Antibody Therapy Targeting a Novel Neuroblastoma Antigen

描述（申请人提供）：神经母细胞瘤是儿童最常见的颅外实体瘤。积极的化疗和手术改善了年轻患者的缓解率，但对青少年或成人则不然，因为神经母细胞瘤对化疗尤其具有耐药性。因此，迫切需要新的治疗方法，特别是对于这一难以治疗的患者群体。本提案的目标是开发一种新的治疗性单克隆抗体（mAb），针对一种新的神经母细胞瘤相关抗原。从小鼠腹水中制备并纯化一组4 - 6个单克隆抗体。这些单克隆抗体将在体外进行鉴定，以选择最佳的一到两个候选抗体进行进一步的II期临床前开发。目标细胞的特异性将通过测试单克隆抗体与大量神经母细胞瘤细胞系的结合来确定，以及通过免疫荧光检测多种其他肿瘤细胞类型。评估单抗与正常非转化细胞的结合也将被研究。免疫组织化学分析将评估mAb与来自患者的神经母细胞瘤组织以及不同正常组织类型的结合。单克隆抗体单独或在补体或抗体依赖的细胞毒性效应细胞存在下的潜在细胞毒性作用将在体外对神经母细胞瘤细胞系进行测试。单克隆抗体内化到神经母细胞瘤细胞系的能力将在体外进行评估。这些研究的结果将表明，在未来的II期动物模型中，选择的单抗是否可以单独治疗，或者是否应该加入毒性部分来杀死神经母细胞瘤细胞。初步结果表明，新抗原NBA260是一种适合的神经母细胞瘤靶向靶点，将通过NBA260的纯化和氨基酸测序来证实。这项研究的结果将为神经母细胞瘤患者以及其他类型的癌症（如卵巢癌和肝癌）提供一种新的治疗选择的有效性。

DESCRIPTION (provided by applicant): Neuroblastoma is the most common extracranial solid tumor of childhood. Aggressive chemotherapy and surgery have improved remission rates for young patients, but not for adolescents or adults, in whom neuroblastoma is especially resistant to chemotherapy. Thus, new therapeutic proaches are desperately needed, especially for this difficult to treat patient group. The goal of this proposal is to develop a new therapeutic monoclonal antibody (mAb) directed against a novel neuroblastoma-associated antigen. A panel of 4 - 6 mAbs will be produced and purified from mouse ascites fluid. These mAbs will be characterized in vitro to select the best one or two candidates for further pre-clinical development in Phase II studies. The target cell specificity will be determined by testing the binding of the mAbs to a large anel of neuroblastoma cell lines, as well as a diverse selection of other tumor cell types by immunofluorescence. Evaluation of mAb binding to normal non-transformed cells will also be studied. Immunohistochemical analysis will evaluate mAb binding to neuroblastoma tissues derived from patients, as well as a panel of different normal tissue types. The potential cytotoxic effects of mAbs alone or in the presence of complement or antibodydependent cytotoxic effector cells will be tested against neuroblastoma cell lines in vitro. The ability of the mAbs to internalize into neuroblastoma cell lines will evaluated in vitro. The results of these studies will indicate whether the mAb of choice may be therapeutic alone or whether it should be armed with a toxic moiety to kill neuroblastoma cells in future Phase II animal models. Preliminary results indicating that the novel antigen termed NBA260 is a suitable target for nueroblastoma targeting will be confirmed by purification of NBA260 and amino acid sequencing. The results of this study will demonstrate the validity of a new therapeutic option for neuroblastoma patients and possibly other types of cancer such as ovarian and liver cancer.