PRESS RELEASE

SILVER SPRING, Md., May 6 /PRNewswire-FirstCall/ -- United Therapeutics Corporation (Nasdaq: UTHR) and its wholly-owned subsidiary Lung Rx, Inc. today announced that data related to the four different routes of administration of the drug, treprostinil, for the treatment of pulmonary arterial hypertension will be presented at the annual meeting of the American Thoracic Society (ATS), to be held in Toronto, Ontario, beginning May 16th and ending May 21, 2008, including the first public presentation of the full data set from the TRIUMPH-1 study of inhaled treprostinil. Additional information concerning presentation topics and times may be accessed via the ATS conference website or at http://ir.unither.com/events.cfm.

United Therapeutics will host an investor Q&A session following the conclusion of the ATS conference at The Westin Harbour Castle, One Harbour Square, Toronto, Ontario, on May 21, 2008, at 5:00 pm EDT. Lewis Rubin, MD, Director of the Pulmonary Hypertension Program at the University of California San Diego, and Vallerie McLaughlin, MD, Director of the Pulmonary Hypertension Program at the University of Michigan, will participate in this Q&A session, which is also being webcast and can be accessed via United Therapeutics' website at http://ir.unither.com/events.cfm.

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.

Lung Rx, Inc. is a biotechnology company focused on unmet medical needs in pulmonary medicine and pulmonary delivery of innovative therapeutic products. [uthr-g]

SOURCE United Therapeutics Corporation