Gan Jinping, Ruan Qian, He Bing, Zhu Mingshe, Shyu Wen C, Humphreys W Griffith
Pharmaceutical Candidate Optimization, Bristol-Myers Squibb Research and Development, Princeton, New Jersey 08543, USA.
Chem Res Toxicol. 2009 Apr;22(4):690-8. doi: 10.1021/tx800368n.
Reactive metabolite formation has been associated with drug-induced liver, skin, and hematopoietic toxicity of many drugs that has resulted in serious clinical toxicity, leading to clinical development failure, black box warnings, or, in some cases, withdrawal from the market. In vitro and in vivo screening for reactive metabolite formation has been proposed and widely adopted in the pharmaceutical industry with the aim of minimizing the property and thus the risk of drug-induced toxicity (DIT). One of the most common screening methods is in vitro thiol trapping of reactive metabolites. Although it is well-documented that many hepatotoxins form thiol adducts, there is no literature describing the adduct formation potential of safer drugs that are widely used. The objective of this study was to quantitatively assess the thiol adduct formation potential of 50 drugs (10 associated with DIT and 40 not associated) and document apparent differences in adduct formation between toxic and safer drugs. Dansyl glutathione was used as a trapping agent to aid the quantitation of adducts following in vitro incubation of drugs with human liver microsomes in the presence and absence of NADPH. Metabolic turnover of these drugs was also monitored by LC/UV. Overall, 15 out of the 50 drugs screened formed detectable levels of thiol adducts. There were general trends toward more positive findings in the DIT group vs the non-DIT group. These trends became more marked when the relative amount of thiol adducts was taken into account and improved further when dose and total daily reactive metabolite burdens were considered. In conclusion, there appears to be a general trend between the extent of thiol adduct formation and the potential for DIT, which would support the preclinical measurement and minimization of the property through screening of thiol adduct formation as part of an overall discovery optimization paradigm.
活性代谢物的形成与许多药物引起的肝脏、皮肤和造血系统毒性有关，这些毒性已导致严重的临床毒性反应，致使临床开发失败、出现黑框警告，或在某些情况下导致药物退市。为了将药物诱导毒性（DIT）的特性及风险降至最低，制药行业已提出并广泛采用体外和体内活性代谢物形成的筛选方法。最常见的筛选方法之一是对活性代谢物进行体外巯基捕获。尽管有充分的文献记载许多肝毒素会形成巯基加合物，但尚无文献描述广泛使用的安全性较高药物的加合物形成潜力。本研究的目的是定量评估50种药物（10种与DIT相关，40种与DIT无关）的巯基加合物形成潜力，并记录有毒药物和安全性较高药物在加合物形成方面的明显差异。在有和没有NADPH存在的情况下，将药物与人肝微粒体进行体外孵育后，使用丹磺酰谷胱甘肽作为捕获剂来辅助加合物的定量分析。还通过LC/UV监测这些药物的代谢周转率。总体而言，在筛选的50种药物中，有15种形成了可检测水平的巯基加合物。与非DIT组相比，DIT组有更明显的阳性结果趋势。当考虑巯基加合物的相对量时，这些趋势变得更加明显，而在考虑剂量和每日活性代谢物总负担时，趋势进一步增强。总之，巯基加合物形成的程度与DIT潜力之间似乎存在总体趋势，这将支持在临床前进行测量，并通过筛选巯基加合物形成来将该特性降至最低，作为整体发现优化范式的一部分。
