GC Biopharma said on Thursday that its drug candidate to treat thrombotic thrombocytopenic purpura (GC1126A) has received orphan drug designation from the U.S. FDA on Sept. 27.

Accordingly, the orphan drug designation will provide tax breaks on research and development expenses, exemption from permit review fees, and exemption from submitting an initial pediatric study plan. Additionally, the drug will also receive market exclusivity for seven years from the date of marketing authorization, upon approval.

Thrombotic thrombocytopenic purpura (TTP) is a rare bleeding disorder that affects between three and eleven people per million but is a fatal condition in which small blood clots form throughout the body, blocking blood flow to vital organs such as the brain and heart. Consequently, this can cause death in approximately 90 percent of patients if adequate treatment is not administered.

The pathogenesis is thought to be due to a deficiency of the proteolytic enzyme ADAMTS13 or its diminished function due to autoantibodies. Autoantibodies are antibodies produced by the immune system that is directed against one or more of the individual's own proteins and is often associated with autoimmune diseases associated with such antibodies.

Accordingly, GC1126A was designed as a modified protein that evades autoantibodies associated with the ADAMTS13 enzyme while extending its half-life.

The latest clinical development was presented at the International Society on Thrombosis and Haemostasis (ISTH) in June.

The drug candidate demonstrated superior efficacy and maintaining high activity compared to existing drugs and wild-type ADAMTS13.

"We are focused on acquiring data with the goal of developing a best-in-class treatment in the rare bleeding disorder family," said a GC Biopharma official. "We are committed to developing innovative drugs to provide new treatment options for patients."