IP Receptor (Ki = 260 nM)

长效口服前药 selexipag (NS-304) 是一种 IP 受体激动剂，其活性形式 MRE-269 对 IP 受体具有很强的选择性。 [3H]伊洛前列素与人和大鼠IP受体的结合被selexipag (NS-304)以浓度依赖性方式抑制。大鼠 IP 受体的 Ki 为 2100 nM，人 IP 受体的 Ki 为 260 nM。硒 (NS-304) 处理后，hIP-CHO 细胞中的细胞内 cAMP 水平以浓度依赖性方式上升，EC50 为 177nM。 selexipag (NS-304) 的 IC50 值分别为 5.5 和 3.4 μM，同样可以预防人类和猴子的血小板聚集，但不能预防狗的血小板聚集 (IC50 > 100 μM) [1]。

大鼠口服 NS-304 后，MRE-269 (active form of Selelexipag/NS-304) 的 Cmax 为 1.1 μg/mL，狗为 9.0 μg/mL。在麻醉大鼠中，以 1 或 3 mg/kg 的剂量双膜内施用 selexipag (NS-304) 可增强 4 小时内的 FSBF。具体而言，3 mg/kg 的 Selelexipag (NS-304) 随着时间的推移增加 FSBF，在给药一小时内 FSBF 达到最大增加 93% [1]。

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大鼠和狗口服NS-304后8小时以上，MRE-269的血浆浓度仍接近峰值水平，NS-304以持久的方式增加了大鼠的股骨皮肤血流量，而不影响血流动力学。这些发现表明，NS-304在体内起着长效IP受体激动剂的作用。NS-304诱发的持续血管舒张没有因反复治疗而减弱，表明NS-304不太可能导致大鼠IP受体的严重脱敏。此外，一项对健康男性志愿者口服NS-304的微剂量药代动力学研究表明，NS-304转化为MRE-269，MRE-269的血浆消除半衰期较长（7.9小时）。总之，NS-304是一种口服长效IP受体激动剂前药，其活性形式MRE-269对IP受体具有高度选择性。因此，NS-304是治疗各种血管疾病，特别是肺动脉高压和动脉硬化闭塞症的有前景的候选药物。

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在Sugen 5416/缺氧肺动脉高压大鼠模型中，硒西帕显著改善了肺动脉阻塞，降低了右心室收缩压，减少了右心室肥大，提高了存活率。[3]

前列环素（PGI2）及其类似物可用于治疗各种血管疾病，但它们的半衰期太短，无法广泛临床应用。为了克服这一缺点，我们合成了一种新型的二苯基吡嗪衍生物2-{4-[（5,6-二苯基吡吡嗪-2-基）（异丙基）氨基]丁氧基}-N-（甲基磺酰基）乙酰胺（NS-304），这是一种活性形式{4-[。NS-304是一种口服的PGI2受体（IP受体）强效激动剂。MRE-269对人IP受体的抑制常数（Ki）为20nM；相比之下，其他前列腺素受体的Ki值>2.6μM。因此，MRE-269是IP受体的高度选择性激动剂[1]。

将表达人IP受体的CHO细胞（hIP-CHO细胞）以1×105个细胞/孔的速度接种在24孔板上，培养48小时。用不含二价阳离子的Dulbecco磷酸缓冲盐水洗涤细胞，在37°C的培养基中预孵育1小时，然后在500μM 3-异丁基-1-甲基黄嘌呤的存在下，在含有每种药物的培养基的37°C下孵育15分钟。移除培养基，加入高氯酸溶液以终止反应。细胞内cAMP水平通过酶联免疫吸附试验测定[1]。

Pregnant Sprague-Dawley rats received either 100 mg nitrofen dissolved in 1 ml olive oil or just olive oil by gavage on gestational age day (E) 9.5. Administration of nitrofen at exactly this time point induces mainly left-sided CDH in ~70% of the offspring, whereas all pups have PH. This study included only pups with an observable diaphragmatic defect. Pregnant rats were divided into eight groups: control, nitrofen (CDH), control + sildenafil, nitrofen + sildenafil (CDH+sildenafil), control + NS-304 , nitrofen + NS-304 (CDH+NS-304), control + sildenafil/NS-304, and nitrofen + sildenafil/NS-304 (CDH+sildenafil/NS-304). Sildenafil (100 mg·kg−1·day−1) and NS-304 (1 mg·kg−1·day−1) were dissolved in 0.8% ethanol in water and administered via oral gavage for 4 consecutive days from E17.5 to E20.5. At E21 pups were delivered by caesarean section and euthanized by lethal injection of pentobarbital (Fig. 1). The dosage of sildenafil was based on our previous study, whereas for NS-304 a dose study was performed.[2]

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Male Sprague-Dawley rats, cynomolgus monkeys, and male beagle dogs are used. Selexipag (NS-304) is orally administered to rats at 10 mg/kg and to dogs at 3 mg/kg, and blood samples are collected at various times and centrifuged to obtain plasma. The plasma concentrations of Selexipag (NS-304) and MRE-269 after oral administration of Selexipag (NS-304) to each animal are determined by high performance liquid chromatography coupled to mass spectrometry (LC/MS), and their pharmacokinetic parameters are calculated.Rats are orally administered Selexipag (NS-304) at 3 mg/kg twice daily for 1, 2, 3, or 4 weeks as a pretreatment. On the day after the final administration in the pretreatment, rats are anesthetized with urethane, and the FSBF is measured with a laser Doppler flowmeter after intraduodenal administration of Selexipag (NS-304) at 3 mg/kg[1].

Absorption, Distribution and Excretion
After oral administration, maximum concentrations of selexipag and its metabolite were observed to be reached at 1-3 and 3-4 hours, respectively. Absorption was impaired in the presence of food, resulting in delayed time to maximum concentration as well as ~30% lower peak plasma concentration. However, exposure was not found to be significantly affected by food.
93% in feces, 12% in urine.
On average, 35 L/hour.

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Metabolism / Metabolites
Selexipag yields its active metabolite by hydrolysis of the acylsulfonamide by the enzyme hepatic carboxylesterase 1. Oxidative metabolism catalyzed by CYP3A4 and CYP2C8 results in hydroxylated and dealkylated products. UGT1A3 and UGT2B7 are involved in the glucuronidation of the active metabolite. Other than active metabolite, other metabolites in circulation do not exceed 3% of the total drug-related material.

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Biological Half-Life
Selexipag's terminal half life is 0.8-2.5 hours. The active metabolite's terminal half life is 6.2-13.5 hours.

Hepatotoxicity
Selexipag is associated with a low rate of serum aminotransferase elevations (0% to 3%) that in clinical trials was similar to the rate among placebo recipients. These elevations were usually mild (rarely above 3 times ULN), transient and not associated with symptoms. There were no cases of serum enzyme elevations with jaundice in these preregistration clinical trials. Since licensure and more wide scale use, there have been no published reports of clinically apparent liver injury with jaundice associated with selexipag, but it has had limited general use.
Likelihood score: E (unlikely cause of clinically apparent liver injury).

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Protein Binding
Both selexipag and its active metabolite are highly protein bound, approximately 99%.

[1]. 2-[4-[(5,6-diphenylpyrazin-2-yl)(isopropyl)amino]butoxy]-N-(methylsulfonyl)acetamide (NS-304), an orally available and long-acting prostacyclin receptor agonist prodrug. J Pharmacol Exp Ther. 2007 Sep;322(3):1181-8.

[2]. Treatment of rat congenital diaphragmatic hernia with sildenafil and NS-304, selexipag's active compound, at the pseudoglandular stage improves lung vasculature. Am J Physiol Lung Cell Mol Physiol. 2018 May 10.

Selexipag is a member of the class of pyrazines that is N-(methanesulfonyl)-2-{4-[(propan-2-yl)(pyrazin-2-yl)amino]butoxy}acetamide carrying two additional phenyl substituents at positions 5 and 6 on the pyrazine ring. An orphan drug used for the treatment of pulmonary arterial hypertension. It is a prodrug for ACT-333679 (the free carboxylic acid). It has a role as an orphan drug, a prostacyclin receptor agonist, a platelet aggregation inhibitor, a vasodilator agent and a prodrug. It is a monocarboxylic acid amide, an ether, a member of pyrazines, an aromatic amine, a tertiary amino compound and a N-sulfonylcarboxamide. It is functionally related to an ACT-333679.
Selexipag was approved by the United States FDA on December 22, 2015 for the treatment of pulmonary arterial hypertension (PAH) to delay disease progression and reduce risk of hospitalization. PAH is a relatively rare disease with usually a poor prognosis requiring more treatment options to prolong long-term outcomes. Marketed by Actelion Pharmaceuticals under brand name Uptravi, selexipag and its active metabolite, ACT-333679 (MRE-269), act as agonists of the prostacyclin receptor to increase vasodilation in the pulmonary circulation and decrease elevated pressure in the blood vessels supplying blood to the lungs.
Selexipag is a Prostacyclin Receptor Agonist. The mechanism of action of selexipag is as a Prostacyclin Receptor Agonist.
Selexipag is prostacyclin receptor agonist that causes vasodilation in pulmonary vasculature and is used in the therapy of pulmonary arterial hypertension (PAH). Selexipag has been associated with a low rate of serum enzyme elevations during therapy, but has yet to be implicated in cases of clinically apparent acute liver injury.

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Drug Indication
Selexipag is indicated for the treatment of pulmonary arterial hypertension (PAH) to delay disease progression and reduce risk of hospitalization.
FDA Label
Uptravi is indicated for the long-term treatment of pulmonary arterial hypertension (PAH) in adult patients with WHO functional class (FC) II–III, either as combination therapy in patients insufficiently controlled with an endothelin receptor antagonist (ERA) and/or a phosphodiesterase type 5 (PDE-5) inhibitor, or as monotherapy in patients who are not candidates for these therapies. , , Efficacy has been shown in a PAH population including idiopathic and heritable PAH, PAH associated with connective tissue disorders, and PAH associated with corrected simple congenital heart disease. ,
Treatment of pulmonary arterial hypertension

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Mechanism of Action
Selexipag is a selective prostacyclin (IP, also called PGI2) receptor agonist. The key features of pulmonary arterial hypertension include a decrease in prostacyclin and prostacyclin synthase (enzyme that helps produce prostacyclin) in the lung. Prostacyclin is a potent vasodilator with anti-proliferative, anti-inflammatory, and anti-thrombotic effects; therefore, there is strong rationale for treatment with IP receptor agonists. Selexipag is chemically distinct as it is not PGI2 or a PGI2 analogue and has high selectivity for the IP receptor. It is metabolized by carboxylesterase 1 to yield an active metabolite (ACT-333679) that is approximately 37 times more potent than selexipag. Both selexipag and its metabolite are selective for the IP receptor over other prostanoid receptors.

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Pharmacodynamics
At the maximum tolerated dose of 1600 mcg twice per day, selexipag was not found to prolong the QT interval to a clinically relevant extent. Both selexipag and its metabolite caused concentration-dependent inhibition of platelet aggregation in vitro with IC50 of 5.5 µM and 0.21 µM, respectively. However, at clinically relevant concentrations, there was no effect on platelet aggregation test parameters following multiple dose administration of selexipag in healthy patients.

C26H32N4O4S

496.62

496.214

C, 62.88; H, 6.50; N, 11.28; O, 12.89; S, 6.46

475086-01-2

Selexipag-d7;1265295-21-3;Selexipag-d6;1265295-92-8

9913767

Typically exists as White to yellow solids at room temperature

1.2±0.1 g/cm3

1.579

4.56

113.36

1

7

12

35

730

0

S(C([H])([H])[H])(N([H])C(C([H])([H])OC([H])([H])C([H])([H])C([H])([H])C([H])([H])N(C1=C([H])N=C(C2C([H])=C([H])C([H])=C([H])C=2[H])C(C2C([H])=C([H])C([H])=C([H])C=2[H])=N1)C([H])(C([H])([H])[H])C([H])([H])[H])=O)(=O)=O

QXWZQTURMXZVHJ-UHFFFAOYSA-N

InChI=1S/C26H32N4O4S/c1-20(2)30(16-10-11-17-34-19-24(31)29-35(3,32)33)23-18-27-25(21-12-6-4-7-13-21)26(28-23)22-14-8-5-9-15-22/h4-9,12-15,18,20H,10-11,16-17,19H2,1-3H3,(H,29,31)

2-[4-[(5,6-diphenylpyrazin-2-yl)-propan-2-ylamino]butoxy]-N-methylsulfonylacetamide

NS 304; ACT293987; NS-304; ACT 293987; NS304; Uptravi; ACT-293987; Selexipag; 475086-01-2; NS-304; Uptravi; ACT-293987; NS 304; ACT 293987; 2-(4-((5,6-diphenylpyrazin-2-yl)(isopropyl)amino)butoxy)-N-(methylsulfonyl)acetamide;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

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

DMSO : ≥ 50 mg/mL (~100.68 mM)

配方 1 中的溶解度: ≥ 2.5 mg/mL (5.03 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 25.0 mg/mL澄清DMSO储备液加入到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: 2.5 mg/mL (5.03 mM) 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), 悬浊液; 超声助溶。
例如，若需制备1 mL的工作液，可将 100 μL 25.0 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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配方 3 中的溶解度: ≥ 2.5 mg/mL (5.03 mM) (饱和度未知) in 10% DMSO + 90% Corn Oil (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 25.0 mg/mL 澄清 DMSO 储备液加入到 900 μL 玉米油中并混合均匀。

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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。