A phase II trial of a reduced intensity conditioned (RIC) allogeneic hematopoietic cell transplant (HCT) with post-transplant cyclophosphamide (PTCy) for idiopathic severe aplastic anemia (SAA), paroxysmal nocturnal hemoglobinuria (PNH), acquired pure red cell aplasia (aPRCA), or acquired amegakaryocytic thrombocytopenia (aAT) utilizing population pharmacokinetic (popPK)-guided individual dosing of pre-transplant conditioning and differential dosing of low dose total body irradiation based on age, presence of myelodysplasia and/or clonal hematopoiesis.
Platelets <20,000/uL or transfusion dependent
Absolute neutrophil count <500/uL without hematopoietic growth factor support
Absolute reticulocyte count <60,000/uL AND bone marrow cellularity <50% (with < 30% residual hematopoietic cells)
Early myelodysplastic features (bone marrow (BM) blasts <5%), without history of MDS/AML pre-treatment.
Pregnant, breastfeeding or intending to become pregnant during the study. Persons of childbearing potential must have a negative pregnancy test (serum or urine) within 7 days of the start of treatment
Uncontrolled infection
Evidence of moderate or severe portal fibrosis or cirrhosis on biopsy
Known allergy to any of the study components