Preclinical and Translational Pharmacokinetics (V.Y., I.F., B.L., S.M., D.L., A.K., B.-Q.S.) and Bio-Analytical Sciences (C.N.), Genentech, South San Francisco, California.
Preclinical and Translational Pharmacokinetics (V.Y., I.F., B.L., S.M., D.L., A.K., B.-Q.S.) and Bio-Analytical Sciences (C.N.), Genentech, South San Francisco, California
Drug Metab Dispos. 2020 Dec;48(12):1247-1256. doi: 10.1124/dmd.120.000145. Epub 2020 Oct 5.
Anti-Ly6E--cyclopropabenzindol-4-one dimer antibody-drug conjugate (ADC) has been reported to form an adduct with 1-microglobulin (A1M) in animal plasma, but with unknown impact on ADC PK and tissue distribution. In this study, we compared the PK and tissue distribution of anti-Ly6E ADC with unconjugated anti-Ly6E mAb in rodents and monkeys. For PK studies, animals received an intravenous administration of anti-Ly6E ADC or unconjugated anti-Ly6E mAb. Plasma samples were analyzed for total antibody (Tab) levels and A1M adduct formation. PK parameters were generated from dose-normalized plasma concentrations. Tissue distribution was determined in tumor-bearing mice after a single intravenous dosing of radiolabeled ADC or mAb. Tissue radioactivity levels were analyzed using a gamma counter. The impact of A1M adduct formation on target cell binding was assessed in an in vitro cell binding assay. The results show that ADC Tab clearance was slower than that of mAb in mice and rats but faster than mAb in monkeys. Correspondingly, the formation of A1M adduct appeared to be faster and higher in mice, followed by rats, and slowest in monkeys. Although ADC tended to show an overall lower distribution to normal tissues, it had a strikingly reduced distribution to tumors compared with mAb, likely due to A1M adduct formation interfering with target binding, as demonstrated by the in vitro cell binding assay. Together, these data 1) demonstrate that anti-Ly6E ADC that forms A1M adduct had slower systemic clearance with strikingly reduced tumor distribution and 2) highlight the importance of selecting an appropriate linker-drug for successful ADC development. SIGNIFICANCE STATEMENT: Anti-lymphocyte antigen 6 complex, locus E, ADC with -cyclopropabenzindol-4-one-dimer payload formed adduct with A1M, which led to a decrease in systemic clearance but also attenuated tumor distribution. These findings demonstrate the importance of selecting an appropriate linker-drug for ADC development and also highlight the value of a mechanistic understanding of ADC biotransformation, which could provide insight into ADC molecule design, optimization, and selection.
抗 Ly6E--环丙苯并吲哚-4-酮二聚体抗体药物偶联物（ADC）已被报道在动物血浆中与 1-微球蛋白（A1M）形成加合物，但对 ADC PK 和组织分布的影响尚不清楚。在这项研究中，我们比较了抗 Ly6E ADC 与未缀合的抗 Ly6E mAb 在啮齿动物和猴子中的 PK 和组织分布。对于 PK 研究，动物接受抗 Ly6E ADC 或未缀合的抗 Ly6E mAb 的静脉内给药。分析血浆样品中的总抗体（Tab）水平和 A1M 加合物形成。从剂量归一化的血浆浓度生成 PK 参数。在荷瘤小鼠单次静脉注射放射性标记的 ADC 或 mAb 后，测定组织分布。使用伽马计数器分析组织放射性水平。在体外细胞结合测定中评估 A1M 加合物形成对靶细胞结合的影响。结果表明，ADC Tab 清除速度慢于小鼠和大鼠中的 mAb，但快于猴子中的 mAb。相应地，A1M 加合物的形成似乎在小鼠中更快更高，其次是大鼠，在猴子中最慢。尽管 ADC 总体上显示出对正常组织的分布较低，但与 mAb 相比，它对肿瘤的分布明显减少，这可能是由于 A1M 加合物的形成干扰了靶结合，如体外细胞结合测定所示。总之，这些数据 1）表明形成 A1M 加合物的抗 Ly6E ADC 具有较慢的系统清除率，并明显减少肿瘤分布，2）强调了为成功开发 ADC 选择合适的连接子-药物的重要性。意义：带有 -cyclopropabenzindol-4-one-dimer 有效载荷的抗淋巴细胞抗原 6 复合物、位置 E、ADC 与 A1M 形成加合物，导致系统清除率降低，但也减弱了肿瘤分布。这些发现表明，为 ADC 开发选择合适的连接子-药物非常重要，并且还强调了对 ADC 生物转化机制的理解的重要性，这可以为 ADC 分子设计、优化和选择提供见解。
