Simvastatin reduces vaso-occlusive pain in sickle cell anaemia: a pilot efficacy trial
Vaso-occlusion crises account for the vast majority of sickle cell-related hospital admissions. The pathophysiology has been increasingly linked to inflammation which exacerbates sickling in experimental models and correlates with clinical disease severity. Statins are known to improve endothelial function independent of their lipid-lowering effects, by suppressing inflammation and restoring nitric oxide (NO) production. This study assesses the efficacy of simvastatin in reducing daily vaso-occlusive pain events in paediatric and adult patients with SCA.
The study was a single centre, open label, non-randomized trial in 19 subjects. All subjects received simvastatin in a single oral dose according to weight once daily for 3 months. The frequency and intensity of pain was measured using a daily e-diary record for 3 months of treatment with simvastatin. The total study duration with follow-up was 5 months. The adherence to treatment with simvastatin, was assessed by verbal report and monthly pill count.
Simvastatin was associated with an 85% reduction in the frequency of self-reported pain events and a parallel reduction in analgesic use. Despite the marked decline in pain rate, pain intensity did not change with simvastatin. There was also improvement in soluble biomarkers of inflammation and an acceptable safety profile.
Open label non-randomized trial with a small sample size with possible selection bias. A much larger and well controlled study is needed to understand the long-term safety and efficacy of simvastatin in SCA.