This information supplements the information presented in the Corporate Governance section of the Annual Report.

President of Actelion Pharmaceuticals US, Inc., the US operation of the Swiss-based biopharmaceutical company Actelion Ltd.

Dr. Buckingham has directed Actelion's sales, marketing, medical and regulatory activities in the United States since the subsidiary‘s inception in 2000. His experience in pharmaceutical sales, marketing and development spans almost 15 years. He joined Actelion early in 2000 having previously held positions of increasing importance in sales and marketing at Parke-Davis US, the pharmaceutical division of Warner Lambert, responsible for products over a range of therapeutic areas including cardiovascular, diabetes, antibiotics, depression and neurology.

Prior to that he worked for Roche as a Global Project Leader in cardiovascular drug development and held several positions in the Roche Australian affiliate in sales and marketing management. He is a veterinarian by training and has a PhD.

Christian Chavy was appointed President Europe, Latin America, Middle East & Africa of Actelion in November 2000.

Previously, he was Vice-President and Head of Global Therapeutic Area Reproductive Health at Serono International in Geneva. Prior to this position he was Managing Director of Serono France. He also spent five years with Rhône-Poulenc Rorer as Managing Director of Rorer France and President of RPR Canada Inc. for both Ethical and OTC activities.

He has also held Marketing Manager positions at Bristol-Myers France, Smith-Kline and Merck Sharp & Dhome. Christian Chavy was educated at ESSEC and holds a Master Degree of Business Management from ICG (Institut de Contrôle de Gestion in Paris)

A cardiologist educated in France, with further training in pharmacology and physiology at the University of Montreal, Canada, and the University of California, San Francisco. After eleven years as a clinician, he decided to move to applied research.

During his 12 years at F. Hoffmann-La Roche, he was responsible for the selection and pre-clinical development of drugs such as the first T-channel blocker, renin inhibitors, and several endothelin receptor antagonists such as bosentan. The group he was heading discovered seven compounds that entered clinical trials. He has developed various, novel experimental models allowing the differentiation of these drugs, work honored with the 1997 Hoffmann-La Roche Research Prize.

At the end of 1997, he founded Actelion, together with his wife, Martine, and work colleagues and friends Walter Fischli and Thomas Widmann. First mainly focusing on Research and Development, he became CEO of the company to bring Actelion to the public in April 2000.

During his 25-year-career in cardiology, he has published widely in peer-reviewed medical and scientific journals. At the same time, his passion has remained unchanged: being as closely as possible involved in bringing innovative medicine to "his" patients.

After graduating from a business school in Paris in 1976, Louis de Lassence started as an external auditor and obtained degrees in Accounting.

From 1982 onwards, he spent 18 years with Roche where he gained broad experience in Finance and Administration. His last positions there were finance manager of Roche in Brussels, assistant of the vice-chairman of the group and finance manager of Pharma International, the department in charge of Pharma sales in Central and Eastern Europe, Africa, Middle-East and C entral and Near A sia.

Kobrin, Isaac - Senior VP, Head of Clinical Development

An internist educated in Israel with further training (Fullbright Fellowship) at the Ochsner Medical Foundation in New Orleans, LA, mainly in the cardiovascular and nephrology fields.

He joined the clinical cardiovascular development department at F. Hoffmann-La Roche in 1989. During his 10 years at F. Hoffmann-La Roche, he was responsible for the worldwide clinical development of key compounds within the company's cardiovascular portfolio (Phase I to NDA). In 1997 he became Group Leader of the cardiovascular development group.

He is the author of more than 70 manuscripts and received the 1997 Hoffman-La Roche Research Prize. Isaac joined Actelion in September 1999 as Head of Clinical Development.

Mueller, André J. - Senior Vice President, Member of the Business Executive Board and the Board of Directors

With two degrees in Chemical Engineering and Business Administration from INSEAD, André Mueller started his career with Sandoz, where he held a number of managerial positions in the strategic planning and finance divisions, both at its headquarters and in the US.

After eleven years with Sandoz, he moved to Biogen, becoming VP of Finance and Administration and subsequently its first CFO. As CFO he was responsible for several financing rounds including Biogen's IPO. Four years later, he became a Founding Partner and Director of Investments for Genevest, the first Swiss venture capital organization.

Over the last 2 decades, he has been involved in the financing and the management of a substantial number of start-up companies, the most recent prior to Actelion being FotoWire Development SA.

He joined Actelion’s four-member management team shortly after it was founded, directing the two rounds of venture capital financing and helping bring Actelion to the public with its IPO in April 2000. He also established Actelion’s financial and management reporting systems.

In April 2001, André J. Mueller relinquished his function as CFO of the company but reoccupied these from April 2002 to December 31. 2002.

Tanaka, Satoshi - President and Representative Director, Japan

Satoshi Tanaka, is a Hematologist, qualified as a Medical Doctor of Medical Science, educated at the Doctor Course of Kyoto Prefectural University of Medicine following the education at the Master Course of Kyoto Pharmaceutical University with qualification as Pharmacist. He also trained at the Behring Institute and University of Mainz in Germany in hemastaseology and immunology.

During his 10 years mainly at Knoll AG in Germany, he was a member of the Global R&D management as President of Knoll Japan as well as Senior Managing Director of Hokuriku Seiyaku. During his period at Knoll, Satoshi’s track record included the successful acquisition of a listed Japanese company as well as licensing and partnering agreements among North America, Europe and Japan.

He received further training in business management at Cranfield University in the UK. He is currently a member of European Business Council, German, Swiss, and Austrian Chamber of Commerce.