Epigenetic Therapy for Thoracic Malignancies

我们发表的关于100多例肺癌和食管癌和胸膜间皮瘤或非胸部恶性肿瘤肺转移患者的研究清楚地表明，地西他滨和罗米地辛单独或联合使用可以调节胸部恶性肿瘤的基因表达，并诱导针对这些肿瘤的免疫应答。我们的目标一直是夫妇表观遗传引发方案过继免疫治疗胸部恶性肿瘤。目前，不良的生物分布和全身毒性阻止了重新编程胸部恶性肿瘤所需的表观遗传剂的最佳长期施用。例如，DNA去甲基化剂在作为口服剂给药时具有非常有限的生物利用度，并且由于胞苷脱氨酶（CDA）以高水平存在于整个身体中，半衰期极短（5分钟）导致实体瘤的吸收不良。为了克服这些局限性，我们与克利夫兰诊所合作，配制了DAC和四氢尿苷（一种强效、无毒的CDA抑制剂）用于口服给药。口服DAC/THU和pembrolizumab治疗不可手术的NSCLC、食管癌或恶性胸膜间皮瘤患者的I/II期研究目前正在进行中。几乎所有患者都表现出系统性表观遗传重编程的证据，在几例患者中观察到令人印象深刻的、接近完全和持久（1年）的反应。为了进一步优化肺恶性肿瘤的表观遗传引发，以实现免疫检查点阻断，同时降低潜在的全身毒性，我们最近启动了一项I/II期试验，以检查通过吸入技术联合M7824（一种双重免疫检查点抑制剂-TGF-β陷阱）给药的AZA在局部晚期肺转移患者中的毒性和潜在疗效。目前在世界其他地方没有类似的努力正在进行中;本试验旨在建立一系列雾化表观遗传药物单独或与过继免疫疗法联合治疗局部晚期肺恶性肿瘤的评价范式。尽管癌症-睾丸抗原在多种人类恶性肿瘤中表达，但由于低水平、异质性抗原表达、抗原加工/呈递缺陷以及局部和全身免疫抑制，对这些蛋白质的免疫应答在胸部肿瘤患者中并不常见。我们发表的细胞系和患者活检的研究表明，胸部恶性肿瘤表现出不同的CTA表达模式和对上调CTA的表观遗传方案的异质性反应。克服这些局限性的策略是使患者对一组CTA免疫，所述CTA可能通过染色质重塑剂的全身施用而上调。为了解决这个问题，我们进行了一项2.5期首次人体试验，以确定肿瘤裂解疫苗是否可以诱导对CTA的广泛免疫，并确定节拍口服环磷酰胺和塞来昔布（cy/cel）是否可以增强疫苗诱导的免疫应答。简而言之，将21名患有原发性胸部恶性肿瘤或转移至胸部的胸外肿瘤的患者随机分配至接受H1299肺癌细胞裂解物与Iscomatrix佐剂，通过深层皮内注射，q月x 6 +/-每日cy/cel。主要终点是第6次接种后1个月对纯化CTA的血清学应答。探索性目的包括分析对碳水化合物抗原的血清学反应性和评估疫苗治疗前后的外周免疫亚群。所有患者在接种疫苗后均表现出持续72-96小时的局部和全身炎症反应。没有剂量限制性治疗相关毒性。14名患者（67%）完成了所有6次疫苗接种。中位随访时间为64.6个月（范围58.8-68.4），12例患者存活且NED; 2例患者存活且继发恶性肿瘤得到控制。14名存活患者中有11名（79%）接受了6次疫苗接种，而7名患者中有3名（42%）死于恶性肿瘤。10名随机接受cy/cel疫苗的患者中有7名接受了所有6次疫苗接种;这7名患者中有3名（43%）死于疾病。11例随机接受单独疫苗接种的患者中有7例完成了6次疫苗接种;这7例患者中无1例（0%）死亡。8名患者（57%）对NY-ESO-1表现出血清学应答。观察到针对GAGE 7、XAGE和MAGE-C2的额外反应性。对肿瘤相关的碳水化合物抗原的反应是罕见的。疫苗治疗降低了TcB百分比（p=0.067*）、TcB上的PD-1表达（p=0.023*）和CD 14+单核细胞（p=0.0089*）、经典单核细胞（p=0.0159*）和中间单核细胞（p= 0.0031*）上的PD-L1表达。Cy/cel不影响免疫应答或疫苗诱导的外周免疫亚群改变。反应的实验室指标似乎与患者生存无关。这项阳性试验的结果最近已在网上发表，并支持在胸部恶性肿瘤患者中进一步开展疫苗接种工作。

Our published studies pertaining to more than 100 patients with lung and esophageal cancers and pleural mesotheliomas, or pulmonary metastases from non-thoracic malignancies have clearly demonstrated that Decitabine and romidepsin alone or in combination can modulate gene expression in thoracic malignancies and induce immune responses against these neoplasms. Our goal has always been to couple epigenetic priming regimens with adoptive immunotherapy for thoracic malignancies. Presently, poor biodistribution and systemic toxicities prevent optimal, chronic administration of epigenetic agents necessary to reprogram thoracic malignancies. For example, DNA demethylating agents have very limited bioavailability when administered as oral agents and extremely short half-lives (5min) resulting in poor uptake into solid tumors due to cytidine deaminase (CDA) which is present at high levels throughout the body. To overcome these limitations, we formulated DAC and tetrahydrouridine (a potent, non-toxic inhibitor of CDA) for oral administration in collaboration with the Cleveland Clinic. A phase I/II study of oral DAC/THU and pembrolizumab for patients with inoperable NSCLC, esophageal cancers, or malignant pleural mesotheliomas is currently underway. Virtually all patients have exhibited evidence of systemic epigenetic reprogramming, and impressive, near complete and durable (1 yr) responses have been observed in several patients. To further optimize epigenetic priming of pulmonary malignancies for immune checkpoint blockade while decreasing potential systemic toxicities, we have recently initiated a phase I/II trial to examine the toxicities and potential efficacy of AZA administered via inhalation techniques in combination with M7824, a dual immune checkpoint inhibitor-TGF-beta trap in patients with locally advanced pulmonary metastases. No similar efforts are currently underway elsewhere in the world; this trial is intended to establish the paradigm for evaluation of a series of aerosolized epigenetic agents alone or in combination with adoptive immunotherapy for the treatment of locally advanced pulmonary malignancies. Whereas cancer-testis antigens are expressed in a variety of human malignancies, immune responses to these proteins are uncommon in thoracic oncology patients due to low level, heterogeneous antigen expression, deficient antigen processing/presentation, and local as well as systemic immunosuppression. Our published studies from cell lines and patient biopsies have demonstrated that thoracic malignancies exhibit diverse patterns of CTA expression and heterogeneous responses to epigenetic regimens that up-regulate CTAs. A strategy to overcome these limitations is to immunize patients against a panel of CTAs that potentially can be up-regulated by systemic administration of chromatin remodeling agents. To address this issue, we conducted a phase 2.5 First-in-Human trial to ascertain if a tumor lysate vaccine can induce broad immunity to CTA and determine if metronomic oral cyclophosphamide and celecoxib (cy/cel) enhances vaccine-induced immune responses. Briefly, 21 patients with primary thoracic malignancies or extra-thoracic neoplasms metastatic to the chest rendered NED by conventional therapies were randomized to receive H1299 lung cancer cell lysates with Iscomatrix adjuvant via deep intradermal injection q month x 6 +/- daily cy/cel. The primary endpoint was serologic response to purified CTA 1 month after the 6th vaccination. Exploratory objectives included analysis of serologic reactivity to carbohydrate antigens and assessment of peripheral immune subsets before and after vaccine therapy. All patients exhibited local and systemic inflammatory responses lasting 72-96 hours following vaccinations. There were no dose limiting treatment related toxicities. 14 patients (67%) completed all six vaccinations. With a median follow-up of 64.6 months (range 58.8-68.4), 12 patients are alive and NED; 2 patients are alive with controlled, second malignancies. 11 of 14 surviving patients (79%) received six vaccinations compared to 3 of 7 patients (42%) who succumbed to their malignancies. Seven of 10 patients randomized to vaccine with cy/cel received all six vaccinations; 3 of these 7 patients (43%) died of disease. Seven of 11 patients randomized to vaccine alone completed six vaccinations; none (0%) of these 7 patients have died. 8 patients (57%) exhibited serologic responses to NY-ESO-1. Additional reactivities were observed against GAGE7, XAGE, and MAGE-C2. Reactivities against tumor-associated carbohydrate antigens were uncommon. Vaccine therapy decreased percent Tregs (p=0.067*), PD-1 expression on Tregs (p=0.023*), and PD-L1 expression on CD14+ monocytes (p=0.0089*), classical monocytes (p=0.0159*), and intermediate monocytes (p= 0.0031*). Cy/cel did not impact immune responses or vaccine-induced alterations in peripheral immune subsets. Laboratory metrics of response did not appear to correlate with patient survival. Results of this positive trial have recently been published online and support further vaccination efforts in patients with thoracic malignancies.