Encysive Pharmaceuticals Announces Launch of Thelin in Germany

First Selective, Once-Daily Oral Endothelin A Receptor Antagonist Now Commercially Available for Pulmonary Arterial Hypertension Patients HOUSTON, Dec. 18, 2006 (PRIME NEWSWIRE) -- Encysive Pharmaceuticals (Nasdaq:ENCY) today announced that THELIN(r)(1) (sitaxentan sodium(2)) 100 mg tablets are now commercially available in Germany for the treatment of pulmonary arterial hypertension (PAH). The Company received European Union marketing authorization for THELIN from the European Commission in August 2006. THELIN is the first selective endothelin A receptor antagonist and the first once-daily oral treatment available for patients with PAH. "As a newly available treatment option, THELIN offers further hope to PAH patients in Germany," commented Leo Kwakkenbos, President of the Pulmonary Hypertension Association of Europe. "With more therapies in existence to help patients manage their symptoms, individuals are able to make bigger strides in improving their quality of life." THELIN is indicated for improving exercise capacity in PAH patients classified as World Health Organization (WHO) functional class III. Efficacy has been shown in primary pulmonary hypertension(3) and pulmonary hypertension associated with connective tissue disease (CTD). "THELIN's ease of use in a once-daily oral tablet, combined with its safe and efficacious profile, makes it a unique new option for treating PAH," said Christian Opitz, M.D., Assistant Professor, Department of Cardiology, DRK Hospital-Westend, Berlin, Germany. "Clinical studies have demonstrated that THELIN can benefit PAH patients with CTD-related disease, which is a significant advancement to the treatment landscape for this patient group," stated Ardeschir Ghofrani, M.D., Associate Professor of Internal Medicine and Head of the Pulmonary Hypertension Division, University Hospital Giessen, Giessen, Germany. The European Commission's centralized licensing procedure permits Encysive to market THELIN in all 25 member states of the EU. THELIN will be launched in successive EU member states as local government approval for reimbursement is obtained. "We are pleased that Germany is the second EU country where THELIN is now available for patients. Physicians have already begun to prescribe THELIN for patients in Germany in anticipation of its commercial availability," said Bruce D. Given, M.D., President and Chief Executive Officer of Encysive Pharmaceuticals. "Our recent United Kingdom launch was well received, and we look forward to continued success in introducing THELIN to additional EU countries in the coming year." THELIN(r) (Sitaxentan Sodium) Overview THELIN is an endothelin A receptor antagonist, a small molecule that blocks the action of endothelin, a potent mediator of blood vessel constriction and growth of smooth muscle in vascular walls. Endothelin receptor antagonists may prove to be effective in the treatment of a variety of diseases where the regulation of vascular constriction is important. THELIN is 6,500-fold selective in the targeting of the endothelin A receptor versus the endothelin B receptor. Highly selective endothelin A receptor antagonism has been shown to increase blood flow and reverse vasoconstriction in human clinical pharmacology studies. For more information, please visit www.encysive.com. Important Safety Information In placebo-controlled clinical trials, the most frequent adverse events that occurred in patients receiving THELIN, which were considered to be possibly related to THELIN treatment, were headache, peripheral edema and nasal congestion. Other adverse events that occurred in at least 2% of THELIN patients, at a rate greater than placebo and considered to be possibly related to THELIN treatment, included dizziness, constipation, epistaxis, flushing, international normalized ratio (INR) increase, insomnia, nausea, upper abdominal pain, vomiting, dyspepsia, diarrhea, fatigue, muscle cramp, and prothrombin time (PT) prolongation. THELIN is also associated with liver function abnormalities. Because THELIN inhibits the metabolism of warfarin and other vitamin K antagonists, a dose adjustment for these drugs is needed when co-administered with THELIN. THELIN and other endothelin receptor antagonists have potential for liver toxicity and are teratogenic. Testing of liver enzymes is required prior to the initiation of THELIN and monthly thereafter. THELIN should not be used during pregnancy unless clearly necessary; female patients are required to undergo a pregnancy test prior to receiving THELIN. THELIN is contraindicated in patients receiving cyclosporine A, patients with mild to severe hepatic impairment (Child-Pugh Class A-C), patients with elevated liver aminotransferases prior to starting treatment (elevation in liver enzymes to levels greater than 3 times the upper limit of normal), lactating patients, or patients with hypersensitivity to the active substance or any excipients. About PAH It is estimated that PAH afflicts approximately 100,000 to 200,000 people in North America and Europe. The disease is characterized by high blood pressure and structural changes in the walls of the pulmonary arteries, the blood vessels that connect the right side of the heart to the lungs. As these arteries become increasingly constricted, blood flow and oxygenation may be inadequate to meet the body's demands. Since the heart must then pump harder to overcome the resistance, patients are susceptible to heart failure. About Encysive Pharmaceuticals Encysive Pharmaceuticals Inc. is a 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://media.primezone.com/prs/single/?pkgid=843 1) THELIN is an EU registered trademark of Encysive Pharmaceuticals Inc. 2) "Sitaxentan" sodium is the spelling recognized by the World Health Organization for Encysive Pharmaceuticals' sitaxsentan sodium. 3) Primary pulmonary hypertension is also known as idiopathic pulmonary arterial hypertension. 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 our estimates concerning the size of the PAH patient population; our ability to quickly and successfully commercialize THELIN in Germany and other countries of the EU; market acceptance of THELIN in Germany and the actual rate of acceptance; the speed with which pricing and reimbursement approvals and product launches for THELIN may be achieved in Germany and other countries of the EU; difficulties or delays in manufacturing, packaging or distributing THELIN in Germany; legislation or regulations within the EU affecting THELIN's pricing, reimbursement or access; our ability to protect our patents and other intellectual property for THELIN; and our ability to earn a profit from sales of THELIN as well as other 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. CONTACT: Encysive Pharmaceuticals Investors: Ann Tanabe, VP, Investor Relations and Corporate Communications (713) 796-8822 BMC Communications Media: Dan Budwick (212) 477-9007 ext. 14 The Trout Group Marcy Strickler (646) 378-2900 ext. 27