William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, and Queen Mary University of London, London, UK.
University of Trieste, Trieste, Italy.
Arthritis Rheumatol. 2015 Oct;67(10):2661-72. doi: 10.1002/art.39232.
Biologic drugs, such as the anti-tumor necrosis factor (anti-TNF) antibody adalimumab, have represented a breakthrough in the treatment of rheumatoid arthritis. Yet, concerns remain over their lack of efficacy in a sizable proportion of patients and their potential for systemic side effects such as infection. Improved biologic prodrugs specifically targeted to the site of inflammation have the potential to alleviate current concerns surrounding biologic anticytokine therapies. The purpose of this study was to design, construct, and evaluate in vitro and ex vivo the targeting and antiinflammatory capacity of activatable bispecific antibodies.
Activatable dual variable domain (aDVD) antibodies were designed and constructed to target intercellular adhesion molecule 1 (ICAM-1), which is up-regulated at sites of inflammation, and anti-TNF antibodies (adalimumab and infliximab). These bispecific molecules included an external arm that targets ICAM-1 and an internal arm that comprises the therapeutic domain of an anti-TNF antibody. Both arms were linked to matrix metalloproteinase (MMP)-cleavable linkers. The constructs were tested for their ability to bind and neutralize both in vitro and ex vivo targets.
Intact aDVD constructs demonstrated significantly reduced binding and anti-TNF activity in the prodrug formulation as compared to the parent antibodies. Human synovial fluid and physiologic concentrations of MMP enzyme were capable of cleaving the external domain of the antibody, revealing a fully active molecule. Activated antibodies retained the same binding and anti-TNF inhibitory capacities as the parent molecules.
The design of a biologic prodrug with enhanced specificity for sites of inflammation (synovium) and reduced specificity for off-target TNF is described. This construct has the potential to form a platform technology that is capable of enhancing the therapeutic index of drugs for the treatment of RA and other inflammatory diseases.
生物药物，如抗肿瘤坏死因子（抗 TNF）抗体阿达木单抗，在治疗类风湿关节炎方面取得了突破。然而，人们仍然担心它们在相当一部分患者中的疗效不佳，以及它们可能产生全身性副作用，如感染。针对炎症部位的改良生物前药具有减轻当前对生物抗细胞因子治疗的担忧的潜力。本研究旨在设计、构建和评估体外和体内激活双特异性抗体的靶向性和抗炎能力。
设计并构建了可激活的双可变结构域（aDVD）抗体，以靶向细胞间黏附分子 1（ICAM-1），ICAM-1 在炎症部位上调，并靶向抗 TNF 抗体（阿达木单抗和英夫利昔单抗）。这些双特异性分子包含一个靶向 ICAM-1 的外部臂和一个包含抗 TNF 抗体治疗结构域的内部臂。两个臂都与基质金属蛋白酶（MMP）可切割接头相连。测试了这些构建物结合和中和体内和体外靶标的能力。
与亲本抗体相比，完整的 aDVD 构建物在前药制剂中表现出明显降低的结合和抗 TNF 活性。人滑膜液和生理浓度的 MMP 酶能够切割抗体的外部结构域，从而揭示出完全活性的分子。激活的抗体保留了与亲本分子相同的结合和抗 TNF 抑制能力。
描述了一种具有增强对炎症部位（滑膜）特异性和降低对非靶标 TNF 特异性的生物前药的设计。该构建物有可能形成一种平台技术，能够提高治疗类风湿关节炎和其他炎症性疾病的药物的治疗指数。
