Oral hydroxyurea vs placeboChange in disability score · children and adults with SMA types II and III2 findings from 1 reviewDrug treatment for spinal muscular atrophy types II and III 2020 · Cochrane Headline outcomes onlyno estimate extracted1 study · 57 participantsLowDrug treatment for spinal muscular atrophy types II and III 2020 · Cochrane Headline outcomes onlyno estimate extracted1 study · 38 participantsModerate