Discovery of AZD8931, an Equipotent, Reversible Inhibitor of Signaling by EGFR, HER2, and HER3 Receptors.

Deregulation of HER family signaling promotes proliferation and tumor cell survival and has been described in many human cancers. Simultaneous, equipotent inhibition of EGFR-, HER2-, and HER3-mediated signaling may be of clinical utility in cancer settings where the selective EGFR or HER2 therapeutic agents are ineffective or only modestly active. We describe the discovery of AZD8931 (2), an equipotent, reversible inhibitor of EGFR-, HER2-, and HER3-mediated signaling and the structure-activity relationships within this series.

Vandetanib inhibits both VEGFR-2 and EGFR signalling at clinically relevant drug levels in preclinical models of human cancer.

Vandetanib is a multi-targeted receptor tyrosine kinase inhibitor that is in clinical development for the treatment of solid tumours. This preclinical study examined the inhibition of two key signalling pathways (VEGFR-2, EGFR) at drug concentrations similar to those achieved in the clinic, and their contribution to direct and indirect antitumour effects of vandetanib. For in vitro studies, receptor phosphorylation was assessed by Western blotting and ELISA, cell proliferation was assessed using a cell viability endpoint, and effects on cell cycle determined using flow cytometry.

Src family kinase inhibitor Saracatinib (AZD0530) impairs oxaliplatin uptake in colorectal cancer cells and blocks organic cation transporters.

Elevated Src family kinase (SFK) activity is associated with tumor invasion and metastasis. The SFK inhibitor saracatinib (AZD0530) is currently in phase II trials in patients including those with colorectal cancer (CRC), where links between SFK activity and poor prognosis are particularly striking. Saracatinib is likely to be used clinically in combination regimens, specifically with 5-fluorouracil (5-FU) and oxaliplatin, in CRC.

Identification of biomarkers in human head and neck tumor cell lines that predict for in vitro sensitivity to gefitinib.

Potential biomarkers were identified for in vitro sensitivity to the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor gefitinib in head and neck cancer. Gefitinib sensitivity was determined in cell lines, followed by transcript profiling coupled with a novel pathway analysis approach. Eleven cell lines were highly sensitive to gefitinib (inhibitor concentration required to give 50% growth inhibition [GI(50)] < 1 microM), three had intermediate sensitivity (GI(50) 1-7 microM), and six were resistant (GI(50) > 7 microM); an exploratory principal component analysis revealed a separation between the genomic profiles of sensitive and resistant cell lines.

AZD8931, an equipotent, reversible inhibitor of signaling by epidermal growth factor receptor, ERBB2 (HER2), and ERBB3: a unique agent for simultaneous ERBB receptor blockade in cancer.

Purpose: To test the hypothesis that simultaneous, equipotent inhibition of epidermal growth factor receptor (EGFR; erbB1), erbB2 (human epidermal growth factor receptor 2), and erbB3 receptor signaling, using the novel small-molecule inhibitor AZD8931, will deliver broad antitumor activity in vitro and in vivo.

Experimental Design: A range of assays was used to model erbB family receptor signaling in homodimers and heterodimers, including in vitro evaluation of erbB kinase activity, erbB receptor phosphorylation, proliferation in cells, and in vivo testing in a human tumor xenograft panel, with ex vivo evaluation of erbB phosphorylation and downstream biomarkers. Gefitinib and lapatinib were used to compare the pharmacological profile of AZD8931 with other erbB family inhibitors.

Epidermal growth factor receptor tyrosine kinase inhibitors: similar but different?

Two small-molecule epidermal growth factor receptor tyrosine kinase inhibitors, gefitinib and erlotinib, have been approved for the treatment of non-small-cell lung cancer. Here, we compare the pharmacology and pharmacokinetics of these agents, and reflect on how these properties may affect important clinical questions including the clinical efficacy, optimum dose, and whether there is a relationship between skin rash and clinical outcome for each of these agents. Gefitinib and erlotinib have similar mechanisms of action and pharmacological profiles; however, different molecular structures confer pharmacokinetic differences that may have important clinical implications.

Preclinical anticancer activity of the potent, oral Src inhibitor AZD0530.

AZD0530, an orally available Src inhibitor, demonstrated potent antimigratory and anti-invasive effects in vitro, and inhibited metastasis in a murine model of bladder cancer. Antiproliferative activity of AZD0530 in vitro varied between cell lines (IC(50) 0.2 ->10μM).

Novel 3-alkoxy-1H-pyrazolo[3,4-d]pyrimidines as EGFR and erbB2 receptor tyrosine kinase inhibitors.

Novel 4-anilino-1H-pyrazolo[3,4-d]pyrimidines have been synthesized and evaluated in vitro for erbB2 and EGFR kinase inhibition. A representative compound displaying oral bioavailability in rat and dog illustrates the potential of this series to provide orally active erbB2 inhibitors.

A new series of neutral 5-substituted 4-anilinoquinazolines as potent, orally active inhibitors of erbB2 receptor tyrosine kinase.

Starting from initial lead 1 containing a basic 5-substituent, optimisation of the glycolamide-derived neutral 5-substituent led to potent inhibitors of erbB2 with good pharmacokinetics. Representative compounds 19 and 21 inhibited phosphorylation of erbB2 in a mouse BT474C xenograft model after oral administration.

Neutral 5-substituted 4-anilinoquinazolines as potent, orally active inhibitors of erbB2 receptor tyrosine kinase.

Neutral 5-substituted 4-anilinoquinazolines addressed high in vivo clearance and phospholipidosis associated with previous basic compounds. A representative compound 8a inhibited tumor growth in a mouse xenograft model when co-administered with the cytochrome P450 inhibitor 1-aminobenzotriazole (ABT), and data are consistent with pharmacology primarily reflecting inhibition of erbB2 receptor tyrosine kinase.

Inhibitors of epidermal growth factor receptor tyrosine kinase: optimisation of potency and in vivo pharmacokinetics.

The structure-activity and structure-property relationships of anilinoquinazoline inhibitors of EGFR were investigated. Strategies to lower volume of distribution and shorten half-life through structure and pKa modulation are discussed.

Inhibitors of epidermal growth factor receptor tyrosine kinase: Novel C-5 substituted anilinoquinazolines designed to target the ribose pocket.

A series of novel C-5 substituted anilinoquinazolines, selected on the basis of docking experiments and overlays with ATP in the active site of EGFR tyrosine kinase, have been prepared and found to be potent inhibitors. In vivo pharmacokinetics and disease model activity are discussed.

5-Substituted 4-anilinoquinazolines as potent, selective and orally active inhibitors of erbB2 receptor tyrosine kinase.

Starting from a 6,7-substituted quinazoline lead 4, optimisation of 5-substituted quinazolines containing an extended aniline motif led to potent and selective inhibitors of erbB2 receptor tyrosine kinase, and a representative compound 12a inhibited tumour growth in a mouse xenograft model.