United Therapeutics Receives Orphan Drug Designation for Treprostinil for Idiopathic Pulmonary Fibrosis

United Therapeutics announced 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. For more information about orphan drug designation, please visit the OOPD website.

Idiopathic pulmonary fibrosis, or IPF, is a serious, chronic, progressive, fibrosing interstitial pneumonia with no known cause; typically occurring in patients above 50 years of age. It is characterized by progressive fibrosis, lung scarring, and a radiological pattern known as usual interstitial pneumonia, or UIP. IPF is associated with increasing cough and dyspnea, greatly impacting patient quality of life and eventually leading to death from respiratory failure or complicating comorbidities. Diagnosis is based on the exclusion of other interstitial lung diseases and similar conditions, and the identification of the UIP pattern on a high-resolution computed tomography scan and/or surgical lung biopsy.

Currently, there is no cure for IPF and only two drugs are approved in the United States to treat the condition. According to the U.S. National Library of Medicine at the National Institutes of Health, about 100,000 people are affected in the United States, and 30,000 to 40,000 new cases are diagnosed each year.

TYVASO (treprostinil) is a prostacyclin vasodilator indicated for the treatment of pulmonary arterial hypertension (PAH; WHO Group 1) to improve exercise ability. Studies establishing effectiveness included predominately patients with NYHA Functional Class III symptoms and etiologies of idiopathic or heritable PAH (56%) or PAH associated with connective tissue diseases (33%).

The effects diminish over the minimum recommended dosing interval of 4 hours; treatment timing can be adjusted for planned activities.

While there are long-term data on use of treprostinil by other routes of administration, nearly all controlled clinical experience with inhaled treprostinil has been on a background of bosentan (an endothelin receptor antagonist) or sildenafil (a phosphodiesterase type 5 inhibitor). The controlled clinical experience was limited to 12 weeks in duration.