HER2-mediated delivery of cytotoxic agents in solid tumors

项目摘要 ERBB 2/HER 2是一种受体酪氨酸激酶（RTK），在15-20%的乳腺癌中扩增/过表达， 胃食管癌，抗HER 2治疗现在是标准治疗。HER 2可以被过度激活 通过过度表达和突变通过受体磷酸化、内化和 增加营业额。过度活化HER 2突变，由数千名非乳腺癌/非乳腺癌患者携带。 胃实体瘤对经典的抗HER 2激酶治疗没有反应。抗HER 2抗体-药物缀合物 ADC为非乳腺/非胃HER 2改变的肿瘤提供了新的治疗途径。ADC结合HER 2， 细胞表面，被内化，并在内溶酶体中释放其细胞毒性有效载荷以诱导细胞死亡。 我们机构的两项“篮子”试验测试了抗HER 2 ADC的抗肿瘤活性， 曲妥珠单抗-美坦新偶联物（T-DM 1）和曲妥珠单抗-德曲替康（T-DXd），n 在肺癌、结直肠癌、涎腺导管癌、胆道癌、卵巢癌和子宫内膜癌中发现了临床反应。 此外，我们发现HER 2突变型肺肿瘤对T-DM 1有反应，而不管HER 2蛋白 程度.在这里，我们计划使用几种基于细胞系和患者来源的临床前模型（类器官， 异种移植物），以研究 受体表达/磷酸化的变化如何调节内吞作用和抗HER 2 ADC活性。 我们发现，不可逆的泛HER抑制剂，如来那替尼，可以增强泛素化，内化， 从而导致HER 2降解。来那替尼还可增加HER 2-ADC复合物的体外内化， 在携带扩增的患者来源的异种移植物模型（肺癌和结肠癌）中完成肿瘤消退 或ERBB 2的突变。我们计划通过整合，确定对DM 1或DXd有效载荷敏感性的决定因素 从敏感和耐药模型获得的基因组、转录组和蛋白质组数据。最后，我们将使用 这些数据优先考虑通过基因组学和蛋白质组学鉴定的对T-DM 1和T-DXd应答的生物标志物 对来自124名患者的肿瘤样本进行分析，并对携带不同HER 2改变的肿瘤进行成像 参加了我们的篮子试验在治疗前和治疗期间收集肿瘤活检和无细胞DNA样品， 并且在疾病进展时，将通过靶向外显子组测序、全外显子组测序和 液滴数字PCR。这些数据将表征治疗期间ERBB 2状态的变化，以及其他 基因组改变调节肿瘤演变过程中对治疗的反应。FRET和其他基于成像的 这些技术将定量HER 2与其他RTK的二聚化水平。肿瘤活检，按总体和 靶向质谱法将鉴定对ADC响应的特异性蛋白质组特征。临床 乳房上/非胃实体瘤， 对ADC的应答也将与HER 2水平相关， 89 Zr-曲妥珠单抗PET/CT。我们的研究将提供 对抗HER 2 ADC作用机制的基本见解，并将开辟新的治疗视野 对于没有有效的靶向治疗选择的患者。

PROJECT SUMMARY ERBB2/HER2 is a receptor tyrosine kinase (RTK) that is amplified/overexpressed in 15-20% of breast and gastroesophageal cancers, for which anti-HER2 therapy is now standard of care. HER2 can be hyperactivated by overexpression and by mutations driving oncogenesis through receptor phosphorylation, internalization, and increased turnover. Hyperactivating HER2 mutations, possessed by thousands of patients with non-breast/non- gastric solid tumors, do not respond to classical anti-HER2 kinase therapy. Anti-HER2 antibody-drug conjugates (ADCs) offer a new treatment avenue for non-breast/non-gastric HER2-altered tumors. ADCs bind to HER2 on the cell surface, get internalized, and release their cytotoxic payloads in the endolysosomes to induce cell death. Two “basket” trials at our institution testing the antitumor activity of the anti-HER2 ADCs, trastuzumab emtansine (T-DM1), and trastuzumab deruxtecan (T-DXd) in n found clinical responses in lung, colorectal, salivary duct, biliary tract, ovarian, and endometrial cancers. Moreover, we showed that HER2 mutant lung tumors are responsive to T-DM1 regardless of HER2 protein levels. Here, we plan to use several cell line-based and patient-derived preclinical models (organoids, xenografts) bearing different HER2 protein levels, mutations, and activation/phosphorylation statuses to study how the variation in receptor expression/phosphorylation modulates endocytosis and anti-HER2 ADC activity. We show that irreversible pan-HER inhibitors, such as neratinib, enhance ubiquitination, internalization, and consequent degradation of HER2. Neratinib also increases HER2-ADC complex internalization in vitro, leading to complete tumor regression in patient-derived xenograft models (lung and colon cancer) bearing amplification or mutations of ERBB2. We plan to identify determinants of sensitivity to DM1 or DXd payloads by integrating genomic, transcriptomic, and proteomic data acquired from sensitive and resistant models. Finally, we will use these data to prioritize biomarkers of response to T-DM1 and T-DXd identified by genomic and proteomic analysis of the tumor samples, and imaging tumors bearing different HER2 alterations from the 124 patients enrolled in our basket trials. Tumor biopsies and cell-free DNA samples collected before and during treatment, and at disease progression will be analyzed by targeted exome sequencing, whole exome sequencing, and droplet digital PCR. These data will characterize changes in ERBB2 status during treatment and whether other genomic alterations modulate response to therapy during tumor evolution. FRET and other imaging-based techniques will quantify the level of HER2 dimerization with other RTKs. Tumor biopsies, analyzed by global and targeted mass spectrometry, will identify a specific proteomic signature of response to the ADCs. Clinical on-breast/non-gastric solid tumors, response to ADCs will also be correlated with HER2 levels by 89Zr-trastuzumab PET/CT. Our studies will provide fundamental insights into the mechanism of action of anti-HER2 ADCs and will open new therapeutic horizons for patients without effective, targeted therapy options.