Therapeutics Corporation announced that the United States Food and Drug Administration (FDA) has approved 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).

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.

"We are thrilled to have a fourth approval from the FDA for treatment of this serious cardio-pulmonary condition," said Martine Rothblatt, Ph.D., United Therapeutics' chairman and chief executive officer. "I want to specially recognize Drs. Werner Seeger of Germany and Lew Rubin of the United States for their critical pioneering efforts in making this new therapy possible. Tyvaso epitomizes the hopes and dreams we had in forming this company."

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, Ph.D., United Therapeutics' president and chief operating officer, "And we think these modifications will make the device more patient-friendly. In the meantime, patients will use the current version of the device." We have committed to complete the PMC no later than October 31, 2010.

Additionally, United Therapeutics has 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. "We welcome the opportunity to gather further information on Tyvaso's safety," continued Dr. Jeffs. We have committed to complete the PMR no later than December 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 over those taking placebo (p<0.0005). The safety and effectiveness in patients with underlying lung disease has not been established. The most common side effects (>= 10%) seen with Tyvaso in the placebo controlled clinical study were cough, headache, nausea, dizziness, flushing, throat irritation, pharyngolaryngeal pain and diarrhoea.

United Therapeutics plans to launch Tyvaso in conjunction with its wholly-owned subsidiary, Lung Rx, Inc., in the United States at the beginning of September 2009.

Tyvaso is an inhaled medicine used to treat PAH, a life-threatening disease that constricts the flow of blood through the pulmonary vasculature. Tyvaso contains the same active ingredient (treprostinil) as Remodulin (treprostinil sodium) Injection, which is also approved for the treatment of PAH. Tyvaso is marketed by United Therapeutics and its wholly-owned subsidiary, Lung Rx, Inc.

Nearly all clinical experience has been on a background of an endothelin receptor antagonist or a phosphodiesterase type 5 inhibitor.

United Therapeutics Corporation is a biotechnology company focused on the development and commercialization of unique products to address the unmet medical needs of patients with chronic and life-threatening cardiovascular and infectious diseases and cancer.