The Food and Drug Administration (FDA) has accepted for review the supplemental New Drug Application (sNDA) for treprostinil (Tyvaso®; United Therapeutics), a prostacyclin vasodilator, for the treatment of pulmonary hypertension associated with interstitial lung disease (PH-ILD).

The sNDA is supported by data from the multicenter, double-blind, placebo-controlled phase 3 INCREASE study that evaluated the efficacy and safety of treprostinil inhalation solution in 326 adult patients with PH-ILD. Patients were randomized 1:1 to receive either inhaled treprostinil 0.6mg/mL 4 times daily or placebo for 16 weeks. The primary end point was the change in 6-minute walk distance (6MWD) at peak exposure from baseline to week 16.

Results showed that treatment with treprostinil was associated with an increase in 6MWD by 21 meters compared with placebo (P =.0043, Hodges-Lehmann estimate). Moreover, the treatment difference in 6MWD was reported to be statistically significant when analyzed using Mixed Model Repeated Measurement (31 meters; P <.001). Additionally, patients treated with treprostinil achieved significant improvements in all secondary end points 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.

With regard to safety, treatment with treprostinil was found to be well tolerated. The safety profile of treprostinil was consistent with that seen in previous studies in pulmonary arterial hypertension and with known prostacyclin-related adverse events. 

The Company expects the FDA to complete its review by April 2021.

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“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, PhD, Chairman and CEO 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.”

Tyvaso is currently approved for the treatment of pulmonary arterial hypertension (PAH; WHO Group 1) to improve exercise ability.

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United Therapeutics announces US FDA filing acceptance of supplemental New Drug Application for Tyvaso® for pulmonary hypertension associated with interstitial lung disease. Accessed August 17, 2020.