Actelion Ltd : Update on the DUAL Program in Digital Ulcers in Systemic Sclerosis

ALLSCHWIL, SWITZERLAND - 02 December 2013 - Actelion Ltd (SIX: ATLN) announced today that following a scheduled meeting the independent Data Monitoring Committee (DMC) has recommended that the Phase III DUAL-2 study should be terminated. The DMC determined that there were no unexpected safety findings but that additional data are unlikely to result in a positive primary outcome measure.

The DUAL studies (DUAL-1 and DUAL-2) investigate the effect of treatment with macitentan (3mg and 10mg) compared to placebo on the reduction of the number of new digital ulcers in patients with systemic sclerosis and ongoing digital ulcers. There are no more patients in DUAL-1 receiving study treatment and this study will be completed as planned.

Actelion will now collect and analyze data from both studies. Data will be made available in the future.

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NOTES TO THE EDITOR

MACITENTAN
Macitentan is an orally available endothelin receptor antagonist (ERA) that resulted from a tailored drug discovery process with the target of developing an ERA to address efficacy and safety.

ABOUT THE SAFETY AND TOLERABILITY PROFILE
The most common adverse reactions observed in patients treated to date with macitentan are anemia, nasopharyngitis / pharyngitis, bronchitis, headache, influenza, and urinary tract infection.

Actelion Ltd

Actelion Ltd is a biopharmaceutical company with its corporate headquarters in Allschwil/Basel, Switzerland. Actelion first drug Tracleer® (bosentan), an orally available dual endothelin receptor antagonist, has been approved as a therapy for pulmonary arterial hypertension. Actelion markets Tracleer through its own subsidiaries in key markets worldwide, including the United States (based in South San Francisco), the European Union, Japan, Canada, Australia 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's over 2,300 employees focus on the discovery, development and marketing of innovative drugs for significant unmet medical needs. Actelion shares are traded on the SIX Swiss Exchange (ticker symbol: ATLN) as part of the Swiss blue-chip index SMI (Swiss Market Index SMI®).

For further information please contact:

Roland Haefeli
Senior Vice President, Head of Investor Relations & Public Affairs
Actelion Pharmaceuticals Ltd, Gewerbestrasse 16, CH-4123 Allschwil
+41 61 565 62 62
+1 650 624 69 36
www.actelion.com:
http://www.actelion.com

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