(Treprostinil)

Easy to use AERx Essence palm-size device delivering an aqueous formulation of treprostinil could be a significant advancement over the existing treatments for Pulmonary Arterial Hypertension

Currently, Aradigm is investigating the application of its AERx delivery technology with Lung Rx, a wholly owned subsidiary of United Therapeutics, with approved injectable drug, treprostinil, for the treatment of pulmonary arterial hypertension. We have completed initial laboratory assessment of both a tresprostinil solution and a sustained release formulation of treprostinil using our palm-size AERx Essence technology, with the view to offer a pain-free alternative to injectable treprostinil. The two companies are currently planning to conduct in 2008 a bridging study with AERx Essence and aqueous formulation against the nebulizer used in the ongoing Phase 3 TRIUMPH study with inhaled treprostinil conducted by United Therapeutics. In future, the liposomal formulation could afford additional convenience to the patients through a once a day administration in a palm-size device.

Pulmonary Arterial Hypertension (PAH) is a rare disease that results in the progressive narrowing of the arteries of the lungs, causing continuous high blood pressure in the pulmonary artery and eventually leading to heart failure.

Trepostinil is currently marketed by United Therapeutics under the name Remodulin and is administered by intravenous or subcutaneous infusion, which can be painful and burdensome to patients.

Milestones
United Therapeutics has funded our activities in this program to date. We are planning to conduct in 2008 a human bridging study with AERx Essence against the nebulizer used in the Phase 3 TRIUMPH study. After successful completion of the bridging study, Lung Rx will be responsible for future funding and conduct of product development, manufacture and commercialization. In addition to an investment in the company, Lung Rx may pay Aradigm milestones up to $9.65M to September 2010, and Aradigm will be also eligible for royalties up to 10% of sales of the product.

Educational Links
For more information on pulmonary arterial hypertension, refer to the following resources:
American Lung Association
Pulmonary Hypertension Association
Mayo Clinic