SILVER SPRING, Md., Oct. 31 /PRNewswire-FirstCall/ -- United Therapeutics Corporation (Nasdaq: UTHR) and its wholly-owned subsidiary, Lung Rx, Inc., announced today that they will release the results of their TRIUMPH-1 Phase 3 trial of Viveta, an inhaled formulation of treprostinil, in pulmonary arterial hypertension (PAH) before market open on Thursday, November 1, 2007.

United Therapeutics will expand its previously scheduled conference call on November 1, 2007, to a full hour to accommodate a discussion of the TRIUMPH-1 results. The call will begin at 9:00 a.m. Eastern Time. Lewis J. Rubin, MD, FCCP, Co-Chair of the TRIUMPH-1 Steering Committee and Professor of Medicine at University of California San Diego Medical Center, will join United Therapeutics' management on the call to answer questions related to TRIUMPH-1.

About TRIUMPH-1

TRIUMPH-1 (TReprostinil Sodium Inhalation Used in the Management of Pulmonary Arterial Hypertension), was a randomized, double-blind, placebo- controlled trial of patients with severe PAH, a chronic, life-threatening illness. The study population consisted of 235 patients who were optimized on an approved oral therapy for PAH, either bosentan (Tracleer), an endothelin receptor antagonist, or sildenafil (Revatio), a phosphodiesterase-5 inhibitor. The primary efficacy endpoint of the trial was the change in six-minute walk distance at 12 weeks measured at peak exposure, defined by the trial protocol as 10-60 minutes after inhalation of Viveta, relative to baseline.

Conference Call

United Therapeutics will host a one-hour teleconference on Thursday, November 1, 2007, at 9:00 a.m. Eastern Time. The teleconference is accessible by dialing 1-800-603-1777, with international callers dialing 1-706-679-8129. A rebroadcast of the teleconference will be available for one week following the teleconference by dialing 1-800-642-1687, with international callers dialing 1-706-645-9291, and using access code 20811764.

This teleconference is also being web cast and can be accessed via United Therapeutics' website at http://ir.unither.com/eventdetail.cfm?eventid=45704.

About United Therapeutics

United Therapeutics is a biotechnology company focused on the development and commercialization of unique products for patients with chronic and life- threatening cardiovascular, cancer and infectious diseases. [uthr-g]

About Lung Rx

Lung Rx is a biotechnology company focused on unmet medical needs in pulmonary medicine and pulmonary delivery of innovative therapeutic products.

Viveta is a trademark of Lung Rx, Inc.

Tracleer is a registered trademark of Actelion Ltd.

Revatio is a registered trademark of Pfizer Inc.

SOURCE United Therapeutics Corporation