CVT-6883 (GS 6201) is an A2B adenosine receptor antagonist originated by CV Therapeutics and developed by Gilead Sciences or the treatment of pulmonary diseases. In vitro studies have suggested that the activation of the A2B adenosine receptor may potentially have Proinflammatory and profibrotic effects that could be significant in the development of lung diseases. In adenosine deaminase (ADA) deficient mice, treatment with GS 6201 resulted in significantly less pulmonary inflammation, fibrosis, and alveolar airway enlargement compared with ADA-deficient mice treated with placebo. A range of doses of GS 6201 was well tolerated in healthy volunteers in a phase I multiple ascending dose trial.