Clinical Research Directory

Inclusion Criteria: * Male and female subjects \> 18 years diagnosed with SSc; * Reduction of blood flow measured by laser Doppler imaging, of at least 50%, distally to the proximal interphalangeal joint, compared to the healthy volunteers; * Women of childbearing potential must have a negative pregnancy test and use a reliable form of contraception; * A history of 1 or more DUs within 2 years prior to inclusion; * No use of bosentan in the past; * Subjects willing and able to sign informed consent. Exclusion Criteria: * Parenteral prostanoid treatment for DU \< 3 months ago; * Chronic treatment with PDE-5 inhibitor or ERA; * History of bosentan use * Irreversible significant limitation of the hand function, e.g. amputation of more than one finger; * Other types of system- or connective tissue diseases; * Significant peripheral (macro-) vascular disease due to e.g. diabetes, hyperlipidemia, uncontrolled systemic hypertension, coagulopathy; * Any serious medical co morbidity (eg, active malignancy) such that the subjects life expectancy is \< 12 months; * Known AST and/or ALT elevations higher than 3 times Upper Limit Normal (ULN); * Moderate to severe liver function disorder; * Pregnancy or breastfeeding; * Treatment with Glibenclamide, Fluconazole, Cyclosporin A, Tacrolimus or other calcineurin inhibitors; * Hypersensitivity for bosentan or one of its components; * Subjects not able to follow the protocol.