Base Editing for Mutation Repair in Hematopoietic Stem & Progenitor Cells for X-Linked Chronic Granulomatous Disease

Stem Cell Mobilizing Agent: Subcutaneous administration for 2 consecutive days to improve stem cell collection.

Stem Cell Mobilizing Agent: Subcutaneous administration for 6 consecutive days. It is necessary to mobilize stem cells for collection.

Mucositis Prophylaxis Agent: Intravenous infusion of keratinocyte growth factor (Palifermin) at 60 mcg/kg/day before (Days -7 to Day -5 administration of busulfan and (Days 1 to 3) post-busulfan administration to prevent oral mucositis.

Transplant Conditioning Agent: An alkylating chemotherapy drug to enhance engraftment of the study agent (base-edited stem cells). Conditioning will be given intravenously over 3 days with an approximate total dose of 12mg/kg. Drug levels obtained will be obtained to achieve the targeted total busulfan AUC of 65,000 ng/mL x hr.

Investigational/Study Agent: Base-edited autologous CD34 plus hematopoietic stem and progenitor cell product. The product is administered intravenously as a single infusion. This product is under an IND.

Immunomodulating agent: Daily oral dosing beginning Day -1 for approximately 3 to 6 months to prevent an immune response to the protein expressed by the BE HSPCs.