New PAH therapy approved in the U.S.
The FDA has approved United Therapeutics' Tyvaso (treprostinil) inhalation solution for the treatment of pulmonary arterial hypertension (PAH), using the Tyvaso inhalation system (which includes the Optineb-ir device and accessories).

According to the Silver Spring, Md.-based company, Tyvaso is indicated to increase walk distance in patients with NYHA Class III symptoms associated with WHO Group I PAH, which includes multiple etiologies such as idiopathic and familial PAH, as well as PAH associated with scleroderma and congenital heart disease.

In connection with the Tyvaso approval, United Therapeutics has agreed to post-marketing commitments (PMC) to modify certain aspects of the Tyvaso inhalation system, perform a usability analysis and collect pharmacokinetic data to verify expected dosing with the modified device. "We are well underway with the modifications to the Tyvaso inhalation system," said Roger Jeffs, PhD, United Therapeutics' president and chief operating officer. "In the meantime, patients will use the current version of the device. We have committed to complete the PMC no later than Oct. 31, 2010."

Additionally, United Therapeutics agreed to a post-marketing requirement (PMR) to conduct a long-term observational study to evaluate the risk of oropharyngeal and pulmonary toxicities among patients using Tyvaso. The company has committed to complete the PMR no later than Dec. 15, 2013.

In the TRIUMPH-1 randomized, double-blind, 12-week placebo-controlled clinical trial, patients taking Tyvaso in four daily inhalation sessions achieved a 20-meter improvement in six-minute walk distance, according to the company. The safety and effectiveness in patients with underlying lung disease has not been established. The most common side effects--in about 10 percent of patients-- were cough, headache, nausea, dizziness, flushing, throat irritation, pharyngolaryngeal pain and diarrhea.

United Therapeutics plans to launch Tyvaso in conjunction with its wholly-owned subsidiary, Lung Rx, in the U.S. at the beginning of September.