Bispecific antibodies (BsAbs) are undergoing continued development for applications in oncology and autoimmune diseases. While increasing activity by having more than one targeting arm, most BsAb engineering employs single Fc engagement as monoclonal antibodies. Here, we designed a novel immunoglobulin gamma-1 (IgG1)-derived dual-Fc BsAb containing two Fc regions and two distinct asymmetric antigen binding arms comprising a Fab arm and another VHH domain. In conjunction with the knob-into-hole technology, dual-Fc BsAbs could be produced with a high yield and good stability. We explore how Fc engineering effects on dual-Fc constructs could boost the desired therapeutic efficacy. This new format enabled simultaneous bispecific binding to corresponding antigens. Furthermore, compared to the one-Fc control molecules, dual-Fc BsAbs were shown to increase the avidity-based binding to FcγRs to result in higher ADCC and ADCP activities by potent avidity via binding to two antigens and Fc receptors. Overall, this novel BsAb format with enhanced effector functionalities provides a new option for antibody-based immunotherapy.

中文翻译：

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具有增强 Fc 效应功能的新型双 Fc 双特异性抗体

双特异性抗体 (BsAb) 正在持续开发，以应用于肿瘤学和自身免疫性疾病。虽然通过拥有多个靶向臂来提高活性，但大多数 BsAb 工程采用单个 Fc 接合作为单克隆抗体。在这里，我们设计了一种新型免疫球蛋白γ-1（IgG1）衍生的双Fc BsAb，包含两个Fc区和两个不同的不对称抗原结合臂（包括一个Fab臂和另一个VHH结构域）。结合knob-into-hole技术，可以生产高产率和良好稳定性的双Fc BsAb。我们探索 Fc 工程对双 Fc 构建体的影响如何提高所需的治疗效果。这种新形式能够同时双特异性结合相应的抗原。此外，与单 Fc 对照分子相比，双 Fc BsAb 被证明可以增加与 FcγR 的亲和力结合，通过与两种抗原和 Fc 受体结合的有效亲和力，导致更高的 ADCC 和 ADCP 活性。总体而言，这种具有增强效应功能的新型双特异性抗体形式为基于抗体的免疫疗法提供了新的选择。