The effects of hydroxycarbamide and magnesium on haemoglobin SC disease: results of the multi‐centre CHAMPS trial

In a phase-II multi-centre double-blinded trial, we evaluated haematological effects of oral hydroxycarbamide (HC) and magnesium (Mg) in patients with HbSC, aged 5-53 years old. Subjects were randomized to HC + placebo, Mg + placebo, HC + Mg, or placebo + placebo. The primary endpoint was the proportion of hyperdense red blood cells after 8 weeks. Thirty-six subjects were evaluable, but the study was terminated early because of slow enrollment. In the combined HC groups, mean cell volume and HbF were increased, but differences were not seen in hyperdense red cells or vaso-occlusive events. Mg had no effects. Further investigation of hydroxycarbamide as monotherapy in HbSC disease is warranted.