores for all activities with a maximum achievable score of 66. Higher scores indicate greater motor function. A positive change from Baseline indicates improvement. MMRM analysis was performed based on the efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in Forced Vital Capacity (FVC) at Month 12 in Participants Aged 6-25 Years | Spirometry is a pulmonary function test that assesses how the lungs work by measuring how much air moves through the airways. Spirometry was performed by all participants aged 6 or older. Forced vital capacity (FVC) is the total volume that can be exhaled after inhaling maximally. The best % predicted value out of all attempts were used for the analysis. MMRM analysis was performed based on the efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in the Caregiver-Reported SMA Independence Scale (SMAIS) Total Score at Month 12 | The SMA Independence Scale (SMAIS) was developed specifically for SMA participants 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 bathing. Each item is scored on a 0-4 scale (with an additional option to indicate that an item is non-applicable). The SMAIS total score ranging from 0-44 is obtained based on 22 items with each item on the 0-2 scale. Lower scores indicate greater dependence on another individual. The SMAIS was completed by participants aged 12 years or older and caregivers of participants aged 2-25 years. MMRM analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Percentage of Participants Rated by Clinicians as Improved in the Clinical Global Impression of Change (CGI-C) Scale Ratings at Month 12 | The Clinical Global Impression of Change (CGI-C) is used to score a clinician's impression of a participant's change in global health. The CGI-C is a single item measure of change in global health, using seven response options: very much improved, much improved, minimally improved, no change, minimally worse, much worse, and very much worse. Participants considered as improved included responses of very much improved, much improved and minimally improved. Logistic regression analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | At Month 12 | 
| Part 2: Percentage of Participants Who Achieve Stabilization or Improvement (Defined as >= 0) in the Total Motor Function Measure (MFM-32) Score at Month 12 | The MFM32 comprises 32 items that evaluate physical function in three dimensions: D1 function related to standing and transfer; D2 axial and proximal function; D3 distal motor function. Tasks are scored with a 4-point Likert scale: 0 - cannot initiate the task or maintain the starting position; 1 - performs the task partially; 2 - performs the task incompletely or imperfectly; 3 - performs the task fully and normally. The 32 scores are summed and expressed on a 0-100 scale for the MFM32 total score. Higher scores indicate increased motor function. Logistic regression analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | At Month 12 | 
| Part 2: Percentage of Participants Who Achieve an Improvement of at Least One Standard Error of Measurement on the Total MFM-32 Score at Month 12 | The MFM32 comprises 32 items that evaluate physical function in three dimensions: D1 standing and transfer; D2 axial and proximal function; D3 distal motor function. Tasks are scored with a 4-point Likert scale: 0-cannot initiate the task or maintain the starting position; 1-performs the task partially; 2-performs the task incompletely or imperfectly; 3-performs the task fully and normally. The 32 scores are summed and expressed on a 0-100 scale for the total score. Higher scores indicate increased motor function. Standard error of measurement (SEM) is derived using 32 items scores and total scores at baseline. Change from baseline > = one SEM is equivalent to a change >= 4. Logistic regression analysis was performed based on efficacy hypothetical estimand included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | At Month 12 | 
| Part 2: Change From Baseline in the MFM-32 Domain 1 (D1) Score at Month 12 | The MFM32 comprises 32 items that evaluate physical function in three dimensions: D1 function related to standing and transfer; D2 axial and proximal function; D3 distal motor function. Tasks are scored with a 4-point Likert scale: 0 - cannot initiate the task or maintain the starting position; 1 - performs the task partially; 2 - performs the task incompletely or imperfectly; 3 - performs the task fully and normally. The D1 items score are summed and expressed on 0-100 scale for the MFM D1 total score. Higher scores indicate increased motor function. A positive change from Baseline indicates improvement. MMRM analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in the MFM-32 Domain 2 (D2) Score at Month 12 | The MFM32 comprises 32 items that evaluate physical function in three dimensions: D1 function related to standing and transfer; D2 axial and proximal function; D3 distal motor function. Tasks are scored with a 4-point Likert scale: 0 - cannot initiate the task or maintain the starting position; 1 - performs the task partially; 2 - performs the task incompletely or imperfectly; 3 - performs the task fully and normally. The D2 items score are summed and expressed on 0-100 scale for the MFM D2 total score. Higher scores indicate increased motor function. A positive change from Baseline indicates improvement. MMRM analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in the MFM-32 Domain 3 (D3) Score at Month 12 | The MFM32 comprises 32 items that evaluate physical function in three dimensions: D1 function related to standing and transfer; D2 axial and proximal function; D3 distal motor function. Tasks are scored with a 4-point Likert scale: 0 - cannot initiate the task or maintain the starting position; 1 - performs the task partially; 2 - performs the task incompletely or imperfectly; 3 - performs the task fully and normally. The D3 items score are summed and expressed on 0-100 scale for the MFM D3 total score. Higher scores indicate increased motor function. A positive change from Baseline indicates improvement. MMRM analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in the Total Combined Scores of MFM-32 Domains 1 and 2 at Month 12 | The MFM32 comprises 32 items that evaluate physical function in three dimensions: D1 function related to standing and transfer; D2 axial and proximal function; D3 distal motor function. Tasks are scored with a 4-point Likert scale: 0 - cannot initiate the task or maintain the starting position; 1 - performs the task partially; 2 - performs the task incompletely or imperfectly; 3 - performs the task fully and normally. The D1+D2 items score are summed and expressed on 0-100 scale for the MFM D1+D2 total score. Higher scores indicate increased motor function. A positive change from Baseline indicates improvement. MMRM analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in the Total Combined Scores of MFM-32 Domains 2 and 3 at Month 12 | The MFM32 comprises 32 items that evaluate physical function in three dimensions: D1 function related to standing and transfer; D2 axial and proximal function; D3 distal motor function. Tasks are scored with a 4-point Likert scale: 0 - cannot initiate the task or maintain the starting position; 1 - performs the task partially; 2 - performs the task incompletely or imperfectly; 3 - performs the task fully and normally. The D2+D3 items score are summed and expressed on 0-100 scale for the MFM D2+D3 total score. Higher scores indicate increased motor function. A positive change from Baseline indicates improvement. MMRM analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in Forced Expiratory Volume in 1 Second (FEV1) at Month 12 in Participants Aged 6-25 Years | Spirometry is a pulmonary function test that assesses how the lungs work by measuring how much air moves through the airways. Spirometry was performed by all participants aged 6 or older. Forced expiratory volume (FEV1) is the volume forcefully exhaled in the first second of the forced vital capacity test. The best % predicted value out of all attempts were used for the analysis. MMRM analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in the Peak Cough Flow (PCF) at Month 12 in Participants Aged 6-25 Years | Spirometry is a pulmonary function test that assesses how the lungs work by measuring how much air moves through the airways. Spirometry was performed by all participants aged 6 or older. Peak cough flow (PCF) is an assessment of cough strength. The best % predicted value out of all attempts were used for the analysis MMRM analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in the Best Sniff Nasal Inspiratory Pressure (SNIP) at Month 12 | The Sniff Nasal Inspiratory Pressure (SNIP) is a volitional, non-invasive test of inspiratory muscle strength that has been successfully applied to children > 2 years of age. Advantages include the simplicity of the maneuver and the absence of a mouthpiece, which is particularly helpful for participants with SMA, who may have bulbar weakness. SNIP also has the advantage of measuring inspiratory pressure during a natural maneuver that is easily performed even by young children with neuromuscular disorders. The best % predicted value out of all attempts were used for the analysis. MMRM analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in Maximal Inspiratory Pressure (MIP) at Month 12 in Participants Aged 6-25 Years | The maximal inspiratory pressure (MIP) is a non-invasive test of muscle strength, which measures the maximum strength of the diaphragm and other inspiratory muscles. MIP was measured in participants aged 6 or older. Participants were asked to perform a forceful inspiration against an occluded mouth piece. The best % predicted value out of all attempts were used for the analysis. MMRM analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in Maximal Expiratory Pressure (MEP) at Month 12 in Participants Aged 6-25 Years | The maximal expiratory pressure (MEP) is a non-invasive test of muscle strength, which measures the maximum strength of the abdominal muscles and other expiratory muscles. MEP was measured in participants aged 6 or older. Participants were asked to perform a forceful inspiration against an occluded mouth piece. The best % predicted value out of all attempts were used for the analysis. MMRM analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Change From Baseline in the Participant-Reported SMA Independence Scale (SMAIS) Total Score at Month 12 | The SMAIS was developed specifically for SMA participants in order to assess function-related independence. It contains 29 items, assessing the amount of assistance required from another individual to perform daily activities such as eating, or bathing. Each item is scored on a 0-4 scale (with an additional option to indicate that an item is non-applicable). The SMAIS total score ranging from 0-44 is obtained based on 22 items with each item on the 0-2 scale. Lower scores indicate greater dependence on another individual. The SMAIS was completed by participants aged 12 years or older and caregivers of participants aged 2-25 years. MMRM analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | Baseline (Day-1) and Month 12 | 
| Part 2: Percentage of Participants Rated by Clinicians as No Change or Improved in the Clinical Global Impression of Change (CGI-C) Scale Ratings at Month 12 | The CGI-C is used to score a clinician's impression of a participant's change in global health. It is a single item measure of change in global health, using seven response options: very much improved, much improved, minimally improved, no change, minimally worse, much worse, and very much worse. Participants considered as no change or improved included responses of no change, very much improved, much improved and minimally improved. Logistic regression analysis was performed based on efficacy hypothetical estimand, which included participants data assuming no prohibited medication intended for treatment of SMA was received and participants continued on their randomized treatment until the analysis time point at Month 12. | At Month 12 | 
| Part 2: Percentage of Participants Who Experience at Least One Disease-Related Adverse Event at Month 12 | Disease-related adverse events (AEs) were identified by applying two different types of baskets to the AE dataset: Narrow prospectively defined baskets of MedDRA lowest level terms. This basket was defined based on a group of CDC terms selected from an age and gender matched case control study comparing CDC code rates observed in participants with and without SMA using commercially available insurance claim data (CLAIMS and Market scan data). The lowest level terms included in each basket, coded using the latest version of MedDRA; Broad prospectively defined basket with events selected at preferred term level from all AEs reported in ongoing clinical trials up to January 2019, i.e., prior to unblinding of Part 2 of Study BP39055. | Baseline up to Month 12 (Week 52; up to CCOD of 06 September 2019) | 
| Part 2: Number of Disease-related Adverse Events Per Patient-years at Month 12 | Disease-related AEs were collected through the AE reporting of the study, and the disease-related AE rate was adjusted for patient years (AE rate per 100 patient-years). They were identified by applying two different types of baskets to the AE dataset: Narrow prospectively defined baskets of MedDRA lowest level terms and Broad prospectively defined basket with events selected at preferred term level from all AEs reported in ongoing clinical trials up to January 2019, i.e., prior to unblinding of Part 2 of Study BP39055. | Baseline up to Month 12 (Week 52; up to CCOD of 06 September 2019) | 
| Part 1: Percentage of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs) | An adverse event (AE) is any untoward medical occurrence in a subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with the treatment. An adverse event can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a pharmaceutical product, whether or not considered related to the pharmaceutical product. Preexisting conditions which worsen during a study are also considered as adverse events. | Day 1 on risdiplam up to end of study (up to approximately 7 years) | 
| Part 2: Percentage of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs) in the Placebo-Controlled Period | An adverse event (AE) is any untoward medical occurrence in a subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with the treatment. An adverse event can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a pharmaceutical product, whether or not considered related to the pharmaceutical product. Preexisting conditions which worsen during a study are also considered as adverse events. | Day 1 up to 12 months of the placebo-controlled period | 
| Part 2: Percentage of Participants With Treatment Discontinuation Due to Adverse Events (AEs) and Serious Adverse Events (SAEs) in the Placebo-Controlled Period | An adverse event (AE) is any untoward medical occurrence in a subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with the treatment. An adverse event can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a pharmaceutical product, whether or not considered related to the pharmaceutical product. Preexisting conditions which worsen during a study are also considered as adverse events. | Day 1 up to 12 months of the placebo-controlled period | 
| Part 2: Number of Participants Aged 6-25 Years With Suicidal Ideation Based on Columbia-Suicide Severity Rating Scale (C-SSRS) in the Placebo-Controlled Period | The Columbia Suicide Severity Rating Scale (C-SSRS) is used to assess the lifetime suicidality of a participant (C-SSRS baseline) as well as any new instances of suicidality (C-SSRS since last visit). The structured interview prompts recollection of suicidal ideation, including the intensity of the ideation, behavior, and attempts with actual/potential lethality. The C-SSRS assessments results were collected for participants aged 6 years and older. | Day 1 up to 12 months of the placebo-controlled period | 
| Part 2: Number of Participants Aged 6-25 Years With Suicidal Behavior Based on Columbia-Suicide Severity Rating Scale (C-SSRS) in the Placebo-Controlled Period | The Columbia Suicide Severity Rating Scale (C-SSRS) is used to assess the lifetime suicidality of a participant (C-SSRS baseline) as well as any new instances of suicidality (C-SSRS since last visit). The structured interview prompts recollection of suicidal ideation, including the intensity of the ideation, behavior, and attempts with actual/potential lethality. The C-SSRS assessments results were collected for participants aged 6 years and older. | Day 1 up to 12 months of the placebo-controlled period | 
| Survival of Motor Neuron 2 (SMN2) Messenger Ribonucleic Acid (mRNA) Levels in Blood |  | Part 2: Days -1, 1, 7, 28, 120, 246, 365, 729 | 
| Survival of Motor Neuron (SMN) Protein Levels in Blood |  | Part 2: Days -1, 7, 28, 120, 246, 365, 729 | 
| Part 1 and 2: Maximum Plasma Concentration (Cmax) of Risdiplam |  | Part 1 and 2: 1, 2, 4, 6 hours post dose on Day 1; Pre-dose (Hour 0) on Days 7, 14, 56 (Part 2), 120, 246, 490, 729; pre-dose (Hour 0) and 1, 2, 4, 6 hours post dose on Days 28, 56 (Part 1), 365, 609 | 
| Part 1 and 2: Area Under the Curve (AUC) of Risdiplam |  | Part 1 and 2: 1, 2, 4, 6 hours post dose on Day 1; Pre-dose (Hour 0) on Days 7, 14, 56 (Part 2), 120, 246, 490, 729; pre-dose (Hour 0) and 1, 2, 4, 6 hours post dose on Days 28, 56 (Part 1), 365, 609 | 
| Part 1 and 2: Concentration at the End of a Dosing Interval (Ctrough) of Risdiplam |  | Part 1 and 2: Pre-dose (Hour 0) on Days 7, 14, 28, 56, 120, 246, 365, 490, 609, 729 |