ALLSCHWIL, Switzerland, July 12, 2005 (PRIMEZONE) -- Actelion Ltd (SWX:ATLN) (Other OTC:ALIOF) announced today that in the BREATHE-5 study evaluating the use of Tracleer(r) (bosentan) in pulmonary arterial hypertension (PAH) related to Eisenmenger's syndrome, patients significantly increased their exercise capacity and decreased pulmonary vascular resistance (PVR) under treatment.
Patients suffering from Eisenmenger's syndrome develop a severe form of PAH as a complication of their congenital heart defect. This syndrome cannot be treated by any conventional means, including surgery. BREATHE-5 is the first ever multi-centre, randomised, double-blind, placebo-controlled study to show benefit in this very sick group of patients. The standard regime of Tracleer(r) was used and patients were studied for 16 weeks.
Dr. Michael Landzberg from Brigham and Womens Hospital, Boston and principal investigator for BREATHE-5 commented: "Eisenmenger's syndrome is a field of high unmet medical need. It is remarkable that in this disease, which was believed to be characterized by irreversible vascular lesions, finally a drug has shown an improvement in exercise capacity. At the same time Tracleer(r) was well tolerated."
Jean-Paul Clozel, MD and Chief Executive Officer, commented: "As a cardiologist I am impressed by the strong results of Tracleer(r) in these patients, with such a condition related to congenital heart defects. As the CEO of Actelion I am proud that once more we have taken the leadership in an areas with high unmet medical need."
The BREATHE-5 top-line data
BREATHE-5 is the first ever placebo-controlled study conducted in patients with Eisenmenger's syndrome. A total of 54 patients with WHO functional class III PAH participated. The results show that patients with bosentan treatment demonstrate a decrease in PVR and an improvement in exercise capacity without a worsening in oxygen saturation. Overall the bosentan safety and tolerability profile was comparable to that observed in previous placebo-controlled clinical trials in PAH with Tracleer(r).
The full results of BREATHE-5 will become available through standard scientific disclosure including presentation at major medical conferences and publication in a peer-reviewed scientific journal.
About Eisenmenger's syndrome
Eisenmenger's syndrome is a progressive heart condition and occurs in people who have a congenital heart defect or hole in the heart. Initially the heart defect allows blood to flow from the left ventricle to the right (left-right shunt) resulting in pulmonary hypertension. Over time damage to the pulmonary blood vessels causes increased resistance to the blood flow, which leads to a reversal of the shunt, with blood flowing from right to left. This causes the most recognizable symptom of Eisenmenger's syndrome, a blue tinge to the skin (cyanosis) resulting from low blood oxygen concentration. The poor oxygenation of their blood severely limits their physical activity. In addition to limiting physical activity, Eisenmenger's syndrome is associated with organ damage and a higher likelihood of premature death. Currently, no intervention significantly improves the clinical status of these patients.
About Tracleer(r) in Pulmonary Arterial Hypertension (PAH)
Tracleer(r), the first oral dual endothelin receptor antagonist, is approved for the treatment of pulmonary arterial hypertension (PAH) and made available by Actelion subsidiaries in the United States, the European Union, Japan, Australia, Canada, Switzerland and other markets worldwide.
In clinical trials leading to the marketing approval of the drug, approximately 11% of PAH patients receiving Tracleer(r) experienced abnormal but reversible liver enzyme elevations. It is therefore important that patients undergo monthly liver monitoring. Due to the risk of birth defects, women who are pregnant, or of childbearing age who do not use a reliable method of contraception, must not take Tracleer(r).
Actelion Ltd
Actelion Ltd is a biopharmaceutical company with its corporate headquarter in Allschwil/Basel, Switzerland. Actelion's first drug, Tracleer(r), an orally available dual endothelin receptor antagonist, has been approved as a therapy for pulmonary arterial hypertension. Actelion markets Tracleer(r) through its own subsidiaries in key markets worldwide, including the United States (based in South San Francisco), the European Union as well as Canada, Australia, Japan and Switzerland. Actelion, founded in late 1997, is a leading player in innovative science related to the endothelium -- the single layer of cells separating every blood vessel from the blood stream. Actelion focuses on the discovery, development and marketing of innovative drugs for significant unmet medical needs. Actelion shares are traded on the SWX Swiss Exchange (ticker symbol: ATLN).