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# FDA Orphan Status for Huntington’s Disease Antibody
- URL: https://www.fdaweb.com/fda-orphan-status-for-huntingtons-disease-antibody/
- Published: 2016-08-23T12:00:00.000Z
- Updated: 2026-09-14T21:26:15.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5136585

FDA has granted Vaccinex an orphan drug designation for its therapeutic monoclonal antibody VX15, which is currently being investigated in a Phase 2 clinical trial (SIGNAL) for treating Huntington’s disease (HD). The company says the SIGNAL trial is based on prior research involving neurodegenerative disease mechanisms, where it was demonstrated in preclinical models that semaphorin 4D (SEMA4D) triggers activation of both microglia and astrocytes, the innate inflammatory cells of the central nervous system. The VX15 antibody is designed to block the functional activity of SEMA4D. “The chronic activation of microglia and astrocytes has been implicated as a potentially important disease mechanism in HD, progressive multiple sclerosis and other neurodegenerative disorders,” it says.