CMPD101 is an inhibitor of G protein-coupled receptor kinase 2 (GRK2) and GRK3 (IC50s = 18 and 5.4 nM, respectively). [1] It is selective for GRK2 and GRK3 over GRK1, GRK5, GRK6, and GRK7 (IC50s = 3,100, 2,300, >30,000, and 25,000 nM, respectively), as well as Rho-associated kinase 2 (ROCK-2) and PKCα (IC50s = 1,400 and 8,100 nM, respectively). CMPD101 induces cAMP accumulation in HEK293 cells expressing human β2-adrenergic receptors (EC50 = 10 &#181M). In isolated human prostate strips, CMPD101 (50 &#181M) inhibits contractions induced by electrical field stimulation, norepinephrine, phenylephrine, endothelin-1 , and U-46619 . [2]

Reference:
[1]. Okawa, T., Aramaki, Y., Yamamoto, M., et al. Design, synthesis, and evaluation of the highly selective and potent G-protein-coupled receptor kinase 2 (GRK2) inhibitor for the potential treatment of heart failure. J. Med. Chem. 60(16), 6942-6990 (2017).
[2]. Yu, Q., Gratzke, C., Wang, Y., et al. Inhibition of prostatic smooth muscle contraction by the inhibitor of G protein-coupled receptor kinase 2/3, CMPD101. Eur. J. Pharmacol. 831, 9-19 (2018).