HER2-mediated delivery of cytotoxic agents in solid tumors

项目总结 ERBB2/HER2是一种受体酪氨酸激酶(RTK)，在15%-20%的乳腺组织中扩增/过表达。 胃食道癌，抗HER2治疗现在是标准治疗。HER2可以被过度激活 通过过度表达和通过受体磷酸化、内化和突变驱动肿瘤发生 营业额增加。数千名非乳房/非乳房患者存在HER2高活性突变 胃实体瘤，对经典的抗HER2激酶治疗无效。抗HER2抗体-药物结合物 (ADC)为非乳腺/非胃HER2改变的肿瘤提供了一种新的治疗途径。ADC绑定到HER2 on 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，从而诱导细胞死亡。 我们机构的两个篮子试验测试抗HER2 ADC的抗肿瘤活性， 曲妥珠单抗恩坦辛(T-DM1)和曲妥珠单抗地拉替康(T-DXd) 在肺癌、结直肠癌、唾液管、胆道、卵巢癌和子宫内膜癌中发现了临床反应。 此外，我们还发现HER2突变的肺癌对T-DM1的反应与HER2蛋白无关。 级别。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(有机化合物， 携带不同HER2蛋白水平、突变和激活/磷酸化状态的异种移植)进行研究 受体表达/磷酸化的变化如何调节内吞作用和抗HER2 ADC活性。 我们发现不可逆的PAN-HER抑制剂，如奈拉替尼，可增强泛素化、内化和 随之而来的HER2的降解。在体外，neratinib还增加了HER2-ADC复合体的内化，导致 在患者来源的带有扩增的异种移植模型(肺癌和结肠癌)中完成肿瘤消退 或ERBB2基因突变。我们计划通过以下方式确定对DM1或DXd有效载荷敏感的决定因素 从敏感和抗性模型获得的基因组、转录组和蛋白质组数据。最后，我们将使用 这些数据用于确定基因组和蛋白质组鉴定的对T-DM1和T-DXd反应的生物标志物的优先顺序 124例患者肿瘤标本的分析及HER2基因不同改变的肿瘤成像 参加了篮下选拔赛。在治疗前和治疗期间收集的肿瘤活检和无细胞DNA样本， AT疾病进展将通过定向外显子组测序、整个外显子组测序和 水滴数字聚合酶链式反应。这些数据将表征治疗期间ERBB2状态的变化，以及其他 在肿瘤进化过程中，基因组的改变调节了对治疗的反应。FRET和其他基于图像的 技术将量化HER2与其他RTK的二聚化水平。肿瘤活组织检查，由Global和 靶向质谱学，将识别对ADC反应的特定蛋白质组特征。临床 乳房/非胃实体瘤， 对ADC的反应也将与HER2水平相关，通过 89Zr-曲妥珠单抗PET/CT。我们的研究将提供 对抗HER2 ADC作用机制的基本见解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.