Mechanism-based Changes in Anti-METH Monoclonal Antibody Therapy During Pregnancy

妊娠期间抗冰毒单克隆抗体治疗的机制变化

• 批准号: 8415542
• 负责人: William Thomas Atchley
• 金额: $ 1.69万
• 依托单位: UNIV OF ARKANSAS FOR MED SCIS
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8415542
• 关键词: Affect; Affinity; Alanine; Amino Acids; Antibodies; Binding; Biological Assay; Blood; Brain; Characteristics; Development; Doctor of Philosophy; Dose; Drug Kinetics; Drug abuse; Engineering; Environment; Fetus; Half-Life; Health; Histidine; Human; Humoral Immunities; Immune system; Immunoglobulin G; Immunohistochemistry; Immunotherapy; Knowledge; Laboratories; MALDI-TOF Mass Spectrometry; Mammals; Medicine; Methamphetamine; Modeling; Modification; Monoclonal Antibodies; Monoclonal Antibody Therapy; Mothers; Mus; Mutate; Mutation; Pathway interactions; Pharmaceutical Preparations; Pharmacodynamics; Physiological; Physiological Processes; Pregnancy; Pregnant Women; Rattus; Recycling; Regulation; Relative (related person); Reporting; Role; Safety; Seminal; Serum; Sprague-Dawley Rats; Staging; Structure; Techniques; Testing; Time; Tissues; Training; Treatment Efficacy; Western Blotting; antigen binding; base; drug of abuse; hemodynamics; improved; in vivo; innovation; insight; neonatal Fc receptor; novel; pharmacokinetic characteristic; pre-clinical; preclinical study; pregnant; public health relevance; receptor; receptor binding; research study

DESCRIPTION (provided by applicant): (+)-Methamphetamine (METH) is one of the most addictive and heavily abused drugs among pregnant women, yet there are no approved medications for protecting the vulnerable fetus or mother from its adverse health effects. The long-term objective of these studies is to develop antibody-based medications that can be given during pregnancy to protect the mother and fetus from the toxic and addictive effects of METH. While monoclonal antibody (mAb) therapy during human pregnancy is untested, seminal studies from our laboratory in pregnant rats reveal novel and therapeutically important changes to mAb pharmacokinetics (PKs) that compromise antibody efficacy. Specifically, mAb half-life, volume of distribution, and clearance all dramatically change with each gestation stage. Similar gestation-stage specific PK changes have not been reported previously, and the mechanisms that drive these changes are currently unknown. In related studies testing mAb function, certain anti-METH mAb medications (e.g., mAb6H4) show significant in vivo reductions in METH-binding function during the first 24 hrs after administration. This occurred even though >94% of the mAb doses were still present. Importantly, binding affinity for METH (KD) did not correlate with in vivo function despite all mAbs being administered at equal doses and displaying similar PK characteristics. The central hypothesis of this proposal is that the neonatal Fc receptor (FcRn) salvage pathway is both a key regulator of mAb clearance changes during pregnancy and facilitates in vivo reductions in mAb METH- binding function. FcRn is a well-characterized receptor that acts via a pH-dependent salvage mechanism to rescue IgG from catabolic elimination (clearance) and facilitate the passive transfer of IgG from mother to fetus. However, the role of FcRn in regulating mAb PKs during pregnancy is unknown. Furthermore, the low pH environment found in the salvage pathway suggests it could facilitate in vivo modifications to mAbs. To test our hypothesis, we will perform the following aims: 1 - Determine FcRn tissue expression levels during rat pregnancy at times when mAb clearance changes are maximal, 2 - Define the role of the FcRn salvage pathway in regulating IgG clearance during pregnancy, and 3 - Define the role of the FcRn salvage pathway in reducing mAb6H4 METH- binding function. The proposed studies will utilize immunohistochemistry and Western blotting techniques in conjunction with in vivo PK experiments in both pregnant and non-pregnant rats. Instrumental to these studies, anti-METH mAb6H4 will be re-engineered with a single amino acid mutation that eliminates FcRn binding and inhibits passage through the salvage pathway. In addition to providing an excellent training opportunity for a MD/PhD candidate, these innovative studies will contribute to the pre-clinical development of mAb medications for the protection of both the mother and fetus from the dangerous health effects of drugs of abuse.

描述（由申请人提供）：（+）-甲基苯丙胺（METH）是孕妇中最容易上瘾和滥用的药物之一，但没有批准的药物用于保护脆弱的胎儿或母亲免受其不良健康影响。这些研究的长期目标是开发基于抗体的药物，可以在怀孕期间给予，以保护母亲和胎儿免受METH的毒性和成瘾作用。虽然人类妊娠期间的单克隆抗体（mAb）治疗未经测试，但我们实验室在妊娠大鼠中进行的精液研究揭示了mAb药代动力学（PK）的新的和具有治疗意义的变化，这些变化会影响抗体疗效。具体而言，mAb半衰期、分布容积和清除率均随每个妊娠阶段显著变化。此前尚未报道过类似的妊娠阶段特定PK变化，驱动这些变化的机制目前尚不清楚。在测试mAb功能的相关研究中，某些抗METH mAb药物（例如，mAb 6 H4）在给药后的前24小时内显示出体内MET结合功能的显著降低。即使>94%的mAb剂量仍然存在，也会发生这种情况。重要的是，对METH的结合亲和力（KD）与体内功能无关，尽管所有mAb均以相同剂量给药并显示出相似的PK特征。该提议的中心假设是新生儿Fc受体（FcRn）补救途径既是妊娠期间mAb清除变化的关键调节因子，又有助于mAb METH结合功能的体内降低。 FcRn是一种充分表征的受体，通过pH依赖性补救机制发挥作用，将IgG从分解代谢消除（清除）中拯救出来，并促进IgG从母体被动转移至胎儿。然而，妊娠期间FcRn在调节mAb PK中的作用尚不清楚。此外，补救途径中发现的低pH环境表明其可促进mAb的体内修饰。为了检验我们的假设，我们将进行以下目的：1 -在大鼠妊娠期间确定mAb清除率变化最大时的FcRn组织表达水平，2 -确定FcRn补救途径在妊娠期间调节IgG清除率中的作用，和3 -确定FcRn补救途径在降低mAb 6 H4 METH结合功能中的作用.拟议的研究将利用免疫组织化学和蛋白质印迹技术，结合妊娠和非妊娠大鼠的体内PK实验。对于这些研究，抗METH mAb 6 H4将被重新工程化，具有消除FcRn结合并抑制通过补救途径的单个氨基酸突变。除了为MD/PhD候选人提供极好的培训机会外，这些创新研究还将有助于mAb药物的临床前开发，以保护母亲和胎儿免受滥用药物的危险健康影响。