Hochreiter Jill, Lapham Jill, Wong-Staal Flossie, McKelvy Jeffrey, Sulkowski Mark, Glesby Marshall J, Johnson Victoria A, Morse Gene D
AIDS Clinical Trials Group Pharmacology Specialty Laboratory, Translational Pharmacology Research Core, School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, Buffalo, NY, USA.
Antivir Ther. 2013;18(3):329-36. doi: 10.3851/IMP2354. Epub 2012 Sep 6.
ITX 5061 is a highly potent small molecule inhibitor of scavenger receptor-B1, an integral transmembrane protein that is found in liver cells and is actively involved in the transport of HCV into hepatocytes. Currently, ITX 5061 is being investigated in monoinfected hepatitis C patients in a proof-of-concept clinical trial carried out by the AIDS Clinical Trial Group (ACTG).
To provide quantitative results in human plasma for pharmacokinetic analysis, an assay for ITX 5061 was validated. ITX 5061 and the internal standard, a deuterated analogue, were separated by isocratic reverse phase chromatography using a Polar RP column (Phenomenex Synergi(™); 2.0 mm × 50 mm, 4 µm) and detected via electrospray coupled to a triple quadrupole mass spectrometer with a run time of 5 min. Multiple reaction monitoring in positive mode was used with ITX 5061 at 585/114 m/z and the internal standard at 592/122 m/z with a linear range of 2.50-5,000 ng/ml. Human plasma was extracted using a protein precipitation combing 400 µl of acetonitrile with 100 µl of EDTA plasma.
The interassay variation ranged from 1.19 to 13.2%, while the intraassay variation ranged from 0.394 to 12.9% over 6 days of testing. The method was successfully applied to the samples collected for the ACTG Protocol A5277. Plasma concentrations at 1 h and 24 h following 150 mg ITX 5061 daily in HCV monoinfected patients (n=3) ranged from 138 to 518 ng/ml and 33 to 111 ng/ml, respectively.
The ITX 5061 assay is accurate and reproducible with a wide linear range and will be used for pharmacokinetic analysis and dose-finding studies in HCV-monoinfected patients.
ITX 5061是一种高效的清道夫受体B1小分子抑制剂，清道夫受体B1是一种存在于肝细胞中的完整跨膜蛋白，积极参与丙型肝炎病毒（HCV）进入肝细胞的过程。目前，艾滋病临床试验组（ACTG）正在进行一项概念验证临床试验，对单纯感染丙型肝炎的患者使用ITX 5061进行研究。
为了获得人血浆中的定量结果用于药代动力学分析，对ITX 5061的检测方法进行了验证。使用Polar RP柱（Phenomenex Synergi™；2.0 mm×50 mm，4 µm）通过等度反相色谱法分离ITX 5061和内标（一种氘代类似物），并通过电喷雾与三重四极杆质谱仪联用进行检测，运行时间为5分钟。采用正模式下的多反应监测，ITX 5061的质荷比为585/114，内标的质荷比为592/122，线性范围为2.50 - 5,000 ng/ml。使用400 µl乙腈与100 µl EDTA血浆进行蛋白沉淀法提取人血浆。
在6天的测试中，批间变异范围为1.19%至13.2%，批内变异范围为从过0.394%至12.9%。该方法成功应用于为ACTG方案A5277收集的样本。在单纯感染HCV的患者（n = 3）中，每日服用150 mg ITX 5061后1小时和24小时的血浆浓度分别为138至518 ng/ml和33至111 ng/ml。
ITX 5061检测方法准确、可重复，线性范围宽，将用于单纯感染HCV患者的药代动力学分析和剂量探索研究。
