Sickle Cell Disease and CardiovAscular Risk - Red Cell Exchange Trial (SCD-CARRE)

The SCD-CARRE trial is a Phase 3, prospective, randomized, multicenter, controlled, parallel two-arm study aimed to determine if automated exchange blood transfusion and standard of care administered to high mortality risk adult SCD patients reduces the total number of episodes of clinical worsening of SCD requiring acute health care encounters (non-elective infusion center/ER/hospital visits) or resulting in death over 12 months as compared with standard of care.

Inclusion Criteria: * Age 18 years or older * Diagnosis of SCD: homozygous sickle cell disease, hemoglobin-SC, Sβ-thalassemia, hemoglobin-SO or hemoglobin-SD. * Patients not on a chronic exchange transfusion program for at least 60 days. * If patients are on a SCD drug (e.g. hydroxyurea, glutamine, or P-selectin inhibitors), the doses must be stable for at least 60 days prior to randomization. At the time of randomization, participants must be off Oxbryta for at least 30 days. * Any one of the following vasculopathy biomarker clinical results (a, b, c, d or e) measured in the last 24 months before randomization that indicates a high-risk patient: 1. Both a TRV 2.5- \300 mg/g) or proteinuria (protein to creatinine ratio \>30 mg/mmol), or estimated glomerular filtration rate (eGFR) \< 60 mL/min/1.73 m2. (It is recommended that local laboratories use Chronic Kidney Disease Epidemiology Collaboration \[CKD-EPI\] equation without ethnic factors when estimating and reporting GFR). Clinical results of these biomarkers measured locally at sites within 24 months prior to randomization are acceptable to determine eligibility. TRV, PAP, NT-proBNP, albumin to creatinine ratio, protein to creatinine ratio, or eGFR values must be measured in a steady state (defined as measured ≥ 14 days since an acute care pain event) on different days. vi. Written informed consent obtained from patient to participate in the trial. Exclusion Criteria: * RBC alloimmunization resulting in inability of blood bank to obtain compatible components for chronic exchange transfusions * Previous history of hyper-hemolysis syndrome * Previous history of severe transfusion reaction resulting in renal failure or due to serious complications such as hypotension or respiratory distress * More than 10 vaso-occlusive episodes in the past 12 months requiring admission to a hospital to receive treatment. * Religious objection to receiving blood transfusion * Diagnosis of ischemic stroke within the past 6 months * Clinical evidence of liver failure or advanced cirrhosis or any co-existing medical condition that in the Investigator's judgement will substantially increase the risk associated with the patient's participation in the trial * Women of childbearing potential who have a positive pregnancy test at baseline