A Study of Risdiplam (RO7034067) in Adult and Pediatric Participants With Spinal Muscular Atrophy

Inclusion Criteria:

   - Confirmed diagnosis of 5q-autosomal recessive SMA

   - Previous enrollment in Study BP29420 (Moonfish) with the splicing modifier RO6885247
   or previous treatment with any of the following: 1.) Nusinersen (defined as having
   received >= 4 doses of nusinersen, provided that the last dose was received >= 90 days
   prior to screening) or 2.) Olesoxime (provided that the last dose was received <= 12
   months and >= 90 days prior to screening) or 3.) AVXS-101 (provided that the time of
   treatment was >= 12 months prior to screening)

   - Adequately recovered from any acute illness at the time of screening and considered
   well enough to participate in the opinion of the Investigator

   - For women of childbearing potential: negative blood pregnancy test at screening,
   agreement to remain abstinent (refrain from heterosexual intercourse) or use
   contraceptive measures, and agreement to refrain from donating eggs for at least 28
   days after the final dose of study drug

   - For men: agreement to remain abstinent (refrain from heterosexual intercourse) or use
   contraceptive measures and agreement to refrain from donating sperm

   - For participants aged 2 years or younger at screening: 1.) Parent or caregiver of
   participant is willing to consider nasogastric, naso-jejunal or gastrostomy tube
   placement, as recommended by the Investigator, during the study to maintain safe
   hydration, nutrition and treatment delivery; 2.) Parent or caregiver of participant is
   willing to consider the use of non-invasive ventilation, as recommended by the
   Investigator during the study

Exclusion Criteria:

   - Inability to meet study requirements

   - Concomitant participation in any investigational drug or device study

   - 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 with the
   exception of studies of olesoxime, AVXS-101, or nusinersen

   - Any history of gene or cell therapy, with the exception of AVXS-101

   - Unstable gastrointestinal, renal, hepatic, endocrine, or cardiovascular system
   diseases as considered to be clinically significant by the Investigator

   - Inadequate venous or capillary blood access for the study procedures, in the opinion
   of the Investigator

   - For patients aged < 2 years, hospitalization for a pulmonary event within 2 months
   prior to screening and pulmonary function not fully recovered at the time of screening

   - Lactating women

   - Suspicion of regular consumption of drugs of abuse

   - For adults and adolescents only, positive urine test for drugs of abuse or alcohol at
   screening or Day -1 visit

   - Presence of clinically significant electrocardiogram (ECG) abnormalities before study
   drug administration from average of triplicate measurement or cardiovascular disease

   - History of malignancy if not considered cured

   - For participants aged > 6 years, significant risk for suicidal behavior, in the
   opinion of the Investigator as assessed by the Columbia-Suicide Severity Rating Scale
   (C-SSRS)

   - 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 for spinal muscular atrophy (within <6 weeks prior to
   enrollment) 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

   - Concomitant disease or condition that could interfere with, or treatment of which
   might interfere with, the conduct of the study, or that would, in the opinion of the
   Investigator, pose an unacceptable risk to the participant in this study

   - Recent history (less than one year) of ophthalmological diseases

   - Any prior use of an inhibitor or inducer of FMO1 or FMO3 taken within 2 weeks (or
   within 5 elimination half-lives, whichever is longer) prior to dosing