(PQ #8) Biomarkers of efficacy and adverse events due to treatment with immune checkpoint inhibitors

肿瘤细胞通过多种机制逃避免疫系统的识别，包括激活 抑制性免疫检查点通路。对这些免疫检查点的治疗抑制已经证明 在多种癌症中疗效显著，是一种很有前途的癌症联合治疗新方法 与其他抗癌疗法相结合。尤其是针对PD-1途径的抗体已经使 治疗晚期黑色素瘤患者并在40%的患者中产生肿瘤反应。 联合应用抗PD-1和抗CTLA-4可在约60%的患者中产生肿瘤反应。 然而，免疫检查点阻断经常会导致炎症和免疫相关的不良事件 (IrAEs)由于破坏了对正常组织的自我耐受保护。这些irAE可能会很严重，导致 停止免疫检查点抑制剂治疗，可能需要免疫抑制治疗。任何 组织可受到损伤，最常见的部位是皮肤、胃肠道、内分泌腺、 肝脏和肺。联合抗PD-1和CTLA-4的毒性明显高于单一治疗 需要更频繁、更积极的管理。虽然用类固醇和其他免疫手段治疗 调节剂可以逆转这些irAEs，免疫抑制可能会损害细胞的抗肿瘤活性 检查站封锁。因此，对经临床验证的非侵入性药物的可用性的需求尚未得到满足。 实时监测和预测治疗中或治疗后irAEs和治疗效果的生物标志物 允许适当处理暴露于免疫检查点抑制剂的癌症患者。在此，我们建议 监测抗肿瘤效果(Aim 1)以及器官特异性irAEs(Aim 2)使用来自 在治疗前、治疗期间和治疗后每隔一段时间连续采集血液样本。在目标1下，我们 建议监测循环中无细胞突变肿瘤DNA(CtDNA)模式的变化，作为抗- 肿瘤的治疗效果。在目标2下，我们建议通过监测来评估自身免疫器官的损害 循环中无细胞、组织特异性甲基化DNA(CmeDNA)丰度的变化。我们目前正在 领导一项联合抗CTLA-4和抗PD-1的国家合作小组试验(EA6134) BRAF突变黑色素瘤患者的治疗。在这项试验中连续采集患者的血液样本 将在他们对治疗有反应、出现irAEs、需要免疫抑制治疗或 停止治疗。我们将ctdna和cmedna生物标志物读数与临床进行比较。 观察试验中的疗效和不良事件，以确定其有效性。

Tumor cells escape recognition by the immune system by multiple mechanisms that include activation of inhibitory immune checkpoint pathways. Therapeutic inhibition of these immune checkpoints has demonstrated striking efficacy in a number of cancers and is a promising new approach to cancer treatment in combination with other anti-cancer regimens. Antibodies against the PD-1 pathway have in particular revolutionized the treatment of patients with advanced melanoma and produce tumor responses in >40% of patients. Combinations of anti-PD-1 with anti-CTLA-4 produces tumor responses in approximately 60% of patients. However, immune checkpoint blockade frequently causes inflammatory and immune-related Adverse Events (irAEs) due to the disruption of self-tolerance protection of normal tissues. These irAEs can be severe, lead to discontinuation of immune checkpoint inhibitor therapy and can require immunosuppressive treatment. Any tissue can be injured with the most frequent occurrences in the skin, gastro-intestinal tract, endocrine glands, liver, and lungs. Combined anti-PD-1 and CTLA-4 has significantly higher toxicity than monotherapy and requires more frequent and aggressive management. Although treatment with steroids and other immune modulators can reverse these irAEs, immunosuppression may compromise the anti-tumor activity of the checkpoint blockade. Thus, there is an unmet need for availability of clinically validated, non-invasive biomarkers for real time monitoring and prediction of on- or post-treatment irAEs and therapeutic efficacy to allow for proper management of cancer patients exposed to immune checkpoint inhibitors. Here we propose to monitor anti-tumor efficacy (Aim 1) as well as organ-specific irAEs (Aim 2) using cell-free DNA analysis from serial blood samples obtained before and at regular intervals during and after treatment. Under Aim 1 we propose to monitor changes in circulating cell-free mutant tumor DNA (ctDNA) patterns as a readout of anti- tumor treatment efficacy. Under Aim 2 we propose to assess autoimmune organ damage by monitoring changes in the abundance of circulating cell-free, tissue-specific methylated DNA (cmeDNA). We are currently leading a national cooperative group trial (EA6134) that involves combination anti-CTLA-4 and anti-PD-1 treatment of patients with BRAF mutant melanoma. Serially collected blood samples from patients on this trial will be analyzed as they respond to treatment, develop irAEs, require immunosuppressive therapy or discontinuation of treatment. We will compare the ctDNA and cmeDNA biomarker readouts with clinical observations of efficacy and adverse events in the trial to establish their utility.