Chk1 0.9 nM (Ki) Chk1 <1 nM (IC50) Chk2 8 nM (IC50)

Prexasertib 二甲磺酸盐（LY2606368 二甲磺酸盐）抑制 BRSK2 (IC50=48 nM)、ARK5 (IC50=64 nM)、SIK (IC50=42 nM) 和 MELK (IC50=38 nM)。 prexasertib 二甲磺酸盐引起的 DNA 损伤需要 CDK2 和 CDC25A 的存在[1]。在 HeLa 细胞中，prexasertib dimesylate (33, 100 nM) 在 S 期引起 DNA 损伤[1]。在 HT-29 细胞中，prexasertib 二甲磺酸盐（8-250 nM；预处理 15 分钟）抑制 CHK1 (S296) 和 CHK2 (S516) 的自身磷酸化。在 U-2 OS 细胞中，prexasertib 二甲磺酸盐（4 nM；24 小时）诱导 H2AX 磷酸化，并导致细胞周期群体从 G1 和 G2-M 显着转变为 S 期[1]。在 HeLa 细胞中，二甲磺酸 proxasertib (33 nM) 作用 12 小时，使染色体断裂。 Prexasertib 二甲磺酸盐（100 nM；0.5 至 9 小时）会减少可与 DNA 结合并导致复制应激的 RPA2 量[1]。

使用 prexasertib 二甲磺酸盐（LY2606368 二甲磺酸盐；1–10 mg/kg；SC；每天两次，持续三天，休息四天）治疗时，肿瘤异种移植物生长速度较慢[1]。用 prexasertib 二甲磺酸盐（15 mg/kg；SC）处理的肿瘤异种移植物表现出生长抑制[1]。抑制血液中的 CHK1 以及 RPA2 (S4/S8) 和 H2AX (S139) 的磷酸化[1]。

细胞周期分析[1]
细胞类型： HeLa 细胞
测试浓度： 33, 100 nM
孵育时间： > 7 小时
实验结果：IC50 为 37 nM，导致 G2-M 群体在 S 期受到 DNA 损伤，但继续在细胞周期中进展到早期有丝分裂。

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蛋白质印迹分析[1]
细胞类型： HT- 29 细胞
测试浓度： 8、16、31、63、 125, 250 nM
孵育时间：预处理 15 分钟
实验结果：抑制 CHK1 自磷酸化 (S296) 和 CHK2 自磷酸化 (S516) (IC50) HT-29 细胞中小于 31 nM)。

Animal/Disease Models: Female CD-1 nu -/nu- mice (26-28 g) with Calu-6 cells[1]
Doses: 1, 3.3, or 10 mg/kg
Route of Administration: SC; twice (two times) daily for 3 days, rest 4 days; for three cycles
Experimental Results: Caused statistically significant tumor growth inhibition (up to 72.3%).

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Animal/Disease Models: Female CD-1 nu-/nu- mice (26-28 g) with Calu-6 cells[1]
Doses: 15 mg/kg (pharmacokinetic/PK Analysis)
Route of Administration: SC (200 μL)
Experimental Results: CHK1 was 7 ng/mL at 12 hrs (hours) and 3 ng/mL by 24 hrs (hours) in plasma exposures. Phosphorylation of both H2AX (S139) and RPA2 (S4/S8) was detectable at 4 hrs (hours), showing the rapid occurrence of DNA damage.

Forty-five patients were treated; seven experienced dose-limiting toxicities (all hematologic). The maximum-tolerated doses (MTDs) were 40 mg/m(2) (schedule 1) and 105 mg/m(2) (schedule 2). The most common related grade 3 or 4 treatment-emergent adverse events were neutropenia, leukopenia, anemia, thrombocytopenia, and fatigue. Grade 4 neutropenia occurred in 73.3% of patients and was transient (typically < 5 days). Febrile neutropenia incidence was low (7%). The LY2606368 exposure over the first 72 hours (area under the curve from 0 to 72 hours) at the MTD for each schedule coincided with the exposure in mouse xenografts that resulted in maximal tumor responses. Minor intra- and intercycle accumulation of LY2606368 was observed at the MTDs for both schedules. Two patients (4.4%) had a partial response; one had squamous cell carcinoma (SCC) of the anus and one had SCC of the head and neck. Fifteen patients (33.3%) had a best overall response of stable disease (range, 1.2 to 6.7 months), six of whom had SCC. Conclusion: An LY2606368 dose of 105 mg/m(2) once every 14 days is being evaluated as the recommended phase II dose in dose-expansion cohorts for patients with SCC.

[1]. LY2606368 Causes Replication Catastrophe and Antitumor Effects through CHK1-Dependent Mechanisms. Mol Cancer Ther. 2015 Sep;14(9):2004-1.

[2]. Chk1 inhibition potentiates the therapeutic efficacy of PARP inhibitor BMN673 in gastric cancer. Am J Cancer Res. 2017 Mar 1;7(3):473-483.

Prexasertib has been used in trials studying the treatment and basic science of mCRPC, Leukemia, Neoplasm, breast cancer, and Ovarian Cancer, among others. Prexasertib is an inhibitor of checkpoint kinase 1 (chk1) with potential antineoplastic activity. Upon administration, prexasertib selectively binds to chk1, thereby preventing activity of chk1 and abrogating the repair of damaged DNA. This may lead to an accumulation of damaged DNA and may promote genomic instability and apoptosis. Prexasertib may potentiate the cytotoxicity of DNA-damaging agents and reverse tumor cell resistance to chemotherapeutic agents. Chk1, a serine/threonine kinase, mediates cell cycle checkpoint control and is essential for DNA repair and plays a key role in resistance to chemotherapeutic agents.

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CHK1 is a multifunctional protein kinase integral to both the cellular response to DNA damage and control of the number of active replication forks. CHK1 inhibitors are currently under investigation as chemopotentiating agents due to CHK1's role in establishing DNA damage checkpoints in the cell cycle. Here, we describe the characterization of a novel CHK1 inhibitor, LY2606368, which as a single agent causes double-stranded DNA breakage while simultaneously removing the protection of the DNA damage checkpoints. The action of LY2606368 is dependent upon inhibition of CHK1 and the corresponding increase in CDC25A activation of CDK2, which increases the number of replication forks while reducing their stability. Treatment of cells with LY2606368 results in the rapid appearance of TUNEL and pH2AX-positive double-stranded DNA breaks in the S-phase cell population. Loss of the CHK1-dependent DNA damage checkpoints permits cells with damaged DNA to proceed into early mitosis and die. The majority of treated mitotic nuclei consist of extensively fragmented chromosomes. Inhibition of apoptosis by the caspase inhibitor Z-VAD-FMK had no effect on chromosome fragmentation, indicating that LY2606368 causes replication catastrophe. Changes in the ratio of RPA2 to phosphorylated H2AX following LY2606368 treatment further support replication catastrophe as the mechanism of DNA damage. LY2606368 shows similar activity in xenograft tumor models, which results in significant tumor growth inhibition. LY2606368 is a potent representative of a novel class of drugs for the treatment of cancer that acts through replication catastrophe.[2]

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The primary objective was to determine safety, toxicity, and a recommended phase II dose regimen of LY2606368, an inhibitor of checkpoint kinase 1, as monotherapy. Patients and methods: This phase I, nonrandomized, open-label, dose-escalation trial used a 3 + 3 dose-escalation scheme and included patients with advanced solid tumors. Intravenous LY2606368 was dose escalated from 10 to 50 mg/m(2) on schedule 1 (days 1 to 3 every 14 days) or from 40 to 130 mg/m(2) on schedule 2 (day 1 every 14 days). Safety measures and pharmacokinetics were assessed, and pharmacodynamics were measured in blood, hair follicles, and circulating tumor cells. Conclusion: An LY2606368 dose of 105 mg/m(2) once every 14 days is being evaluated as the recommended phase II dose in dose-expansion cohorts for patients with SCC.[1]

C20H27N7O8S2

557.600481271744

557.136

1234015-58-7

Prexasertib;1234015-52-1;Prexasertib dihydrochloride;1234015-54-3;Prexasertib Mesylate Hydrate;1234015-57-6;Prexasertib mesylate;1234015-55-4

137364590

Light yellow to yellow solid powder

260

5

14

8

37

592

0

S(C)(=O)(=O)O.S(C)(=O)(=O)O.O(CCCN)C1C=CC=C(C=1C1=CC(NC2C=NC(C#N)=CN=2)=NN1)OC

HXYBEKZGRNUTBN-UHFFFAOYSA-N

InChI=1S/C18H19N7O2.2CH4O3S/c1-26-14-4-2-5-15(27-7-3-6-19)18(14)13-8-16(25-24-13)23-17-11-21-12(9-20)10-22-17;2*1-5(2,3)4/h2,4-5,8,10-11H,3,6-7,19H2,1H3,(H2,22,23,24,25);2*1H3,(H,2,3,4)

5-[[5-[2-(3-aminopropoxy)-6-methoxyphenyl]-1H-pyrazol-3-yl]amino]pyrazine-2-carbonitrile;methanesulfonic acid

Prexasertib (dimesylate); Prexasertib dimesylate; 1234015-58-7; 5-[[5-[2-(3-aminopropoxy)-6-methoxyphenyl]-1H-pyrazol-3-yl]amino]pyrazine-2-carbonitrile;methanesulfonic acid; 5-((5-(2-(3-Aminopropoxy)-6-methoxyphenyl)-1H-pyrazol-3-yl)amino)pyrazine-2-carbonitrile dimethanesulfonate; LY2606368 (dimesylate); SCHEMBL20591301;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

注意： 请将本产品存放在密封且受保护的环境中（例如氮气保护），避免吸湿/受潮。

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : 100 mg/mL (179.34 mM)
H2O : 50 mg/mL (89.67 mM)

配方 1 中的溶解度: ≥ 3.5 mg/mL (6.28 mM) (饱和度未知) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将100 μL 35.0 mg/mL澄清DMSO储备液加入400 μL PEG300中，混匀；然后向上述溶液中加入50 μL Tween-80，混匀；加入450 μL生理盐水定容至1 mL。
*生理盐水的制备：将 0.9 g 氯化钠溶解在 100 mL ddH₂O中，得到澄清溶液。

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配方 2 中的溶解度: ≥ 3.5 mg/mL (6.28 mM) (饱和度未知) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将 100 μL 35.0 mg/mL澄清DMSO储备液加入900 μL 20% SBE-β-CD生理盐水溶液中，混匀。
*20% SBE-β-CD 生理盐水溶液的制备（4°C，1 周）：将 2 g SBE-β-CD 溶解于 10 mL 生理盐水中，得到澄清溶液。

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请根据您的实验动物和给药方式选择适当的溶解配方/方案：
1、请先配制澄清的储备液(如：用DMSO配置50 或 100 mg/mL母液(储备液));
2、取适量母液，按从左到右的顺序依次添加助溶剂，澄清后再加入下一助溶剂。以 下列配方为例说明 (注意此配方只用于说明，并不一定代表此产品 的实际溶解配方):
10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
假设最终工作液的体积为 1 mL, 浓度为5 mg/mL: 取 100 μL 50 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀/澄清；向上述体系中加入50 μL Tween-80，混合均匀/澄清；然后继续加入450 μL ddH2O (或 saline)定容至 1 mL；
3、溶剂前显示的百分比是指该溶剂在最终溶液/工作液中的体积所占比例;
4、 如产品在配制过程中出现沉淀/析出，可通过加热(≤50℃)或超声的方式助溶;
5、为保证最佳实验结果，工作液请现配现用！
6、如不确定怎么将母液配置成体内动物实验的工作液，请查看说明书或联系我们;
7、 以上所有助溶剂都可在 Invivochem.cn网站购买。