Background: Altiratinib is a Type II switch pocket inhibitor of MET kinase as well as TIE2 and VEGFR2 kinases. This profile provides an agent that exhibits anti-tumor activity in cancers driven by MET overexpression or genomic mutation, and also blocks angiogenic and metastatic processes mediated by the tumor microenvironment. Material and Methods: Altiratinib was evaluated in MET, TIE2, and VEGFR2 biochemical studies, including evaluation in a number of MET activation mutants. Cellular activity was evaluated in tumor cell lines exhibiting MET amplification (MKN-45 gastric, EBC-1 NSCLC) or overexpression (B16/F10 melanoma; U87 glioblastoma). In vivo pharmacokinetic/pharmacodynamic studies were performed in an MKN45 xenograft model. Efficacy was demonstrated in a battery of xenograft/ allograft models including: gastric (MKN-45), melanoma (B16/F10, A375), ovarian (SKOV-3), colorectal (COLO-205), lung (EBC-1), breast (PyMT), and glioblastoma (U87). Results: Altiratinib afforded balanced inhibition of MET, TIE2, and VEGFR2 kinases in the low nM range (IC50s 2−9 nM) and blocked HGF-, ANG-, or VEGFA-induced HUVEC activation and capillary tube formation. Altiratinib retained potency versus activation loop mutant forms of MET (D1228X, Y1230X, M1250X), inhibiting all forms with IC50 24 hr after a single 10mg/kg oral dose in an MKN-45 xenograft pharmacodynamic model. Altiratinib exhibited anti-tumor activity in melanoma (B16/F10, A375), gastric (MKN-45), lung (EBC-1), colorectal (COLO-205), breast (PyMT), ovarian (SKOV-3) and GBM (U87) xenograft or allograft models. In these in vivo studies, altiratinib was shown to inhibit tumor growth, angiogenesis, invasion and/or metastasis. Altiratinib also blocked recruitment of TIE2-expressing monocytes in the PyMT breast cancer model. In some models, altiratinib was shown to increase overall survival. In particular, in the i.c.v. orthotopically implanted U87 glioblastoma model, altiratinib extended survival by 1.7-fold vs vehicle (112 days vs 66 days), while the combination of altiratinib + bevacizumab extended survival by 2.5 fold vs vehicle and by 1.9-fold vs bevacizumab single agent (166 days vs. 88 days). Conclusions: Altiratinib is a balanced inhibitor of MET, TIE2, and VEGFR2 kinases. This profile provides robust inhibition of tumors driven by MET amplification or overexpression, and also provides the potential for altiratinib to block tumor microenvironment angiogenic resistance mechanisms and pro-tumoral effects of TIE2-expressing macrophages in the clinical setting. Altiratinib is currently in Phase 1 clinical trials in patients with solid tumors.

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Fibroblast growth factors (FGFs) and their receptors (FGFR1 through 4) regulate a variety of key cellular processes, including proliferation, migration, survival, and differentiationa. Aberrant activation of FGF/FGFR is strongly implicated in oncogenic signalling in many tumor types. This has stimulated the development of a number of FGFR inhibitors, with diverse kinase inhibition and pharmacological profiles that are currently being evaluated in clinical studies. We conducted a fragment screening campaign and this resulted in identification of a 6-aminoquinoxalinyl fragment with a binding affinity in the micromolar range. Structure-guided medicinal chemistry led to the identification of a novel quinoxaline-based chemical series with nanomolar affinity for FGFR1, 2, 3, and 4, activity in cells, and selectivity with respect to VEGFR-2. Further optimisation resulted in the generation of JNJ-42756493, a compound with favourable drug-like properties that demonstrated strong anti-tumoral activity in a FGFR2-dependent SNU-16 human gastric carcinoma xenograft model. This report represents the first disclosure of the structure-activity relationships as well as the chemical synthesis pathway of the JNJ-42756493 series and illustrates how a fragment-based drug discovery approach has been efficiently used to discover FGFR1-4 inhibitors with nanomolar affinity. aTurner, N. and Grose, R. Nat. Rev. Cancer, 2010, 10, 116-129. Citation Format: Patrick R. Angibaud, Laurence Mevellec, Gordon Saxty, Christophe Adelinet, Rhalid Akkari, Valerio Berdini, Pascal Bonnet, Marine Bourgeois, Xavier Bourdrez, Anne Cleasby, Helene Colombel, Imre Csoka, Werner Embrechts, Eddy Freyne, Ronaldus Gilissen, Eleonora Jovcheva, Peter King, Jean Lacrampe, Delphine Lardeau, Yannick Ligny, Steve Mcclue, Lieven Meerpoel, David R. Newell, Martin Page, Alexandra Papanikos, Elisabeth Pasquier, Isabelle Pilatte, Virginie Poncelet, Olivier Querolle, David C. Rees, Sharna Rich, Bruno Roux, Elodie Sement, Yvan Simonnet, Matthew Squires, Virginie Tronel, Tinne Verhulst, Jorge Vialard, Marc Willems, Steven J. Woodhead, Berthold Wroblowski, Christopher W. Murray, Timothy Perera. Discovery of JNJ-42756493, a potent fibroblast growth factor receptor (FGFR) inhibitor using a fragment based approach. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4748. doi:10.1158/1538-7445.AM2014-4748