Defining the determinants of response and resistance to therapy for Richter's Syndrome

摘要 里希特综合征(RS)起源于慢性淋巴细胞白血病(CLL)，长期以来被认为是 为慢性淋巴细胞性白血病患者呈现黯淡的临床前景。然而，新的治疗组合纳入了新的 药物提示RS患者获得更深更持久的缓解的可行性。这些 包括免疫检查点阻断治疗(icb；-pd1治疗)和伊布鲁替尼，以及 Bcl2抑制剂文奈德与化疗联合应用。这些经历提供了鼓舞人心的 迄今为止被认为对慢性淋巴细胞性白血病患者判处死刑的实体的进展。尽管有这些有希望的事情 治疗进展方面，关于这些药物临床反应的决定因素的信息很少。 治疗。最近对RS新型治疗药物的临床研究增加，现在提供了一种 有机会更始终如一地收集生物标本。此外，最近新测序的可用性 能力、分析工具和动物模型(由我们在过去的资助期内的努力产生)现在能够 US从原代RS最大限度地提取有关不同分子和表型特征的信息 病人材料。我们假设RS治疗的治疗反应和抵抗力是由 肿瘤的内在特征和非内在特征，而这些特征是区分敏感性的基础 RS和CLL之间的新型代理。在此，我们将对收集到的样本进行深入分析 治疗试验，重点是对RS样本及其微环境的纵向分析，以及 在一种新的动物模型中对这些发现进行了功能验证。这些研究得到了强烈的相互作用的支持 包括项目1和项目3，以及每个单独的核心。因此，我们的目标是：(I)定义RS-内在特征 控制着对RS疗法的反应。我们将评估连续收集的RS的分子特征 来自接受以下治疗的患者的样本：(I)基于bcl2抑制剂的治疗和(Ii)基于ICB的治疗，并将这些 与临床特征相结合，以确定预测治疗反应或抵抗的标记/途径。(Ii) 描述影响治疗反应的RS免疫微环境的关键成分。新的 免疫基因组学方法使我们能够直接从分析患者中获得新的机械性见解 样本。我们将对来自RS的骨髓或淋巴浸润性免疫细胞进行scRNA-seq分析 每种疗法的应答者和无应答者(参加上述试验)以系统地描述 参与对新型RS反应或抗性的细胞群体的组成和功能状态 治疗组合。最后，我们将：(Iii)RS对-PD1治疗的差异治疗敏感性模型 与CLL相比。使用反映CLL或RS疾病的新型基因工程小鼠模型，我们将 进行体内治疗研究和免疫细胞的功能/表型分析，以确定基因 与CLL相比，ICB对RS响应的微环境基础。

Abstract Richter's Syndrome (RS) arises from chronic lymphocytic leukemia (CLL) and has long been acknowledged as presenting a bleak clinical outlook for CLL patients. New treatment combinations, however, incorporating novel agents suggest the feasibility of achieving deeper and longer-lasting remissions in patients with RS. These include treatment with immune checkpoint blockade (ICB; -PD1 therapy) together with ibrutinib, and combination of the BCL2 inhibitor venetoclax with chemotherapy. These experiences provide encouraging developments for an entity hitherto considered a death sentence for CLL patients. Despite these promising therapeutic developments, little information is available regarding the determinants of clinical response to these therapies. The recent increase in clinical investigation of novel therapeutic agents for RS now provides an opportunity to more consistently collect biospecimens. Moreover, the recent availability of novel sequencing capabilities, analytic tools and animal models (generated by our efforts over this past funding period) now enable us to maximally extract information about the diverse molecular and phenotypic features of RS from primary patient material. We hypothesize that therapeutic response and resistance to RS therapy are shaped by both tumor-intrinsic and -extrinsic features, and that these features underlie the differential sensitivity to novel agents between RS and CLL. Herein, we will undertake in-depth analysis of specimens collected on therapeutic trials, focusing on longitudinal analyses of both RS specimens and their microenvironment, and also functional validation of these findings in a novel animal model. These studies are supported by strong interactions with Projects 1 and 3, and each of the individual Cores. Our aims are thus to: (i) Define the RS-intrinsic features that govern responses to RS therapies. We will evaluate the molecular characteristics of serially collected RS specimens from patients treated with: (i) BCL2 inhibitor-based and (ii) ICB-based therapy, and link these attributes with clinical features to identify markers/pathways predictive of response or resistance to therapy. (ii) Delineate the key components of the RS immune microenvironment impacting therapeutic response. New immunogenomic approaches enable us to gain fresh mechanistic insights directly from analyzing patient samples. We will perform scRNA-seq profiling of marrow or lymph node-infiltrating immune cells from RS responders and nonresponders per therapy (enrolled on the aforementioned trials) to systematically characterize the composition and functional state of cellular populations participating in response or resistance to novel RS therapeutic combinations. Finally, we will: (iii) Model differential therapeutic sensitivity of RS to -PD1 therapy compared to CLL. Using novel genetically engineered mouse models that reflect CLL or RS disease, we will perform in vivo treatment studies and functional/phenotypic analyses of immune cells to determine the genetic and microenvironmental basis of RS response to ICB compared to CLL.