C2N Diagnostics and AbbVie announced that the US Food and Drug Administration (FDA) has granted their investigational recombinant humanized anti-tau antibody, C2N-8E12 (ABBV-8E12), an orphan drug designation for the treatment of progressive supranuclear palsy (PSP). The companies also have begun a phase 1 clinical study of C2N-8E12 in patients with PSP.

"The FDA's orphan drug designation recognises the lack of treatment options for patients with PSP, a debilitating neurological disease, and is an important milestone in the development of potential therapies," stated Joel Braunstein, M.D., chief executive officer, C2N Diagnostics.

"We are encouraged by the preclinical data of anti-tau antibodies and are committed to exploring the potential of this class of molecules," said Jim Sullivan, Ph.D., vice president, pharmaceutical discovery, AbbVie.

C2N-8E12 is a humanized antibody targeting the tau protein found in neurofibrillary tangles in the brain of patients with tauopathies such as PSP and Alzheimer's disease (AD). The phase 1 study is a randomized, double-blind, placebo-controlled, single ascending dose, multicenter study that will evaluate the safety, tolerability and pharmacokinetics of C2N-8E12 in an estimated 32 subjects with PSP.

The Orphan Drug designation programme provides orphan status to drugs and biologics which are defined as those intended for the safe and effective treatment, diagnosis or prevention of rare diseases or disorders that affect fewer than 200,000 people in the United States, or that affect more than 200,000 persons but are not expected to recover the costs of developing and marketing a treatment drug.

The approval of an orphan designation request does not alter the standard regulatory requirements and process for obtaining marketing approval for an investigational use. Sponsors must establish safety and efficacy of a compound in the treatment of a disease through adequate and well-controlled studies.

Progressive supranuclear palsy (also known as Steele-Richardson-Olszewski syndrome) is a progressive neurodegenerative disorder, with an estimated annual incidence of one per 100,000 people over the age of 60. Within the US, the disease affects approximately 20,000 individuals. The most common features of PSP are the presence of loss of balance leading to unexplained falls and, in later stages, blurred vision and problems controlling eye movement may occur. Other nonspecific symptoms of PSP, such as slowed movements or behavioural or cognitive changes, are similar to other brain disorders, particularly Parkinson's disease. For this reason, correct diagnosis of PSP is often delayed. The course of PSP is progressive and may predispose individuals to serious complications, such as choking, pneumonia, head injury and fractures caused by falls. Currently, there are no approved treatments for PSP. It is one of more than 20 different neurodegenerative disorders characterized by neurofibrillary degeneration and tau inclusions as a predominant central nervous system lesion.

AbbVie is a global, research-based biopharmaceutical company formed in 2013 following separation from Abbott Laboratories.

C2N Diagnostics, formed by scientific co-founders Drs. David Holtzman and Randall Bateman of Washington University School of Medicine in St. Louis, MO and LifeTech Research, a technology research and venture development firm is commercialising a suite of biomarker assays and tools to enable drug discovery, clinical drug development at lower risk and cost, and early detection of debilitating neurodegenerative disorders.