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

描述(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巨大的前景，但对针对CTLA-4和PD-1的抗体的响应率一直不高，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有关。在我们机构所做的工作中，已经在T细胞上发现了一些PD-1抗体BMS 936558和CTLA-4抗体ipilimumab疗效的生物标志物。使用这些抗体，特别是PD-L1治疗的患者肿瘤的治疗前标志物也可能对抗PD-1治疗的结果进行预测。在体内，抗PD-1抗体可上调T细胞表面CTLA-4的表达，反之亦然，CD4T细胞CTLA-4的表达增加可能与PD-1抗体反应不足有关，为这两种抗体的测序提供了合理的依据。在P-7997的Moffitt进行的由NCI RO1支持的试验中，用ipilimumab治疗的出现疾病进展的患者随后可能对PD-1抗体有反应，而在这两个机构，PD-1抗体失效对ipilimumab有反应，因此这两种抗体在治疗上可能是非交叉耐药的。为了研究外周血单核细胞和肿瘤内的生物标志物，并评估它们是否与序贯治疗的抗肿瘤活性有关，我们将进行一项双中心II期随机研究，研究对象为PD-1抗体BMS 936558，随后是CTLA-4抗体ipilimumab，反之亦然。在该提案的第一个目标中，我们将在第一个周期的ipilimumab或PD-1抗体治疗之前和之后，以及在第二个治疗周期之后，通过白细胞分离采集外周血，并在两种抗体相互排序方案之前和之后测量循环T细胞上和循环中的各种标记物，这是基于PI在莫菲特的实验室之前的工作。为了探索这些抗体或肿瘤内靶向肿瘤的T细胞中的哪些因素 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的表达，计算浸润性T细胞的“免疫分数”，以及在第二个目标的工作中，在Dana Farber所做工作的基础上，在治疗之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和宿主效应T细胞中的哪些因素与两个手臂的联合抗体治疗的临床结果有关。如果成功，这项建议将确定一种新的序贯免疫疗法的耐受性和潜在疗效，并建议新的预测性和药效学生物标记物将在该组合的更大第三阶段试验中得到验证，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.