Uzansertib (INCB053914)

INCB053914 potently inhibits the activities of all three PIM isozymes with half maximal inhibitory concentration (IC50) values in the order of PIM1 ≈ PIM3 < PIM2. It is highly selective against a panel of more than 50 kinases (>475-fold selectivity), except for RSK2 for which INCB053914 has modest potency (IC50 = 7.1 μM). No kinase other than Per-Arnt-Sim (PAS) kinase is significantly inhibited by INCB053914 (100 nM)^[1]. In cell proliferation assays, INCB053914 is active as a single agent in the majority of cell lines derived from different hematological malignancies, including MM, AML, DLBCL, MCL and T-ALL, with IC50 values ranging from 3-300 nM. INCB053914 synergizes with a variety of cytotoxic and targeted agents, reducing the viability of a panel of hematological tumor cell lines^[2].

10⁶ MOLM-16 (AML), Pfeiffer (DLBCL), KMS-12-PE (MM), and KMS-12-BM (MM) cells are incubated with INCB053914 at concentrations ranging from 0 (phosphate-buffered saline [PBS]) to 1 μM for 2 hours in RPMI medium. Cells are centrifuged at 1,000 rpm for 10 minutes and lysed with 1× lysis buffer supplemented with 1 mM phenylmethane sulfonyl fluoride and proteinase inhibitor cocktail. Cell lysates are stored at -80°C before determining phosphoprotein and PIM2 levels by Western blotting.

In vivo, single-agent INCB053914 inhibits Bcl-2-associated death promoter protein phosphorylation and dose-dependently inhibited tumor growth in acute myeloid leukemia and multiple myeloma xenografts^[2]. INCB053914 inhibits tumor growth in a dose-dependent manner in mice bearing MOLM-16 (AML) or KMS-12-BM (MM) tumors. A pharmacokinetic analysis of INCB053914 plasma concentrations up to 16 hours post oral administration in MOLM-16 and KMS-12-BM tumor-bearing mice suggests dose proportionality^[1].