Clinical trial schemas and STARD diagrams of flow of participants through the study. An open-label phase 1/2 trial was conducted to evaluate CD34⁺ HSPC mobilization with IV plerixafor. (A) Phase 1 donor mobilization schema and STARD flow diagram. HLA-identical sibling donors (≥18 years old) received IV plerixafor the morning of day 1 over 30 minutes with blood sampling obtained before and throughout the course of mobilization. After a 4-day washout period, SC plerixafor (0.24 mg/kg) was administered on day 6, approximately 4 hours before initiation of a 20-L apheresis. Products were cryopreserved and if the desired target of ≥2 × 10⁶ CD34⁺ HSPCs/kg recipient weight was not achieved, the donor was remobilized using 0.24 mg/kg SC plerixafor. (B) Phase 1 recipient transplant schema and STARD flow diagram. Similar to our prior SC plerixafor trial, recipient conditioning used myeloablative cyclophosphamide (60 mg/kg per day on days −3 and −2) and single-dose total body irradiation (TBI; 550 cGy, day −1). Cyclosporine A (CSA) was used as GVHD prophylaxis and G-CSF was administered starting on day 1 until neutrophil engraftment. (C) Phase 2 donor mobilization schema and STARD flow diagram. HLA-identical sibling donors (≥18 years old) received IV plerixafor the morning of day 1 over 30 minutes with blood sampling obtained before initiation of a 20-L apheresis. Products were cryopreserved, and if the desired target of ≥2 × 10⁶ CD34⁺ HSPCs/kg recipient weight was not achieved, the donor was remobilized the following day using 0.32 mg/kg IV plerixafor. If ≥2 × 10⁶ CD34⁺ HSPCs/kg recipient weight was not achieved after 2 days of IV plerixafor, the donor was remobilized using G-CSF. (D) Phase 2 recipient transplant schema and STARD flow diagram. In contrast to our prior study, recipients in phase 2 of this study were conditioned with myeloablative or reduced intensity regimens (as outlined in the schema), followed by infusion of the entire collected product on day 0 and short-course methotrexate (MTX) and tacrolimus GVHD prophylaxis. In addition, G-CSF was administered starting on day 7 until neutrophil engraftment. STARD, Standards for Reporting of Diagnostic Accuracy.