Overcoming Resistance Mechanisms to Anaplastic Lymphoma Kinase Inhibitors

项目摘要 携带致癌间变性淋巴瘤激酶(ALK)基因的非小细胞肺癌 重排(即‘ALK’)包括肺癌的一个独特的分子亚群，对ALK具有显著的敏感性 酪氨酸激酶抑制剂(TKIs)。虽然ALK TKIs最初是高效的，但获得性耐药性仍然存在 这是一个根本性的挑战，限制了临床益处，并导致大多数患者的疾病复发。我们和其他人 具有抵抗机制的特征，特别是所谓的“目标”抵抗，由 继发性获得性ALK激酶结构域突变，可通过更强大的下一代(2- 或第三代)抑制剂。近年来，诊断为慢性病患者的标准治疗模式 晚期ALK肺癌已经从使用第一代ALK TKI crizotinib的序贯治疗转向 然后是下一代TKI，再到使用下一代ALK TKI的初步治疗。我们的初步数据 表明在下一代之后，脱靶(即与ALK无关)抗性机制很普遍 ALK TKIS。然而，偏离目标的抵抗机制和克服这些障碍的战略仍然存在。 知之甚少，给这些患者的治疗选择的发展带来了障碍。这个 拟议研究的首要目标是确定和发展互补性、知情的机制 以及与机制无关的方法，用于克服对下一代ALK TKI的脱靶抗性。我们会 对扩大的患者肿瘤样本进行全面的基因组和非基因组评估 确定一线使用下一代ALK后非靶向耐药机制的临床谱 TKIS，我们将开发新的方法来识别最有可能发生旁路介导的耐药性的患者 受益于合理设计的联合疗法。使用来源为ALK TKI的肿瘤细胞株 患者活检，我们将筛选不依赖于常规搭桥术的表观遗传学机制来驱动耐药性 信号通路，最初的研究集中在确定转录辅助激活因子p300/CBP的作用 作为脱靶的ALK TKI抵抗和治疗靶点的新的驱动因素。这些努力将使针对患者的、 机制知情的治疗策略。同时，我们将开发一种与机制无关的方法， 利用ALK作为肿瘤特异性的新抗原，其表达在耐药肿瘤中保持不变。使用T 基于细胞的功能筛选，我们将识别ALK反应性T细胞受体(TCR)，这些受体能够 识别耐药的ALK非小细胞肺癌。这将为工程设计ALK TCR采用细胞奠定基础 治疗作为一种与TKI正交的、基于免疫的方法来克服耐药性。总的来说，建议的 研究将提供对下一代ALK TKI抵抗力的全面了解，并为 用于开发新的治疗策略，可以有效地克服大多数非靶向耐药 最终改善和延长晚期ALK肺癌患者的生命。

Project Summary Non-small cell lung cancers (NSCLC) harboring oncogenic anaplastic lymphoma kinase (ALK) gene rearrangements (i.e., ‘ALK+’) comprise a distinct molecular subset of lung cancer with marked sensitivity to ALK tyrosine kinase inhibitors (TKIs). While ALK TKIs are initially highly effective, acquired drug resistance remains a fundamental challenge that limits clinical benefit and causes disease relapse in most patients. We and others have characterized mechanisms of resistance, in particular so-called “on-target” resistance mediated by secondary acquired ALK kinase domain mutations that can be overcome with more potent next-generation (2nd- or 3rd-generation) inhibitors. In recent years, the standard treatment paradigm for patients diagnosed with advanced ALK+ lung cancers has shifted from sequential therapy using the 1st-generation ALK TKI crizotinib followed by next-generation TKIs, to initial therapy using a next-generation ALK TKI upfront. Our preliminary data indicate that off-target (i.e., ALK-independent) resistance mechanisms are prevalent following next-generation ALK TKIs. Yet, the spectrum of off-target resistance mechanisms and strategies to overcome these remain poorly understood, presenting a barrier to the development of treatment options for these patients. The overarching objective of the proposed research is to identify and develop complementary, mechanism-informed and mechanism-agnostic approaches for overcoming off-target resistance to next-generation ALK TKIs. We will use comprehensive genomic and non-genomic assessment of an expanded cohort of patient tumor specimens to determine the clinical spectrum of off-target resistance mechanisms after first-line use of next-generation ALK TKIs, and we will develop new methods for identifying patients with bypass-mediated resistance most likely to benefit from rationally designed combination therapies. Using ALK TKI-resistant tumor cell lines derived from patient biopsies, we will screen for epigenetic mechanisms that drive resistance independent of canonical bypass signaling pathways, with initial studies focused on defining the role of the transcriptional co-activator p300/CBP as a novel driver of off-target ALK TKI resistance and therapeutic target. These efforts will enable patient-specific, mechanism-informed therapeutic strategies. In parallel, we will develop a mechanism-agnostic approach that leverages ALK as a tumor-specific “neoantigen” whose expression is maintained in resistant tumors. Using T cell-based functional screens, we will identify ALK-reactive T cell receptors (TCRs) that are capable of recognizing resistant ALK+ NSCLCs. This will provide the foundation for engineering ALK TCR adoptive cellular therapy as a TKI-orthogonal, immune-based approach for overcoming resistance. Collectively, the proposed studies will provide a comprehensive understanding of resistance to next-generation ALK TKIs and pave the way for the development of new therapeutic strategies that can effectively overcome most of off-target resistance in the clinic, ultimately improving and prolonging the lives of patients with advanced ALK+ lung cancers.