The FDA has issued a hold, pending Chemistry, Manufacturing & Controls (CMC) clearance, on Mustang Bio Inc's (NASDAQ:MBIO) Investigational New Drug (IND) application for MB-207 in patients with X-linked severe combined immunodeficiency (XSCID).

• The application was submitted to initiate a pivotal Phase 2 study to assess MB-207 (lentiviral gene therapy) in patients who have been previously treated with a hematopoietic stem cell transplantation, and for whom re-treatment is indicated. 
• The FDA has previously granted MB-207 Orphan Drug and Rare Pediatric Disease Designations. 
• Related content: Benzinga's Full FDA Calendar.
• An additional Phase 1/2 trial for XSCID in newly diagnosed infants is ongoing.
• Mustang expects to initiate a pivotal Phase 2 trial of MB-107 in newly diagnosed infants with XSCID who are between two months to two years in Q3 of 2022. 
• The primary efficacy endpoint will be event-free survival. 
• XSCID, also known as bubble boy disease, is a rare genetic disorder characterized by the absence or lack of function of key immune cells, resulting in a severely compromised immune system.
• Mustang was founded by Fortress Biotech Inc (NASDAQ:FBIO). 
• Price Action: MBIO shares are closed at $1.30 on Monday.