Lorraine Hassall

Discovery of a Potent and Selective EGFR Inhibitor (AZD9291) of Both Sensitizing and T790M Resistance Mutations That Spares the Wild Type Form of the Receptor

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.

Discovery of 4-{4-[(3R)-3-Methylmorpholin-4-yl]-6-[1-(methylsulfonyl)cyclopropyl]pyrimidin-2-yl}-1H-indole (AZ20): a potent and selective inhibitor of ATR protein kinase with monotherapy in vivo antitumor activity.

ATR is an attractive new anticancer drug target whose inhibitors have potential as chemo- or radiation sensitizers or as monotherapy in tumors addicted to particular DNA-repair pathways. We describe the discovery and synthesis of a series of sulfonylmorpholinopyrimidines that show potent and selective ATR inhibition. Optimization from a high quality screening hit within tight SAR space led to compound 6 (AZ20) which inhibits ATR immunoprecipitated from HeLa nuclear extracts with an IC50 of 5 nM and ATR mediated phosphorylation of Chk1 in HT29 colorectal adenocarcinoma tumor cells with an IC50 of 50 nM. Compound 6 potently inhibits the growth of LoVo colorectal adenocarcinoma tumor cells in vitro and has high free exposure in mouse following moderate oral doses. At well tolerated doses 6 leads to significant growth inhibition of LoVo xenografts grown in nude mice. Compound 6 is a useful compound to explore ATR pharmacology in vivo.

Novel thienopyrimidine and thiazolopyrimidine kinase inhibitors with activity against Tie-2 in vitro and in vivo.

The SAR and improvement in potency against Tie2 of novel thienopyrimidine and thiazolopyrimidine kinase inhibitors are reported. The crystal structure of one of these compounds bound to the Tie-2 kinase domain is consistent with the SAR. These compounds have moderate potency in cellular assays of Tie-2 inhibition, good physical properties, DMPK, and show evidence of in vivo inhibition of Tie-2.

Discovery of Novel 3-Quinoline Carboxamides as Potent, Selective and Orally Bioavailable Inhibitors of Ataxia Telangiectasia Mutated (Atm) Kinase.

A novel series of 3-quinoline carboxamides has been discovered and optimized as selective inhibitors of the ataxia telangiectasia mutated (ATM) kinase. From a modestly potent HTS hit (4), we identified molecules such as 6-[6-(methoxymethyl)-3-pyridinyl]-4-{[(1R)-1-(tetrahydro-2H-pyran-4-yl)ethyl]amino}-3-quinolinecarboxamide (72) and 7-fluoro-6-[6-(methoxymethyl)pyridin-3-yl]-4-{[(1S)-1-(1-methyl-1H-pyrazol-3-yl)ethyl]amino}quinoline-3-carboxamide (74) as potent and highly selective ATM inhibitors with overall ADME properties suitable for oral administration. 72 and 74 constitute excellent oral tools to probe ATM inhibition in vivo. Efficacy in combination with the DSB-inducing agent irinotecan was observed in a disease relevant model.

Potent cyclic peptide inhibitors of VLA‐4 (α4β1 integrin)‐mediated cell adhesion. Discovery of compounds like cyclo(MePhe‐Leu‐Asp‐Val‐d‐Arg‐d‐Arg) (ZD7349) compatible with depot formulation

Additional structure–activity relationship studies on potent cyclic peptide inhibitors of very late antigen‐4 (VLA‐4) are reported. The new N‐ to C‐terminal cyclic hexa‐, hepta‐ and octapeptide inhibitors like cyclo(MeIle/MePhe‐Leu‐Asp‐Val‐X) (X=2–4 amino acids containing hydrophobic and/or basic side chains) were synthesized using solid phase peptide synthesis methods. The peptides were evaluated in in vitro cell adhesion assays and in in vivo inflammation models. Many of the peptides like cyclo(MePhe‐Leu‐Asp‐Val‐d‐Arg‐d‐Arg) (ZD7349) (17), cyclo(MeIle‐Leu‐Asp‐Val‐d‐Arg‐d‐Arg‐d‐Phe) (20), cyclo(MeIle‐Leu‐Asp‐Val‐d‐Arg‐d‐Arg‐MePhe) (21) and cyclo(MePhe‐Leu‐Asp‐Val‐d‐Arg‐d‐Arg‐d‐Ala‐d‐Ala) (23) were potent inhibitors of VLA‐4‐mediated cell adhesion and inhibited ovalbumin‐induced delayed type hypersensitivity (DTH) response in mice. The more potent compounds were highly selective and did not affect U937 cell adhesion to fibronectin (VLA‐5), phorbolmyristate acetate or PMA‐differentiated U937 cell adhesion to intercellular cell adhesion molecule‐1 (ICAM‐1)‐expressing Chinese hamster ovary cells (LFA‐1) and adenosine diphosphate (ADP)‐induced platelet aggregation (GPIIb/IIIa). In contrast to the inhibitors like Ac‐cyclo(d‐Lys‐d‐Ile‐Leu‐Asp‐Val) and cyclo(CH2CO‐Ile‐Leu‐Asp‐Val‐Pip‐CH2CO‐Ile‐Leu‐Asp‐Val‐Pip) described earlier, the new compounds were much more compatible with the depot formulations based on poly(dl‐lactide‐co‐glycolide) polymers. The hexapeptide cyclo(MePhe‐Leu‐Asp‐Val‐d‐Arg‐d‐Arg) (ZD7349) (17) inhibited MOLT‐4 cell adhesion to fibronectin and vascular cell adhesion molecule‐1 (VCAM‐1) with IC50 values of 260 and 330 nm, respectively, and did not show any significant effect against other integrins (IC50>300 μm). ZD7349 inhibited ovalbumin‐induced DTH response in mice when administered continuously using a mini‐pump (ED50 0.01 mg/kg/day) or when given as an s.c. or i.v. bolus injection at a dose of 1–10 mg/kg. ZD7349 was also active in type II collagen‐induced arthritis (CIA) and experimental autoimmune encephalomyelitis (EAE) tests at a dose of 3–10 mg/kg. The peptide was released from some formulations over a period of 10–20 days. ZD7349 is currently undergoing pre‐clinical investigation. Copyright

Synthesis of Azabicycles via Cascade Aza-Prins Reactions: Accessing the Indolizidine and Quinolizidine Cores

The first detailed studies of intramolecular aza-Prins and aza-silyl-Prins reactions, starting from acyclic materials, are reported. The methods allow rapid and flexible access toward an array of [6,5] and [6,6] aza-bicycles, which form the core skeletons of various alkaloids. On the basis of our findings on the aza-Prins and aza-silyl-Prins cyclizations, herein we present simple protocols for the intramolecular preparation of the azabicyclic cores of the indolizidines and quinolizidines using a one-pot cascade process of N-acyliminium ion formation followed by aza-Prins cyclization and either elimination or carbocation trapping. It is possible to introduce a range of different substituents into the heterocycles through a judicial choice of Lewis acid and solvent(s), with halo-, phenyl-, and amido-substituted azabicyclic products all being accessed through these highly diastereoselective processes.

Potent Cyclic Monomeric and Dimeric Peptide Inhibitors of VLA-4 (?4?1 Integrin)-Mediated Cell Adhesion Based on the Ile-Leu-Asp-Val Tetrapeptide

Potent monomeric and dimeric cyclic peptide very late antigen‐4 (VLA‐4) inhibitors have been designed based on a tetrapeptide (Ile‐Leu‐Asp‐Val) sequence present in a 25‐amino acid peptide (CS‐1) reported in the literature. The peptides, synthesized by the SPPS techniques, were evaluated in the in vitro cell adhesion assays and in the in vivo inflammation models. The N‐ to C‐terminal cyclic peptides such as cyclo(Ile‐Leu‐Asp‐Val‐NH‐(CH2)2‐S‐(CH2)2‐CO) (28) and cyclo(MeIle‐Leu‐Asp‐Val‐D‐Ala‐D‐Ala) (31), monomeric and dimeric peptides containing piperazine (Pip) or homopiperazine (hPip) residues as linking groups, e.g. cyclo(MeIle‐Leu‐Asp‐Val‐Pip‐CH2CO‐NH‐(CH2)2‐S‐CH2‐CO) (49) and cyclo(MeIle‐Leu‐Asp‐Val‐hPip‐CH2CO‐MeIle‐Leu‐Asp‐Val‐hPip‐CH2CO) (58) and cyclic peptides containing an amide bond between the side chain amino group of an amino acid such as Lys and the C‐terminal Val carboxyl group, e.g. Ac‐cyclo(D‐Lys‐D‐Ile‐Leu‐Asp‐Val) (62) and β‐Ala‐cyclo(D‐Lys‐D‐Leu‐Leu‐Asp‐Val) (68) were more potent than CS‐1 in inhibiting the adhesion of the VLA‐4‐expressing MOLT‐4 cells to fibronectin. The more potent compounds were highly selective and did not affect U937 cell adhesion to fibronectin (VLA‐5), PMA‐differentiated U937 cell adhesion to intercellular cell adhesion molecule‐1‐expressing Chinese hamster ovary cells (LFA‐1) and ADP‐induced platelet aggregation (GPIIb/IIIa). A number of the more potent compounds inhibited ovalbumin‐induced delayed type hypersensitivity in mice and some were 100–300 times more potent (ED50=0.003–0.009 mg/kg/day, s.c.) than CS‐1. Two peptides, Ac‐cyclo(D‐Lys‐D‐Ile‐Leu‐Asp‐Val) (62) and cyclo(CH2CO‐Ile‐Leu‐Asp‐Val‐Pip‐CH2CO‐Ile‐Leu‐Asp‐Val‐Pip) (55), were formulated in poly(DL‐lactide‐co‐glycolide) depots and the release profile was investigated in vitro over a 30‐day period. Copyright

Preparation of 1-Substituted Tetrahydro-β-carbolines by Lithiation-Substitution.

A method to prepare 1-substituted N-Boc-tetrahydro-β-carbolines was developed by lithiation followed by electrophilic substitution. The deprotonation to give the organolithium was optimized by in situ IR spectroscopy and showed that the Boc group rotates slowly at low temperature. The chemistry was applied to the synthesis of 9-methyleleagnine (N-methyltetrahydroharman) and 11-methylharmicine.

The Identification of Potent, Selective, and Orally Available Inhibitors of Ataxia Telangiectasia Mutated (ATM) Kinase: The Discovery of AZD0156 (8-{6-[3-(Dimethylamino)propoxy]pyridin-3-yl}-3-methyl-1-(tetrahydro-2H-pyran-4-yl)-1,3-dihydro-2H-imidazo[4,5-c]quinolin-2-one)

ATM inhibitors, such as 7, have demonstrated the antitumor potential of ATM inhibition when combined with DNA double-strand break-inducing agents in mouse xenograft models. However, the properties of 7 result in a relatively high predicted clinically efficacious dose. In an attempt to minimize attrition during clinical development, we sought to identify ATM inhibitors with a low predicted clinical dose (<50 mg) and focused on strategies to increase both ATM potency and predicted human pharmacokinetic half-life (predominantly through the increase of volume of distribution). These efforts resulted in the discovery of 64 (AZD0156), an exceptionally potent and selective inhibitor of ATM based on an imidazo[4,5- c]quinolin-2-one core. 64 has good preclinical phamacokinetics, a low predicted clinical dose, and a high maximum absorbable dose. 64 has been shown to potentiate the efficacy of the approved drugs irinotecan and olaparib in disease relevant mouse models and is currently undergoing clinical evaluation with these agents.

Two-Directional Approach for the Rapid Synthesis of 2,4-Bis-Aminoaryl Pyridine Derivatives

Abstract We have developed two different approaches in parallel to rapidly access 2,4-bis aminoaryl pyridine compounds from a common starting material. The C-4/C-2 approach uses palladium-mediated coupling reactions to sequentially functionalize C-4 and then C-2. An alternative C-2/C-4 route uses a regioselective SNAr reaction to first substitute at C-2 then subsequently at C-4 by a palladium-mediated reaction. Both approaches have been used successfully to provide a range of 2,4-bis-aminoaryl pyridine compounds. GRAPHICAL ABSTRACT