MB-207

MB-207 is a **lentiviral gene therapy** developed for patients with **X-linked severe combined immunodeficiency (XSCID)**, also known as "bubble boy disease," who have previously received hematopoietic stem cell transplantation (HSCT) and require re-treatment[1][2][3][5][6][9][11][13]. The therapy uses a lentiviral vector to deliver genetic material into host cells, enabling correction of the genetic defect that impairs immune function. MB-207 is intended for patients over the age of two who received prior HSCT but have declining immune function or symptomatic infections[2][5][9][11]. Its mechanism of action centers on gene transfer to restore immune system function. The gene therapy method was co-developed by researchers at the National Institute of Allergy and Infectious Diseases (NIAID) and St. Jude Children's Research Hospital[3][5][11]. Mustang Bio is developing and sponsoring current clinical trials. MB-207 has received FDA Orphan Drug and Rare Pediatric Disease designations, and is currently being studied in Phase 1/2 and pivotal Phase 2 trials (clinical hold as of early 2023 pending Chemistry, Manufacturing, and Controls clearance)[6][7][9].