Mitigating ADA Through Site-specific Conjugation Technology

摘要： 抗体药物结合物(ADC)的免疫原性越来越受到人们的关注，这是因为人们对免疫- 刺激药物输送技术。诺华公司最近的一项研究表明，14名患者中有14名服用了 在实验免疫刺激下，ADC产生了可测量的抗药物抗体(ADA)反应。 ADA通过中和药物、增加药物清除量和引起严重过敏而对治疗产生负面影响 反应。迫切需要一种有效的方法将有效载荷与抗体偶联，同时 最大限度地减少发展和反兴奋剂的影响。我们开发了一种ADC生物偶联技术 这采用了保守的Q295残基(由NIH 1RO1GM140026-O1A1继续提供资金)，我们 Believe将缓解ADA的许多担忧。这项提议的目标是证明这一点 技术降低了抗原提呈细胞(APC)对Fc-γ的摄取，并掩盖了药物与 通过将它们隐藏在Fc结构域上空间封闭的疏水口袋中。这个目标一定会实现的 通过这两个目标。目标1专注于开发基于核磁共振和荧光的工具来证明 Q295站点的ADC有效载荷被限制在空间封闭的IgG1疏水口袋内。对这件事 最后，我们建议使用不同的连接子(如短烷基， 多肽和聚乙二醇)，并使用两种实验方法确定它们与疏水口袋的接近程度： 1)使用俄勒冈州绿488的邻近诱导荧光猝灭试验，由于其具有自猝灭能力 和2)使用三氟甲基探针的F-19蛋白质核磁共振，由于其高灵敏度和低背景水平 生物样本。目标2专注于证明附着在立体闭塞的Q295上的有效载荷 减少了ADA结合并降低了Fc-γ引起的免疫原性的可能性 介导的ADC摄取。本文所述目标的实现将导致抗体偶联 降低ADA风险的技术，可能对免疫刺激的设计有用 抗体偶联。

Summary: Antibody drug conjugate (ADC) immunogenicity is a growing concern due to the increased interest in immune- stimulating drug delivery technology. A recent study by Novartis demonstrated that 14 out of 14 patients dosed with an experimental immune-stimulatory ADC developed a measurable anti-drug antibody (ADA) response. ADA negatively affects treatment by neutralizing drugs, increasing drug clearance, and causing severe allergic reactions. There is an urgent need for an effective method of conjugating payload to antibodies while minimizing the development and the effects of ADAs. We have developed an ADC bioconjugation technology that employs the conserved Q295 residue (continued funding provided by NIH 1RO1GM140026-O1A1) that we believe will mitigate many of these ADA concerns. The goal of this proposal is to demonstrate that this technology reduces Fc-gamma uptake in antigen presenting cells (APCs) and masks the drugs from binding to ADAs by hiding them in a sterically occluded hydrophobic pocket on the Fc domain. This goal will be achieved through the two aims. Aim #1 focuses on developing NMR and fluorescence-based tools to demonstrate that ADC payloads at the Q295 site are constrained within the sterically occluded IgG1 hydrophobic pocket. To this end we propose conjugating model payloads to the Q295 site using various linkers (such as short alkyl, peptide, and PEG) and determining their proximity to the hydrophobic pocket using two experimental methods: 1) a proximity induced fluorescent quenching assay using Oregon Green 488, due to its ability to self-quench and 2) F-19 protein NMR using a trifluoromethyl probe, due to its high sensitivity and low background level in biological samples. Aim #2 focuses on demonstrating that payloads attached to the sterically occluded Q295 position have reduced ADA binding and reduced potential for eliciting immunogenicity caused by Fc-gamma mediated uptake of ADCs. Achievement of the aims outlined herein will result in an antibody conjugation technology that exhibits a reduced risk of ADA and may be useful for the design of immune-stimulating antibody conjugates.