BAY-545 is a potent and selective A2B adenosine receptor antagonist, with an IC50 of 59 nM. BAY-545 also exhibits IC50s of 66, 400, 280 nM for human, mouse, rat A2B adenosine receptor in cells, respectively, and a Ki of 97 nM for human A2B adenosine receptor, with more selectivity over A1, A2A, and A3 adenosine receptor[1].

IC50: 59 nM (A2B adenosine receptor), 66 nM (Human A2B adenosine receptor), 400 nM (Mouse A2B adenosine receptor), 280 nM (Rat A2B adenosine receptor), 1300 nM (Human A1 adenosine receptor), 820 nM (Human A2A adenosine receptor), 470 nM (Mouse A2A adenosine receptor) and 750 nM (Rat A2A adenosine receptor)[1]
Ki: 97 nM (A2B adenosine receptor)[1]

BAY-545 is selective at A2B adenosine receptor over A1, A2A, and A3 adenosine receptor, with IC50s of 1300 nM (Human A1 adenosine receptor), 820 nM (Human A2A adenosine receptor), 470 nM (Mouse A2A adenosine receptor) and 750 nM (Rat A2A adenosine receptor)[1].

Reference:

[1]. Harter M, et al. Novel non-xanthine antagonist of the A2B adenosine receptor: From HTS hit to lead structure. Eur J Med Chem. 2019 Feb 1;163:763-778.