PDF file - 182KB, Pharmacokinetic analysis of AZD9291, AZ5104 and AZ7550 total plasma concentrations vs time following single oral dose of 25mg/kg AZD9291 in mice.

PDF file - 470KB, Effect of AZD9291 and AZ5104 in transgenic models of EGFR-TKI sensitizing (C/L858R and C/ex19del) and T790M resistant (C/L+T) lung cancer.

PDF file - 312KB, Efficacy of AZD9291 in H3255, PC-9VanR and A431 xenograft models. Weight loss data for chronically dosed AZD9291 in PC-9 and H1975 xenograft models.

PDF file - 107KB, Mass Spectrometry study showing covalent binding of AZD9291 to cysteine 797 in EGFR T790M.

PDF file - 89KB, Additional biochemical and cellular profiling data for AZD9291 and metabolites.

PDF file - 294KB, Phenotype and phosphorylation assay data for AZD9291 against lung cancer associated HER2 mutation.

PDF file - 235KB, Activity of AZD9291 and metabolites against rare EGFR mutations using cellular phosphorylation assays.

Increasing the pH of a neutral salt solution of sodium hyaluronate to 12.5 produces a rapid drop in viscosity which is reversible upon restoring the pH to neutrality. Light scattering data showing a decrease in radius of gyration with no change in molecular weight and negative results with chondroitin and other acidic glycosaminoglycans suggest that the conformational change is specific for hyaluronate molecules.

9030 Background: EGFR exon 20 insertions (Ex20Ins), the 3rd most common EGFR activating mutation, are generally unresponsive to 1st and 2nd generation EGFR-TKIs. Development of EGFR-TKIs that effectively target NSCLC with Ex20Ins mutations represents a major unmet need. Osimertinib is an EGFR TKI approved for the treatment of advanced NSCLC harboring EGFR T790M, but the potential of osimertinib remains to be fully assessed in patients (pts) with Ex20Ins NSCLC. Methods: CRISPR engineered Ex20Ins cell line xenografts representing the two most common Ex20Ins (D770_N771InsSVD and V769_D770InsASV) and pt derived xenograft (PDX) of 3 EGFR Ex20Ins (V769_D770InsASV, M766_A767insASV, H773_V774insNPH) were used for in vivo experiments. Xenografts were treated by oral gavage with vehicle, erlotinib (50 mg/kg/day) or afatinib (20 mg/kg/day), osimertinib metabolite AZ5104 (50 mg/kg/day) and osimertinib (25 mg/kg/day) and assessed for tumor growth inhibition (TGI). Immunoblotting was performed for EGFR and relevant signaling pathways. A pt from whom the V769_D770InsASV Ex20ins PDX was derived was treated on a UC Davis IRB approved protocol with osimertinib at 160 mg PO once-daily (QD). Results: At completion of treatment, QD administration of osimertinib or AZ5104 induced significant TGI in xenografts across the 4 EGFR Ex20ins tested (range 60-95% TGI, p < 0.001 compared to control for all models) that was superior to either afatinib or erlotinib. Robust decrease in p-EGFR, p-ERK, p-Akt, p-Stat3 was observed with osimertinib treatment. The patient corresponding to the V769_D770InsASV Ex20ins PDX treated with osimertinib exhibited clinical improvement and tumor shrinkage; unfortunately he was found to have interstitial pneumonitis that necessitated drug discontinuation. Conclusions: Osimertinib at clinically representative doses has in vivo activity across multiple EGFR Ex20ins that comprising the most common Ex20ins detected in patients (~50% prevalence); metabolite AZ5104 may contribute to efficacy. Tumor shrinkage was observed in a patient with lung cancer harboring an Ex20ins treated for a limited time with osimertinib. Based on this in vivo xenograft and pt data, osimertinib warrants further study in pts with EGFR Ex20ins NSCLC.

Abstract First-generation EGFR tyrosine kinase inhibitors (EGFR TKI) provide significant clinical benefit in patients with advanced EGFR-mutant (EGFRm+) non–small cell lung cancer (NSCLC). Patients ultimately develop disease progression, often driven by acquisition of a second T790M EGFR TKI resistance mutation. AZD9291 is a novel oral, potent, and selective third-generation irreversible inhibitor of both EGFRm+ sensitizing and T790M resistance mutants that spares wild-type EGFR. This mono-anilino–pyrimidine compound is structurally distinct from other third-generation EGFR TKIs and offers a pharmacologically differentiated profile from earlier generation EGFR TKIs. Preclinically, the drug potently inhibits signaling pathways and cellular growth in both EGFRm+ and EGFRm+/T790M+ mutant cell lines in vitro, with lower activity against wild-type EGFR lines, translating into profound and sustained tumor regression in EGFR-mutant tumor xenograft and transgenic models. The treatment of 2 patients with advanced EGFRm+ T790M+ NSCLC is described as proof of principle. Significance: We report the development of a novel structurally distinct third-generation EGFR TKI, AZD9291, that irreversibly and selectively targets both sensitizing and resistant T790M+ mutant EGFR while harboring less activity toward wild-type EGFR. AZD9291 is showing promising responses in a phase I trial even at the first-dose level, with first published clinical proof-of-principle validation being presented. Cancer Discov; 4(9); 1046–61. ©2014 AACR. This article is highlighted in the In This Issue feature, p. 973

Epidermal growth factor receptor (EGFR) inhibitors have been used clinically in the treatment of non-small-cell lung cancer (NSCLC) patients harboring sensitizing (or activating) mutations for a number of years. Despite encouraging clinical efficacy with these agents, in many patients resistance develops leading to disease progression. In most cases, this resistance is in the form of the T790M mutation. In addition, EGFR wild type receptor inhibition inherent with these agents can lead to dose limiting toxicities of rash and diarrhea. We describe herein the evolution of an early, mutant selective lead to the clinical candidate AZD9291, an irreversible inhibitor of both EGFR sensitizing (EGFRm+) and T790M resistance mutations with selectivity over the wild type form of the receptor. Following observations of significant tumor inhibition in preclinical models, the clinical candidate was administered clinically to patients with T790M positive EGFR-TKI resistant NSCLC and early efficacy has been observed, accompanied by an encouraging safety profile.

A novel series of small-molecule inhibitors has been developed to target the double mutant form of the epidermal growth factor receptor (EGFR) tyrosine kinase, which is resistant to treatment with gefitinib and erlotinib. Our reported compounds also show selectivity over wild-type EGFR. Guided by molecular modeling, this series was evolved to target a cysteine residue in the ATP binding site via covalent bond formation and demonstrates high levels of activity in cellular models of the double mutant form of EGFR. In addition, these compounds show significant activity against the activating mutations, which gefitinib and erlotinib target and inhibition of which gives rise to their observed clinical efficacy. A glutathione (GSH)-based assay was used to measure thiol reactivity toward the electrophilic functionality of the inhibitor series, enabling both the identification of a suitable reactivity window for their potency and the development of a reactivity quantitative structure-property relationship (QSPR) to support design.

Abstract The first generation EGFR TKIs gefitinib and erlotinib provide significant clinical benefit in patients with advanced lung adenocarcinoma harbouring activating EGFR mutants (EGFRm+), but patients will ultimately develop disease progression due to acquired resistance. Acquisition of the EGFR T790M mutation is the most common mechanism of drug resistance, detected in more than 50% of gefitinib/erlotinib resistant patients. Current therapeutic strategies are limited for advanced lung adenocarcinoma patients with EGFR T790M (EGFRm+/T790M), so this remains a key area of unmet need. AZD9291 (structure to be disclosed at meeting) is an oral, irreversible, third generation, selective inhibitor of both EGFR activating (EGFRm+) and resistance (EGFRm+/T790M) mutations. The mechanistic and functional activity of AZD9291 was characterised in vitro and in vivo across a number of cell lines harbouring various EGFR-mutations or wild type EGFR. Presented data shows AZD9291 potently inhibits EGFR phosphorylation in EGFRm+ (e.g. PC9; <25nM) and EGFRm+/T790M (e.g. H1975; <25nM) cell lines in vitro, whilst demonstrating much less activity against wild-type EGFR lines (e.g. LoVo; >500nM). Consistently, AZD9291 showed significantly more potent inhibition of proliferation in mutant EGFR cell lines compared to wild-type in vitro. In addition, AZD9291 administered once daily orally at 5mg/kg caused profound regression of tumours across EGFRm+ (PC9; 178% growth inhibition) and EGFRm+/T790M (H1975; 119% growth inhibition) tumour models in vivo, after 14 days dosing. Furthermore 5mg/kg AZD9291 was sufficient to cause significant shrinkage of EGFRm+ and EGFRm+/T790M transgenic mouse lung tumours. Tumour growth inhibition was associated with profound inhibition of EGFR phosphorylation and key downstream signaling pathways such as AKT and ERK. Chronic long-term treatment of PC9 and H1975 xenograft tumours with AZD9291 led to a complete and sustained macroscopic response, with no visible tumours after 40 days dosing, and being maintained beyond 100 days. Furthermore, pre-clinical data also indicates that AZD9291 could target tumours that have acquired resistance to the more recently identified HER2-amplification mechanism, thus potentially extending its benefit in TKI resistant patients. Taken together, preclinical data demonstrates that AZD9291 is a potent and effective inhibitor of both EGFR activating (EGFRm+) and resistance (EGFRm+/T790M) mutations whilst sparing wild-type EGFR. These data support the further clinical investigation of AZD9291 in advanced EGFR mutant lung adenocarcinoma. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A109. Citation Format: Darren Cross, Sue Ashton, Caroline Nebhan, Cath Eberlein, M. Raymond V. Finlay, Gareth Hughes, Vivien Jacobs, Martine Mellor, Monica Red Brewer, Catherine Meador, Jonathon Orme, Paula Spitzler, Steve Powell, Amar Rahi, Paula Taylor, Richard A. Ward, Paula Daunt, Anne Galer, Teresa Klinowska, Graham Richmond, William Pao. AZD9291: an irreversible, potent and selective third generation tyrosine kinase inhibitor (TKI) targeting EGFR activating (EGFRm+) and resistance (T790M) mutations in advanced lung adenocarcinoma. [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 A109.

The design of compounds that selectively inhibit a single kinase is a significant challenge, particularly for compounds that bind to the ATP site. We describe here how protein-ligand crystal structure information was able both to rationalize observed selectivity and to guide the design of more selective compounds. Inhibition data from enzyme and cellular screens and the crystal structures of a range of ligands tested during the process of identifying selective inhibitors of FGFR provide a step-by-step illustration of the process. Steric effects were exploited by increasing the size of ligands in specific regions in such a way as to be tolerated in the primary target and not in other related kinases. Kinases are an excellent target class to exploit such approaches because of the conserved fold and small side chain mobility of the active form.

The design of compounds that selectively inhibit a single kinase is a significant challenge, particularly for compounds that bind to the ATP site. We describe here how protein−ligand crystal structure information was able both to rationalize observed selectivity and to guide the design of more selective compounds. Inhibition data from enzyme and cellular screens and the crystal structures of a range of ligands tested during the process of identifying selective inhibitors of FGFR provide a step-by-step illustration of the process. Steric effects were exploited by increasing the size of ligands in specific regions in such a way as to be tolerated in the primary target and not in other related kinases. Kinases are an excellent target class to exploit such approaches because of the conserved fold and small side chain mobility of the active form. ■ INTRODUCTION It has become apparent over recent years that selective inhibition of a single kinase is a significant challenge. Several surveys of kinase inhibition profiles and correspondence (or lack of it) with overall sequence, or just binding site sequence, demonstrate the challenges involved in achieving selectivity. The so-called gatekeeper residue is often highlighted as a key determinant of selectivity. Such surveys do not provide a route map for how to get from a given compound, or set of compounds, with a given profile to a more selective profile, should that be desired. A compound’s selectivity profile depends upon the detail of the interactions of that compound with each binding site. Crystal structures of the protein−ligand complex can provide insight and understanding. Such structures are particularly powerful for addressing the issue of selectivity among kinases because of the remarkable degree of conservation of the protein fold among the various kinases. This similarity means that the structure of a ligand in complex with its desired target kinase in combination with the crystal structure of a second kinase or a sequence alignment with a second kinase can provide insights into how the ligand might be achieving selectivity and further might suggest structural changes to the ligand that would improve the selectivity. Some inhibitors that achieve selectivity rely upon covalent bonding to their target which can make it more difficult to obtain safe and orally bioavailable compounds. Others rely upon variations in the degree of protein flexibility, which remains difficult to predict a priori. In the work reported here, we describe how protein−ligand crystal structure information was used to rationalize observed selectivity between FGFR1, IGF1R, and KDR to guide the design of more selective FGFR1 inhibitors. During the course of routine screening of compounds from the AstraZeneca compound collection against a panel of kinase assays (employing the activated enzymes), a small number of pyrazolylaminopyrimidines that inhibited FGFR1 more potently than any of the other kinases in the panel was identified. A lead identification campaign was initiated with the aim of identifying a compound that was sufficiently selective to provide clear evidence for FGFR driven effects in in vivo studies. The relative merits of “clean” kinase inhibitors that selectively inhibit one kinase and broad spectrum inhibitors that inhibit many are a subject of vigorous discussion focused particularly around the generally perceived trade-off between efficacy and tolerability. In this case, these starting points had marginal selectivity compared to KDR and were closely related to compounds that were potent inhibitors of IGF1R, the target against which these compounds were originally designed. Plots of potency for inhibiting these two kinases versus that for FGFR1 for the whole series of pyrazolylaminopyrimidines available at the initiation of this program are shown in Figure 1. FGFR1 has been linked to a number of tumor types including bladder cancers and represents an attractive target for medicinal chemistry efforts. With this in mind, a crystal structure for a complex of FGFR1 with one of the initial compounds that had prominent FGFR1 inhibition was sought. Received: November 15, 2011 Published: May 21, 2012 Article