Combination Immunotherapy for Lung Cancer

描述（由申请人提供）：尽管有化疗，但肺转移性腺癌患者预后较差，因此正在开发新的治疗方式，如免疫治疗。最近进行了两项利用基于转基因csf的肿瘤细胞疫苗的试验，报告了免疫和临床反应。Colombo的研究小组扩展了使用GM-CSF的概念，在小鼠模型中加入了树突状细胞（dc）的一种强效激活剂CD40配体的表达，并表明这种组合比单独使用GM-CSF更有效。Brenner的研究小组表明，转染CD40配体基因的旁观者细胞与肿瘤细胞混合，在小鼠模型中是一种有效的疫苗。基于这些观察结果，我们创建了一个表达GM-CSF和CD40配体（GM.CD40L）的人类旁观者细胞系。在离体人自体肿瘤细胞/淋巴结细胞混合模型中，该细胞系增强了抗肿瘤T细胞反应的激活。诱导DC分泌IL-12和MJP-1a，表达CD83、HLA-DR和CD86，证实DC活化。我们完成了一项涉及实体肿瘤患者的I期试验，测试GM.CD40L细胞与自体肿瘤细胞的混合。疫苗是安全的，这些患者的疫苗部位密集浸润了活化的（CD86阳性）dc和T细胞。我们现在建议在II期试验中测试这种疫苗的有效性。该疫苗将由两部分组成：(1)两种人肺腺癌细胞系的混合物，作为肿瘤抗原的来源；(2)GM.CD40L细胞在疫苗部位招募和激活DCs。鉴于目前的观点，疫苗作为单一剂没有也不可能产生合理的肿瘤反应率，我们建议加入全反式维甲酸（ATRA）来增强疫苗的效果。ATRA分化未成熟髓样细胞（ImC），存在于过量的癌症患者。ImC的积累是肿瘤源性因子干扰DC分化的结果，这些ImC实际上抑制抗原特异性T细胞反应。由于我们的疫苗需要功能性dc，我们建议在接种疫苗之前治疗ATRA患者。在我们的临床前模型中，ATRA改善了GM.CD40L细胞诱导的抗肿瘤T细胞反应。除了确定临床疗效外，我们还将确定该策略是否导致肿瘤抗原特异性T细胞反应的激活以及治疗患者DC: ImC比率的改善。

DESCRIPTION (provided by applicant): Despite chemotherapy, patients with metastatic adenocarcinoma of the lung have a poor prognosis, therefore novel modalities such as immunotherapy are being developed for this disease. Two recent trials have been conducted utilizing GM-CSF-based tumor cell vaccines, with both immune and clinical responses reported. Colombo's group extended the concept of using GM-CSF by adding the expression of a potent activator of dendritic cells (DCs), CD40 ligand, in a murine model and showed that the combination was more effective than GM-CSF alone. Brenner's group showed that bystander cells transfected with the CD40 ligand gene admixed with tumor cells is an effective vaccine in a murine model. Based on these observations, we created a human bystander cell line that expresses both GM-CSF and CD40 ligand (GM.CD40L). This cell line enhanced the activation of an anti-tumor T cell response in an ex vivo human mixed autologous tumor cell/lymph node cell model. IL-12 and MJP-1a secretion, as well as expression of CD83, HLA-DR, and CD86 on DCs was induced confirming DC activation. We completed a phase I trial involving patients with solid tumors, testing GM.CD40L cells admixed with autologous tumor cells. The vaccine was safe, and the vaccine sites of these patients were densely infiltrated with activated (CD86 positive) DCs and T cells. We now propose to test the efficacy this vaccine in a phase II trial. The vaccine will consist of two components: (1) a mixture of two human lung adenocarcinoma cell lines that will serve as the source of tumor antigens, and (2) GM.CD40L cells to recruit and activate DCs at the vaccine site. Given the current view that vaccines given as a single agent have not and are unlikely to ever produce reasonable tumor response rates, we propose to incorporate all-trans retinoic acid (ATRA) to augment the effect of the vaccine. ATRA differentiates the immature myeloid cells (ImC) that are present in excess in cancer patients. ImC's accumulate as a result of tumor derived factor interference with DC differentiation, and these ImC in fact inhibit antigen specific T cell responses. Since our vaccine requires functional DCs, we propose to treat patients with ATRA before administering vaccines. In our pre-clinical model ATRA improved anti-tumor T cell responses induced by GM.CD40L cells. In addition to determining clinical efficacy, we will also determine if the strategy results in the activation of tumor antigen-specific T cell responses and an improvement in the DC: ImC ratio in treated patients.