KZR-504 is a highly selective and orally active inhibitor of immunoproteasome low molecular mass polypeptide 2 (LMP2), with IC50s of 51 nM, 4.274 μM for LMP2 and LMP7, respectively.
Evaluating the inhibition of LMP2, and antitargets LMP7 and β5, in mouse tissues reveals that KZR-504 (compound 12) is both selective and potent in vivo with >50% target inhibition achieved at >1 mg/kg in all tissues tested except brain[1].
[1]. Johnson HWB, et al. Discovery of Highly Selective Inhibitors of the Immunoproteasome Low Molecular Mass Polypeptide 2 (LMP2) Subunit. ACS Med Chem Lett. 2017 Mar 9;8(4):413-417.