A Study of RO6885247 in Adult and Pediatric Patients With Spinal Muscular Atrophy (MOONFISH)

Inclusion Criteria: * Males and females, aged 2 to 55 years inclusive or below 7 months inclusive * Confirmed diagnosis of 5q-autosomal recessive SMA (Types 1 to 3), for patients aged 7 months or below clinical symptoms attributable to type 1 SMA and 2 SMN2 copies * Able and willing to provide informed consent and to comply with the study protocol. Alternatively, a legally authorized representative must be able to consent for the patient and assent must be given by the subject wherever possible. * Female patients of childbearing potential and male patients with a female partner of childbearing potential must agree with the required contraceptive methods as defined per protocol. * For patients aged 7 months or below, Gestational age of 37 to 42 weeks and not considered small for gestational age at birth Exclusion Criteria: * Concomitant or previous participation in any investigational drug or device study within 90 days prior to screening * Concomitant or previous participation in a SMN2-targeting antisense oligonucleotide study within 12 months prior to screening * Concomitant or previous participation at any time in a gene therapy study * For patients aged 2-55 years, hospitalization for pulmonary event within the last 2 months or planned at the time of screening * Surgery for scoliosis in the last 6 months from screening or planned within 6 months from screening * Unstable gastrointestinal, renal, hepatic, endocrine or cardiovascular system disease * Clinically relevant ECG abnormalities at screening or baseline; personal or family history (first degree relatives) of congenital long QT syndrome * Clinically significant abnormalities in laboratory test results at screening * Any concomitant disease or condition that could interfere with the conduct of the study, or pose an unacceptable risk to the subject in this study * Use of prohibited medications as per protocol within 90 days prior to randomization. Patients who are on inhaled corticosteroids, administered either through a nebulizer or an inhaler, are allowed. * Recently initiated treatment (within \<6 months prior to randomization) with oral salbutamol or another beta2-adrenergic agonist taken orally is not allowed. Patients who have been on oral salbutamol (or another beta2-adrenergic agonist) for at least 6 months before randomization are allowed. Use of inhaled beta2-adrenergic agonists is allowed. * For patients aged 7 months or below, patients requiring invasive ventilation or tracheostomy, presence of non-SMA related morbidities