PRN1008 Receives Orphan Drug Designation for Immune Thrombocytopenic Purpura

Drug Could Temper Immune System’s Attack on Platelets

The FDA has granted orphan drug designation to PRN1008 (Principia Biopharma Inc., San Francisco, California), an oral, reversible covalent Bruton’s Tyrosine Kinase (BTK) inhibitor, for the treatment of patients with immune thrombocytopenic purpura (ITP).

ITP, a rare, often chronic autoimmune disease, is characterized by a diminished number of platelets, which are key for clot formation. Approximately 150,000 individuals in the U.S. have ITP, two-thirds of whom are characterized as chronic. ITP patients can be asymptomatic but often experience periods of nose and gum bleeding and a tendency to bruise through capillaries’ leaking blood into the skin and mucous membranes. In addition, patients suffer from serious fatigue and have a lower quality of life.

Currently, Principia is conducting a phase 2 clinical trial to evaluate the safety and efficacy of PRN1008 in patients with ITP. It is possible that PRN1008 could modulate the immune system’s attack on platelets, which is the underlying cause of ITP.

PRN1008, designed for use as a chronic therapy, is an oral, small molecule, reversible covalent BTK inhibitor. The drug was produced using Principia’s proprietary technology, which has resulted in prolonged and reversible action as well as rapid elimination from the body. This type of approach limits systemic exposure to PRN1008 and allows for the rapid reversibility of effects on the immune system.

Source: Principia Biopharma, October 19, 2018