Mustang Bio, Inc., a clinical-stage biopharmaceutical company focused on cell therapies for hard-to-treat cancers, announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation to its MB-101 therapy for treating recurrent diffuse and anaplastic astrocytomas and glioblastoma (GBM).
The designation covers MB-101, an IL13Ra2-targeted CAR T-cell therapy, which is designed to treat rare brain cancers affecting fewer than 200,000 people in the U.S. This status provides Mustang Bio with benefits including tax credits for clinical trials, user fee waivers, and seven years of market exclusivity upon approval.
Manuel Litchman, Mustang Bio’s CEO, highlighted the significance of the designation, noting it is broader than initially proposed. He emphasized the company’s innovative approach combining MB-101 with MB-108, an oncolytic virus therapy aimed at reshaping the tumor microenvironment to enhance MB-101’s effectiveness against malignant gliomas, including GBM and high-grade astrocytomas.
Preclinical and early clinical data support this combination strategy. At the 2022 AACR Annual Meeting, data showed that MB-108 could turn “cold” tumors “hot,” potentially improving CAR T-cell therapy outcomes. A 2024 study published in Nature Medicine reported two complete responses in patients treated with MB-101 alone, with durable remission lasting over 7 and 66 months, respectively, in patients whose tumors were already “hot” before treatment.
Ongoing Phase 1 trials of MB-101 at City of Hope and MB-108 at the University of Alabama at Birmingham are actively enrolling patients. Mustang Bio noted that advancing these programs will depend on securing additional funding or forming strategic partnerships.