Anti-CD138-IFN fusion proteins for the immunotherapy of multiple myeloma

项目摘要/摘要 多发性骨髓瘤(MM)仍然是一种无法治愈的恶性肿瘤，新的治疗方法的发展 方法是必需的。该项目将开发的治疗剂是I型融合蛋白 或将II型干扰素(干扰素)与识别MM上存在的CD138抗原的抗体基因融合 细胞。干扰素具有强大的抗肿瘤特性，有可能成为有效的癌症治疗药物。事实上，干扰素α 已被用于治疗多发性骨髓瘤，但其临床应用一直受到限制，因为它是困难的，如果不是 在不引起全身毒性的情况下，不可能在肿瘤部位获得有效的治疗剂量。 我们假设，与识别CD138的抗体融合的干扰素将选择性地靶向肿瘤 并将能够达到有效的浓度而不会产生毒性。我们到目前为止的实验支持这一点 假设。目前的目标之一是开发和表征体外和体内的 高表达干扰素α-2、干扰素α-14和α-2突变体(α-2YNS)融合蛋白的免疫效力 干扰素受体或干扰素γ的亲和力，目的是确定治疗MM的最佳疗法。 蛋白酶体抑制剂Bortezomib和反应停衍生物来那度胺是FDA批准的治疗方法 在治疗MM方面有效，但不能治愈。我们现在将确定是否将最有效的FP与这些 标准疗法将导致体外和体内抗肿瘤作用的相加或协同作用。多发性骨髓瘤 不仅包括浆细胞和浆母细胞，还包括前浆母细胞亚群和CD20+ B细胞祖细胞。为了彻底根除所有多发性骨髓瘤细胞，我们现在将检验这样一种假设：结合 抗CD20-干扰素FP与抗CD138-干扰素FP将在移植MM的小鼠中产生更好的疗效。一 干扰素的重要特性是它们能够增强抗肿瘤免疫反应。研究FP疗法 在模拟人类MM的生理相关系统中，包括骨髓的作用 微环境，我们将使用两个很好的模型，Vκ*myc和bclxl/myc细胞系，以及 将靶向小鼠CD138。在免疫功能正常的小鼠身上建立这种治疗方法的模型将允许 需要探索的重要变量，包括负责的免疫效应机制，可能的免疫- 相关毒性，以及二次“就地接种”影响的可能性。宿主干扰素受体的作用 将使用Vκ*myc模型和干扰素受体缺陷的C57BL/6小鼠进行评估。干扰素的作用 MM细胞上表达的受体将通过RNAi抑制其在589细胞上的表达来评估。 利用这些模型，FPS和硼替佐米或来那度胺在预防肿瘤方面的潜在协同作用 增长将是决定性的。免疫检查点阻断增强FP疗效的能力也将被 使用抗PD-1/L1治疗进行评估。我们相信，这些研究的成功完成可能会 为抗CD138融合蛋白的临床转译提供数据支持。

Project Summary/Abstract Multiple myeloma (MM) remains an incurable malignancy for which the development of new therapeutic approaches is required. The therapeutic agents to be developed in this project are fusion proteins with type I or type II interferon (IFN) genetically fused to an antibody that recognizes the CD138 antigen present on MM cells. IFNs have potent anti-tumor properties and the potential to be effective cancer therapeutics. Indeed IFNα has been used in the treatment of MM, but its clinical use has been limited because it is difficult if not impossible to achieve therapeutically effective doses at the site of the tumor without causing systemic toxicity. We hypothesize that IFN fused to an antibody that recognizes CD138 will be selectively targeted to the tumor and will be able to achieve an effective concentration without being toxic. Our experiments to date support this hypothesis. One objective of the current undertaking is to develop and characterize the in vitro and in vivo effectiveness of fusion proteins (FPs) containing IFNα2, IFNα14, a mutant of IFNα2 (IFNα2YNS) with high affinity for the IFN receptor, or IFNγ, with the goal of identifying the optimal therapeutic for MM. The proteasome inhibitor bortezomib and the thalidomide derivative lenalidomide are FDA-approved therapies effective in treating but not curing MM. We will now determine if combining the most efficacious FPs with these standard therapies will result in additivity or synergy of the in vitro and in vivo anti-tumor effects. MM tumors consist not only of plasma cells and plasmablasts, but also of subpopulations of pre-plasmablasts and CD20+ B cell progenitors. In an effort to fully eradicate all MM cells, we will now test the hypothesis that combining anti-CD20-IFN FPs with anti-CD138-IFN FPs will yield improved efficacy in mice bearing MM xenografts. One important property of the IFNs is their ability to potentiate anti-tumor immune responses. To study FP therapy in a physiologically-relevant system that mimics human MM, including the role of the bone marrow microenvironment, we will use two well-characterized models, the Vκ*MYC and the Bcl-XL/Myc cell lines, and will target murine CD138. Modeling of this therapeutic approach in immunocompetent mice will allow several important variables to be explored, including the responsible immune effector mechanisms, possible immune- related toxicities, and the potential for secondary “in situ vaccination” effects. The role of host IFN receptors will be evaluated using the Vκ*MYC model and IFN receptor deficient C57BL/6 mice. The role of the IFN receptors expressed on the MM cells will be evaluated by inhibiting their expression on 589 cells using RNAi. Using these models, the potential synergy between FPs and bortezomib or lenalidomide in preventing tumor growth will be determined. The ability of immune checkpoint blockade to enhance FP efficacy will also be evaluated using treatment with anti-PD-1/L1. We believe that successful completion of these studies may provide the data to support the translation of anti-CD138 fusion proteins into the clinic.