Department of Clinical Immunology, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA.
J Immunol Methods. 2013 Oct 31;396(1-2):44-55. doi: 10.1016/j.jim.2013.07.010. Epub 2013 Aug 6.
As with other protein therapeutics, trebananib (AMG 386), an investigational peptide Fc-fusion protein ("peptibody") that inhibits angiogenesis by neutralizing the interaction of angiopoietin-1 (Ang1) and angiopoietin-2 (Ang2) with the Tie2 receptor, has the potential to trigger an immune response in cancer patients treated with the therapeutic. An electrochemiluminescence bridging anti-drug antibody (ADA) assay that was utilized to support early-phase clinical trials in the development of trebananib was found to lack adequate sensitivity and drug tolerance in later-phase clinical studies when higher doses of trebananib were administered. Therefore, we developed a surface plasmon resonance (SPR) immunoassay method utilizing a secondary confirmatory detector antibody (goat anti-human IgG F[ab']2) known to cross-react with human IgG and IgM to better assess the potential impact of immunogenicity on the pharmacokinetics, pharmacodynamics, and toxicity of trebananib. The SPR method was more sensitive than the electrochemiluminescence bridging assay because of signal amplification from the confirmatory binding of the detector antibody; drug tolerance was improved since antibody binding avidity does not affect detection on this platform. Despite the inability of the confirmatory detector antibody to bind angiopoietins in protein-free buffer, false-positive ADA results were generated from patient serum samples containing Ang1 and Ang2 through an apparently specific binding between the angiopoietins and the confirmatory detector antibody, likely mediated by the interaction of the angiopoietins with serum immunoglobulins. Addition to the sample diluent of a human antibody that specifically binds to Ang1 and Ang2 with high affinity resulted in a complete block of angiopoietin interference without affecting ADA detection. This biosensor-based assay provides a reliable method for assessing immunogenicity in phase 3 clinical trials.
与其他蛋白治疗药物一样，替班尼布（AMG 386）是一种研究中的肽 Fc 融合蛋白（“肽抗体”），通过中和血管生成素-1（Ang1）和血管生成素-2（Ang2）与 Tie2 受体的相互作用来抑制血管生成，有可能在接受治疗的癌症患者中引发免疫反应。在替班尼布的开发过程中，用于支持早期临床试验的电化学发光桥接抗药物抗体（ADA）检测方法在后期临床试验中发现缺乏足够的灵敏度和药物耐受性，当时给予了更高剂量的替班尼布。因此，我们开发了一种表面等离子体共振（SPR）免疫分析方法，该方法利用已知与人 IgG 和 IgM 交叉反应的二级确认检测抗体（山羊抗人 IgG F[ab']2），以更好地评估免疫原性对替班尼布药代动力学、药效学和毒性的潜在影响。SPR 方法比电化学发光桥接检测方法更灵敏，因为来自确认结合的检测抗体的信号放大；由于抗体结合亲和力不会影响该平台上的检测，因此药物耐受性得到改善。尽管确认检测抗体在无蛋白缓冲液中不能结合血管生成素，但来自含有 Ang1 和 Ang2 的患者血清样本的假阳性 ADA 结果是通过血管生成素与确认检测抗体之间显然的特异性结合产生的，这可能是由血管生成素与血清免疫球蛋白的相互作用介导的。在样品稀释剂中添加与人 Ang1 和 Ang2 具有高亲和力特异性结合的抗体可完全阻断血管生成素干扰，而不影响 ADA 检测。这种基于生物传感器的测定法为在 3 期临床试验中评估免疫原性提供了一种可靠的方法。
