SILVER SPRING, Md. and RESEARCH TRIANGLE PARK, N.C., April 1, 2021 /PRNewswire/ -- United Therapeutics Corporation (Nasdaq: UTHR) today announced that the U.S. Food and Drug Administration (FDA) has approved Tyvaso® (treprostinil) Inhalation Solution for the treatment of patients with pulmonary hypertension associated with interstitial lung disease (PH-ILD; WHO Group 3) to improve exercise ability. This is the second FDA-approved indication for Tyvaso, which was first approved in July 2009 for the treatment of pulmonary arterial hypertension (PAH; WHO Group 1) to improve exercise ability.