(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，所述机制包括激活免疫细胞。 抑制免疫检查点通路。这些免疫检查点的治疗抑制已经证明 在许多癌症中具有惊人的疗效，是一种有前途的联合治疗癌症的新方法。 与其他的抗癌疗法。针对PD-1通路的抗体特别地彻底改变了 治疗晚期黑色素瘤患者，并在>40%的患者中产生肿瘤反应。 抗PD-1与抗CTLA-4的组合在大约60%的患者中产生肿瘤应答。 然而，免疫检查点阻断经常导致炎症和免疫相关不良事件 （irAE）由于破坏正常组织的自身耐受性保护。这些irAE可能很严重，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 组织可能受到损伤，最常发生在皮肤，胃肠道，内分泌腺， 肝脏和肺组合的抗PD-1和CTLA-4具有比单一疗法显著更高的毒性， 需要更频繁和积极的管理。虽然用类固醇和其他免疫治疗 调节剂可以逆转这些irAE，免疫抑制可能损害免疫调节剂的抗肿瘤活性。 检查站封锁。因此，对于临床验证的、非侵入性的、可用于治疗的药物的可用性存在未满足的需求。 用于真实的实时监测和预测治疗中或治疗后irAE和治疗疗效的生物标志物， 允许适当管理暴露于免疫检查点抑制剂的癌症患者。在此，我们建议 使用无细胞DNA分析监测抗肿瘤疗效（目标1）以及器官特异性irAE（目标2）， 在治疗前和治疗期间及治疗后定期采集系列血样。根据目标1， 建议监测循环无细胞突变肿瘤DNA（ctDNA）模式的变化，作为抗- 肿瘤治疗效果。在目标2下，我们建议通过监测来评估自身免疫性器官损伤 循环无细胞、组织特异性甲基化DNA（cmeDNA）丰度的变化。我们目前正在 领导一项涉及抗CTLA-4和抗PD-1联合治疗的国家合作组试验（EA 6134） 治疗BRAF突变型黑色素瘤患者。从本试验患者中连续采集血液样本 将在患者对治疗有反应、发生irAE、需要免疫抑制治疗或 停止治疗。我们将比较ctDNA和cmeDNA生物标志物读数与临床 观察试验中的疗效和不良事件，以确定其效用。

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.