Apatinib | Kinase Inhibitor | VEGFR-2 Inhibitor | KDR Inhibitor | Angiogenesis Inhibitor | Anti-Tumor Drug

Apatinib [N-[4-(1-cyano-cyclopentyl)phenyl]-2-(4-pyridylmethyl)amino-3-pyridine carboxamide] is an orally available, selective small molecule inhibitor of vascular endothelial growth factor-2 (VEGFR-2 also known as KDR) tyrosine kinase. It is more potent than Sunitinib in inhibiting VEGFR2 (IC₅₀ Apatinib, Sunitinib = 0.001, 0.005 uM) [1, 2].

Apatinib is an analogue of Valatinib and shows similar anti-angiogenic/anti-tumour efficacy. It binds with VEGFR-2 tyrosine kinase targeting the intracellular ATP binding site of the receptor, preventing phosphorylation and subsequent downstream signalling. Apatinib has shown a superior in vivo efficacy compared to Valatinib in xenograft models.

Apatinib has been approved by the Chinese Food and Drug Administration (CFDA) in October 2014 for the treatment of metastatic gastric carcinoma. It is an investigational cancer drug in many other countries including USA, EU etc and currently undergoing clinical trials as a potential targeted treatment for metastatic gastric carcinoma, metastatic breast cancer and advanced hepatocellular carcinoma.

Apatinib: 2D and 3D Structure

Angiogenesis, Tumor Angiogenesis and VEGFRs

Angiogenesis, the formation of new blood vessels from pre-existing ones, plays a central role in the process of tumor growth and metastasis. The proliferation of endothelium and formation of new blood vessels further the size of solid tumors. It is expected that blocking angiogenesis will be an efficient therapeutic approach against many tumor types.

Tumor angiogenesis plays a critical role in the malignant tumor growth and metastasis. When tumors grow beyond 1 mm³, angiogenesis or generation of vascular arborizations by budding from existing vessels is necessary to provide enough blood for the survival of tumor cells. The growth speed and tendency of metastasis of tumors are associated with the level of neovascularization factors and the quantity of nascent microvessels. Since the hypothesis “anti-angiogenesis therapy” was put forward by Folkman in early 1970s, people have made considerable progress in this field, and inhibiting angiogenesis of tumors has been universally accepted as a new anticancer strategy. 

Tyrosine kinase vascular endothelial growth factor (VEGF) and its receptor (VEGFR) play significantly important roles in angiogenesis of tumors, and they are both important targets in blocking angiogenesis of tumors. Vascular endothelial growth factor (VEGF) is the foremost factor in vivo promoting the angiogenesis. The binding of VEGF with vascular endothelial growth factor receptor (VEGFR) in endothelial cells leads to various reactions of angiogenesis, such as cells proliferation, cells metastasis, the increase of vascular permeability, and the move of endothelial cells precursors out of marrow. VEGFR family comprises VEGFR1 (Flt-1), VEGFR2 (KDR/Flk-1) and VEGFR3 (Flt-4). Promotion of the angiogenesis is mainly mediated by the bonded VEGF and VEGFR2 (KDR/Flk-1).

Compared with traditional cytotoxic drugs which inhibit the growth of tumors, angiogenesis targeting drugs are more specific and less toxic as well as helpful to overcome the drug resistance of tumors and can be used for the treatment of various tumors [3, 4].

Apatinib as Kinase Inhibitor

In vitro enzyme experiments showed that Apatinib was an even more selective inhibitor of VEGFR-2 than Sunitinib, with an IC₅₀ of 0.001 uM and 0.005 uM, respectively. Apatinib could also potently suppress the activities of Ret, c-Kit and c-Src with an IC₅₀ of 0.013 uM, 0.429 uM and 0.53 uM, respectively. Apatinib had no significant effects on EGFR, Her-2 or FGFR1 in concentrations up to 10 uM [1].

Summary

Common name: YN968D1; YN 968D1; YN-968D1

Trademarks: -

Molecular Formula: C24H23N5O

CAS Registry Number: 811803-05-1; 1218779-75-9 (mesylate)

CAS Name: N-[4-(1-cyano-cyclopentyl)phenyl]-2-(4-pyridylmethyl)amino-3-pyridine carboxamide

Molecular Weight: 397.48

SMILES:O=C(NC1=CC=C(C2(C#N)CCCC2)C=C1)C3=CC=CN=C3NCC4=CC=NC=C4

InChI Key: WPEWQEMJFLWMLV-UHFFFAOYSA-N

InChI: InChI=1S/C24H23N5O/c25-17-24(11-1-2-12-24)19-5-7-20(8-6-19)29-23(30)21-4-3-13-27-22(21)28-16-18-9-14-26-15-10-18/h3-10,13-15H,1-2,11-12,16H2,(H,27,28)(H,29,30)

Mechanism of Action: Kinase Inhibitor; KDR Inhibitor; Multi-Kinase Inhibitor

Activity: Treatment of Metastatic Gastric Carcinoma; Anti-cancer Agents; Angiogenesis Inhibitors

Status: Launched 2014 (China)

Chemical Class: Small-molecules; Nitrile containing; Pyrimidine containing

Originator: Advenchen Laboratories (USA)/ Jiangsu Hengrui Medicine Co. Ltd (China)

Apatinib Synthesis

US20040259916A1: It appears to be the industrial process.

Identification:

1H NMR (Estimated) for Apatinib

References:
1. Tian, S.; et al. YN968D1 is a novel and selective inhibitor of vascular endothelial growth factor receptor-2 tyrosine kinase with potent activity in vitro and in vivo. Cancer Sci 2011, 102(7), 1374-80. (FMO only)
2. Chen, G. Six membered amino-amide derivatives an angiogenisis inhibitors. US20040259916A1
3. Yuan, K.; et al. The salts of n-[4-(1-cyanocyclopentyl)phenyl]-2-(4-pyridyl methyl)amino-3-pyridinecarboxamide. WO2010031266A1
4. Sharma, P. S.; et al. VEGF/VEGFR pathway inhibitors as anti-angiogenic agents: present and future. Curr Cancer Drug Targets 2011, 11(5), 624-53. (FMO only)

CHMFL-ABL-053 | Treatment for Chronic Myeloid Leukemia | ABL Inhibitor | Multi-Kinase Inhibitor

CHMFL-ABL-053 [2-((3-Amino-4-methylphenyl)amino)-N-(2-methyl-5-(3-(trifluoromethyl)benzamido)phenyl)-4-(methylamino)pyrimidine-5-carboxamide] is an orally available, small molecule multi-kinase inhibitor for BCR-ABL,SRC and p38 kinases. Invitrogen SelectScreen biochemical assay revealed that CHMFL-ABL-053 exhibited an IC₅₀ of 70 nM against ABL1 kinase and also strongly inhibited p38α (IC₅₀ = 62 nM) and SRC kinases (IC₅₀ = 90 nM). In addition, CHMFL-ABL-053  did not exhibit apparent potency against c-KIT kinase (IC₅₀ = over 10000 nM), which is the common off-target for clinically used BCR-ABL inhibitors Imatinib, Nilotinib, Bosutinib, and Dasatinib. Moreover, it exhibited better selectivity against DDR1/2 kinases [1, 2].

CHMFL-ABL-053: 2D and 3D Structure

CHMFL-ABL-053 exhibited potent antiproliferation efficacies against all of the three BCR-ABL driven CML cell lines K562 (GI₅₀ = 14 nM), KU812 (GI₅₀ = 25 nM), and MEG-01 (GI₅₀ = 16 nM) but not other AML cell lines, implying strong and selective on-target effects. In addition, CHMFL-ABL-053 did not display any apparent activity against the CHL cell line, indicating a good nonspecific toxicity profile.

In a K562 cell inoculated xenograft mouse model, 16 days of continuous treatment of CHMFL-ABL-053 dose-dependently inhibited the growth of the K562 tumor, and a 50 mg/kg/ day dosage could almost completely suppress tumor progression.

As a potential useful drug candidate for Chronic myeloid leukemia (CML), CHMFL-ABL-053  is under extensive preclinical safety evaluation now. CHMFL-ABL-053 is developed via joint efforts of Chinese Academy of Sciences and Hefei Institute of Physical Science, China [1].

Summary

Common name: CHMFL-ABL-053; CHMFL-ABL053; CHMFL-ABL 053

Trademarks:

Molecular Formula: C28H26F3N7O2

CAS Registry Number: 1808287-83-3

CAS Name: 2-((3-Amino-4-methylphenyl)amino)-N-(2-methyl-5-(3-(trifluoromethyl)benzamido)phenyl)-4-(methylamino)pyrimidine-5-carboxamide

Molecular Weight: 549.21

SMILES:O=C(C1=CN=C(NC2=CC=C(C)C(N)=C2)N=C1NC)NC3=CC(NC(C4=CC=CC(C(F)(F)F)=C4)=O)=CC=C3C

InChI Key: GXMFPDCIAWSZFR-UHFFFAOYSA-N

InChI: InChI=1S/C28H26F3N7O2/c1-15-7-9-19(12-22(15)32)36-27-34-14-21(24(33-3)38-27)26(40)37-23-13-20(10-8-16(23)2)35-25(39)17-5-4-6-18(11-17)28(29,30)31/h4-14H,32H2,1-3H3,(H,35,39)(H,37,40)(H2,33,34,36,38)

Activity: Treatment of CML; Treatment of Chronic Myeloid Leukemia; Anti-neoplastics Drug

Status: Pre-Clinical

Originator: Chinese Academy of Sciences and Hefei Institute of Physical Science

CHMFL-ABL-053 Synthesis

CN104876879A: This is the first disclosed synthesis. Also, see Ref. 2.

Step 1: Intermediate synthesis

Step 2: Final synthesis

Identifications:

1H NMR (Estimated) for CHMFL-AABL-053

References:
1. Jing, L.; et. al. A novel bcr-abl kinase inhibitor. CN104876879A
2. Liang, X.; et. al. Discovery of 2-((3-Amino-4-methylphenyl)amino)-N-(2-methyl-5-(3-(trifluoromethyl)benzamido)phenyl)-4-(methylamino)pyrimidine-5-carboxamide (CHMFL-ABL-053) as a Potent, Selective, and Orally Available BCR-ABL/SRC/p38 Kinase Inhibitor for Chronic Myeloid Leukemia. J Med Chem 2016

Drugs in Clinical Pipeline: Foretinib | EXEL-2880 | HGF, VEGF Inhibitor | Multi-Kinase Inhibitor | Angiogenesis Inhibitor

Foretinib [N-(3-fluoro-4-((6-methoxy-7-(3-morpholinopropoxy)quinolin-4-yl)oxy)phenyl)-N-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide] is a small-molecule kinase inhibitor that targets members of the HGF and VEGF receptor tyrosine kinase families, with additional inhibitory activity toward KIT, Flt-3, platelet-derived growth factor receptor β, and Tie-2. Binding of Foretinib to Met and VEGF receptor 2 (KDR) is characterized by a very slow off-rate, consistent with X-ray crystallographic data showing that the inhibitor is deeply bound in the Met kinase active site cleft [1].

Foretinib: 2D and 3D Structure

Foretinib inhibits cellular HGF-induced Met phosphorylation and VEGF-induced extracellular signal-regulated kinase phosphorylation and inhibits growth of tumor cells under both normoxic and hypoxic conditions with increased potency against Met-amplified gastric cancer cell lines. In vitro, Foretinib inhibits HGF-induced responses of tumor cells and HGF/VEGF-induced responses of endothelial cells that are thought to contribute to invasion, metastasis, and angiogenesis in vivo. Consistent with this profile, Foretinib inhibits tumor formation in an in vivo murine model of lung metastasis. Foretinib therefore has the potential to prevent tumor growth through a direct effect on tumor cell proliferation and indirectly through inhibition of the host angiogenic response.

Using high-throughput unbiased screening approach to identify small-molecule kinase inhibitors with potent activity against orphan RTK c-ros oncogene 1 (ROS1), researchers found that Foretinib is a highly effective inhibitor of ROS1 in human and murine model systems, demonstrating greater potency compared with Crizotinib both in vitro and in vivo. Despite the reported binding affinity (K_d) of Crizotinib for ROS1 being lower than that of Foretinib (4.4 nM and 14 nM, respectively), researchers found Foretinib to be a significantly more potent ROS1 inhibitor in cell-based assays, accentuating that the in vitro binding affinity does not directly translate to inhibitory efficacy in the cellular context.

Exelixis is credited with discovering Foretinib. It was called EXEL-2880 at Exelixis. Subsequently, the compound was licensed to GlaxoSmithKline in December 2007 where it was called GSK1363089. It is in Phase II trials for various cancers.

The activity of Foretinib is as follows:

IC₅₀ (Met enzyme assay) = 0.4 ± 0.04 nM

IC₅₀ (Ron enzyme assay) = 3 ± 0.2 nM

IC₅₀ (KDR enzyme assay) = 0.86 ± 0.04 nM

IC₅₀ (Flt-1 enzyme assay) = 6.8 ± 0.7 nM

IC₅₀ (Flt-4 enzyme assay) = 2.8 ± 0.4 nM

IC₅₀ (KIT enzyme assay) = 6.7 ± 0.6 nM

IC₅₀ (Flt-3 enzyme assay) = 3.6 ± 0.4 nM

IC₅₀ (PDGFR-α enzyme assay) = 3.6 ± 0.4 nM

IC₅₀ (PDGFR-β enzyme assay) = 9.6 ± 1.1 nM

IC₅₀ (Tie-2 enzyme assay) = 1.1 ± 0.1 nM

IC₅₀ (FGFR1 enzyme assay) = 660 ± 50 nM

IC₅₀ (EGFR enzyme assay) = 2990 ± 38 nM


Common Name: Foretinib

Synonyms: XL880; XL 880; XL-880; EXEL-2880; GSK1363089; GSK 1363089; GSK-1363089; SK1363089; GSK089

IUPAC Name: N-(3-fluoro-4-((6-methoxy-7-(3-morpholinopropoxy)quinolin-4-yl)oxy)phenyl)-N-(4-fluorophenyl)cyclopropane-1,1-dicarboxamide

CAS Number: 849217-64-7

SMILES: 

Mechanism of Action: Kinase Inhibitor; Multi-Kinase Inhibitor; MET Kinase Inhibitor; KDR Inhibitor

Indication: Various Cancers; Anti-tumor Agents; Angiogenesis Inhibitor

Development Stage: Phase II

Company: Exelixis Inc/GlaxoSmithKline

1H NMR (Estimated) for Foretinib

References:
1. Qian, F.; et. al. Inhibition of tumor cell growth, invasion, and metastasis by EXEL-2880 (XL880, GSK1363089), a novel inhibitor of HGF and VEGF receptor tyrosine kinases. Cancer Res 2009, 69(20), 8009-8016.

Entrectinib | Multi-Kinase Inhibitor | pan-TRK Inhibitor | ALK Inhibitor | ROS-1 Inhibitor | Orphan Drug

Entrectinib [N-(5-(3,5-difluorobenzyl)-1H-indazol-3-yl)-4-(4-methylpiperazin-1-yl)-2-((tetrahydro-2H-pyran-4-yl)amino)benzamide] is an oral small molecule inhibitor of TrkA (IC₅₀ = 1 nM), TrkB (IC₅₀ = 2, 3 nM) and TrkC (IC₅₀ = 5 nM), as well as ROS1 (IC₅₀ = 7 nM) and ALK (IC₅₀ = 12 nM), with high potency and selectivity. Entrectinib has demonstrated potent pharmacological activity in preclinical studies and has the potential to be first-in-class against the Trk family of kinases [1, 5].

Entrectinib: 2D and 3D Structure

Entrectinib was being developed as Anaplastic Lymphoma Kinase (ALK) inhibitor where studies showed that it induces tumor regression in mouse models of NPM-ALK–driven lymphoma and EML4-ALK-driven NSCLC; it also has activity against the Crizotinib-resistant ALK mutants L1196M and C1156Y. Entrectinib also crosses the blood-brain barrier, inhibits tumor growth, and prolongs survival in mice with intracranially injected NCI-H2228 EML4-ALK cells [2]. 

Due to the structural similarity between ALK and ROS1 kinases, the activity of Entrectinib on ROS1 was evaluated in biochemical and cellular assays. The compound was found to be a potent, ATP competitive inhibitor of ROS1 (IC₅₀ = 7 nM). This biochemical potency translates into inhibition of the proliferation of HCC-78, a NSCLC cell line characterized by ROS1-driven activated signaling, due to the presence of the SCL34A2-ROS1 fusion gene. To further characterize the compound in cells, an activated form of ROS1 was expressed in Ba/F3 cells generating an IL3-independent, ROS1-driven tumor model. NMS-E628 strongly inhibits the proliferation of Ba/F3-ROS1 cells in vitro with confirmed dose-dependent decrease of ROS1 phosphorylation. When tested in vivo, the compound was found to induce complete tumor regression after 10-day continuous treatment in nude mice bearing established Ba/F3-ROS1 tumors [3]. 

Important timelines in the history of Entrectinib:

a: In Nov 2009, Nerviano Medical Sciences revealed NMS-E628, a small molecule inhibitor of anaplastic lymphoma kinase with antitumor efficacy in ALK-dependent lymphoma and non-small cell lung cancer models at AACR-NCI-EORTC International Conference. 

b: In Nov 2011, Nerviano Medical Sciences revealed NMS-E628 also potently inhibits ROS1 and induces tumor regression in ROS-driven models at American Association Cancer Society Annual Meeting.

c: In Nov 2013 Nerviano Medical Sciences signed a license agreement with Ignyta Inc granting the American biotech company exclusive global development and marketing rights to RXDX-101 and RXDX-102. 

d: In 2014 at ASCO Annual Meeting Nerviano Medical Sciences/Ignyta Inc added pan-TRK activity to the pre-existing ALK and ROS1 activities.

Dosages and Approvals:

On December 29, 2014, Ignyta, Incorporated announced that the FDA had granted Orphan Drug status and a Rare Pediatric Disease designation for Entrectinib for the treatment of neuroblastoma.

On Feburary 05, 2015 Ignyta announced that the Food and Drug Administation (FDA) has granted Orphan Drug designation to Entrectinib for the treatment of TrkA-positive, TrkB-positive, TrkC-positive, ROS1-positive and ALK-positive non-small cell lung cancer (NSCLC).

Entrectinib is currently in Phase I/II clinical trials with activity against TrkA as well as TrkB, TrkC, ALK and ROS1 proteins (encoded by NTRK1, NTRK2, NTRK3, ALK and ROS1 genes, respectively). Entrectinib is indicated for patients with advanced, refractory, relapsed or metastatic solid tumors who have exhausted standard treatment options and who exhibit molecular alterations in any of the target genes. 

The activity of Entrectinib is as follows:

IC₅₀ (TRKA enzyme assay) = 1 nM
IC₅₀ (TRKB enzyme assay) = 2 nM; 3 nM [5]
IC₅₀ (TRKC enzyme assay) = 5 nM
IC₅₀ (ROS1 enzyme assay) = 7 nM
IC₅₀ (ALK enzyme assay) = 12 nM; 55 nM [4]
IC₅₀ (IGF1R enzyme assay) = 263 nM
IC₅₀ (AURKA enzyme assay) = 338 nM

Summary

Common Name: Entrectinib

Synonyms: RXDX-101; RXDX 101; RXDX101; NMS-E628; NMSE628; NMS E628

IUPAC Name: N-(5-(3,5-difluorobenzyl)-1H-indazol-3-yl)-4-(4-methylpiperazin-1-yl)-2-((tetrahydro-2H-pyran-4-yl)amino)benzamide

CAS Number: 1108743-60-7

SMILES:O=C(NC1=NNC2=C1C=C(CC3=CC(F)=CC(F)=C3)C=C2)C4=CC=C(N5CCN(C)CC5)C=C4NC6CCOCC6

Mechanism of Action: Kinase Inhibitor; Multi-Kinase Inhibitor; pan-TRK Kinase Inhibitor; ALK Kinase Inhibitor; ROS1 Kinase Inhibitor

Indication: Various Cancers; Anti-tumor Agents

Development Stage: Phase II

Company: Nerviano Medical Sciences/Ignyta Inc

The Trk family of kinases, which include TrkA, TrkB and TrkC, are high affinity receptors for the neurotrophin family of nerve growth factors. Deregulated kinase activities of Trk family members due to chromosome rearrangements, gene mutations, splicing variants and overexpression have been shown to be associated with tumorigenesis and poor prognosis in a number of cancer types. Particularly, several chromosomal rearrangements involving TrkA have been reported in lung, colorectal, papillary thyroid, glioblastoma, melanoma and other cancers, and are believed to be the key oncogenic driver in these tumors. Therefore oncogenic Trk may represent a promising therapeutic target in Trk-driven tumors.

In KM-12, a human colorectal cancer cell line driven by constitutively active TrkA fusion TPM3-NTRK1, Entrectinib exhibited in vitro anti-proliferative activity with an IC₅₀ of 17 nM, accompanied by inhibition of TrkA phosphorylation and concomitant inactivation of downstream effectors, PLCgamma1, AKT and ERK, as well as cell cycle arrest and apoptosis. In mice bearing KM- 12 xenografts, treatment with Entrectinib resulted in tumor regression and durable stasis under either intermittent or continuous dosing regimens, accompanied by sustained intratumoral inhibition of phospho-TrkA and PLCgamma1. In these studies, Entrectinib was well tolerated during the course of treatment [1].

Entrectinib Synthesis

J Med Chem 2016, 59(7), 3392-3408: The article reports synthesis of Entrectinib and its analogues. Pre-clinical data is also reported.

Intermediate:

Final Synthesis:

Identifications:

1H NMR (Estimated) for Entrectinib

Experimental: ¹H NMR (400.5 MHz, DMSO-d6) δ ppm 1.29-1.41 (m, 2H) 1.89-1.97 (m, 2H) 2.24 (s, 3 H) 2.41-2.48 (m, 4H) 3.23-3.29 (m, 4 H) 3.49 (ddd, J = 11.7, 10.2, 2.3 Hz, 2 H) 3.62-3.72 (m, 1 H) 3.80(ddd, J = 11.7, 3.8, 3.8 Hz, 2 H) 4.04 (s, 2 H) 6.13 (d, J = 2.1 Hz, 1 H) 6.23 (dd, J = 9.0, 2.2 Hz, 1 H) 6.93-7.04 (m, 3 H) 7.25 (dd, J = 8.7, 1.5 Hz, 1 H) 7.40 (d, J = 8.7 Hz, 1 H) 7.48 (s, 1 H) 7.80 (d, J = 9.0 Hz, 1 H) 8.29 (d, J = 7.6 Hz, 1 H) 10.07 (s, 1 H) 12.62 (s, 1 H).

References:

1. Anderson, D.; et. al. Inhibition of Trk-driven tumors by the pan-Trk inhibitor RXDX-101. Euro J Cancer 2014, 50(supp 6),101. (FMO only)

2. Ardini, E.; et. al. Abstract A243: Characterization of NMS-E628, a small molecule inhibitor of anaplastic lymphoma kinase with antitumor efficacy in ALK-dependent lymphoma and non-small cell lung cancer models Mol Cancer Ther 2009, 8(12 suppl), A244. (FMO only)

3. Ardini, E.; et. al. Abstract 2092: The ALK inhibitor NMS-E628 also potently inhibits ROS1 and induces tumor regression in ROS-driven models . Cancer Res 2013, 73(8 suppl), 2092. (free copy)

4. Lombardi, B. A.; et. al. Substituted indazole derivatives active as kinase inhibitors. WO2009013126A1

5. Menichincheri, M.; et. al. Discovery of Entrectinib: A New 3-Aminoindazole As a Potent Anaplastic Lymphoma Kinase (ALK), c-ros Oncogene 1 Kinase (ROS1), and Pan-Tropomyosin Receptor Kinases (Pan-TRKs) inhibitor. J Med Chem 2016, 59(7), 3392-3408. (FMO only)

Drugs in Clinical Pipeline: AZD2932

AZD2932 [2-(4-(6,7-dimethoxyquinazolin-4-yloxy)phenyl)-N-(1-isopropyl-1H-pyrazol-4-yl)acetamide] is a potent and mutil-targeted protein tyrosine kinase inhibitor with IC₅₀ of 8 nM, 4 nM, 7 nM, and 9 nM for VEGFR-2, PDGFR-β, Flt-3, and c-Kit, respectively [1].

AZD2932 does not inhibit the various cytochrome P450 isoforms with the worst IC₅₀ being against 2C9 (IC₅₀ = 8.0 uM). It has a good fraction unbound between 3.3% free in human and 7.0% in dog sera and has no activity against hERG (IC₅₀ = 137 uM).

AZD2932 belong to the quinazoline family of kinase inhibitors, where fine-tuning of the lipophilicity of the pyrazole series provided a balanced 1:1 ratio of activity vs both VEGFR-2 and PDGFR-β. Moreover, AZD2932 potently inhibited both PDGFR-α (IC₅₀ = 2 nM) and PDGFR-β (IC₅₀ = 4 nM) phosphorylation with a correlation close to 1:1.

Common Name: AZD2932

Synonyms: AZD2932; AZD 2932; AZD-2932

IUPAC Name: 2-(4-((6,7-dimethoxyquinazolin-4-yl)oxy)phenyl)-N-(1-isopropyl-1H-pyrazol-4-yl)acetamide

CAS Number: 883986-34-3

SMILES:COC1=CC2=C(C(OC3=CC=C(CC(NC4=CN(C(C)C)N=C4)=O)C=C3)=NC=N2)C=C1OC

Mechanism of Action: Kinase Inhibitor; Multi-Kinase Inhibitor; KDR Inhibitor;  PDGFR Inhibitor; Angiogenesis Inhibitor

Indication: Various Cancers; Anti-tumor Therapy

Development Stage: Pre-Clinical

Company: AstraZeneca

References:
1. Ple, P. A.; et. al. Discovery of AZD2932, a new Quinazoline Ether Inhibitor with high affinity for VEGFR-2 and PDGFR tyrosine kinases. Bioorg Med Chem Lett 2012, 22(1), 262-266.

Drugs in Clinical Pipeline: KW-2449

KW-2449 [(E)-(4-(2-(1H-indazol-3-yl)vinyl)phenyl)(piperazin-1-yl)methanone] is an orally available multikinase inhibitor of FMS-like receptor tyrosine kinase (FLT3), ABL, ABL-T315I, and Aurora kinase. It is currently in Phase I trials for leukemia patients. KW-2449 inhibited FLT3 and ABL kinases with half-maximal inhibitory concentration (IC₅₀) values of 0.0066 and 0.014 µM, respectively. In addition, it potently inhibited ABL-T315I, which is associated with IM resistance, with an IC₅₀ value of 0.004 µM. On the other hand, KW-2449 had little effect on PDGFRβ, IGF-1R, EGFR, and various serine/threonine kinases even at a concentration of 1 µM. Among various serine/threonine kinases examined, KW-2449 inhibited Aurora A kinase with IC₅₀ of 0.048 µM and Aurora B kinase with the equivalent potency.

The researchers at Kyowa Hakko Kirin (previously Kyowa Hakko Kogyo) aimed at designing an orally available and highly potent FLT3 inhibitor with low toxicity profile for leukemia patients. For this goal, they screened the in-house chemical libraries using several leukemia cells, which have several activated mutations in FLT3 or BCR-ABL translocation. As a result, they identified several chemo-types with different kinase inhibition profiles, intensively studied the structures of the identified chemo-types to improve the potency and selectivity, and then finally generated KW-2449 [1].

Preclinical studies revealed that KW-2449 is converted by monoamine oxidase-B (MAO-B) and aldehyde oxidase into its major metabolite M1. Metabolite M1 is 3.6-fold less potent than the parent drug. The combination of KW-2449 and metabolite can successfully inhibit FLT3 in patients, and FLT3 mutant patients treated with KW-2449 on a twice daily schedule display the typical, short-lived reduction in peripheral blasts that has been seen with the other FLT3 inhibitors in development.

The activity of KW-2449 is as follows:

IC₅₀ (FLT3 enzyme assay) = 0.0066 uM

IC₅₀ (FLT3-D835Y enzyme assay) = 0.001 uM

IC₅₀ (KIT enzyme assay) = 0.3 uM

IC₅₀ (PDFGRα enzyme assay) = 1.7 uM

IC₅₀ (ABL enzyme assay) = 0.014 uM

IC₅₀ (ABL-T315I enzyme assay) = 0.004 uM

IC₅₀ (SRC enzyme assay) = 0.4 uM

IC₅₀ (JAK2 enzyme assay) = 0.15 uM

IC₅₀ (FGFR1 enzyme assay) = 0.036 uM

IC₅₀ (AURKA enzyme assay) = 0.048 uM

Common Name: KW-2449

Synonyms: KW2449; KW-2449; KW 2449

IUPAC Name: (E)-(4-(2-(1H-indazol-3-yl)vinyl)phenyl)(piperazin-1-yl)methanone

CAS Number: 1000669-72-6

Mechanism of Action: Kinase Inhibitor; FLT3 Inhibitor; ABL Inhibitor; Aurora Kinase Inhibitor; MultiKinase Inhibitor

Indication: Various Cancers; Leukemia

Development Stage: Phase I

Company: Kyowa Hakko Kirin Pharmaceuticals

FMS-like receptor tyrosine kinase (FLT3) is a class III receptor tyrosine kinase together with cKIT, FMS, and PDGFR. FLT3 mutations were first reported as internal tandem duplication (FLT3/ITD) of the juxtamembrane domain-coding sequence; subsequently, a missense point mutation at the Asp835 residue and point mutations, deletions, and insertions in the codons surrounding Asp835 within a tyrosine kinase domain of FLT3 (FLT3/KDM) have been found. FLT3 mutation is the most frequent genetic alteration in acute myeloid leukemia (AML) and involved in the signaling pathway of proliferation and survival in leukemia cells. Several large-scale studies have confirmed that FLT3/ITD is strongly associated with leukocytosis and a poor prognosis. In addition to FLT3 mutation, overexpression of FLT3 is an unfavorable prognostic factor for overall survival in AML, and it has been revealed that overexpressed FLT3 had the same sensitivity to the FLT3 inhibitor as FLT3/ITD [1]. Acute leukemia is a complex multigenetic disorder, a simultaneous inhibition of multiple protein kinases is thought to be advantageous over the increasing potency against the selective kinases.

In vitro kinase inhibition profile of KW-2449 indicated its extreme potency against FLT3 kinase. KW-2449 showed growth inhibitory activities against FLT3/ITD-, FLT3/D835Y-, and wt-FLT3/FL-expressing 32D cells, MOLM-13 and MV4;11 with half-maximal growth inhibitory concentration (GI₅₀) values of 0.024, 0.046, 0.014, 0.024, and 0.011 µM, respectively [1].

References:

1. Shiotsu, Y.; et. al. KW-2449, a novel multikinase inhibitor, suppresses the growth of leukemia cells with FLT3 mutations or T315I-mutated BCR/ABL translocation. Blood 2009, 114(8), 1607-1617.

2. ClinicalTrials.gov Safety, Tolerability, and Pharmacokinetic/Pharmacodynamic Study of KW-2449 in Acute Myelogenous Leukemia (AML) (Protocol Number: 2449-US-002). NCT00779480. Retrieved (01-09-2015)

3. ClinicalTrials.gov An Ascending Dose Study of KW-2449 in Acute Leukemias, Myelodysplastic Syndromes, and Chronic Myelogenous Leukemia. NCT00346632. Retrieved (01-09-2015)

Drugs in Clinical Pipeline: Cerdulatinib

Cerdulatinib [4-(cyclopropylamino)-2-({4-[4-(ethylsulfonyl)piperazin-1-yl]phenyl}amino) pyrimidine-5-carboxamide], is an orally active kinase inhibitor that demonstrates activity against spleen tyrosine kinase (SYK, IC₅₀ = 32 nM) and Janus kinase (JAK1, 2, 3 IC₅₀ = 12, 6, 8 nM, respectively) [1].

Dual inhibition of SYK and JAK represents such a strategy and may elicit several benefits relative to selective kinase inhibition, such as gaining control over a broader array of disease etiologies, reducing probability of selection for bypass disease mechanisms, and the potential that an overall lower level suppression of individual targets may be sufficient to modulate disease activity.

Cerdulatinib behaves like a multikinase inhibitor as in specificity assays it showed affinity towards other kinases also. It inhibited nearly 25 tested kinases with IC₅₀ less than 200 nM. Cerdulatinib blocks the B-cell receptor pathway via Syk and cytokine pathways via JAK 1, 3 and Tyk 2, hence it has a unique profile where it inhibits two validated tumor proliferation pathways that contribute to tumor cell growth and survival in certain hematologic malignancies. Moreover, Cerdulatinib has a favorable pharmacokinetic profile with a half-life of 14-18 hours that supports once-daily dosing. There parameters suggest that Cerdulatinib can be used in treatment of patients with genetically-defined hematologic cancers, as well as those who have failed therapy due to relapse or acquired mutations.

Cerdulatinib was discovered at Portola Pharmaceuticals. A Phase 1/2a study involving Cerdulatinib is ongoing in chronic lymphocytic leukemia (CLL) and B-cell non-Hodgkin lymphoma (NHL) patients. Results of in vitro studies suggest that the anti-tumor activity of Cerdulatinib is mediated by dual inhibition of Syk and JAK signaling pathways, and that Cerdulatinib may be a potent treatment for diffuse large B-cell lymphoma (DLBCL), an aggressive form of non-Hodgkin’s lymphoma (NHL). Cerdulatinib also has shown in vitro efficacy in ibrutinib-resistant chronic lymphocytic leukemia (CLL) and in DLBCL with certain mutations.

The activity of Cerdulatinib is as follows:

IC₅₀ (SYK enzyme assay) = 32 nM

IC₅₀ (JAK1 enzyme assay) = 12 nM

IC₅₀ (JAK2 enzyme assay) = 6 nM

IC₅₀ (JAK3 enzyme assay) = 8 nM

IC₅₀ (TYK2 enyme assay) =  0.5  nM

IC₅₀ (MST1 enyme assay) = 4  nM

IC₅₀ (ARK5 enyme assay) = 4  nM

IC₅₀ (MLK1 enyme assay) = 5  nM

IC₅₀ (Fms enyme assay) = 5  nM

IC₅₀ (AMPK enyme assay) = 6  nM

IC₅₀ (TBK1 enyme assay) = 10  nM

IC₅₀ (MARK1 enyme assay) = 10  nM

IC₅₀ (PAR1B-a enyme assay) = 13  nM

IC₅₀ (TSSK enyme assay) = 14  nM

IC₅₀ (MST2 enyme assay) = 15  nM

IC₅₀ (GCK enyme assay) = 18  nM

IC₅₀ (JNK3 enyme assay) = 18  nM

IC₅₀ (RSK2 enyme assay) = 20  nM

IC₅₀ (RSK4 enyme assay) = 28  nM

IC₅₀ (Chk1 enyme assay) = 42  nM

IC₅₀ (FLT4 enyme assay) = 51  nM

IC₅₀ (FLT3 enyme assay) = 90  nM

IC₅₀ (RET enyme assay) = 105  nM

IC₅₀ (ITK enyme assay) = 194  nM

Common Name: Cerdulatinib

Synonyms:  PRT2070; PRT-2070; PRT 2070; PRT-062070; PRT 062070; PRT062070

IUPAC Name: 4-(cyclopropylamino)-2-((4-(4-(ethylsulfonyl)piperazin-1-yl)phenyl)amino) pyrimidine-5-carboxamide

CAS Number: 1198300-79-6

Mechanism of Action: Kinase Inhibitor; Dual-Kinase Inhibitor; SYK Inhibitor; JAK Inhibitor

Indication: Various Cancers; Chronic Lymphocytic Leukemia; B-cell Non-Hodgkin Lymphoma

Development Stage: Phase II

Company: Portola Pharmaceuticals

In cellular assays Cerdulatinib demonstrated specific inhibitory activity against signaling pathways that use SYK and JAK1/3. Limited inhibition of JAK2 was observed, and Cerdulatinib did not inhibit phorbol 12-myristate 13-acetate-mediated signaling or activation in B and T cells nor T-cell antigen receptor-mediated signaling in T cells, providing evidence for selectivity of action. Potent antitumor activity was observed in a subset of B-cell lymphoma cell lines. After oral dosing, Cerdulatinib suppressed inflammation and autoantibody generation in a rat collagen-induced arthritis model and blocked B-cell activation and splenomegaly in a mouse model of chronic B-cell antigen receptor stimulation [1].      

References:
1. Coffey, G.; et. al. The novel kinase inhibitor PRT062070 (Cerdulatinib) demonstrates efficacy in models of autoimmunity and B-cell cancer. J Pharmacol Exp Ther 2014, 351(3), 538-548.