The U.S. FDA has granted Orphan Drug Designation to C2N-8E12 (ABBV-8E12) for the treatment of progressive supranuclear palsy (PSP). C2N-8E12 is an investigational recombinant humanized anti-tau antibody under development jointly by AbbVie, a global biopharmaceutical company headquartered in Chicago, IL, and C2N Diagnostics, a privately held diagnostic and therapeutic discovery company based in Saint Louis, MO. PSP is a rare, progressive neurodegenerative disorder characterized by loss of control of gait and balance, difficulty in controlling eye movement and changes in personality. The cause of PSP is unknown. Pathological studies demonstrate a gradual deterioration of brain cells in the brainstem region of the brain and the cellular hallmark of the disease is the accumulation of tau protein. There is currently no effective treatment for this debilitating neurological disorder. The designation is encouraged by the preclinical data of anti-tau antibodies, and the companies are planning a phase I trial to evaluate the safety, tolerability and pharmacokinetics of C2N-8E12 in PSP patients.