“We are very pleased with the EMA Committee of Orphan Medicinal Products designation of orphan status for ubenimex in PAH,” said Joanne Quan, M.D., chief medical officer at California-based Eiger, in a recent press release. “We will soon begin enrolling the LIBERTY study, a Phase 2, randomized, double-blind, placebo-controlled, multi-center study of ubenimex in PAH patients.”
Bestatin (ubenimex) is an oral, potent dual-inhibitor of aminopeptidase and leukotriene A4 hydrolase (LTA4H), which is the enzyme involved in the formation of LTB4, an important proinflammatory mediator.
In Japan, Bestatin is approved as an adjunct treatment to chemotherapy drugs to prolong survival and to maintain remission following treatment for adults with acute non-lymphocytic leukemia. The drug has been used in Japan for more than 25 years, and is commercially available through Nippon Kayaku. Bestatin is not approved for any indication in Europe or in the United States.
Orphan medicinal products are intended for the diagnosis, prevention, or treatment of life-threatening or very serious conditions that affect no more than 5 in 10,000 people in the European Union. To date, the European Commission has already authorized 120 orphan medicines for the benefit of patients suffering from rare diseases. The sponsors responsible for these medicines benefit from incentives such as fee waivers for the regulatory procedures or a 10-year market exclusivity.
PAH is a rare, underdiagnosed condition defined as elevation of mean pulmonary arterial pressure in lung arteries. Patients with PAH typically exhibit an average pulmonary arterial pressure greater than 25 mm Hg at rest (compared with 15 mm Hg in patients without the disease), or 30 mm Hg during physical activity, as assessed through right heart catheterization. The prevalence of PAH varies among specific populations, but one study estimated that it affects 15 in one million adults.
Risk factors for PAH include a family history of PAH, portal hypertension, connective tissue disease, congenital heart disease, thyroid disease, sickle cell disease, human immunodeficiency virus (HIV), and the use of certain drugs and toxins.
Eiger BioPharmaceuticals will soon start a Phase 2 clinical trial to test Bestatin in this patient group.