Rational Sequencing of PD-1 and CTLA-4 Antibodies in Metastatic Melanoma

描述（由申请人提供）：免疫检查点蛋白的抑制剂在黑色素瘤和其他肿瘤中显示出很大的前景，但对CTLA-4和PD-1抗体的应答率一直不高，没有明确的迹象表明哪些治疗前或药效学生物标志物与其疗效相关。在我们机构所做的工作中，已经在T细胞上鉴定了PD-1抗体BMS 936558和CTLA-4抗体伊匹单抗疗效的许多生物标志物。来自用这些抗体治疗的患者的肿瘤上的治疗前标志物，特别是PD-L1，也可能有希望预测抗PD-1的结果。抗PD-1可以在体内上调T细胞上CTLA-4的表达，反之亦然，并且CD 4 T细胞上CTLA-4表达的增加似乎与缺乏对PD-1抗体的应答相关，这表明对这两种抗体进行测序的合理基础。在Moffitt，P-7997正在进行的NCI RO 1支持的试验中，接受ipilimumab治疗的患者显示疾病进展，随后可能对PD-1抗体有反应，在这两个机构，PD-1抗体失败已显示对ipilimumab有反应，因此这两种抗体可能在治疗上无交叉耐药。为了研究PBMC上和肿瘤内的生物标志物并评估它们是否与序贯疗法的抗肿瘤活性相关，我们将进行PD-1抗体BMS 936558随后CTLA-4抗体伊匹单抗或反之亦然的双中心II期随机研究。在该提案的第一个目的中，我们将在伊匹单抗或PD-1抗体的第一个周期之前、之后和第二个治疗周期之后通过白细胞分离术收集外周血，并基于Moffitt PI实验室的先前工作，在两种抗体的测序方案之前和之后测量循环T细胞上和循环T细胞中的各种标志物。为了探索浸润肿瘤的T细胞中哪些因子被这些抗体靶向或在肿瘤内 微环境可能是其疗效的重要生物标志物，我们将分析肿瘤PD-L1表达，计算浸润T细胞的“免疫评分”，并在第二个目标的工作中，基于Dana Farber进行的工作，在治疗前对肿瘤内的这些细胞进行表型表征。在第三个目标中，我们将尝试确定肿瘤微环境中和宿主效应T细胞上的哪些因子与任一组中联合抗体疗法的临床结果相关。该提案将确定一种新的序贯免疫治疗方案的耐受性和潜在疗效，并提出新的预测性和药效学生物标志物，以在更大规模的联合治疗III期试验中进行验证。并允许更合理地选择使用这些药物治疗的专利。

DESCRIPTION (provided by applicant): Inhibitors of immune checkpoint proteins have shown great promise in melanoma and other tumors, but response rates to antibodies against CTLA-4 and PD-1 have been modest, with no clear indication of what pre-treatment or pharmacodynamic biomarkers are associated with their efficacy. In work done at our institutions, a number of biomarkers of the efficacy of PD-1 antibody BMS 936558 and CTLA-4 antibody ipilimumab have been identified on T cells. Pre-treatment markers on tumors from patients treated with those antibodies, particularly PD-L1, may also have promise for prediction of outcome with anti-PD-1. Anti-PD-1 can up-regulate expression of CTLA-4 on T cells in vivo and vice-versa, and increased CTLA-4 expression on CD4 T cells appears to be associated with lack of response to PD-1 antibody, suggesting a rational basis for sequencing those two antibodies. In an ongoing NCI RO1- supported trial at Moffitt, P-7997, patients treated with ipilimumab that show progression of disease may subsequently respond to PD-1 antibody, and at both institutions, PD-1 antibody failures have been shown to respond to ipilimumab, so the two antibodies may be therapeutically non-cross resistant. In order to study biomarkers on PBMC and within the tumor and assess if they are associated with anti- tumor activity with sequential therapy we will perform a two-center phase II randomized study of PD-1 antibody BMS 936558 followed by CTLA-4 antibody ipilimumab or vice versa. In the first aim of the proposal, we will collect peripheral blood by leukapheresis prior to, after the first cycle of eithr ipilimumab or PD-1 antibody, and after the second cycle of treatment and measure a variety of markers on and in circulating T cells prior to and after the reciprocally sequenced regimens of the two antibodies based on prior work in the PI's laboratory at Moffitt. In order to explore what factors in T cells infiltrating the tumor that are targeted by these antibodies or within the tumor microenvironment which may be important biomarkers for their efficacy, we will analyze tumor PD-L1 expression, calculate an "immunoscore" of infiltrating T cells as well as phenotypically characterize those cells within the tumor prior to treatment in the work of the second aim, based on work performed at Dana Farber. In the third aim we will then attempt to determine what factors in the tumor microenvironment and on the host effector T cells are associated with clinical outcome with the combined antibody therapy in either arm. If successful, this proposal will establish the tolerability and potential efficacy of a new sequential immunotherapy regimen and suggest novel predictive and pharmacodynamic biomarkers to be validated in larger phase III trials of the combination and allow a more rational selection of patents for treatment with these drugs.