This is a multicenter, open-label, dose-ranging study of ticagrelor followed by a double blind, placebo-controlled extension phase in paediatric patients with sickle cell disease (SCD).
Part A: Patients will be randomised 1:1 to receive one of two dosing schedules consisting of two single weight-adjusted doses of ticagrelor. Pharmacokinetic (PK) parameters and pharmacodynamic (PD) measurements will be determined following each dose. Platelet aggregation will be measured using the VerifyNow™ P2Y12 assay.
Following these 2 single doses, all patients will receive open-label one-week treatment with ticagrelor twice daily to determine tolerability prior to randomisation into Part B.
Part B: In this part patients will be randomised (2:1 ratio) to ticagrelor twice daily or placebo for a 4-week treatment phase.
During the study, patients will be followed for the occurrence of vaso-occlusive crisis (VOC) and for other disease manifestations such as daily pain, analgesic use and complications of SCD.
