Benjamin Henley

Discovery of N-(4-(2-Amino-3-chloropyridin-4-yloxy)-3-fluorophenyl)-4-ethoxy-1-(4-fluorophenyl)-2-oxo-1,2-dihydropyridine-3-carboxamide (BMS-777607), a Selective and Orally Efficacious Inhibitor of the Met Kinase Superfamily

Substituted N-(4-(2-aminopyridin-4-yloxy)-3-fluoro-phenyl)-1-(4-fluorophenyl)-2-oxo-1,2-dihydropyridine-3-carboxamides were identified as potent and selective Met kinase inhibitors. Substitution of the pyridine 3-position gave improved enzyme potency, while substitution of the pyridone 4-position led to improved aqueous solubility and kinase selectivity. Analogue 10 demonstrated complete tumor stasis in a Met-dependent GTL-16 human gastric carcinoma xenograft model following oral administration. Because of its excellent in vivo efficacy and favorable pharmacokinetic and preclinical safety profiles, 10 has been advanced into phase I clinical trials.

Discovery of Pyrrolopyridine-Pyridone Based Inhibitors of Met Kinase : Synthesis, X-ray Crystallographic Analysis, and Biological Activities

Conformationally constrained 2-pyridone analogue 2 is a potent Met kinase inhibitor with an IC50 value of 1.8 nM. Further SAR of the 2-pyridone based inhibitors of Met kinase led to potent 4-pyridone and pyridine N-oxide inhibitors such as 3 and 4. The X-ray crystallographic data of the inhibitor 2 bound to the ATP binding site of Met kinase protein provided insight into the binding modes of these inhibitors, and the SAR of this series of analogues was rationalized. Many of these analogues showed potent antiproliferative activities against the Met dependent GTL-16 gastric carcinoma cell line. Compound 2 also inhibited Flt-3 and VEGFR-2 kinases with IC50 values of 4 and 27 nM, respectively. It possesses a favorable pharmacokinetic profile in mice and demonstrates significant in vivo antitumor activity in the GTL-16 human gastric carcinoma xenograft model.

The Antiangiogenic Activity in Xenograft Models of Brivanib, a Dual Inhibitor of Vascular Endothelial Growth Factor Receptor-2 and Fibroblast Growth Factor Receptor-1 Kinases

Tumor angiogenesis is a complex and tightly regulated network mediated by various proangiogenic factors. The fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) family of growth factors, and associated tyrosine kinase receptors have a major influence in tumor growth and dissemination and may work synergistically to promote angiogenesis. Brivanib alaninate is the orally active prodrug of brivanib, a selective dual inhibitor of FGF and VEGF signaling. Here, we show that brivanib demonstrates antitumor activity in a broad range of xenograft models over multiple dose levels and that brivanib alaninate shows dose-dependent efficacy equivalent to brivanib in L2987 human tumor xenografts. Brivanib alaninate (107 mg/kg) reduced tumor cell proliferation as determined by a 76% reduction in Ki-67 staining and reduced tumor vascular density as determined by a 76% reduction in anti-CD34 endothelial cell staining. Furthermore, Matrigel plug assays in athymic mice showed that brivanib alaninate inhibited angiogenesis driven by VEGF or basic FGF alone, or combined. Dynamic contrast-enhanced magnetic resonance imaging, used to assess the effects of brivanib alaninate on tumor microcirculation, showed a marked decrease in gadopentetate dimeglumine contrast agent uptake at 107 mg/kg dose, with a reduction in area under the plasma concentration-time curve from time 0 to 60 minutes at 24 and 48 hours of 54% and 64%, respectively. These results show that brivanib alaninate is an effective antitumor agent in preclinical models across a range of doses, and that efficacy is accompanied by changes in cellular and vascular activities. Mol Cancer Ther; 9(2); 369–78

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

Purpose: The extensive involvement of the HER kinases in epithelial cancer suggests that kinase inhibitors targeting this receptor family have the potential for broad spectrum antitumor activity. BMS-690514 potently inhibits all three HER kinases, and the VEGF receptor kinases. This report summarizes data from biochemical and cellular pharmacology studies, as well as antitumor activity of BMS-690514. Experimental Design: The potency and selectivity of BMS-690514 was evaluated by using an extensive array of enzymatic and binding assays, as well as cellular assays that measure proliferation and receptor signaling. Antitumor activity was evaluated by using multiple xenograft models that depend on HER kinase signaling. The antiangiogenic properties of BMS-690514 were assessed in a matrigel plug assay, and effect on tumor blood flow was measured by dynamic contrast-enhanced MRI. Results: BMS-690514 is a potent and selective inhibitor of epidermal growth factor receptor (EGFR), HER2, and HER4, as well as the VEGF receptor kinases. It inhibits proliferation of tumor cells with potency that correlates with inhibition of receptor signaling, and induces apoptosis in lung tumor cells that have an activating mutation in EGFR. Antitumor activity was observed with BMS-690514 at multiple doses that are well tolerated in mice. There was evidence of suppression of tumor angiogenesis and endothelial function by BMS-690514, which may contribute to its efficacy. Conclusions: By combining inhibition of two receptor kinase families, BMS-690524 is a novel targeted agent that disrupts signaling in the tumor and its vasculature. Clin Cancer Res; 17(12); 4031–41. ©2011 AACR.

Synthesis, SAR, and Evaluation of 4-[2,4-Difluoro-5-(cyclopropylcarbamoyl)phenylamino]pyrrolo[2,1-f][1,2,4]triazine-based VEGFR-2 kinase inhibitors

Introduction of the 2,4-difluoro-5-(cyclopropylcarbamoyl)phenylamino group at the C-4 position of the pyrrolo[2,1-f][1,2,4] triazine scaffold led to the discovery of a novel sub-series of inhibitors of VEGFR-2 kinase activity. Subsequent SAR studies on the 1,3,5-oxadiazole ring appended to the C-6 position of this new sub-family of pyrrolotriazines resulted in the identification of low nanomolar inhibitors of VEGFR-2. Antitumor efficacy was observed with compound 37 against L2987 human lung carcinoma xenografts in athymic mice.

Design, synthesis and structure–activity relationships of novel biarylamine-based Met kinase inhibitors

Biarylamine-based inhibitors of Met kinase have been identified. Lead compounds demonstrate nanomolar potency in Met kinase biochemical assays and significant activity in the Met-driven GTL-16 human gastric carcinoma cell line. X-ray crystallography revealed that these compounds adopt a bioactive conformation, in the kinase domain, consistent with that previously seen with 2-pyridone-based Met kinase inhibitors. Compound 9b demonstrated potent in vivo antitumor activity in the GTL-16 human tumor xenograft model.

Discovery and preclinical studies of 5-isopropyl-6-(5-methyl-1,3,4-oxadiazol-2-yl)-N-(2-methyl-1H-pyrrolo[2,3-b]pyridin-5-yl)pyrrolo[2,1-f][1,2,4]triazin-4-amine (BMS-645737), an in vivo active potent VEGFR-2 inhibitor.

We report herein a series of substituted N-(1H-pyrrolo[2,3-b]pyridin-5-yl)pyrrolo[2,1-f][1,2,4]triazin-4-amines as inhibitors of vascular endothelial growth factor receptor-2 tyrosine kinase. Through structure-activity relationship studies, biochemical potency, pharmacokinetics, and kinase selectivity were optimized to afford BMS-645737 (13), a compound with good preclinical in vivo activity against human tumor xenograft models.

Abstract 5395: Anti-tumor activity of BMS-595, a novel CK2 kinase inhibitor

The CK2 protein kinases are a small family of two highly related serine/threonine kinases composed of two catalytic subunits, α and α’, and a single β subunit. Numerous substrates have been reported for CK2 and these proteins are known to participate in diverse cellular processes, including cell signaling, transcription, DNA repair, apoptosis regulation and tumor suppression. Elevated CK2 expression and kinase activity has been observed in many cancer types. Further, mRNA knockdown and enzyme inhibition studies have demonstrated that many cancer cell lines are dependent on CK2 for growth and survival. To further evaluate CK2 kinases as targets for therapeutic intervention in cancer, we identified BMS-595, a potent and selective, ATP-competitive CK2 inhibitor. BMS-595 inhibits the in vitro proliferation of human colorectal and lung cancer cell lines with IC50s ranging from less than 10 nM to greater than 1 μM. In sensitive cell lines, anti-proliferative effects of BMS-595 and structurally related analogs strongly correlated with cellular CK2 kinase inhibition. Oral administration of BMS-595 to mice bearing colorectal cancer and lung cancer xenografts demonstrated pharmacodynamic effects and robust efficacy at tolerated doses. These studies confirm the dependence of a subset of human colon and lung cancer cell lines on CK2 activity for growth and demonstrate that pharmacologic inhibition of CK2 can produce anti-tumor efficacy at tolerated doses. Citation Format: Brent A. Rupnow, Chiang Yu, Jonathan G. Pabalan, Urvashi V. Roongta, Jonathan S. Lippy, Ashok R. Dongre, Mary T. Obermeier, Aberra Fura, Paul A. Elzinga, Benjamin J. Henley, Joseph Fargnoli, Francis Y. Lee, William R. Foster, Christine M. Tarby, Brian E. Fink, John S. Tokarski, Ashvinikumar V. Gavai, Tai W. Wong, John T. Hunt, Gregory D. Vite, Ashok V. Purandare. Anti-tumor activity of BMS-595, a novel CK2 kinase inhibitor. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5395. doi:10.1158/1538-7445.AM2015-5395

Abstract 5417: The identification of BMS-595, an orally active imidazo[1,2-b]pyridazine CK2 inhibitor with in vivo anti-tumor activity

CK2 is a highly conserved, and constitutively active family of serine/threonine kinases abnormally elevated in a wide variety of cancers and linked to poor prognosis and disease progression. The enzymes form as hetero-tetrameric complexes comprised of two highly related catalytic subunits (α or α´) with two regulatory β subunits in various combinations and distributions, depending on cell type. While CK2 plays a role in normal growth and development, deregulation of the enzymes has been shown to promote and maintain a malignant phenotype through mechanisms in both the anti-apoptotic and the pro-proliferative signaling pathways. CK2 has been reported to modulate the activity of several oncogenic transcription factors including CREB, Myc, Jun and Fos. Studies with RNAi and small molecule compounds have demonstrated tumor cell dependence on CK2. We sought to identify potent CK2 inhibitors to probe the function of CK2 in cancer-linked pathways and for evaluation in CK2 dependent tumor xenograft models. Herein we report SAR studies in the imidazo[1,2-b]pyridazine chemotype leading to the discovery of BMS-595, a highly potent and selective ATP-competitive CK2 inhibitor with a commensurate level of cellular potency. BMS-595 demonstrates strong PK/PD correlations and robust, oral anti-tumor efficacy in CK2-driven xenograft models at tolerated doses. Citation Format: Christine M. Tarby, Liqi He, Brian E. Fink, Andrew Nation, Yufen Zhao, Soong-Hoon Kim, Libing Chen, John S. Tokarski, Chiang Yu, Jonathan G. Pabalan, Urvashi V. Roongta, Jonathan Lippy, Mary Obermeier, Paul A. Elzinga, Aberra Fura, Benjamin Henley, Joseph J. Fargnoli, William R. Foster, Ashvinikumar V. Gavai, Tai W. Wong, John T. Hunt, Gregory D. Vite, Ashok V. Purandare, Brent A. Rupnow. The identification of BMS-595, an orally active imidazo[1,2-b]pyridazine CK2 inhibitor with in vivo anti-tumor activity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5417. doi:10.1158/1538-7445.AM2015-5417

Abstract B284: Discovery of imidazopyridazinecarbonitriles as potent, selective inhibitors of CK2.

Casein kinase 2 (CK2) is a serine/threonine kinase that has been implicated in the regulation of a number of oncogenic or tumor suppressor proteins. CK2 activity has been shown to be elevated in numerous studies in a variety of cancer types. CK2 has been shown to phosphorylate numerous cellular proteins. Among the proteins regulated directly or indirectly by CK2 phosphorylation are oncogenes and tumor suppressor proteins including beta-catenin, c-Myc, PML, and PTEN as well as proteins directly involved in cell cycle, apoptosis, and transcriptional regulation. The plethora of CK2 substrates and their participation in various cellular processes is a major confounding factor in understanding the role of CK2 in oncogenesis. Unlike other kinase targets that participate in relatively linear growth factor signaling pathways, CK2 appears to function more “laterally,” across many important signaling pathways to promote growth and survival of cancer cells. It is clear from numerous studies using siRNA as well as small molecule CK2 inhibitors that cancer cells are highly dependent upon CK2 for growth and survival. As a result, new small molecule inhibitors of CK2 may provide useful tools for probing CK2 biology and may also provide therapeutic benefits against several cancer types. Herein, we report our efforts toward the identification of CK2 inhibitors based on an imidazopyridazine carbonitrile scaffold. Lead compounds from this series demonstrate low nanomolar CK2 biochemical potency, while achieving excellent selectivity versus the majority of kinases in the human kinome. The development of structure-activity relationships and the establishment of a strong correlation between biochemical potency, inhibition of cellular protein target phosphorylation and anti-proliferative effects in targeted cancer cell lines will be presented. In addition, the optimization of pharmacokinetic properties resulting in compounds with excellent in vivo exposure has allowed for the investigation of CK2 inhibition in a pharmacodynamic model. Finally, our efforts to elucidate pathway effects mediated by CK2 in model colon cancer cell lines, including gene expression profiling using advanced small molecules leads, will be disclosed. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B284. Citation Format: Brian Fink, Ashvinikumar Gavai, Soong-Hoon Kim, Yufen Zhao, Ashok Purandare, Gregory Vite, John Tokarski, Chiang Yu, Benjamin Henley, Joseph Fargnoli, Heshani Desilva, Petra Ross-MacDonald, Brent Rupnow, Tai W. Wong. Discovery of imidazopyridazinecarbonitriles as potent, selective inhibitors of CK2. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B284.