(PQD5) A novel genetic strategy to predict efficacy of anti-CD20 antibodies

描述(申请人提供)：非霍奇金淋巴瘤(NHL)是美国第六大常见恶性肿瘤，今年新增约7万例。利妥昔单抗是一种针对B细胞表面CD20抗原的单抗，用于治疗大多数NHL患者，显著提高了生存率。然而，并不是所有的患者最初对利妥昔单抗都有反应，许多其他患者最终会产生耐药性。正因为如此，大量生物相似的新一代抗CD20抗体正处于临床开发的不同阶段，需要更好的抗体反应预测指标来优化治疗选择。我们的长期目标是开发基因策略，为个别患者量身定做治疗选择。这种遗传方法特别适用于免疫疗法，因为复杂和遗传可变的免疫系统介导了药物反应。利妥昔单抗介导细胞死亡的两种机制是抗体依赖性细胞毒作用(ADCC)和补体依赖性细胞毒作用(CDC)。介导ADCC和CDC、FCGR3A和C1QA的基因的遗传多态可以预测利妥昔单抗治疗的结果。我们已经发现了第三个基因CBLB，它在体外介导利妥昔单抗反应，尽管它在体内的重要性尚未得到测试。用动物模型进行体内实验来测试人源化抗体的作用机制并不容易，因为需要完整的免疫系统来识别人源化抗体本身是外来的。因此，我们采用了一种新的遗传学方法，使用带注释的人类样本来解决将体内和体外反应联系起来的可能性，以表征和预测患者对利妥昔单抗的反应。我们假设FCGR3A、C1QA和CBLB三个基因的遗传多态性决定了体外的利妥昔单抗应答，并准确地预测了体内的利妥昔单抗应答。这项建议的具体目的是在体外测试这三个基因的变化的效果， 用CDC和ADCC法检测各基因对利妥昔单抗应答的影响。然后，我们将测试弥漫性大B细胞淋巴瘤(DLBCL)患者的大型临床试验队列，以测量这三个基因在体内的多态效应。我们将比较体外和体内的结果，以验证体外系统。最后，我们将在我们的体外系统中测试新的抗CD20抗体，以与利妥昔单抗相比，测量FCGR3A、C1QA和CBLB基因多态性的效果。通过这种方式，未来这些药物的临床使用可以根据患者的基因型进行个性化，优化抗CD20抗体的使用，以改善临床结果。

DESCRIPTION (provided by applicant): Non-Hodgkin lymphoma (NHL) is the sixth most common malignancy in the U.S., with ~70,000 new cases this year. Rituximab, a monoclonal antibody targeting the CD20 antigen on B-cells, is used to treat the majority of NHL patients, and has improved survival rates significantly. However, not all patients respond to rituximab initially, and many other patients eventually develop resistance. Because of this, a plethora of biosimilar and next-generation anti-CD20 antibodies are in various stages of clinical development, necessitating better predictors of antibody response to optimize choice of therapy. Our long-term objective is to develop genetic strategies to tailor therapy choices to individual patients. This genetic approach is particularly pertinent for immunotherapies, with a complex and genetically variable immune system mediating drug response. Two mechanisms of rituximab-mediated cell death are antibody-dependent cell mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). Inherited polymorphisms in genes mediating ADCC and CDC, FCGR3A and C1QA, predict outcomes after rituximab treatment. We have discovered a third gene, CBLB, which mediates rituximab response in vitro, although its significance in vivo is untested. In vivo experiments to test mechanism of action of humanized antibodies are not easily addressed with animal models, since the intact immune system that is required recognizes the humanized antibody itself as foreign. Therefore, we employ a novel genetic approach using annotated human samples to address the potential for linking in vivo and in vitro responses to characterize and predict response to rituximab in patients. We hypothesize that inherited polymorphisms in three genes, FCGR3A, C1QA, and CBLB, determine rituximab response in vitro, and accurately predict rituximab response in vivo. The specific aims of this proposal are to test the effect of alterations in these three genes in vitro, using CDC and ADCC assays, to measure the effect of each gene on rituximab response. We will then test a large clinical trial cohort of diffuse large B-cell lymphoma (DLBCL) patients to measure the effect of polymorphisms in the three genes in vivo. We will compare in vitro and in vivo results to validate the in vitro system. Finally, we will test newer anti-CD20 antibodies usin our in vitro system, to measure effects of FCGR3A, C1QA, and CBLB polymorphisms compared with rituximab. In this way, future clinical use of these agents can be personalized based on patient genotype, optimizing use of anti-CD20 antibodies for improved clinical outcomes.