Mustang Bio is a clinical-stage biopharmaceutical company focused on developing a combination cancer immunotherapy for malignant brain tumors, specifically relapsed or refractory glioblastoma (GBM) and high-grade astrocytoma. Mustang's lead candidate, MB-109, combines two licensed academic technologies: MB-101, a CAR T cell therapy that engineers a patient's T cells to target a protein overexpressed on GBM tumors, delivered directly into the brain; and MB-108, an oncolytic herpes simplex virus designed to selectively replicate in and kill tumor cells while making the tumor microenvironment more receptive to CAR T therapy. Mustang has no approved products and no revenue. The company licenses early-stage technologies from academic institutions — primarily City of Hope and Nationwide Children's Hospital — funds their development, and relies on these partners to conduct and sponsor clinical trials. Mustang's monetization path would involve either out-licensing MB-109 to a larger pharma company for upfront payments, milestones, and royalties, or independent commercialization. Mustang is a majority-controlled subsidiary of Fortress Biotech, funds operations through capital raises, and has accumulated a deficit of approximately $399M since inception. The company operates with just 4 full-time employees, relying on Fortress and its academic partners for most operational functions. Both MB-101 and MB-108 have received FDA Orphan Drug Designation.