Vascular biomarkers and digital ulcerations in systemic sclerosis: results from a randomized controlled trial of oral treprostinil (DISTOL-1).

• Currently we lack robust biomarkers to predict vascular outcomes or response to therapy in scleroderma patients with Raynaud's phenomenon.• Longitudinal assessment of vascular biomarkers in a clinical trial setting provides a unique opportunity to define biomarkers that predict vascular outcomes.• In a randomized controlled trial of oral treprostinil diolamine for treatment of scleroderma-associated digital ulcers, biomarkers involved in several vascular, inflammatory, and angiogenic pathways did not predict short-term clinical response to therapy or digital ulcer outcomes.• Further study of these and other biomarkers should be considered in Raynaud's clinical trials in scleroderma patients without prevalent digital ulcers.