Targeting Neuroblastoma with armed T cells

描述（由申请人提供）：4期神经母细胞瘤（NB）是一种侵袭性疾病，发生于0 ~ 18个月大的儿童，通常在诱导治疗成功后复发。尽管进行了强化治疗，但生存率仍然令人无法接受。在NB上表达的神经节苷脂GD2是抗体依赖性细胞毒性的理想靶点。抗gd2单克隆抗体（mAb）免疫治疗可显著延长无进展生存期（PFS）和提高总生存期（OS）；然而，37%的IV期患者在2年内复发。不幸的是，抗gd2单克隆抗体的临床疗效受到毒性的限制。我们需要新的和创新的方法来增加抗肿瘤活性而不增加毒性。我们最近发现，用小鼠GD2Bi（抗cd3 x抗gd2双特异性抗体）武装的抗cd3激活T细胞（ATC）和用抗cd3 x抗gd2（人源化3F8）武装的ATC在体外和体内对NB细胞表现出增强的效力。在输注hu3F8Bi武装ATC后的NB异种移植模型中，肿瘤生长延迟，生存率提高。在一项针对转移性乳腺癌的I期临床试验中，多次输注抗cd3 x抗Her2双特异性抗体（Her2Bi）的ATC联合低剂量IL-2和粒细胞-巨噬细胞集落刺激因子（GM-CSF），对重度预处理的IV期转移性0-3+ Her2阳性乳腺癌患者是安全的，可诱导抗乳腺癌细胞毒性、抗乳腺癌抗体、血清Th1细胞因子模式和IL-12水平。令人惊讶的是，中位生存期为36个月，在开始免疫治疗后15周，22名可评估患者中有1名肝转移患者有非常好的部分缓解，12名患者病情稳定。我们假设hu3F8Bi武装ATC会增强抗NB细胞毒性，并使患者接种疫苗对抗自身的NB抗原。为了验证这个假设,我们提出以下具体目标:1)提交印第安纳州,生产GD2Bi (hu3F8Bi),并执行一个阶段我剂量递增协议复发/难治性患者NB和阻止GD2 +肿瘤确定hu3F8Bi武装ATC的MTD注入每周两次8注入结合日常低剂量(每天300000 IU / m2) - 2在一个标准的3 + 3剂量升级模式与40,80,和160 x 106细胞/公斤/注入剂量水平;2)开展22例患者的II期临床试验，利用MTD探索hu3F8Bi武装ATC的疗效并确认其毒性特征；3)连续监测针对NB(细胞毒性，IFN？elispot)、表型、细胞因子模式和NB抗体；4)评估血液和肿瘤活检中武装ATC的生存和持久性，以确认武装ATC向肿瘤贩运；5)选择10例PET/CT可测量的软组织和骨骼病变患者，对[18F] FDG PET/CT进行探索性研究，评估武装ATC的贩运情况。如果成功，这些研究将为NB的治疗模式提供一个转变，细胞毒性不仅可以减少最小的残留疾病，还可以“接种”患者对抗自身肿瘤，从而显著改善PFS和OS。

DESCRIPTION (provided by applicant): Stage IV neuroblastoma (NB) in children >18 months of age is an aggressive disease that often recurs after successful induction therapy. Despite intensive treatment regimens, survival rates are unacceptable. Ganglioside GD2 expressed on NB is an ideal target for antibody-dependent cellular cytotoxicity. Anti-GD2 monoclonal antibody (mAb) immunotherapy in stage IV patients with minimal residual disease significantly prolongs progression free survival (PFS) and increased overall survival (OS); however, 37% of these stage IV patients relapse within 2 years. Unfortunately, clinical efficacy of anti-GD2 mAbs has been limited by toxicities. There is a need for novel and innovative approaches that increase anti-tumor activity without increasing toxicities. We recently showed that anti-CD3 activated T cells (ATC) armed with murine GD2Bi (anti-CD3 x anti-GD2 bispecific antibody) and ATC armed with anti-CD3 x anti-GD2 (humanized version of 3F8) exhibit enhanced in vitro and in vivo potency against NB cells. Delayed tumor growth and improved survival was seen in a NB xenograft model following infusions of hu3F8Bi armed ATC. In a phase I clinical trial for metastatic breast, multiple infusions of anti-CD3 x anti-Her2 bispecific antibody (Her2Bi) armed ATC in combination with low dose IL-2 and granulocyte-macrophage colony stimulating factor (GM-CSF) in women with heavily pretreated stage IV metastatic 0-3+ Her2 positive breast cancer were safe, induced anti-breast cancer cytotoxicity, anti-breast cancer antibodies, serum Th1 cytokine patterns, and IL-12 levels. Surprisingly, median OS was 36 months with 1 very good partial response in a patient with liver metastases and 12 patients with stable disease out of 22 evaluable pts at 15 weeks after starting immunotherapy. We hypothesized that hu3F8Bi armed ATC will enhance anti-NB cytotoxicity and vaccinate the pts against their own NB antigens. To test this hypothesis, we propose the following specific aims: 1) Submit a IND, produce GD2Bi (hu3F8Bi), and perform a phase I dose-escalation protocol in patients with recurrent/refractory NB and GD2+ tumors to determine the MTD for hu3F8Bi armed ATC infused twice a week for 8 infusions in combination with daily low dose IL-2 (300,000 IU/m2/day) in a standard 3 + 3 dose escalation schema with 40, 80, and 160 x 106 cells/kg/infusion dose levels; 2) Conduct a phase II clinical trial in 22 patients to explore efficacy and confirm the toxicity profile of hu3F8Bi armed ATC using the MTD; 3) Sequentially monitor immune responses directed at NB (cytotoxicity, IFN? EliSpots), phenotyping, cytokine patterns, and antibodies to NB; 4) Assess survival and persistence of armed ATC in the blood and tumor biopsies to confirm trafficking of armed ATC to tumor; and 5) Conduct an exploratory study of [18F] FDG PET/CT in 10 selected patients with PET/CT measurable soft tissue and skeletal lesions to evaluate trafficking of armed ATC. If successful, these studies will provide a shift in the treatment paradigm for NB where cytotoxicity would not only reduce minimal residual disease but also "vaccinate" the patients against their own tumor resulting in significant improvement in PFS and OS.