News | May 30, 2007

Canadian Health Authority Approves THELIN for Pulmonary Arterial Hypertension

May 31, 2007 — Encysive Pharmaceuticals today announced that Health Canada's Therapeutic Products Directorate has approved THELIN (sitaxsentan sodium) 100 mg tablets.

THELIN, which is the first selective endothelin A receptor antagonist (ETRA) available, and the only once-daily oral treatment approved for PAH, is indicated for the treatment of primary pulmonary arterial hypertension (PAH) and pulmonary hypertension secondary to connective tissue disease, in patients with World Health Organization (WHO) functional class III who have not responded to conventional therapy. THELIN is also indicated in patients with WHO functional class II who did not respond to conventional therapy and for whom no appropriate alternative can be identified.

PAH is characterized by high blood pressure and structural changes in the walls of the pulmonary arteries. As these arteries become increasingly constricted, blood flow and oxygenation may be inadequate to meet the body's demands. The heart must then pump harder to overcome the resistance, and patients become susceptible to heart failure.

For more information visit:

The disease is estimated to afflict approximately 100,000 to 200,000 people in North America and Europe.

``The approval of THELIN represents an advance in the treatment options available for PAH patients in Canada,'' commented David Langleben, M.D., Professor of Medicine, McGill University and Director of the Center for Pulmonary Vascular Disease, Jewish General Hospital, Montreal. ``THELIN's safety and efficacy profile and once-a-day oral formulation make it an attractive therapeutic option, and I look forward to its commercial availability.''

THELIN's approval is based on the largest database of patients with PAH ever assembled in an original Canadian New Drug Submission, with more than 1,000 PAH patients receiving THELIN. Encysive received European Union marketing authorization for THELIN in August 2006, marketing approval from the Australian Therapeutic Goods Administration in March 2007 and the drug is currently under evaluation by the Food and Drug Administration (FDA) in the United States.

``This approval is another important step in our effort to commercialize THELIN worldwide,'' stated Bruce D. Given, M.D., President and Chief Executive Officer of Encysive Pharmaceuticals. ``We're extremely proud to have achieved this milestone and look forward to bringing THELIN to PAH patients in Canada.''