Preclinical Antitumor Activity of BMS-599626, a pan-HER Kinase Inhibitor That Inhibits HER1/HER2 Homodimer and Heterodimer Signaling

Abstract

Purpose: The studies described here are intended to characterize the ability of BMS-599626, a small-molecule inhibitor of the human epidermal growth factor receptor (HER) kinase family, to modulate signaling and growth of tumor cells that depend on HER1and/or HER2. Experimental Design: The potency and selectivity of BMS-599626 were assessed in biochemical assays using recombinant protein kinases, as well as in cell proliferation assays using tumor cell lines with varying degrees of dependence on HER1 or HER2 signaling. Modulation of receptor signaling was determined in cell assays by Western blot analyses of receptor autophosphorylation and downstream signaling. The ability of BMS-599626 to inhibit receptor heterodimer signaling in tumor cells was studied by receptor coimmunoprecipitation. Antitumor activity of BMS-599626 was evaluated using a number of different xenograft models that represent a spectrum of human tumors with HER1or HER2 overexpression. Results: BMS-599626 inhibited HER1and HER2 with IC 50 of 20 and 30 nmol/L, respectively, and was highly selective when tested against a broad panel of diverse protein kinases. Biochemical studies suggested that BMS-599626 inhibited HER1 and HER2 through distinct mechanisms. BMS-599626 abrogated HER1 and HER2 signaling and inhibited the proliferation of tumor cell lines that are dependent on these receptors, with IC 50 in the range of 0.24 to 1 Amol/L. BMS-599626 was highly selective for tumor cells that depend on HER1/HER2 and had no effect on the proliferation of cell lines that do not express these receptors. In tumor cells that are capable of forming HER1/HER2 heterodimers, BMS-599626 inhibited heterodimerization and downstream signaling. BMS-599626 had antitumor activity in models that overexpress HER1 (GEO), as well as in models that have HER2 gene amplification (KPL4) or overexpression (Sal2), and there was good correlation between the inhibition of receptor signaling and antitumor activity. Conclusions: BMS-599626 is a highly selective and potent inhibitor of HER1and HER2 kinases and inhibits tumor cell proliferation through modulation of receptor signaling. BMS-599626 inhibits HER1/HER2 receptor heterodimerization and provides an additional mechanism of inhibiting tumors in which receptor coexpression and heterodimerization play a major role in driving tumor growth.The preclinical data support the advancement of BMS-599626 into clinical development for the treatment of cancer.

Evaluation of the Antitumor Effects and Mechanisms of PF00299804, a Pan-HER Inhibitor, Alone or in Combination with Chemotherapy or Targeted Agents in Gastric Cancer

“…Until now, there have been studies on the activity of pan-HER TKIs, such as BMS-599626 and HM781-36B (22,23), in gastric cancer, and a phase II study of PF00299804 as monotherapy in patients with HER2-positive advanced gastric cancer is currently ongoing (24). In the present study, we evaluated the activity of PF00299804 in a large panel of gastric cancer cell lines and sought to determine the mechanisms of selectivity of PF00299804 for gastric cancer cell lines through investigating alteration of HER family heterodimer formation during treatment.…”

Antitumor and Antiangiogenic Activities of BMS-690514, an Inhibitor of Human EGF and VEGF Receptor Kinase Families

“…Lapatinib and erlotinib were obtained from LC Laboratories. Recombinant enzymes and biochemical assays of protein kinase activity were as described previously (31). KinomeScan profiling of BMS-690514 was done by Ambit Biosciences (32).…”

“…LX1 cells, which do not express EGFR or HER2, were transfected with EGFR L858R mutant plasmid by Fugene 6 (Roche Applied Science). At 48 hours after transfection, cells were treated for 1 hour with BMS-690514, and cell lysates were prepared as described previously (31). Immunoprecipitation was conducted by an anti-EGFR antibody and the immunoprecipitates were analyzed in Western blots by using antiphosphotyrosine and anti-EGFR antibodies.…”

“…Vehicles used were 40% propylene glycol, 50% water, and 10% Tween 80 for BMS-690514, sodium citrate buffer (pH 3.5) for BMS-582664, and 0.5% (w/v) hydroxypropyl methylcellulose, and 0.1% Tween 80 for erlotinib. Tumor measurement and data analyses were carried out as described (31).…”

Molecular targeted therapies in advanced gastric cancer: does tumor histology matter?

“…These include BMS-599626 [Wong et al 2006], HM781-36B [Nam et al 2011] and PF00299804 [Nam et al 2012]. A phase II study of PF00299804 monotherapy in patients with HER2-positive AGC is currently ongoing [ClinicalTrials.gov identifier: NCT01152853].…”