Dual Blockade of IGF1R and MEK synergistically inhibits pediatric cancers

IGF1R 和 MEK 的双重阻断可协同抑制儿童癌症

• 批准号: 10486986
• 负责人: Marielle Yohe
• 金额: $ 74.11万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10486986
• 关键词: 1-Phosphatidylinositol 3-Kinase; Animals; BRAF gene; Cancer Therapy Evaluation Program; Cell Line; Cells; Cessation of life; Childhood Solid Neoplasm; Clinical; Clinical Trials; Collaborations; Disease; FRAP1 gene; Gene Expression; Genes; Goals; Histology; Human; IGF1 gene; IGF1R gene; IRS1 gene; Institution; Ligands; MAP Kinase Gene; MEK inhibition; MEKs; Malignant Childhood Neoplasm; Mediating; Modeling; Monoclonal Antibodies; Mus; Mutate; Mutation; NF1 gene; Neuroblastoma; PI3K/AKT; PIK3CA gene; PTEN gene; PTPN11 gene; Pathway interactions; Pediatric Oncology Group; Pharmaceutical Preparations; Pharmacodynamics; Phase I/II Clinical Trial; Phosphorylation; Process; Proto-Oncogene Proteins c-akt; RAS genes; Ras/Raf; Research Personnel; Resistance; Resistance development; Rhabdomyosarcoma; Testing; Translating; Vincristine; Work; Xenograft Model; Xenograft procedure; clinical development; clinical translation; efficacy evaluation; exceptional responders; exome sequencing; in vivo; inhibitor/antagonist; knock-down; novel; patient derived xenograft model; pediatric patients; phosphoproteomics; preclinical study; resistance mechanism; small molecule; standard of care; synergism; targeted agent; transcriptome sequencing; tumor

In collaboration with LASP, we conducted an in vivo study of trametinib and ganitumab in mouse xenograft models of Ras-mutated rhabdomyosarcoma. We have found that the combination of trametinib and ganitumab provided a survival advantage compared to either agent alone, and also compared to a standard of care chemotherapeutic, vincristine. We also identified that this combination provided the expected pharmacodynamic effects within the tumors, i.e. ERK phosphorylation and IGF1R expression was decreased in tumors that were treated with the combination of trametinib and ganitumab as compared to controls. We also identified that the human Ras-mutated rhabdomyosarcoma cell line, SMS-CTR, is an exceptional responder to the combination of trametinib and ganitumab. In an effort to identify the reason why SMS-CTR responds so well to this combination, we showed that of the Ras-mutated rhabdomyosarcoma cell lines, SMS-CTR has the highest expression of IGF1R. We aimed to identify mechanisms of co-targeting the RAS-RAF-MEK-ERK pathways and the IGF1R-IRS1/2-PI3K-AKT-mTOR pathways that would be effective in cell lines that do not have high IGF1R expression, including monoclonal antibodies specific for the ligand of IGF1R, IGF1/2, and an inhibitor of IRS1/2. This work is currently ongoing. Importantly, we have also tested the combination of trametinib and ganitumab in several PDX models of RAS-mutated RMS. We show efficacy of the combination in cell line xenograft and PDX models driven by both NRAS and HRAS. The models with relative intrinsic resistance to the combination are models that also have an alteration in genes of the PI3 kinase pathway, either PIK3CA mutation or loss of expression of PTEN. Importantly, knockdown of PTEN expression in SMS-CTR cells confers resistance to trametinib. Current work is aimed at better understanding the effectors downstream of PI3 kinase that might mediate this resistance. We were in discussions with CTEP and the Children's oncology group regarding the initiation of a phase I/II clinical trial of trametinib and ganitumab in pediatric patients. We were also in discussions with ImmunityBio regarding an investigator-initiated single institution trial. Unfortunately, ganitumab is no longer available for new clinical trials. We are now in discussions with BI regarding xentuzumab, a monoclonal antibody specific for IGF1/2. We will perform preclinical studies of xentuzumab in combination with trametinib prior to clinically translating this combination. In order to facilitate the clinical translation of this combination, we are evaluating the efficacy of trametinib/ganitumab in other disease histologies. We have shown efficacy of trametinib/ganitumab in two cell line xenografts of RAS-mutated neuroblastoma, and are continuing to evaluate the combination in neuroblastoma models driven by alterations in the MAPK pathway that are not RAS itself, as well as in MPNST, driven by alterations in NF1 or BRAF. In the course of the animal study of the trametinib and ganitumab combination, we created an SMS-CTR cell line that is resistant to trametinib. We are currently in the process of identifying the mechanism of resistance to trametinib in this cell line. Whole exome sequencing and whole transcriptome sequencing did not reveal a new SNV or fusion responsible for the resistance. However. gene expression and phosphoproteomic analysis has revealed that these cells upregulate RTKs to activate the PI3K/AKT pathway. This is a novel finding, as most RAS-mutated cells upregulate RTKs to re-activate the MAPK pathway in a SHP2/SOS1 dependent manner, and could explain the lack of efficacy of SHP2 inhibitors in FN-RMS. Our current work is aimed at vaildating these results.

我们与LASP合作，在RAS突变的小鼠横纹肌肉瘤异种移植模型中进行了曲美替尼和加尼替单抗的体内研究。我们发现，曲美替尼和格尼单抗联合用药比单独使用任何一种药物都有生存优势，也比标准的化疗药物长春新碱提供了生存优势。我们还发现，这种联合用药在肿瘤内提供了预期的药效学效应，即与对照组相比，曲美替尼和加尼替单抗联合治疗的肿瘤中ERK磷酸化和IGF1R的表达减少。我们还发现，RAS突变的人横纹肌肉瘤细胞系SMS-CTR对曲美替尼和甘尼单抗的联合治疗有特殊的反应。为了确定SMS-CTR对这种组合反应良好的原因，我们发现在RAS突变的横纹肌肉瘤细胞系中，SMS-CTR具有最高的IGF1R表达。我们的目标是确定共同靶向RAS-RAF-MEK-ERK通路和IGF1R-IRS1/2-PI3K-AKT-mTOR通路的机制，这些通路在IGF1R表达不高的细胞系中是有效的，包括针对IGF1R、IGF1/2配体的单抗和IRS1/2的抑制物。这项工作目前正在进行中。重要的是，我们还在几种RAS突变的RMS的PDX模型中测试了曲美替尼和加尼妥单抗的组合。我们在NRAS和HRAS驱动的异种细胞移植和PDX模型中展示了这种组合的有效性。对这种结合具有相对内在抵抗力的模型是PI3激酶途径基因也发生变化的模型，要么是PIK3CA突变，要么是PTEN表达缺失。重要的是，下调SMS-CTR细胞中PTEN的表达使其对曲美替尼产生耐药性。目前的工作旨在更好地了解可能介导这种耐药性的PI3激酶下游的效应器。我们正在与CTEP和儿童肿瘤学小组讨论在儿科患者中启动曲美替尼和加尼替单抗的I/II期临床试验。我们还在与免疫生物公司讨论由调查员发起的单一机构试验。不幸的是，ganitumab不再可用于新的临床试验。我们现在正在与BI讨论xentuzumab，一种针对IGF1/2的单抗。在临床转换该组合之前，我们将进行xentuzumab与曲美替尼的临床前研究。为了便于这种组合的临床翻译，我们正在评估曲美替尼/加尼替单抗在其他疾病组织学中的疗效。我们已经在两个RAS突变的神经母细胞瘤的异种移植细胞系中显示了曲美替尼/加尼替单抗的有效性，并正在继续评估由MAPK通路(不是RAS本身)变化驱动的神经母细胞瘤模型以及由NF1或BRAF变化驱动的MPNST。在曲美替尼和加尼替尼联合的动物研究过程中，我们创建了一个对曲美替尼具有耐药性的SMS-CTR细胞系。我们目前正在确定该细胞系对曲美替尼的耐药机制。全外显子组测序和全转录组测序没有发现新的SNV或融合导致抗性。然而。基因表达和磷酸化蛋白质组学分析表明，这些细胞上调RTKs激活PI3K/AKT途径。这是一个新的发现，因为大多数RAS突变的细胞上调RTK以依赖SHP2/SOS1的方式重新激活MAPK通路，并可以解释SHP2抑制剂在FN-RMS中缺乏疗效的原因。我们目前的工作就是为了验证这些结果。