Proof of Biological Activity of SAR100842 in Systemic Sclerosis

Primary Objective: - To evaluate safety and tolerability of 8-week oral administration of SAR100842 in patients with diffuse cutaneous systemic sclerosis. Secondary Objectives: * To evaluate the pharmacodynamic effect of SAR100842 in patients with systemic sclerosis as measured by disease related biomarkers and Lysophosphatidic acid (LPA) receptor signaling markers in blood and skin; * To explore the effect of SAR100842 on skin thickness in patients with systemic sclerosis as measured by the modified Rodnan Skin Score (mRSS); * To explore the effect of SAR100842 on quality of life as measured by the Scleroderma Modified Health Assessment Questionnaire (SHAQ); * To document long term safety of SAR100842 during the extension part.