This is an open label, single center study to determine the efficacy and safety of ambrisentan and antifibrotic agent combination in systemic sclerosis. Up to twenty patients will be recruited within the next year who have early diffuse systemic sclerosis and are presently receiving treatment with any of the following antifibrotic agents - cellcept, colchicine, azathioprine, D-penicillamine, methotrexate or cyclophosphamide. Ambrisentan will be added to the present agent and then followed for 12 months.