FIREFISH is a two-part study in babies between 1 to 7 months of age with Type 1 SMA. It is an open label study, which means that all babies receive risdiplam and there is no placebo. The objective of Part 1 was to assess the safety and determine the dose of risdiplam for Part 2 of the study. Part 1 has been completed and the participants of Part 1 are continuing to receive risdiplam in an open-label extension phase of the study. Part 2 will assess the safety and efficacy of risdiplam, the main analysis will be based on how many babies can sit without assistance at one year of treatment. Part 2 of FIREFISH is ongoing, but is no longer open to new participants.