AMG 900 is a potent and highly selective pan-Aurora kinases inhibitor for Aurora A/B/C with IC50 of 5 nM/4 nM /1 nM. It is >10-fold selective for Aurora kinases than p38α, Tyk2, JNK2, Met and Tie2. Phase 1.

Aurora A:5 nM, Aurora B:4 nM, Aurora C:1 nM

AMG 900 是一种新型的、与ATP竞争的 phthalazinamine 小分子抑制剂，针对aurora kinases。在HeLa细胞中，AMG 900 抑制aurora-A和-B的自磷酸化以及histone H3在Ser位点的磷酸化。肿瘤细胞对AMG 900处理的主要细胞反应是终止细胞分裂而不是延长的有丝分裂停滞，这最终导致细胞死亡。AMG 900能够在低纳摩尔浓度（约2-3 nM）抑制26种肿瘤细胞系的增殖，包括对抗有丝分裂化合物紫杉醇和其他aurora kinase抑制剂（AZD1152、MK-0457和PHA-739358）耐药的细胞系。此外，AMG 900 在一株对AZD1152耐药且携带aurora-B突变（W221L）的HCT116变异细胞系中也显示出活性。[1]

AMG 900通过口服给药方式能以剂量依赖性的方式阻断组蛋白H3的磷酸化，并显著抑制HCT116肿瘤异种移植物的生长。AMG 900在多个异种移植模型中表现出广泛的活性，包括代表5种肿瘤类型的3个多药物耐药性移植模型。[1] AMG 900表现出低至中等的清除率和小的分布体积，其终末消除半衰期介于0.6到2.4小时之间。在禁食的动物中，AMG 900具有良好的口服生物利用度，范围为31%至107%。食物摄入会影响AMG 900的口服吸收率（大鼠）或吸收程度（狗）。在人体中，稳态时的清除率和分布体积预计分别为27.3 mL/h/kg和93.9 mL/kg。AMG 900在临床前物种中显示出可接受的药代动力学（PK）属性，并预计在人体中具有低清除率。[2]

Enzyme kinase assays: Recombinant GST- or His-tagged aurora-A (TPX2), and aurora-B proteins are expressed using a baculovirus system and purified by affinity chromatography. AMG 900 activity is assessed using a standardized homogenous time-resolved fluorescence (HTRF) assay. Enzyme assays for 24 other kinases (aurora-C, p38α, TYK2, JNK2, JAK3, c-Met, VEGFR2, p38β, TIE-2, ABL (T315I), ERK1, BTK, JNK3, CDK5, PKAα, JNK1, p70S6K, PKBα, MSK1, LCK, SRC, IGFR, JAK2, and c-KIT) are done internally in a similar manner. Concentrations of enzyme, peptide substrate, and ATP in the reaction are optimized depending on the specific activity of the kinase and measured Km values for their corresponding substrates. AMG 900 is evaluated in a kinome competition binding assay (n = 353 unique kinases) by Ambit Biosciences. AMG 900 is initially screened at a single concentration of 1000 nM, and quantitative binding constants (Kd) are determined for each positive hit (< 20 percentage of control).

Tumor cells are treated with AMG 900 for 48 hours, washed twice with complete media, and cells are replated at a density of 5000 cells per well in drug-free complete media. Cells are grown until the DMSO control wells are confluent. Cells are stained with crystal violet dye, washed with distilled water, and imaged using a digital scanner.(Only for Reference)