FDA Issues Third Approvable Letter for Thelin Houston, TX â€“ June 15, 2007 â€“ Encysive Pharmaceuticals today announced that the Company has received its third approvable letter from the U.S. Food and Drug Administration (FDA) for THELIN(tm) (sitaxsentan sodium), which is under review for the treatment of pulmonary arterial hypertension (PAH). In this third approvable letter, the FDA stated that Encysive's development program for THELIN did not demonstrate the evidence of effectiveness needed for approval. The FDA did note, however, that the THELIN development program provides some evidence that THELIN improves exercise tolerance in PAH. The FDA encouraged the Company to conduct an additional study to demonstrate the drug's effectiveness in exercise capacity as measured by change in six-minute walk distance. "We believe we adequately addressed the issue raised by the FDA in the second approvable letter and we are deeply disappointed in their decision. Encysive remains committed to THELIN in Europe, Australia and Canada, where it has been approved for sale," commented Bruce Given, M.D., President and CEO of Encysive Pharmaceuticals Inc. "We greatly appreciate the PAH patients and clinicians in the U.S. and worldwide who have been so supportive of the THELIN development program," he added. Encysive plans to discuss the most recent approvable letter with the FDA as soon as possible to determine the appropriate path forward. The Company may be required to make significant reductions in its infrastructure and workforce in the U.S. as a result of the decision by FDA. The Company is reviewing its strategic alternatives and intends to communicate its plans at a later date. Conference Call Information Encysive will host a conference call on Monday, June 18, 2007, at 8:00 a.m. ET, to discuss the FDA approval of THELIN. You may access the call either through the call-in number below or through the audio webcast. Please dial in 15 minutes prior to the start time to allow for call processing. The access number for the call is: Number: (320) 365-3844 Access Code: 877197 About Encysive Pharmaceuticals Encysive Pharmaceuticals Inc. is a global biopharmaceutical company engaged in the discovery, development and commercialization of novel, synthetic, small molecule compounds to address unmet medical needs. Our research and development programs are predominantly focused on the treatment and prevention of interrelated diseases of the vascular endothelium and exploit our expertise in the area of the intravascular inflammatory process, referred to as the inflammatory cascade, and vascular diseases. To learn more about Encysive Pharmaceuticals please visit our web site: www.encysive.com. The Encysive Pharmaceuticals Inc. logo is available at http://www.primenewswire.com/newsroom/prs/?pkgid=843 This press release contains "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements are subject to certain risks, trends and uncertainties that could cause actual results to differ materially from those projected. Among those risks, trends and uncertainties are: decisions by the FDA regarding whether and when to approve our NDA for Thelin(tm); unexpected delays in regulatory approval of Thelin(tm) by the FDA in the U.S. and our other products under development; the unpredictability of the duration and results of regulatory review of new drug applications and investigational new drug applications by the FDA; our estimate of the sufficiency of our existing capital resources; our ability to raise additional capital to fund cash requirements for future operations; the availability of sufficient funds to commercialize Thelin(tm) in the U.S. should it be approved by the FDA; the availability of sufficient funds to commercialize Thelin(tm) in the EU, Canada and Australia; market acceptance of Thelin(tm) in the EU, Canada and Australia and the actual rate of acceptance; the impact of reimbursement policies and governmental regulation of prices for Thelin(tm) in the EU, Canada and Australia; our inability to predict revenues from Thelin(tm) and our expense levels in 2007 and beyond; our ability to manufacture and sell any products, potential drug candidates, their potential therapeutic effect, market acceptance or our ability to earn a profit from sales or licenses of any drug candidate; and our ability to discover new drugs in the future, as well as more specific risks, trends and uncertainties facing Encysive such as those set forth in its reports on Forms 8-K, 10-Q and 10-K filed with the U.S. Securities and Exchange Commission. Given these risks, trends and uncertainties, any or all of these forward-looking statements may prove to be incorrect. Therefore you should not rely on any such forward-looking statements. Furthermore, Encysive undertakes no duty to update or revise these forward-looking statements. The Private Securities Litigation Reform Act of 1995 permits this discussion.