Epigenetic Therapy for Thoracic Malignancies

我们已发表的关于实验室实验和相关临床方案的研究已经清楚地表明，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、无毒的胞苷脱氨酶抑制剂)口服给药。一项针对无法手术的非小细胞肺癌、食道癌或恶性胸膜间皮瘤患者的口服DAC/清华和培溴利珠单抗的I/II期研究于2017年底启动，但由于药物稳定性问题于今年关闭。这是不幸的，因为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，并且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反应。为了进一步优化肺部恶性肿瘤的表观遗传学启动以阻断免疫检查点，同时减少潜在的全身毒性，我们最近启动了临床前研究，以考察通过雾化技术给药的氮胞苷(AZA)的药代动力学和潜在疗效。我们利用从高致死性同基因肺癌和肉瘤细胞系分离的肿瘤干细胞，开发了一种独特的具有免疫活性的小鼠肺转移模型，用于系统、合理地评估DNA去甲基化药物、LSD1抑制剂和细胞因子，如IL-12。一项I/II期临床方案试验目前正在接受FDA的审查，该试验旨在检查通过吸入技术联合杜伐单抗作为可手术非小细胞肺癌患者诱导疗法的AZA的毒性和潜在疗效。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这样的临床努力。我们的临床前和转化研究工作的结果在2023年AACR年会上以正式全体会议的形式公布。癌症生殖系抗原包括一组共有的肿瘤抗原，仅在体细胞或免疫优势部位(如睾丸、卵巢或胎盘)的癌症中表达。因此，癌症生殖系抗原已成为癌症免疫治疗的极具吸引力的靶点。虽然癌症胚系抗原在多种人类恶性肿瘤中都有表达，但由于低水平、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在胸部肿瘤患者中并不常见。我们发表的对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，以及对上调这些蛋白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。根据2.5期首例人体试验的阳性结果，评估了将癌细胞裂解疫苗用作原发胸部恶性肿瘤或肺部转移瘤患者的辅助治疗，我们使用这种裂解疫苗(由我们实验室开发)作为肺癌或食道癌患者的辅助治疗，编写了两项新的方案。肺癌方案将评估裂解疫苗与IL-15超级激动剂N-803相结合作为术后辅助治疗，而食道癌方案将在放化疗+/-手术后评估裂解物与HDAC抑制剂Eninostat和免疫检查点抑制剂nivolumab的联合。这两个方案都已得到FDA和NIH IRB的批准，预计将在24财年第一季度初向患者开放。

Our published studies pertaining to laboratory experiments and our related clinical protocols 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 cytidine deaminase) 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 was initialed in late 2017, but was closed this year due to drug stability issues. This was unfortunate as virtually all patients had exhibited evidence of systemic epigenetic reprogramming, and impressive, near complete and durable responses were observed in several patients. To further optimize epigenetic priming of pulmonary malignancies for immune checkpoint blockade while decreasing potential systemic toxicities, we recently initiated preclinical studies to examine the pharmacokinetics and potential efficacy of azacytidine (AZA) administered by aerosolization techniques. We have developed a unique immunocompetent murine pulmonary metastasis model using cancer stem cells isolated from highly lethal syngeneic lung cancer and sarcoma cell lines for systematic, rational evaluation of DNA demethylating agents, LSD1 inhibitors, and cytokines such as IL-12. A phase I/II clinical protocol trial to examine the toxicities and potential efficacy of AZA administered via inhalation techniques in combination with durvalumab as induction therapy for patients with operable NSCLC is presently undergoing FDA review. 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. No such clinical efforts are currently underway elsewhere in the world. Results of our preclinical and translational research efforts were presented as a formal plenary session talk at the Annual Meeting of the AACR in 2023. Cancer-germline antigens comprise a group of shared tumor antigens that are only expressed in cancers arising from somatic cells or immune-privileged sites such as testes, ovary, or placenta. As such, cancer-germline antigens have emerged as highly attractive targets for cancer immunotherapy. Although cancer-germline 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 these proteins. A strategy to overcome these limitations is to immunize patients against a panel of CTAs that potentially can be upregulated by systemic administration of chromatin remodeling agents. Following positive results of a phase 2.5 First-in-Human trial evaluating the use of a cancer cell lysate vaccine as adjuvant therapy in patients with primary thoracic malignancies or tumors metastatic to the lungs, we have written two new protocols using this lysate vaccine (which was developed in our lab) as adjuvant therapy for patients with lung or esophageal cancers. The lung cancer protocol will evaluate the lysate vaccine in combination with the IL-15 super-agonist N-803 as post-operative adjuvant therapy, while the esophageal cancer protocol will evaluate the lysate in combination with the HDAC inhibitor, entinostat, and the immune checkpoint inhibitor, nivolumab following chemo-radiation +/- surgery. Both protocols have been approved by the FDA and NIH IRB and are expected to be open for patient accrual in early Q1 of FY24.