FDA Accepts sNDA for Tyvaso from United Therapeutics

United Therapeutics announced the U.S. Food and Drug Administration (FDA) accepted for review the supplemental New Drug Application (sNDA) for Tyvaso® (treprostinil) Inhalation Solution for the treatment of pulmonary hypertension associated with interstitial lung disease (PH-ILD). United Therapeutics expects the agency's review to be complete in April 2021.

"Tyvaso, if approved by the FDA, would be the first and only therapeutic approved for the treatment of PH-ILD, a condition that afflicts approximately 30,000 people in the United States," said Martine Rothblatt, Ph.D., Chairman and Chief Executive Officer of United Therapeutics. "We look forward to working with the Agency during the regulatory review process, with the goal of expanding the population of patients with pulmonary hypertension who could benefit from this important medicine."

The sNDA is based on data from the phase 3 INCREASE clinical study of Tyvaso in adult patients suffering from World Health Organization (WHO) Group 3 PH-ILD. As previously announced on February 24, 2020, the INCREASE study met its primary endpoint as Tyvaso increased six-minute walk distance (6MWD) by 21 meters versus placebo (p=0.0043, Hodges-Lehmann estimate) after 16 weeks of treatment. In addition, the treatment difference in 6MWD at Week 16 was statistically significant when analyzed using Mixed Model Repeated Measurement (31 meters; P<0.001). Benefits of Tyvaso were observed across several key subgroups, including etiology of PH-ILD, disease severity, age, gender, dose, and baseline hemodynamics.

Significant improvements were also observed in each of the study's secondary endpoints, including reduction in the cardiac biomarker NT-proBNP, time to first clinical worsening event, change in peak 6MWD at Week 12, and change in trough 6MWD at week 15. Treatment with Tyvaso of up to 12 breaths per session, four times daily, in the INCREASE study was well tolerated. The safety profile was consistent with previous Tyvaso studies in pulmonary arterial hypertension and known prostacyclin-related adverse events (see the Important Safety Information below under "About Tyvaso").

Interstitial lung disease (ILD) is a group of lung diseases that are characterized by significant scarring or fibrosis of the bronchioles and alveolar sacs within the lungs. Increased fibrotic tissue in ILD prevents oxygenation and free gas exchange between the pulmonary capillaries and alveolar sacs, and the condition can present with a wide range of symptoms, including shortness of breath with activity, labored breathing and fatigue. Pulmonary hypertension (PH) frequently complicates the course of patients with interstitial lung disease and is associated with worse functional status measured by exercise capacity, greater supplemental oxygen needs, decreased quality of life, and worse outcomes.

An estimated 30,000 patients in the United States may suffer from PH-ILD, which is included within Group 3 of the World Health Organization (WHO) classification of PH. However, no treatments are approved by the FDA for patients with this disease.