PRESS RELEASE

SILVER SPRING, Md., March 21, 2011 /PRNewswire/ -- United Therapeutics Corporation (Nasdaq: UTHR) announced today that enrollment in its FREEDOM-C(2) registration trial was completed on March 18, 2011.

FREEDOM-C(2) is a 16-week, multi-center, international, double-blind, randomized, placebo-controlled study of a sustained release oral formulation of treprostinil diethanolamine (UT-15C) in pulmonary arterial hypertension (PAH) patients receiving an endothelin receptor antagonist and/or a phosphodiesterase-5 inhibitor.

The FREEDOM-C(2) study randomized 313 patients, compared to a target enrollment of 300 patients.  The primary endpoint of the trial is change in six-minute walk distance at Week 16 in the treatment group compared to placebo.

"Completion of enrollment in FREEDOM-C(2) represents another significant milestone toward the planned filing of the UT-15C NDA," said Roger Jeffs, Ph.D., President and Chief Operating Officer of United Therapeutics. "This study, if successful, will support the use of UT-15C as add-on therapy to currently approved oral medications, and should significantly enhance early adoption and market uptake of UT-15C."

United Therapeutics expects to unblind and announce preliminary analysis of the FREEDOM-C(2) study results in September 2011.

About United Therapeutics Corporation

United Therapeutics 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 conditions. [uthr-g]

Forward-looking Statements

Statements included in this press release that are not historical in nature are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements include, among others, our expectations on the timing of unblinding of the FREEDOM-C(2) study, our belief that the FREEDOM-C(2) study unblinding will bring us closer to the goal of achieving an approved oral prostacyclin therapy for PAH and our expectations that the study will enhance early adoption and market uptake of UT-15C.  These forward-looking statements are subject to certain risks and uncertainties, such as those described in our periodic reports filed with the Securities and Exchange Commission, that could cause actual results to differ materially from anticipated results.  Consequently, such forward-looking statements are qualified by the cautionary statements, cautionary language and risk factors set forth in our periodic reports and documents filed with the Securities and Exchange Commission, including our most recent Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and current reports on Form 8-K.  We claim the protection of the safe harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. We are providing this information as of March 21, 2011, and assume no obligation to update or revise the information contained in this press release whether as a result of new information, future events or any other reason.

SOURCE United Therapeutics Corporation