Feasibility and benefit of hydroxycarbamide as a long-term treatment for sickle cell disease patients: Results from the North West London Sickle Cell Disease Registry

Despite the benefits of hydroxycarbamide (HU) for sickle cell disease (SCD) patients, it is currently underutilized in routine clinical management because of concerns about effectiveness and safety and ambivalence surrounding optimal HU regimes for heterogeneous SCD clinic populations [1-6]. This UK study followed up 62 SCD patients treated with HU for up to 9 years (IQR 1-6 yrs). Patients benefited from sustained significant increases in mean annual hemoglobin (Hb), fetal hemoglobin (HbF%), mean cell volume (MCV) and reduction in absolute neutrophil count (ANC), mean annual inpatient (IP) days, acute chest syndrome (ACS) and transfusion events compared to pretreatment. Mean daily dose and maximum tolerated dose (MTD) achieved were constrained by patients' concordance with treatment and drug tolerance. All serious adverse events were not prevented during therapy. Side effects did not warrant cessation of HU but deteriorating medical condition did. Long-term treatment warrants close monitoring with multiagency involvement in care.