This phase II clinical trial studies how well treosulfan, thiotepa, fludarabine, and rabbit anti-thymocyte globulin (rATG) before donor stem cell transplantation works in treating patients with nonmalignant (non-cancerous) diseases. Hematopoietic cell transplantation has been shown to be curative for many patients with nonmalignant (non-cancerous) diseases such as primary immunodeficiency disorders, immune dysregulatory disorders, hemophagocytic lymphohistiocytosis, bone marrow failure syndromes, and hemoglobinopathies. Powerful chemotherapy drugs are often used to condition the patient before infusion of the new healthy donor cells. The purpose of the conditioning therapy is to destroy the patient's abnormal bone marrow which doesn't work properly in order to make way for the new healthy donor cells which functions normally. Although effective in curing the patient's disease, many hematopoietic cell transplantation regimens use intensive chemotherapy which can be quite toxic, have significant side effects, and can potentially be life-threatening. Investigators are investigating whether a new conditioning regimen that uses less intensive drugs (treosulfan, thiotepa, and fludarabine phosphate) results in new blood-forming cells (engraftment) of the new donor cells without increased toxicities in patients with nonmalignant (non-cancerous) diseases.
Patient with nonmalignant disease treatable by allogeneic HCT
Patient with a nonmalignant disease that is not clearly defined (a patient with a non-malignant disease for whom genetic testing has been done and a genetic mutation responsible for their non-malignant disease phenotype has not been identified) are eligible for the study following discussion with and approval by the protocol principal investigator (PI) (Dr. Lauri Burroughs)
Age < 50 years
DONOR: Human leukocyte antigen (HLA)-identical related donor OR unrelated donor matched for HLA-A, B, C, DRB1 and DQB1 or mismatched for a single allele at HLA-A, B, C, or a single DQB1 antigen or allele mismatch by high resolution deoxyribonucleic acid (DNA) typing
Patients with idiopathic aplastic anemia and Fanconi anemia; patients with aplastic anemia associated with paroxysmal nocturnal hemoglobinuria (PNH) or inherited marrow failure syndromes (except Fanconi anemia) will be allowed
Impaired cardiac function as evidenced by ejection fraction < 35% (or, if unable to obtain ejection fraction, shortening fraction of < 26%) or cardiac insufficiency requiring treatment or symptomatic coronary artery disease. Patients with a shortening fraction of < 26% may be enrolled if approved by a cardiologist
Impaired pulmonary function as evidenced by carbon monoxide diffusing capability (DLCO) corrected < 50% of predicted (or, if unable to perform pulmonary function tests, then oxygen [O2] saturation < 92% on room air)
Estimated creatinine clearance < 60 mL/min/1.73m² using either the Chronic Kidney Disease Epidemiology Collaboration (CKD EPI) equation for adult patients (>= 18 years old), or the updated Schwartz formula for pediatric patients (< 18 years old). If the estimated creatinine clearance is < 60 mL/min/1.73m², then renal function must be measured by 24-hour creatinine clearance, Iothalamate, Iohexol or nuclear GFR and the patient is excluded if their measured creatinine clearance is < 50 mL/min/1.73 m², OR