 The FDA has issued a hold, pending Chemistry, Manufacturing Controls CMC clearance, on Mustang Bio Incs 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. 