Mustang Bio Licenses LentiBOOSTTM Technology from SIRION Biotech

Mustang Bio Inc (Mustang) and SIRION Biotech GmbH (SIRION) are pleased that Mustang has acquired the rights to SIRION’s LentiBOOST™ technology for the development of MB-207.

MB-207 is Mustang’s lentiviral gene therapy for the treatment of patients with X-linked severe combined immunodeficiency (“XSCID”), also known as bubble boy disease, previously treated with a hematopoietic stem cell transplantation (“HSCT”) and for whom re-treatment is indicated. LentiBOOST™ is SIRION’s proprietary non-cytotoxic transduction enhancer for lentiviral vectors.

Under the terms of the agreement, SIRION will receive an undisclosed upfront payment and development and sales milestones, as well as royalties on future product sales.

“We are pleased to enter this agreement with SIRION to enable the utilisation of the LentiBOOST™ technology in our development of MB-207,” said Manuel Litchman, M.D., President and Chief Executive Officer of Mustang. “Transduction enhancers were added to the cell processing of the lentiviral gene therapy in 2019 and several advantages have been observed. We look forward to incorporating LentiBOOST™ into MB-207, for which we plan to file an investigational new drug application (“IND”) with the U.S. Food and Drug Administration (“FDA”) to initiate a pivotal Phase 2 clinical trial for XSCID in patients over the age of two who have received prior HSCT in the next few months.”

“LentiBOOST™ was developed to improve lentiviral transduction of therapeutic cell types like T-cells and hematopoietic stem cells. This technology enables a robust and reproducible process and the reduction of manufacturing costs by lowering the number of lentiviral vectors needed for the production of the cell product while at the same time improving clinical efficacy,” said Christian Thirion, Ph.D., Chief Executive Officer and founder of SIRION. “We are delighted that Mustang has chosen the LentiBOOST™ technology to develop and bring this groundbreaking XSCID therapy to patients.”

About MB-207

MB-207 is a lentiviral gene therapy for the treatment of patients with X-linked severe combined immunodeficiency (“XSCID”), also known as bubble boy disease, who have been previously treated with a hematopoietic stem cell transplantation (“HSCT”) and for whom re-treatment is indicated. The lentiviral gene-therapy method employed in MB-207 was co-developed by scientists at the National Institute of Allergy and Infectious Diseases (“NIAID”), part of the National Institutes of Health, and St. Jude Children’s Research Hospital. MB-207 has been studied at NIAID since 2012 and continues to be assessed in an NIAID-supported Phase 1/2 clinical trial for XSCID in patients over the age of two who have received prior HSCT. Mustang expects to file an IND with the FDA to initiate a multi-centre pivotal Phase 2 clinical trial of MB-207 in this patient population in the fourth quarter of 2020. The FDA has granted Orphan Drug Designation and Rare Pediatric Disease Designation to MB-207 for the treatment of XSCID in previously treated patients with HSCT.

About Mustang Bio

Mustang Bio, Inc. is a clinical-stage biopharmaceutical company focused on translating today’s medical breakthroughs in cell and gene therapies into potential cures for hematologic cancers, solid tumours and rare genetic diseases. Mustang aims to acquire rights to these technologies by licensing or otherwise acquiring an ownership interest, to fund research and development, and to out-license or bring the technologies to market. Mustang has partnered with top medical institutions to advance the development of CAR T therapies across multiple cancers, as well as lentiviral gene therapy for XSCID. Mustang is registered under the Securities Exchange Act of 1934, as amended, and files periodic reports with the U.S. Securities and Exchange Commission (“SEC”). Mustang was founded by Fortress Biotech, Inc. (NASDAQ: FBIO). For more information, visit www.mustangbio.com.

About SIRION Biotech GmbH

SIRION Biotech was founded in 2005 to lead the next generation of viral vector technologies for gene and cell therapy as well as vaccine development. Now SIRION offers one of the world’s most comprehensive viral vector technology platforms based on lenti, adeno, and adeno-associated viruses which expedites gene therapy research and advances drug development. SIRION is becoming a partner of choice in this growing sector. LentiBOOST™ has been used in a number of clinical trials from early-stage clinical Phase 1/2 through late-stage clinical Phase 3 trials and demonstrated clinical success in improving the transduction of the therapeutic vector.

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