Mustang Bio, Inc.

Mustang Bio, Inc. is a clinical-stage biopharmaceutical company whose core business model involves developing cell and gene therapies that require preclinical testing on animals. The company's pipeline of oncology and rare disease treatments is predicated on animal research to demonstrate safety and efficacy before human trials. This places animal testing at the center of its product development process.

A 2025 audit report compiling hundreds of welfare violations from U.S. laboratories documented evidence of widespread animal suffering and systemic failures in animal care, a regulatory environment in which Mustang Bio operates. In 2016, an antibody manufacturer was fined $3.5 million and lost its license for violations of the federal Animal Welfare Act, a penalty an order of magnitude greater than any previous fines, highlighting the severe consequences for non-compliance in this sector. While specific, recent enforcement actions against Mustang Bio were not identified in the provided evidence, the company functions within an industry and research model inherently reliant on the commercial exploitation of animals.