Open-label Study With Bosentan in Interstitial Lung Disease

Long-term Open-label Study in Patients With Interstitial Lung Disease Associated With Systemic Sclerosis Who Completed the Protocol AC-052-330.

This study will asses the long term safety and efficacy of oral bosentan to patients suffering from Interstitial Lung Disease.

Inclusion Criteria:

• To have completed the 12-month treatment period of the AC-052-330/BUILD 2.
• Women should not be pregnant
• Women of childbearing potential must have a negative pre-treatment pregnancy test and use a reliable method of contraception
• Signed informed consent prior to initiation of any study-mandated procedure

Exclusion Criteria:

• Any major violation of the protocol AC-052-330.