NCT00568802.

Methods	Randomised, placebo‐controlled, double‐blind trial
Participants	Participants with SMA types II and III, aged 1–10 years
Interventions	Hydroxyurea (dose and route) or placebo Duration of treatment: not mentioned
Outcomes	Motor function (Gross Motor Function Measure and timed motor tests), adverse events, pulmonary function, motor unit number estimation, SMN protein and SMN mRNA
Notes	Study completed, not enough data or results available for analysis or inclusion (or both). Unknown date of completion, last date received 2008.