Fig 1.
Structure of INCB053914 and IC50 values for the inhibition of PIM isozymes by INCB053914 in biochemical assays.
Fig 2.
INCB053914 inhibits cellular proliferation in hematologic tumor cell lines (A), inhibits phosphorylation of PIM substrates (B), including pBAD (C), and increases PIM2 expression (D) in hematologic tumor cell lines. For all Western blots, actin controls confirmed equivalent loading. IC50 values for pBAD inhibition were determined by fitting the percent inhibition versus the log [INCB053914] data to sigmoidal dose–response (variable slope) curve. Error bars represent standard deviation. GI50 values >3 μM are not shown. *pP70S6K band intensities in KMS-12-BM (MM) cells were below the limit of detection at all INCB053914 concentrations tested. HL, Hodgkin lymphoma; ND, not determined. Original Western blot images are shown in Supporting Information S4 File.
Fig 3.
INCB053914 inhibits phosphorylation of PIM substrates and increases PIM2 expression in primary bone marrow (BM) blasts (A), and increases PIM2 expression in PBMCs derived from whole blood samples from patients with AML (B). Pharmacodynamic effects of INCB053914 on PIM2 expression and 4E-BP1 phosphorylation in whole blood samples obtained 0 to 6 hours post-dose from two separate patients with AML enrolled in the ongoing phase 1/2 trial (C). The EC50 for increased PIM2 expression were determined by fitting data to a sigmoidal dose–response (variable slope) curve. Original Western blot images are shown in Supporting Information S4 File.
Fig 4.
INCB053914 inhibits erythroid colony formation in patients with JAK2 V617F-positive MPNs.
Error bars represent standard deviation. *p < 0.05; **p < 0.01.
Fig 5.
INCB053914 inhibits the phosphorylation of BAD in mice bearing MOLM-16 (AML) (A) or KMS-12 (MM) tumors (B), and inhibits growth of MOLM-16 (AML) (C) and KMS-12 (MM) (D) tumors in vivo. Mean INCB053914 plasma concentrations were determined at 2, 4, 8, and 16 hours post oral administration in mice bearing MOLM-16 tumors (E) or KMS-12-BM tumors (F). EC50 values for pBAD inhibition were determined by fitting data to a sigmoidal dose–response (variable slope) curve. Error bars represent standard error of the mean. BID, twice a day; PO, orally.
Fig 6.
Effects of the selective PI3Kδ inhibitor, INCB050465, on PIM isozyme expression in Pfeiffer DLBCL cells (A). Effects of INCB053914 alone, or in combination with INCB050465, on the in vitro proliferation of Pfeiffer DLBCL cells (B). Effects of INCB053914 alone or in combination with INCB050465 on tumor growth in a DLBCL xenograft model (C); with cytarabine on tumor growth in an AML xenograft model (D); with the JAK1-selective inhibitor, itacitinib, on BAD, STAT3 phosphorylation, and MYC levels (E), and on tumor growth in an INA-6 MM xenograft model (F). Error bars represent standard error of the mean. BW, twice a week; CR, complete regression; IP, intraperitoneally; QD, once a day.