Information Orelabrutinib (ICP-022) Orelabrutinib (ICP-022) is a potent, orally active and irreversible inhibitor of Bruton's tyrosine kinase (BTK) . Orelabrutinib has potential antineoplastic activity. Targets BTK In vitro Orelabrutinib potently inhibits BTK enzymatic activity with an IC50 value of 1.6 nM. In KINOMEscan assay conducted in parallel at 1 μM against a panel of 456 kinases, orelabrutinib only targets BTK with > 90% inhibition while ibrutinib inhibits additional many other kinases including EGFR, TEC and BMX, demonstrating orelabrutinib\'s superior kinase selectivity. In vivo Orelabrutinib has a favorable PK profile with an ideal T1/2 (~1.5-4 h) and good oral bioavailability (~20-80%) as well as prolonged BTK target occupancy in preclinical PK/PD studies. The superior selectivity translates into improved safety profile and large safety window in the GLP toxicology studies in rats and dogs.