FDA Reviewing Application for Tyvaso as Treatment for PH-ILD

The U.S. Food and Drug Administration (FDA) has accepted for review the  application for Tyvaso (inhaled treprostinil) as a potential treatment for pulmonary hypertension associated with interstitial lung disease (PH-ILD).

The supplemental new drug application (sNDA) was submitted by United Therapeutics, which markets Tyvaso. The company expects a decision from the FDA by 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,” Martine Rothblatt, PhD, the chairman and CEO of United Therapeutics, said in a press release.

“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,” Rothblatt added. 

ILD is a term that encompasses several conditions characterized by scarring (fibrosis) in the lung. This can lead to WHO group 3 pulmonary hypertension (defined as PH due to lung disease and/or chronic low oxygen levels).

At present, Tyvaso is approved in the U.S. to treat WHO group 1 pulmonary hypertension (also called pulmonary arterial hypertension). The medication works by making blood cells widen, which reduces blood pressure.

The sNDA is supported by data from the Phase 3 clinical trial INCREASE (NCT02630316), which enrolled 326 people with PH-ILD. Participants were  assigned randomly to receive either Tyvaso or a placebo, administered as an inhaled solution using a hand-held portable device, four times per day.

After 16 weeks of treatment, participants given Tyvaso had an average increase of 21 meters (about 69 feet) in six-minute walking distance (6MWD) compared to those given placebo, a statistically significant difference. 6MWD is the distance a person can walk in six minutes; it is used routinely in medical research to measure physical function in ambulatory people.

There also were significant improvements in 6MWD at shorter time intervals (12 and 15 weeks), and a significant increase in the time to the first clinical worsening event. Also, compared to placebo, Tyvaso significantly reduced the levels of NT-proBNP, a marker of poor heart function (lower levels indicate less strain on the heart).

Treatment benefits were seen across subgroups, including those based on the cause of PH-ILD, disease severity, age, sex, dose, and blood flow measurements prior to the trial.