Crizotinib-resistant Non-small Cell Lung Cancer Research Articles

ROS1 Positive Non-Small Cell Lung Cancer Patient with Brain Metastases Who Overcame Crizotinib Resistance with Lorlatinib: Case Report

Background: ROS1-positive patients account for 1-2% of non small cell lung cancer (NSCLC) cases. Crizotinib is the first tyrosine kinase inhibitor (TKI) indicated in first line treatment of ROS1-rearranged NSCLC. However, crizotinib resistance is frequent within the first 12 months of treatment. Lorlatinib is a novel tyrosine kinase inhibitor of ROS-1 recently indicated for metastatic or locally advanced crizotinib-resistant NSCLC. Case report: We report a case of a 43-year-old female patient with no medical history, diagnosted with stage IVB NSCLC including asymptomatic brain metastasis, and harboring ROS1 rearrangement. Within the first three months of starting crizotinib, the patient showed on CT scan evaluation new bone and brain metastases. Lorlatinib in the second line revealed a noteworthy improvement in metastasis and primary lesion. Conclusion: Brain metastases frequently occur in ROS1-rearranged NSCLC at the time of diagnosis and treatment course. However the efficacy of crizotinib might not translate to intracranial control of the disease, one of the cause of resistance to this drug.

Density Functional Theory and Raman Spectroscopy Studies of Adsorption Sites of Au Nanoparticles with Alectinib.

Alectinib is an ALK tyrosine kinase inhibitor, which is mainly used in patients with crizotinib-resistant nonsmall cell lung cancer. Alectinib has attracted much clinical attention for its longest progression-free survival time and the best therapeutic effect. The chemical adsorption of Au nanoclusters (AuNPs) with alectinib molecules is studied by density functional theory (DFT) and surface-enhanced Raman scattering spectroscopy (SERS) experiments. DFT/B3LYP-D3/6-311G** was used for optimization and vibration analysis of alectinib-Au6 complexes, as well as molecular electrostatic potential, frontier molecular orbital, and electro-optic-based charge transfer descriptors. Comparing the results of the DFT theory and SERS experiment, alectinib and AuNPs can form Au-N6 bonds primarily through chemical adsorption of N6 atoms, and the experimental results showed that the enhancement factor (EFCHEM) could reach 4.27. The results provide a theoretical basis for exploring the mechanism of chemical enhancement between AuNPs and alectinib.

Discovery of 2,4-pyrimidinediamine derivatives as potent dual inhibitors of ALK and HDAC.

Combination of anaplastic lymphoma kinase (ALK) inhibitor with histone deacetylases (HDAC) inhibitor could exert synergistically anti-proliferative effects on ALK positive non-small cell lung cancer (NSCLC) naïve or resistant cells. In this work, we designed and synthesized a series of 2,4-pyrimidinediamine derivatives as dual ALK and HDAC inhibitors based on pharmacophore merged strategy. Among which, compound 10f displayed the most potent and balanced inhibitory activity against ALK (IC50=2.1nM) and HDAC1 (IC50=7.9nM), respectively. In particular, 10f was also potent against the frequently observed Crizotinib-resistant ALKL1196M (IC50=1.7nM) as well as the Ceritinib-resistant ALKG1202R (IC50=0.4nM) mutants. In antiproliferative activity assay, 10f exhibited impressive activity on ALK-addicted cancer cell lines at low micromole concentrations, which was comparable to that of Crizotinib and Ceritinib. Further flow cytometric analysis indicated that 10f could effectively induce cell death via cell apoptosis and cell cycle arrest. Taken together, these results suggested 10f would be a promising lead compound for the ALK-positive NSCLC treatment, especially the Ceritinib- or Crizotinib-resistant NSCLC.

The role of brigatinib in crizotinib-resistant non-small cell lung cancer.

Despite the advances in new targeted therapies in ALK positive population, most patients progress under ALK inhibitors within first 2 years; being the brain the most frequent site of relapse. ALK mutations, in ~30% of patients, are the main known mechanism of resistance. Classically, second-generation ALK inhibitors have been the standard of care in the crizotinib-resistant population; however, each ALK inhibitor has a different spectrum of sensitivity to ALK mutations, complicating the optimal treatment strategy for the resistant population. Brigatinib (AP26113) is a novel highly selective and potent inhibitor of ALK and ROS1 with a high degree of selectivity. In vitro, brigatinib not only inhibited ALK with 12-fold higher potency compared to crizotinib, but also inhibited IGF-1R, FLT3 and EGFR mutants, with some activity against the EGFRT790M resistance mutation. In xenograft models, brigatinib overcomes resistance to ALK inhibitors, including the ALK G1202R mutation, which is resistant to first- and second-generation inhibitors. The efficacy of brigatinib in crizotinib-resistant, ALK-positive patients has been demonstrated in two early studies, which led to its approval in this setting, and it is currently being investigated as the first-line therapy versus crizotinib in tyrosine kinase inhibitor-naïve patients. Brigatinib demonstrates not only promising whole-body activity, but also an impressive improvement of intracranial outcomes in terms of both objective response rate and progression-free survival in the crizotinib-resistant population, with optimal efficacy at 180 mg (following a 90 mg run-in for 7 days) and good tolerance. These data confirm brigatinib as an excellent therapeutic strategy after crizotinib failure, particularly in the setting of central nervous system involvement. In this review, we summarize the two main clinical studies reported to date with brigatinib in ALK-positive advanced NSCLC patients, in particular, in the crizotinib-resistant population. We also address the mechanism of action for development of resistance and the challenging issues of optimal implementation for sequences of administration for ALK inhibitors.

Abstract 3141: Combined cetuximab and pemetrexed therapy enhances cytotoxicity against crizotinib-resistant non-small cell lung cancer cells by downregulating thymidylate synthase

Abstract Although non-small cell lung cancer (NSCLC) cells with anaplastic lymphoma kinase (ALK)-rearranged initially show a dramatic response to crizotinib, these cells eventually develop resistance to crizotinib. This resistance is caused by secondary mutations and copy number gain in the ALK gene. However, other resistance mechanisms through activation of the bypass tracts have yet to be clearly elucidated. To investigate the mechanisms of acquired resistance to ALK fusion-directed treatment in NSCLC, we generated crizotinib-resistant NSCLC cell lines in vitro through chronic exposure of an ALK fusion NSCLC line (SNU2292) to crizotinib. Interestingly, the resultant SNU2292-CR cells maintained activation of epidermal growth factor receptor (EGFR) and expressed increased levels of transforming growth factor alpha (TGF-α), an EGFR ligand. Additionally, we found that thymidylate synthase (TS) was overexpressed in SNU2292-CR cells compared with the parental cells. We showed reduction of TS enhanced synergistic inhibition of cell proliferation when cetuximab, an EGFR inhibitor, was combined with pemetrexed, a TS inhibitor. As a result, combined therapy was found to exhibit a synergistic growth inhibitory effect against crizotinib-resistant cells by downregulating TS expression. Taken together, these results support a potential role of activation of the bypass tracts in acquired resistance to ALK-directed treatment in ALK-rearranged NSCLC, and provide insights into strategies for preventing and/or overcoming this resistance in patients Citation Format: Hwang-Phill Kim, Sae-Won Han, Sang-Hyun Song, Tae-You Kim. Combined cetuximab and pemetrexed therapy enhances cytotoxicity against crizotinib-resistant non-small cell lung cancer cells by downregulating thymidylate synthase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3141. doi:10.1158/1538-7445.AM2017-3141

Elucidation of Resistance Mechanisms to Second-Generation ALK Inhibitors Alectinib and Ceritinib in Non–Small Cell Lung Cancer Cells

Crizotinib is the first anaplastic lymphoma kinase (ALK) inhibitor to have been approved for the treatment of non–small cell lung cancer (NSCLC) harboring an ALK fusion gene, but it has been found that, in the clinic, patients develop resistance to it. Alectinib and ceritinib are second-generation ALK inhibitors which show remarkable clinical responses in both crizotinib-naive and crizotinib-resistant NSCLC patients harboring an ALK fusion gene. Despite their impressive activity, clinical resistance to alectinib and ceritinib has also emerged. In the current study, we elucidated the resistance mechanisms to these second-generation ALK inhibitors in the H3122 NSCLC cell line harboring the EML4-ALK variant 1 fusion in vitro. Prolonged treatment of the parental H3122 cells with alectinib and ceritinib led to two cell lines which are 10 times less sensitive to alectinib and ceritinib than the parental H3122 cell line. Although mutations of ALK in its kinase domain are a common resistance mechanism for crizotinib, we did not detect any ALK mutation in these resistant cell lines. Rather, overexpression of phospho-ALK and alternative receptor tyrosine kinases such as phospho-EGFR, phospho-HER3, and phospho-IGFR-1R was observed in both resistant cell lines. Additionally, NRG1, a ligand for HER3, is upregulated and responsible for resistance by activating the EGFR family pathways through the NRG1-HER3-EGFR axis. Combination treatment with EGFR inhibitors, in particular afatinib, was shown to be effective at overcoming resistance. Our study provides new mechanistic insights into adaptive resistance to second-generation ALK inhibitors and suggests a potential clinical strategy to combat resistance to these second-generation ALK inhibitors in NSCLC.

Upregulation of PD-L1 by EML4-ALK fusion protein mediates the immune escape in ALK positive NSCLC: Implication for optional anti-PD-1/PD-L1 immune therapy for ALK-TKIs sensitive and resistant NSCLC patients

ABSTRACTDriver mutations were reported to upregulate programmed death-ligand 1 (PD-L1) expression. However, how PD-L1 expression and immune function was affected by ALK-TKIs and anti-PD-1/PD-L1 treatment in ALK positive non-small-cell lung cancer (NSCLC) remains poorly understood. In the present study, western-blot, real-time PCR, flow cytometry and immunofluorescence were employed to explore how PD-L1 was regulated by ALK fusion protein. ALK-TKIs and relevant inhibitors were used to identify the downstream signaling pathways involved in PD-L1 regulation. Cell apoptosis, viability and Elisa test were used to study the immune suppression by ALK activation and immune reactivation by ALK-TKIs and/or PD-1 blocking in tumor cells and DC-CIK cells co-culture system. We found that PD-L1 expression was associated with EGFR mutations and ALK fusion genes in NSCLC cell lines. Over-expression of ALK fusion protein increased PD-L1 expression. PD-L1 mediated by ALK fusion protein increased the apoptosis of T cells in tumor cells and DC-CIK cells co-culture system. Inhibiting ALK by sensitive TKIs could enhance the production of IFNγ. Anti-PD-1 antibody was effective in both crizotinib sensitive and resistant NSCLC cells. Synergistic tumor killing effects were not observed with ALK-TKIs and anti-PD-1 antibody combination in co-culture system. ALK-TKIs not only directly inhibited tumor viability but also indirectly enhanced the antitumor immunity via the downregulation of PD-L1. Anti-PD-1/PD-L1 antibodies could be an optional therapy for crizotinib sensitive, especially crizotinib resistant NSCLC patients with ALK fusion gene. Combination of ALK-TKIs and anti-PD-1/PD-L1 antibodies treatment for ALK positive NSCLC warrants more data before moving into clinical practice.

ALK inhibitors in non-small cell lung cancer: the latest evidence and developments.

The treatment of patients with advanced non-small cell lung cancer (NSCLC) harbouring chromosomal rearrangements of ALK (anaplastic lymphoma kinase) was revolutionized by crizotinib, a small molecule inhibitor of ALK, ROS1 and MET. Unfortunately, the disease progressed within the first 12 months in most of the patients because of the development of crizotinib resistance in the majority of patients and the emergence of acquired resistance mutations in most of them. Many of them had been reported even before its approval leading to the rapid development of second-generation ALK inhibitors for crizotinib-resistant NSCLC. In the last few years, novel potent ALK inhibitors with promising results and a good toxicity profile have become available: ceritinib (LDK378), alectinib (RG7853/AF-802/RO5424802/CH5424802), brigatinib (AP26113), entrectinib (RXDX-101, NMS-E628), PF-06463922, ASP3026, TSR-011, X-376/X-396 and CEP-28122/CEP-37440. Moreover, HSP90 (90 kDa heat shock protein) inhibitors have demonstrated clinical activity in patients with ALK+ NSCLC. This review focuses on the molecular and clinical properties of this new generation of ALK inhibitors under development in the clinic.

Methodology of Establishing and Identifying NCI-H2228/Crizotinib-resistant Cell Lines In Vitro

背景与目的小分子靶向药物发生耐药的机制及寻找克服耐药的手段是目前提高临床疗效需要迫切解决的问题。本研究探讨采用不同方法建立对Crizotinib耐药的非小细胞肺癌NCI-H2228/Crizotinib细胞株的可行性及鉴定分析，为深入研究Crizotinib耐药发生的机制并寻找克服耐药的手段提供实验基础和理论依据。方法采用逐步增加药物浓度和化学诱变剂处理NCI-H2228细胞，诱导细胞对Crizotinib耐药。MTT法检测亲本细胞和耐药细胞的50%抑制浓度（50% inhibitory concentration, IC50）和群体倍增时间。RT-PCR和Western blot实验检测棘皮动物微管相关蛋白样4-间变性淋巴瘤激酶（echinoderm microtubule-associated protein like 4-anaplastic lymph kinase, EML4-ALK）基因表达。对耐药细胞和亲本细胞的EML4-ALK基因全长测序并对比分析发生耐药的机制。结果逐步增加药物浓度的方法耗时过长，细胞恢复生长缓慢，不能有效诱导NCI-H2228细胞对Crizotinib耐药；化学诱变剂ENU可以在短时间内诱导NCI-H2228细胞对Crizotinib耐药[IC50=（3.810±1.100）μmol/L，P=0.002, 9，vs亲本细胞]。耐药细胞EML4-ALK基因发生点突变的频率高于亲本细胞。结论化学诱变剂诱导细胞耐药操作简便，可有效缩短实验流程，为深入研究耐药发生机制，寻找克服靶向药物耐药的手段提供了前期技术方法和实验依据。

The treatment of advanced non-small-cell lung cancer with anaplastic lymphoma kinase genetic alterations: reality and hopes

Targeted therapies based on molecular diagnostics have opened a new era of personalized medicine in lung cancer treatment. Recently, anaplastic lymphoma kinase (ALK) fusion gene emerged as an important biomarker for identifying a small proportion of non-small-cell lung cancer (NSCLC) patients that will benefit from ALK kinase inhibitor crizotinib, like EGFR activating mutations and EGFR tyrosine kinase inhibitors. Despite the remarkable initial responses, acquired resistance to crizotinib develops within a year and promising second generation of ALK inhibitors are in current development to overcome it. This review will focus on the basic molecular pathology of ALK gene rearrangement in NSCLC, current testing methods, treatment strategies against ALK-positive and crizotinib-resistant NSCLCs.

Ceritinib for the treatment of non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) represents the paradigm of personalized treatment in human cancer. Several oncogenic alterations with druggable potential have been identified, with ALK rearrangements representing one of the newest and most appealing. Crizotinib is now recognized as the standard of care in chemotherapy-pretreated ALK-positive NSCLC due to the positive results of a recently published trial. Unfortunately, no patient exposed to crizotinib can be cured, and after a median time of 1 year, resistance inevitably occurs. Overcoming resistance is the major challenge in clinical oncology and many molecules are currently under evaluation, including ceritinib (LDK-378). Ceritinib is an oral, potent, second-generation ALK inhibitor recently approved by the U.S. Food and Drug Administration. Preclinical data showed impressive antitumor activity against crizotinib-resistant clones, and based on available data, ceritinib could represent a suitable option in crizotinib-resistant NSCLC.