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.

SCH-58261 is an antagonist of the Adenosine A2A receptor with a Kd of 2.3 nM. It was initially identified and developed by Schering-Plough as a potential treatment for neurological conditions such as Parkinson's Disease and Depression. However, the compound suffered from poor solubility and is not active when orally dosed. SCH-58261 became the scaffold for the development of Preladenant (SCH 412348), which did progress to Phase III clinical trials before being discontinued. There has also been an investigation of SCH-58261 as a treatment of hypotension in rat models.