Mustang Bio, Inc. announced that the U.S. Food and Drug Administration ("FDA") has accepted the Company's Investigational New Drug ("IND") application of MB-109 for the treatment of recurrent glioblastoma ("GBM") and high-grade astrocytoma. Mustang is planning to initiate a Phase 1 multicenter clinical trial at City of Hope ("COH") and the University of Alabama at Birmingham ("UAB") to assess the safety, tolerability and efficacy of MB-109, a novel combination of MB-101 (COH-developed IL13Ra2-targeted CAR-T cell therapy) and MB-108 [Nationwide Children's Hospital- ("Nationwide") developed HSV-1 oncolytic virus] in adult patients with recurrent GBM and high-grade astroCytomas that express IL13Ra2 on the surface of the tumor cells. As previously reported, preclinical data presented at the American Association for Cancer Research ("AACR") Annual Meeting in 2022 supported this combination therapy to potentially optimize results to treat recurrent GBM.

The combination leverages MB-108 to reshape the tumor microenvironment ("TME") and make cold tumors "hot," thereby potentially improving the efficacy of MB-101 CAR-T cell therapy. Data presented separately on MB-101 and MB-108 showed that administration of these therapies was well tolerated in recurrent GBM patients. Phase 1 clinical trials of MB-101 at COH and of MB-108 at UAB continue to enroll patients.

R risks and uncertainties include, among other things, risks related to whether the Company's third-party manufacturer is able to successfully perform its obligation to produce the Company's products under the manufacturing services agreement on a timely basis and to acceptable standards; disruption from the sale of the Company's manufacturing facility making it more difficult to maintain business and operational relationships; negative effects of the announcement of the consummation of the sale of the Company's Manufacturing facility on the market price of the Company's common stock; significant transaction costs; the development stage of the Company's primary product candidates, ability to obtain, perform under, and maintain financing and strategic agreements and relationships; risks relating to the results of research and development activities; risks relating to the timing of starting and completing clinical trials; uncertainties relating to preclinical and clinical testing; dependence on third-party suppliers; ability to attract, integrate and retain key personnel; the early stage of products under development; need for substantial additional funds; government regulation; patent and regulatory approvals; patent and regulatory approvals and regulatory approvals.