Epigenetic Therapy for Thoracic Malignancies

我们发表的关于100多名肺癌、食道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，地西他滨和罗米地平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反应。我们的目标一直是将表观遗传启动疗法与胸部恶性肿瘤的过继免疫治疗结合起来。目前，较差的生物分布和全身毒性阻碍了对重新编程的胸部恶性肿瘤所需的表观遗传剂的最佳、长期给药。为了克服这些局限性，我们与克利夫兰诊所合作，开发了DAC和四氢尿苷(一种有效的、无毒的CDA抑制剂)口服给药。口服DAC/清华和培布罗利珠单抗治疗不能手术的非小细胞肺癌、食道癌或恶性胸膜间皮瘤的I/II期研究目前正在进行中。几乎所有的患者都表现出系统性表观遗传学重新编程的证据，在几名患者中观察到了令人印象深刻的、接近完全的和持久的(1年)反应。为了进一步优化肺部恶性肿瘤免疫检查点阻断的表观遗传学启动，同时减少潜在的全身毒性，我们最近启动了临床前研究，以检查通过雾化技术给药的氮胞苷的药代动力学和潜在疗效。NIH IRB批准了一项I/II期临床方案试验，以检查通过吸入技术联合应用AZA与M7824的毒性和潜在疗效。M7824是一种双重免疫检查点抑制剂-转化生长因子-β陷阱，用于治疗局部晚期肺转移患者，但由于公司决定不进一步开发M7824，该试验被关闭。这项试验旨在建立评价一系列雾化表观遗传剂单独或与过继免疫疗法联合治疗局部晚期肺部恶性肿瘤的范例。目前，世界其他地方还没有开展类似的努力。一旦我们得到一家制药公司对替代免疫检查点抑制剂的承诺，将重新启动试验。此外，我们已经得到阿斯利康的初步承诺，将在可手术的早期非小细胞肺癌患者中联合使用吸入性AZA试验和Durvalumab。该议定书正在准备进行科学审查。虽然肿瘤-睾丸抗原在多种人类恶性肿瘤中都有表达，但在胸部肿瘤患者中，由于低水平、异质性抗原表达、抗原处理/提呈缺陷以及局部和全身免疫抑制，对这些蛋白的免疫反应并不常见。我们发表的来自细胞系和患者活检组织的研究表明，胸部恶性肿瘤表现出不同的CTA表达模式，以及对上调CTA的表观遗传方案的异质性反应。克服这些局限性的一种策略是使患者对一组CTA产生免疫，这些CTA可能通过系统地给予染色质重建剂而上调。为了解决这个问题，我们进行了2.5期首例人体试验，以确定肿瘤裂解疫苗是否可以诱导对CTA的广泛免疫，并确定节律口服环磷酰胺和塞来昔布(Cy/cel)是否增强疫苗诱导的免疫反应。主要终点是第6次接种后1个月对纯化CTA的血清学反应。探索性目标包括对碳水化合物抗原的血清学反应性分析和疫苗治疗前后外周免疫亚群的评估。所有患者在接种疫苗后都出现了持续72-96小时的局部和全身炎症反应。21名患者在试验中没有出现与剂量限制治疗相关的毒性反应。14名患者(67%)完成了所有六种疫苗接种。8名患者(57%)对NY-ESO-1有血清学反应。还观察到针对GAGE7、XAGE和MAGE-C2的其他反应。对肿瘤相关碳水化合物抗原的反应并不常见。疫苗治疗降低了T细胞百分率(p=0.067*)、T细胞上PD-1的表达(p=0.023*)、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*)的PD-L1表达。CY/CEL不影响免疫反应或疫苗诱导的外周免疫亚群的改变。实验室的反应指标似乎与患者的存活率无关。这项阳性试验的结果最近已经发表，并支持在胸部恶性肿瘤患者中进一步接种疫苗的努力。两项第二阶段试验目前正在接受FDA和IRB的批准，预计将于2022年秋季向患者开放。其中一项试验是将裂解疫苗与IL-15超级激动剂N-803联合用于肺癌患者的术后辅助治疗，另一项是将裂解疫苗与Eninostat和nivolumab联合用于食道癌放化疗+/-手术后的患者。

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. 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 preclinical studies to examine the pharmacokinetics and potential efficacy of azacytidine administered by aerosolization techniques. A phase I/II clinical protocol 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 was approved by NIH IRB only to be closed due to a company decision not to further develop M7824. This trial was 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. No similar efforts are currently underway elsewhere in the world. The trial will be reinitiated once we have commitment from a pharmaceutical company for a replacement immune checkpoint inhibitor. Additionally, we have tentative commitment from AstraZeneca to conduct an inhaled AZA trial in combination with Durvalumab in patients with operable early-stage NSCLC. This protocol is being prepared for scientific review. 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. 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 in 21 patients accrued to the trial. 14 patients (67%) completed all six vaccinations. 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 and support further vaccination efforts in patients with thoracic malignancies. Two phase two trials one using the lysate vaccine in combination with the IL-15 superagonist N-803 as post-operative adjuvant therapy in lung cancer patients, and the other using the lysate in combination with entinostat and nivolumab in esophageal cancer patients post chemo-radiation +/- surgery are undergoing FDA and IRB approval at this time and are expected to be open for patient accrual in Autumn of 2022.