Kelnar Kevin, Peltier Heidi J, Leatherbury Neil, Stoudemire Jay, Bader Andreas G
Mirna Therapeutics, Inc., 2150 Woodward Street, Suite 100, Austin, Texas 78701, United States.
Anal Chem. 2014 Feb 4;86(3):1534-42. doi: 10.1021/ac403044t. Epub 2014 Jan 17.
MRX34, a microRNA (miRNA)-based therapy for cancer, has recently entered clinical trials as the first clinical candidate in its class. It is a liposomal nanoparticle loaded with a synthetic mimic of the tumor suppressor miRNA miR-34a as the active pharmaceutical ingredient. To understand the pharmacokinetic properties of the drug and to rationalize an optimal dosing regimen in the clinic, a method is needed to quantitatively detect the miRNA mimic. Here, we report the development and qualification of a quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay in support of pharmacokinetic and toxicokinetic assessments in the nonhuman primate. Detection and quantification were performed on total ribonucleic acid (RNA) isolated from whole blood. The qualified range of the standard curve spans 6 orders of magnitude from 2.5 × 10(-7) to 2.5 × 10(-1) ng per reverse transcription (RT) reaction, corresponding to an estimated blood concentration from 6.2 × 10(-5) to 6.2 × 10(1) ng/mL. Our results demonstrate that endogenous as well as the exogenous miR-34a can be accurately and precisely quantified. The assay was used to establish the pharmacokinetic profile of MRX34, showing a favorable residence time and exposure of the miRNA mimic in whole blood from nonhuman primates.
MRX34是一种基于微小RNA（miRNA）的癌症治疗药物，最近作为该类别的首个临床候选药物进入临床试验。它是一种脂质体纳米颗粒，载有肿瘤抑制性miRNA miR-34a的合成模拟物作为活性药物成分。为了了解该药物的药代动力学特性并确定临床上的最佳给药方案，需要一种定量检测miRNA模拟物的方法。在此，我们报告了一种定量逆转录-聚合酶链反应（qRT-PCR）检测方法的开发与验证，以支持在非人类灵长类动物中的药代动力学和毒代动力学评估。检测和定量是在从全血中分离的总核糖核酸（RNA）上进行的。标准曲线的合格范围跨越6个数量级，从每个逆转录（RT）反应2.5×10^(-7)到2.5×10^(-1) ng，对应估计的血药浓度为6.2×10^(-5)到6.2×10^(1) ng/mL。我们的结果表明，内源性以及外源性miR-34a都可以被准确且精确地定量。该检测方法用于建立MRX34的药代动力学概况，显示出该miRNA模拟物在非人类灵长类动物全血中的良好驻留时间和暴露情况。
