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（NSCLC） 重排（即，“ALK+”）包含对ALK具有显著敏感性的肺癌的不同分子亚组 酪氨酸激酶抑制剂（TKI）。虽然ALK TKI最初非常有效，但获得性耐药性仍然存在 这是一个根本性的挑战，限制了临床获益，并导致大多数患者的疾病复发。我们和其他人 已经表征了抗性机制，特别是所谓的“靶向”抗性， 继发性获得性ALK激酶结构域突变，可以通过更有效的下一代（第2代- 或第三代）抑制剂。近年来，标准治疗模式的患者诊断为 晚期ALK+肺癌已从使用第一代ALK TKI克唑替尼的序贯治疗转移 随后是下一代TKI，以使用下一代ALK TKI进行前期初始治疗。我们的初步数据 指示偏离目标（即，ALK非依赖性）耐药机制在下一代 ALK TKI。然而，脱靶耐药机制和克服这些耐药机制的策略仍然存在 对这些疾病的认识不足，阻碍了为这些患者开发治疗方案。的 拟议研究的总体目标是确定和发展互补的，机制知情的 以及克服下一代ALK TKI脱靶耐药的机制不可知方法。我们将 对患者肿瘤样本的扩展队列进行全面的基因组和非基因组评估 确定下一代ALK一线使用后脱靶耐药机制的临床谱 TKI，我们将开发新的方法来识别旁路介导的耐药患者， 从合理设计的联合疗法中获益。使用ALK TKI耐药肿瘤细胞系， 患者活检，我们将筛选表观遗传机制，驱动阻力独立于典型旁路 信号通路，最初的研究集中在定义转录辅激活因子p300/CBP的作用 作为ALK TKI脱靶耐药和治疗靶点的新型驱动因素。这些努力将使患者特异性， 机制知情的治疗策略。同时，我们将开发一种机制不可知的方法， 利用ALK作为肿瘤特异性“新抗原”，其表达在耐药肿瘤中得以维持。使用T 在基于细胞的功能筛选中，我们将鉴定ALK反应性T细胞受体（TCR）， 识别耐药ALK+ NSCLC。这将为改造ALK TCR过继细胞提供基础。 作为TKI正交，免疫为基础的方法来克服耐药性的治疗。总体而言，拟议的 研究将全面了解下一代ALK TKI的耐药性，并为 开发新的治疗策略，可以有效地克服大多数脱靶耐药， 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.