Mustang Bio Provides an Update on its IND Application for MB-207, a Lentiviral Gene Therapy for Treatment of X-linked Severe Combined Immunodeficiency (“XSCID”) in Previously Transplanted Patients

WORCESTER, Mass., Jan. 24, 2022 (GLOBE NEWSWIRE) -- Mustang Bio, Inc. (“Mustang”) (NASDAQ: MBIO), a clinical-stage biopharmaceutical company focused on translating today’s medical breakthroughs in cell and gene therapies into potential cures for hematologic cancers, solid tumors and rare genetic diseases, today announced that the U.S. Food and Drug Administration (“FDA”) has issued a hold, pending Chemistry, Manufacturing and Controls (“CMC”) clearance, on the Company’s Investigational New Drug (“IND”) application. Submitted in December 2021, the IND is to initiate a pivotal Phase 2 multicenter study to assess the safety, tolerability and efficacy of MB-207, Mustang’s 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 FDA has previously granted MB-207 Orphan Drug and Rare Pediatric Disease Designations. As such, if an MB-207 Biologics License Application (“BLA”) is approved by the FDA, then MB-207 would be eligible for a rare pediatric disease voucher.

An additional Phase 1/2 clinical trial for XSCID in newly diagnosed infants under the age of two is ongoing at St. Jude, UCSF Benioff Children’s Hospital in San Francisco and Seattle Children’s Hospital. The product candidate in this trial is designated as MB-107. Mustang expects to initiate a multi-center pivotal Phase 2 clinical trial of MB-107 under a Mustang-sponsored IND in newly diagnosed infants with XSCID who are between two months to two years of age in the third quarter of 2022. The trial is expected to enroll 10 patients who, together with 15 patients enrolled in the current multi-center trial led by St. Jude, will be compared with 25 matched historical control patients who have undergone HSCT. The primary efficacy endpoint will be event-free survival. Similar to MB-207, if an MB-107 BLA is approved by the FDA, then MB-107 would be eligible for a rare pediatric disease voucher.

The FDA previously granted Rare Pediatric Disease, Orphan Drug and Regenerative Medicine Advanced Therapy Designations to MB-107 for the treatment of XSCID in newly diagnosed infants. Additionally, the European Medicines Agency granted Advanced Therapy Medicinal Product Classification, Orphan Drug and PRIME designation to MB-107.