Overcoming BRAF and MEK Inhibitors Resistance in Advanced Melanoma

克服晚期黑色素瘤中的 BRAF 和 MEK 抑制剂耐药性

• 批准号: 9032562
• 负责人: Niramol Savaraj
• 金额: --
• 依托单位: MIAMI VA HEALTH CARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9032562
• 关键词: Accounting; Address; Aftercare; Ammonia; Antibodies; Antitumor Response; Apoptosis; Apoptotic; Arginine; Arginine deiminase; Attenuated; Autophagocytosis; BRAF gene; Biochemical; Biological Assay; Blood Circulation; Cell Death; Cell Line; Cells; Cessation of life; Citrulline; Clinic; Clinical Trials; Clinical Trials Design; Cutaneous Melanoma; Cytotoxic T-Lymphocyte-Associated Protein 4; Data; Disease; Disease Progression; Drug Targeting; Drug resistance; Enzymes; Exhibits; Failure; Future; Genes; Goals; Grant; Growth; Heat shock proteins; Immune; Immunotherapy; In Vitro; Laboratory Finding; Ligands; Ligase; Lymphocyte; MEKs; Melanoma Cell; Modality; Mutation; Normal Cell; Organelles; PDCD1LG1 gene; Patients; Pharmaceutical Preparations; Phase; Progressive Disease; Publishing; Recombinants; Relapse; Reporting; Resistance; Role; Salvage Therapy; Sampling; Signal Transduction; Stable Disease; Survival Rate; Time; Toxic effect; Translating; Work; antitumor effect; argininosuccinate synthase; base; c-Myc Staining Method; clinically relevant; combinatorial; deprivation; improved outcome; in vivo; inhibitor/antagonist; killings; melanoma; neoplastic cell; novel; outcome forecast; programs; public health relevance; resistance mechanism; response; targeted agent; treatment planning; tumor; tumor growth; urea cycle

 DESCRIPTION (provided by applicant): BRAF inhibitor (BRAFi) has emerged as one of the key treatments for BRAFV600E mutation which accounts for 60% of cutaneous melanomas. While the response rate is high and responses can be rapid, relapse is inevitable and often occurs within 6 months. The addition of MEK inhibitor (MEKi) could increase the duration of response from 6 to 9 months and increase one year survival to 40%. However, relapse invariably occurs and there is no effective salvage treatment available. Another approach is the use of immunotherapy with checkpoint inhibitors. Ipilimumab (anti-CTLA 4 antibody) and anti-programmed death 1 (anti-PD1) antibody (Nivolumab and Pembrolizumab) showed an increase in duration of response (99 weeks) and increased overall survival (63% one year survival rate). However, the time to response is often long for these agents, and when rapid disease progression occurs, especially after BRAF failure, patients may not be able to complete the planned treatment course, as has been reported for ipilimumab. Currently, there is a paucity of published data on the antitumor activity of anti-PD1 and anti-PD-L1 after BRAFi failure or BRAFi and MEKi failure patients. In this application, we plan to target to treat this group of patients which has rapid progressive disease and extremely poor prognosis. Our preliminary data showed that these resistant cells are very sensitive to arginine deprivation and pegylated arginine deiminase (ADI-PEG20) which degrades arginine to citrulline produced >80% decrease in these resistant tumors in vivo. We plan to investigate the underlying mechanism(s) and translate this into clinical trial. Our previou work and others have shown that certain melanomas do not express argininosuccinate synthetase (ASS), a key enzyme in the urea cycle, to synthesize arginine. These tumors depend on exogenous arginine to survive. ADI-PEG20 inhibits tumor growth with minimal toxicity since normal cells can take up citrulline to make arginine. However, we have found that autophagy does occur which can blunt the antitumor effect and re-expression of ASS can develop. These two mechanisms can account for drug resistance seen with this treatment. Importantly, we have found that cMyc is a positive regulator for re- expression of ASS. Interestingly, we have found that both BRAF resistant (BR) and dual resistant [resistant to both BRAFi and MEKi (BMR)] cells cannot readily undergo autophagy due to decrease in AMPK1-α and Atg5. This makes these resistant cells exquisitely sensitive to ADI-PEG20 treatment. In addition, both BR and BMR cells are unable to re-express ASS gene due to decrease in cMyc, and hence they cannot evade the apoptotic effect by ADI-PEG20 treatment. We plan to investigate how cMyc, AMPK1-α, and Atg5 are down regulated. Importantly, we plan to investigate the clinical relevance of our laboratory findings by examining tumor samples obtained from BR and BRM patients for AMPK1-α, Atg5 and ASS expression and for ADI-PEG20 sensitivity using tumor explant and primary culture as outlined in aim 2. Clinically, BR and BMR patients usually progress very rapidly and ADI-PEG20 alone may not be sufficient to control the tumor. In aim 3, we plan to investigate which combination with ADI-PEG20 yields the best antitumor efficacy. Based on our preliminary data, we plan to combine ADI-PEG20 with MEKi in BR tumors and ADI-PEG20 with Hsp-90 inhibitors in BMR tumors. Our ultimate goal is to apply this combination to treat this group of extremely poor prognosis patients. Immune checkpoint inhibitors have become a major component for the treatment of melanoma, and the effect of ADI- PEG20 on PD-1 and PD-L1 expression has not been explored. Our preliminary data showed that ADI-PEG20 can upregulate PD-L1 in BR and BMR cells, which may potentiate the antitumor effect of anti-PD-1 and anti- PD-L1 antibody. We plan to examine tumor explants, BR, and BMR cells for PD-1/PD-L1 expression before and after ADI-PEG20 treatment. Furthermore, we will also examine PD-1 expression from lymphocytes in these patients before and after treatment with ADI-PEG20. Thus, future combinatorial treatment using both agents can be rationally formulated to treat ASS (-) melanoma patients.

 描述（由申请人提供）： BRAF抑制剂（BRAFI）已成为BRAFV600E突变的关键治疗方法之一，占皮肤黑色素瘤的60％。虽然响应率很高，并且响应可能很快，但反传输是不可避免的，并且经常在6个月内发生。 MEK抑制剂（MEKI）的添加可能会将反应持续时间从6个月增加到9个月，并将一年的生存时间增加到40％。但是，接力总是发生，并且没有有效的打捞处理。另一种方法是将免疫疗法与检查点抑制剂一起使用。 ipilimumab（抗CTLA 4抗体）和抗编程死亡1（抗PD1）抗体（Nivolumab和pembrolizumab）显示出反应持续时间（99周）和总生存期增加（63％的生存率）。但是，这些药物通常很长的时间，并且当发生快速疾病进展时，尤其是在BRAF失败后，患者可能无法完成计划的治疗过程，正如iPilimumab报道的那样。目前，关于BRAFI失败或BRAFI和MEKI衰竭患者抗PD1和抗PD-L1抗肿瘤活性的已发表数据很少。在此应用中，我们计划以快速进行性疾病且预后极差的患者进行针对治疗这组患者。我们的初步数据表明，这些抗性细胞对精氨酸的剥夺非常敏感，而精氨酸脱节酶（ADI-PEG20）将精氨酸降解为瓜氨酸的我们的体内耐药性肿瘤降低了> 80％。我们计划研究基本机制，并将其转化为临床试验。我们的Previou工作和其他工作表明，某些黑色素瘤不表达尿素周期中的关键酶（ASS）的精氨酸合成酶（ASS）来合成精氨酸。这些肿瘤取决于外源精氨酸的生存。 ADI-PEG20抑制肿瘤的生长，毒性最小，因为正常细胞可以服用瓜氨酸来生成精氨酸。但是，我们发现确实会发生自噬，这可以钝化抗肿瘤效应，并且可以发展出屁股的重新表达。这两种机制可以解释这种治疗方法的耐药性。重要的是，我们发现CMYC是重新表达ASS的积极调节剂。有趣的是，我们发现，由于AMPK1-α和ATG5的降低，抗BRAF抗性（BR）和双抗药性[对BRAFI和MEKI（BMR）的抗性[对BRAFI和MEKI（BMR）]都无法轻易发生自噬。这使得这些抗性细胞对ADI-PEG20处理完全敏感。此外，由于CMYC的降低，BR和BMR细胞均无法重新表达ASS基因，因此它们无法通过ADI-PEG20处理来逃避凋亡效应。我们计划研究CMYC，AMPK1-α和ATG5如何受到调节。重要的是，我们计划通过检查从BR和BRM患者获得AMPK1-α，ATG5和ASS表达以及使用AIM 2中概述的肿瘤epplan依和原发性培养的ADI-PEG20敏感性的肿瘤样本来研究实验室发现的临床相关性。在临床上，BR和BMR患者通常会非常迅速，并且ADI-peg20不足以控制tumor tum tum tum tum tum a tum a tum tum tumor tumor tumor tumor tumor tumor tumor tumor tumor tumor tum tum tum a py a的敏感性很大。在AIM 3中，我们计划研究哪种与ADI-PEG20的组合产生最佳的抗肿瘤效率。根据我们的初步数据，我们计划将ADI-PEG20与BR肿瘤中的MEKI和ADI-PEG20与BMR肿瘤中的HSP-90抑制剂相结合。我们的最终目标是应用这种组合来治疗这组极差的预后患者。免疫检查点抑制剂已成为治疗黑色素瘤的主要成分，并且尚未探索ADI-PEG20对PD-1和PD-L1表达的影响。我们的初步数据表明，ADI-PEG20可以更新BR和BMR细胞中的PD-L1，这可能有可能寄主抗PD-1和抗PD-L1抗体的抗肿瘤作用。我们计划在ADI-PEG20处理前后检查肿瘤外植体，BR和BMR细胞的PD-1/PD-L1表达。此外，我们还将在用ADI-PEG20治疗前后检查这些患者中淋巴细胞的PD-1表达。那就是，可以合理制定使用两种药物的未来组合治疗来治疗屁股（ - ）黑色素瘤患者。