United Therapeutics Corporation announced today that the United States Food and Drug Administration (FDA) has granted orphan drug designation to treprostinil for the treatment of patients with idiopathic pulmonary fibrosis (IPF). United Therapeutics intends to initiate a phase 3 study, called TETON, to evaluate the use of Tyvaso (treprostinil) Inhalation Solution in patients with IPF. FDA recently cleared United Therapeutics' investigational new drug application (IND) for the TETON study, and the company expects to commence enrollment in 2021. Orphan drug designation is the first step in receiving orphan drug exclusivity following approval, which confers seven years of market exclusivity for the relevant indication. This exclusivity would also benefit Treprostinil Technosphere, United Therapeutics' next-generation dry powder inhalation form of treprostinil, upon FDA approval of that product for the IPF indication.

"We're excited that treprostinil has received orphan drug designation, as it validates our drive to address orphan diseases, like IPF, with a significant unmet need," said Martine Rothblatt, Ph.D., Chairman and Chief Executive Officer of United Therapeutics. "TETON represents a significant move outside the pulmonary hypertension space, but based on data collected during the recent INCREASE study we're confident that inhaled treprostinil can help address clinical gaps presented by existing therapies in IPF."

Orphan drug designation is granted by the FDA Office of Orphan Products Development (OOPD) to advance the evaluation and development of safe and effective therapies for the treatment of rare diseases or conditions affecting fewer than 200,000 people in the U.S. Under the Orphan Drug Act, FDA may provide grant funding toward clinical trial costs, tax advantages, FDA user-fee benefits, and seven years of market exclusivity in the United States following marketing approval by FDA. The granting of an orphan drug designation request does not alter the standard regulatory requirements and process for obtaining marketing approval.