Echinoderm Microtubule-associated Protein-like 4 Research Articles

Afatinib Overcomes Pemetrexed-Acquired Resistance in Non-Small Cell Lung Cancer Cells Harboring an EML4-ALK Rearrangement.

Background: The aim of this study is to elucidate the mechanisms of acquired resistance to pemetrexed in echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) rearranged non-small cell lung cancer. Methods: We analyzed the sensitivity to pemetrexed and the expression patterns of various proteins after pemetrexed treatment in the cell lines, A549, NCI-H460, NCI-H2228 harboring EML4-ALK variant 3, and NCI-H3122 harboring EML4-ALK variant 1. Pemetrexed-resistant cell lines were also generated through long-term exposure to pemetrexed. Results: The EML4-ALK variant 1 rearranged NCI-H3122 was found to be more sensitive than the other cell lines. Cell cycle analysis after pemetrexed treatment showed that the fraction of cells in the S phase increased in A549, NCI-H460, and NCI-H2228, whereas the fraction in the apoptotic sub-G1 phase increased in NCI-H3122. The pemetrexed-resistant NCI-H3122 cell line showed increased expression of EGFR and HER2 compared to the parent cell line, whereas A549 and NCI-H460 did not show this change. The pan-HER inhibitor afatinib inhibited this alternative signaling pathway, resulting in a superior cytotoxic effect in pemetrexed-resistant NCI-H3122 cell lines compared to that in the parental cells line. Conclusion: The activation of EGFR-HER2 contributes to the acquisition of resistance to pemetrexed in EML4-ALK rearranged non-small cell lung cancer. However, the inhibition of this alternative survival signaling pathway with RNAi against EGFR-HER2 and with afatinib overcomes this resistance.

Dual drive coexistence of ALK rearrangement and KRAS mutation advanced lung adenocarcinoma and response to crizotinib

Chromosomal translocation resulting in the fusion between the echinoderm microtubule-associated protein-like 4 (EML4) gene and the anaplastic lymphoma kinase (ALK) gene has been considered as a novel oncogenic fusion in a subset of non-small cell lung cancer (NSCLC), mostly in non-smokers with adenocarcinoma. EML4-ALK translocations are commonly reported to be mutually exclusive with epidermal growth factor receptor (EGFR) or KRAS mutations. Herein, we reported a rare case of 47-year-old female was diagnosed with lung adenocarcinoma and treated with three cycles of chemotherapy. A biopsy acquired after disease progression revealed concurrent KRAS mutation and ALK translocation by an next-generation sequencing (NGS) assay. The patient had a favorable tumor response to crizotinib, a tyrosine kinase inhibitor (TKI). A further understanding of the molecular biology with multiple oncogenic drivers will promote the optimal treatment for NSCLC.

Abstract 2982: Monomerization of ALK fusion proteins as a therapeutic strategy in ALK rearranged cancers

Abstract Introduction: Since the discovery of the anaplastic lymphoma kinase (ALK) and echinoderm microtubule-associated protein like-4 (EML4) fusion protein, ALK tyrosine kinase inhibitors have been shown to have great anti-tumor activities against ALK rearranged non-small cell lung cancers (NSCLC). As previously reported, the EML4-ALK fusion proteins induce constitutive phosphorylation of ALK via the trimeric coiled-coil domain within EML4. ALK F1174L mutations known in neuroblastoma, can induce autophosphorylation without dimerization. We hypothesize that monomerization of ALK fusion proteins decreased tumorigenesis via competitive dissociation of the trimeric coiled-coil domain of EML4. Methods: We established Ba/F3 cells stably expressing wild-type (wt) ALK intracellular domain or F1174L mutant (mu) with using iDimerize system (Takara Bio). Using this system, monomer or dimer of ALK fusion proteins were controlled by adding AP20187 (Takara Bio). These Ba/F3 cells were subcutaneously injected into BALB nu/nu mice followed by intraperitoneal administration of AP20187 or Mock intermittently. A chemically synthesized peptide composed of amino acid sequences of coiled-coil domain within EML4, was administered for H3122 (EML4-ALK) or A549 (KRAS) cells and the viabilities were analyzed after 24 hours. In order to demonstrate the specificity of the peptide, a synthesized peptide in which two amino acids were substituted was also used as a control. Each peptide was solubilized in DMSO and the peptide concentration was optimized. Results: We successfully established the Ba/F3 stably expressing fusion-ALKwt, fusion-ALKmu under continuous administration of AP20187. Subsequently, ALK proteins were depolymerized by withdrawal of AP20187. The number of cells expressing ALKwt were decreased while the same of ALKmu were increased. The protein expression of phosphorylation of ALK or downstream survival signaling proteins were weakened after 24hours from AP20187 withdrawal. In fusion-ALKwt cells, tumor xenograft was developed in every mice with AP20187 (n=6) administration, while tumor was not developed in Mock controls (n=6). In fusion-ALKmu cells, tumor xenograft was developed in all mice with or without AP20187 administration (n=12). In vitro assay, cell growth of H3122 was 40% decreased by adding coiled-coil peptides, while increased cell growth was observed in control peptide groups and A549 cells. Conclusion: Monomerization of ALK intracellular domain induced cell death and suppressed tumorigenesis. The coiled-coil peptide specifically suppressed the activity of EML4-ALK cell line. Monomerization of ALK fusion proteins via coiled-coil peptide is a promising therapeutic strategy for ALK rearranged NSCLC. Citation Format: Noriko Hirai, Takaaki Sasaki, Yoshinobu Ohsaki. Monomerization of ALK fusion proteins as a therapeutic strategy in ALK rearranged cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2982.

Abstract 3460: MPRIP-ALK,a novel ALK rearrangement that responds to ALK inhibitor in non-small-cell lung cancer

Abstract Oncogenic rearrangements of the anaplastic lymphoma receptor tyrosine kinase (ALK gene) have recently been described in 3% to 5% of lung adenocarcinomas. Kinds of fusion partners of ALK have been reported in non-small-cell lung cancer (NSCLC), with echinoderm microtubule-associated protein-like 4 (EML4)-ALKbeing the most prevalent one. Several tyrosine kinase inhibitors have been approved for treating patients with advanced-stage ALK-positive, NSCLC by Food and Drugs Administration (FDA). Comprehensive genomic profiling performed by means of next-generation sequencing assay demonstrated a novel myosin phosphatase-Rho-interacting protein gene (MPRIP)-ALK fusion in our case, in which a translocation involving chromosomes 2 and 9 has taken place. The rearrangement was verified by reverse transcription reverse transcription polymerase chain reaction (RT-PCR) and Sanger sequencing. ALK immunohistochemistry demonstrated strong staining in patient’s tumor sample as extracted from formalin-fixed paraffin-embedded (FFPE) sections. We expressed MPRIP-ALK cDNA construct in non-cancer cell line Ba/F3 which showed IL-3-independent growth compared the growth stop of cells carrying empty vector, moreover, hyper-activation of the protein ALK, ERK, AKT were detected in Ba/F3 cells with MPRIP-ALK over-expressed. Furthermore, the colonies and activations of ALK downstream signaling pathways could be inhibited by crizotinib. The patient received standard chemotherapy on the first-line. She experienced progressive disease after 7 months, and commenced on crizotinib (250mg, twice per day) from March 2018. The patient showed significant improvement in cough, dorsalgia, and polypnea within one week. Partial response was gained after one month treatment and confirmed at the third month. She still remains on the crizotinib treatment without disease relapse up to now. In this study, we report a novel ALK rearrangement in a patient with NSCLC by RNA-seq. Our in vivo and in vitro studies have shown that the novel MPRIP-ALK fusion is a driver gene and can be targetable by crizotinib. Citation Format: Wenfeng Fang, Jiadi Gan, Feng Lu, Yangyang Deng, Liang Chen, Yunpeng Yang, Li Zhang. MPRIP-ALK,a novel ALK rearrangement that responds to ALK inhibitor in non-small-cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3460.

Dual drive coexistence of ALK rearrangement and KRAS mutation advanced lung adenocarcinoma and response to crizotinib

Chromosomal translocation resulting in the fusion between the echinoderm microtubule-associated protein-like 4 ( EML4 ) gene and the anaplastic lymphoma kinase ( ALK ) gene has been considered as a novel oncogenic fusion in a subset of non-small cell lung cancer ( NSCLC ), mostly in non-smokers with adenocarcinoma. EML4-ALK translocations are commonly reported to be mutually exclusive with epidermal growth factor receptor (EGFR) or KRAS mutations. Herein, we reported a rare case of 47-year-old female was diagnosed with lung adenocarcinoma and treated with three cycles of chemotherapy. A biopsy acquired after disease progression revealed concurrent KRAS mutation and ALK translocation by an next-generation sequencing (NGS) assay. The patient had a favorable tumor response to crizotinib, a tyrosine kinase inhibitor (TKI). A further understanding of the molecular biology with multiple oncogenic drivers will promote the optimal treatment for NSCLC.

Feasibility of liquid biopsy using plasma and platelets for detection of anaplastic lymphoma kinase rearrangements in non-small cell lung cancer

PurposeFluorescence in situ hybridization (FISH) using tumor tissue is the gold standard for detection of anaplastic lymphoma kinase (ALK) rearrangement in non-small cell lung cancer (NSCLC). However, this method often is not repeatable due to difficulties in the acquisition of tumor tissues. Blood-based liquid biopsy using reverse transcription polymerase chain reaction (RT-PCR) is expected to be useful to overcome this limitation. Here, we investigated the feasibility of liquid biopsy using plasma and platelets for detection of ALK rearrangement and prediction of ALK inhibitor treatment outcomes.MethodsALK-FISH assays were performed in 1128 tumor specimens of NSCLC between January 2015 and June 2018. We retrospectively analyzed formalin-fixed paraffin-embedded (FFPE) tissues from previously confirmed FISH-positive (n = 199) and -negative (n = 920) cases. We recruited patients who had available tissue specimens and agreed to venous sampling. RNA was extracted from FFPE blocks, plasma, and platelets. Fusion RNA of echinoderm microtubule-associated protein-like 4 (EML4)-ALK was detected by quantitative PCR.ResultsThirty-three FISH-positive and 28 FISH-negative patients were enrolled. In validation, data compared with FISH, RT-PCR using FFPE tissues showed 54.5% sensitivity, 78.6% specificity, and 75.5% accuracy. Liquid biopsy had higher sensitivity (78.8%), specificity (89.3%) and accuracy (83.6%). Higher positivity for liquid biopsy was shown in subgroups with delayed (≥ 6 months from diagnosis) blood sampling (plasma, 85.7%; platelets, 87.0%). In 26 patients treated with crizotinib, the platelet-positive subgroup showed longer median duration of treatment (7.2 versus 1.5 months), longer median progression-free survival (5.7 months versus 1.7 months), a higher overall response rate (70.6% versus 11.1%), and a higher disease control rate (88.2% versus 44.4%) than the platelet-negative subgroup.ConclusionLiquid biopsy could have applications in the diagnosis of ALK-positive NSCLC, even when using RT-PCR, and platelets can be useful for predicting treatment outcomes of ALK inhibitors.

Synthesis and structure-activity relationships of pyrazine-2-carboxamide derivatives as novel echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) inhibitors.

Echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) is a valid therapeutic target for the treatment of EML4-ALK-positive non-small cell lung cancer (NSCLC). We discovered 12c as a novel and potent EML4-ALK inhibitor through structural optimization of 5a. In mice xenografted with 3T3 cells expressing EML4-ALK, oral administration of 12c demonstrated potent antitumor activity. This article describes the synthesis and biological evaluation of pyrazine-2-carboxamide derivatives along with studies of their structure-activity relationship (SAR) using computational modeling.

MiR-100-5p confers resistance to ALK tyrosine kinase inhibitors Crizotinib and Lorlatinib in EML4-ALK positive NSCLC

Lung cancer causes the highest number of cancer-related deaths worldwide. Resistance to therapy is a major clinical issue contributing to the poor prognosis of lung cancer. In recent years, targeted therapy has become a concept where subgroups of non-small cell lung cancer (NSCLC) with genetically altered receptor tyrosine kinases are targeted by tyrosine kinase inhibitors (TKIs). One such subgroup harbors a gene fusion of echinoderm microtubule-associated protein-like 4 (EML4) with anaplastic lymphoma kinase (ALK). Although most NSCLC patients with EML4-ALK fusions initially respond to ALK TKI-therapy they eventually develop resistance. While ALK kinase domain mutations contribute to ALK TKI-refractoriness, they are only present in a fraction of all ALK TKI-resistant tumors. In this study we sought to explore a possible involvement of microRNAs (miRNAs) in conferring resistance to ALK TKIs in ALK TKI-refractory NSCLC cell lines. We subjected our ALK TKI-refractory cancer cells along with parental cancer cells to systematic miRNA expression arrays. Furthermore, ALK TKI-refractory cancer cells were exposed to a synthetic miRNA inhibitory Locked Nucleic Acid (LNA)-library in the presence of ALK TKIs Crizotinib or Lorlatinib. The outcome of the combined approaches uncovered miR-100-5p to confer resistance to Crizotinib and Lorlatinib in EML4-ALK NSCLC cells and to be a potential therapeutic target in drug resistance.

Personalized genomic medicine: non-small-cell lung cancer and anaplastic lymphoma kinase

Genomic medicine, that is to say, using genomic information about a patient in order to set the diagnostic path and to tailor therapy to his/her specific characteristics, is one of the cornerstones of modern precision medicine and forms an integral part of several fields, oncology first of all. Lung cancer is the leading cause of cancer mortality, causing more than 1.6 million deaths worldwide per year and non-small-cell lung cancer (NSCLC) accounts for approximately 85% of lung cancers. In a small subset of NSCLC (5%-8%), we can detect a genomic rearrangement on chromosome 2, between the Echinoderm microtubule-associated protein-like 4 (EML4) gene and the anaplastic lymphoma kinase (ALK) gene, resulting in the chimeric protein EML4-ALK, that acts as an oncogene and that can be specifically targeted by an ALK-tyrosine kinase inhibitor (TKI) therapy. However, a major clinical challenge is represented by the fact that, after a first line ALK-TKI treatment, patients eventually develop acquired resistance to these agents, opening new scenarios for the right second-line drug choice.

Anaplastic lymphoma kinase fusions: Roles in cancer and therapeutic perspectives.

Receptor tyrosine kinase (RTK) anaplastic lymphoma kinase (ALK) serves a crucial role in brain development. ALK is located on the short arm of chromosome 2 (2p23) and exchange of chromosomal segments with other genes, including nucleophosmin (NPM), echinoderm microtubule-associated protein-like 4 (EML4) and Trk-fused gene (TFG), readily occurs. Such chromosomal translocation results in the formation of chimeric X-ALK fusion oncoproteins, which possess potential oncogenic functions due to constitutive activation of ALK kinase. These proteins contribute to the pathogenesis of various hematological malignancies and solid tumors, including lymphoma, lung cancer, inflammatory myofibroblastic tumors (IMTs), Spitz tumors, renal carcinoma, thyroid cancer, digestive tract cancer, breast cancer, leukemia and ovarian carcinoma. Targeting of ALK fusion oncoproteins exclusively, or in combination with ALK kinase inhibitors including crizotinib, is the most common therapeutic strategy. As is often the case for small-molecule tyrosine kinase inhibitors (TKIs), drug resistance eventually develops via an adaptive secondary mutation in the ALK fusion oncogene, or through engagement of alternative signaling mechanisms. The updated mechanisms of a variety of ALK fusions in tumorigenesis, proliferation and metastasis, in addition to targeted therapies are discussed below.

526P - Correlation between the response to critzotinib and concomitant genetic alterations in advanced lung cancer patients with ALK rearrangement

Background: The fusion gene echinoderm microtubule-associated protein-like 4 (EML4) - anaplastic lymphoma kinase (ALK) was found to be a driver mutation in lung cancer in 2007. Crizotinib can significantly prolong a patient’s survival and improve the quality of life in patients harboring ALK fusion gene. Methods: The specimens enrolled in the study underwent next generation sequencing. The types of ALK fusion gene and contaminant mutations were identified and their correlation with crizotinib efficacy was explored. Results: 197 patients with advanced ALK-positive lung cancer received crizotinib treatment at Peking Union Medical College Hospital and Peking University Cancer Hospital from January 2013 to December 2017. After excluding cases with incomplete medical records and inadequate tissue samples, 16 cases were enrolled in the study and the specimen underwent next-generation sequencing. The main ALK fusion type was V1 fusion (37.5%); followed by V3 fusion (31.25%). No difference was found in clinical characteristics and crizotinib efficacy between patients with different types of ALK fusion genes. Patients with shorter progression free survival (PFS) have a larger number of genetic mutations (p = 0.048). According to the mutation types, three mutational signatures were identified, namely, signature A, B and C. Patients with mutation signature A have a prolonged PFS (p = 0.026). Conclusions: No association between crizotinib efficacy and types of ALK fusion variant was found. However, crizotinib efficacy was associated with mutation signature and mutation number. Legal entity responsible for the study: Peking Union Medical College Hospital. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.

Identification of a highly lethal V3+ TP53+ subset in ALK+ lung adenocarcinoma.

Tyrosine kinase inhibitors (TKI) have improved prognosis in metastatic anaplastic lymphoma kinase (ALK)-driven lung adenocarcinoma, but patient outcomes vary widely. We retrospectively analyzed the clinical course of all cases with assessable baseline TP53 status and/or ALK fusion variant treated at our institutions (n = 102). TP53 mutations were present in 17/87 (20%) and the echinoderm microtubule-associated protein-like 4 (EML4)-ALK variant 3 (V3) in 41/92 (45%) patients. The number of metastatic sites at diagnosis was affected more by the presence of V3 than by TP53 mutations, and highest with both factors (mean 5.3, p < 0.001). Under treatment with ALK TKI, progression-free survival (PFS) was shorter with either TP53 mutations or V3, while double positive cases appeared to have an even higher risk (hazard ratio [HR] = 2.9, p = 0.015). The negative effect of V3 on PFS of TKI-treated patients was strong already in the first line (HR = 2.5, p = 0.037) and decreased subsequently, whereas a trend for PFS impairment under first-line TKI by TP53 mutations became stronger and statistically significant only when considering all treatment lines together. Overall survival was impaired more by TP53 mutations (HR = 4.9, p = 0.003) than by V3 (HR = 2.4, p = 0.018), while patients with TP53 mutated V3-driven tumors carried the highest risk of death (HR = 9.1, p = 0.02). Thus, TP53 mutations and V3 are independently associated with enhanced metastatic spread, shorter TKI responses and inferior overall survival in ALK+ lung adenocarcinoma. Both markers could assist selection of cases for more aggressive management and guide development of novel therapeutic strategies. In combination, they define a patient subset with very poor outcome.

Characteristics and Response to Crizotinib in ALK-Rearranged, Advanced Non-Adenocarcinoma, Non-Small Cell Lung Cancer (NA-NSCLC) Patients: a Retrospective Study and Literature Review.

Oncogenic fusion genes consisting of echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) can be detected in 5-7% of lung adenocarcinoma cases. The prevalence of ALK rearrangement in non-adenocarcinoma, non-small cell lung cancers (NA-NSCLC) is currently unknown. In addition, the efficacy of crizotinib in these patients has not been well established. The aim of this study was to investigate the prevalence of ALK rearrangement in NA-NSCLC patients and the therapeutic efficacy of crizotinib in these patients. We included NA-NSCLC patients who were tested for the presence of ALK rearrangement in our institution from January 2013 to May 2018. The effectiveness of crizotinib in ALK-positive patients was retrospectively analyzed. A literature review was performed and eligible previously published cases were analyzed in combination with our data. A total of 4662 patients were screened and 1696 NA-NSCLC patients were tested for the presence of ALK rearrangement during the study period. Thirty-two positive patients were identified (1.9%, 95% CI, 1.2-2.5%). A statistically higher percentage of younger (58.0 vs. 63.0, p = 0.01), female patients (53.1% vs. 10.8%, p < 0.01) who were non-smokers (71.9% vs. 40.6%, p < 0.01) and whose tumors contained adenocarcinoma components (34.4% vs. 6.1%, p < 0.01) were observed in the ALK-positive group. Eighteen patients were excluded from the study and 14 eligible patients were included for survival analysis. The median duration of crizotinib treatment (MDT) as a proxy for progression-free survival of the 14 eligible patients in our institution was 6.0months (95% CI, 1.2-10.8months). We combined our data with sporadic cases from 16 previous publications (total n = 37) and found that the MDT was 7.0months (95% CI, 6.0-8.0months). Our study suggests the opportunity to test ALK rearrangement in NA-NSCLC patients, especially in younger, female, non-smoking patients containing adenocarcinoma components. Crizotinib provides an option for the treatment of NA-NSCLC patients who have an ALK rearrangement.

Heterogeneity of PD-L1 Expression and Relationship with Biology of NSCLC.

Immunotherapy with monoclonal antibodies against programmed cell death (PD-1), such as nivolumab and pembrolizumab, has significantly improved the survival of patients with metastatic non-small cell lung cancer (NSCLC). In order to determine the subset of patients that can benefit most from these therapies, biomarkers such as programmed death ligand-1 (PD-L1) have been proposed. However, the predictive and prognostic role of the use of PD-L1 is controversial. Anti-PD-L1 immunohistochemistry may not represent the actual status of the tumour because of individual variability and tumour heterogeneity. Additionally, there may be analytical variability due to the use of different assays and antibodies to detect PD-L1. Moreover PD-L1 expression is also regulated by oncogenic drivers in NSCLC, such as epidermal growth factor receptor (EGFR), echinoderm microtubule-associated protein-like 4 (EML4) fusion with anaplastic lymphoma kinase (ALK), and Kirsten rat sarcoma viral oncogene homolog (KRAS). Preclinical studies have shown the potential role of targeted therapy in immune escape mechanisms in NSCLC cells. This review summarizes current literature data on the heterogeneity of PD-L1 expression and the relationship with such factors and with clinicopathological features of NSCLC.

Correlation between EML4-ALK, EGFR and clinicopathological features based on IASLC/ATS/ERS classification of lung adenocarcinoma.

To investigate the correlation between echinodermmicro tubule associated protein-like 4 (EML4)-anaplasticlymphomakinase (ALK), epidermal growth factor receptor (EGFR) and clinicopathological features in patients diagnosed with lung adenocarcinoma according to International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) international multidisciplinary classification of lung adenocarcinoma.Ninety patients diagnosed with lung adenocarcinoma underwent surgical pathological classification. Ventana immunohistochemical staining of the EML4-ALK was performed. The mutation of EGFR and EML4-ALK was detected by real-time polymerase chain reaction (RT-PCR) using the amplification refractory mutation system.The positive rate of EML4-ALK mutation was calculated as 6.7% (6/90), dominantly occurring in patients aged < 60 years. However, it was not correlated with the gender, smoking history, maximal tumor diameter, pleural invasion, lymphatic metastasis, or clinical staging. EML4-ALK fusion gene mutation was mainly associated with the predominant subtypes of acinar and solid tumors with mucin secretion. The mutation rate of EGFR was 60% (27/45). EGFR gene mutation mainly occurred in the female, those with no smoking history and tumor size < 3 cm, whereas it had no association with age, pleural invasion, lymphatic metastasis, or clinical staging. It was histologically characterized with micropapillary, lepidic, and papillary subtypes.The mutation rate of EML4-ALK is relatively high in lung adenocarcinoma patients aged<60 years, pathologically characterized with acinar and solid subtypes with mucin secretion. Female patients with no smoking habit, tumor size<3 cm, pathologically characterized with micropapillary, lepidic, and papillary subtypes had a high mutation rate of EGFR.

Management of Resistance to First-Line Anaplastic Lymphoma Kinase Tyrosine Kinase Inhibitor Therapy.

A decade after the discovery of echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (EML4-ALK) rearrangements in non-small cell lung cancer (NSCLC), several inhibitors have gained regulatory approval, and their sequential use has deferred platinum-based chemotherapy to later lines of therapy. Nevertheless, although most ALK-driven tumors dramatically respond to ALK TKIs , all patients ultimately develop drug-resistant disease. Analysis of post-progression biopsy samples has provided invaluable insight into the mechanisms of resistance, now informing on subsequent therapeutic strategies. In particular, the identification of secondary ALK mutations, which are a common mechanism of resistance to both first-generation and to an even larger extent to second-generation ALK TKIs, may shape a personalized optimal treatment strategy beyond the current first-line choice. Alectinib has now become a preferred treatment option in the first line of therapy, and extrapolation of data obtained from post-progression samples after second-line next-generation ALK TKIs suggests that acquired resistance is likely to be mediated in more than half of patients by ALK resistance mutations. Nevertheless, clinical and preclinical evidence suggests that multiple resistance mechanisms may co-exist at different levels in the same TKI-resistant patient. Newer ALK tyrosine kinase inhibitors (TKIs) overcome some resistance mutations through higher exposure and potency, and generally present greater CNS activity, but are unlikely to overcome resistance mediated through separate oncogenic pathway activations, or epithelial to mesenchymal transition (EMT) and small cell lung cancer (SCLC) transformation. Furthermore, while resistance mutations can be detected through commonly available sequencing methods, the identification of other mechanisms of resistance is much less straightforward in the clinic. We hypothesize that the ALK resistance mutation status will likely be crucially important in the choice of second-line therapy after a second-generation TKI. Emerging clinical data also refines the optimal placing of PD-1- and PD-L1-directed immunotherapy in the treatment sequence.

A lung adenocarcinoma patient with EGFR mutation in exon 18 and ALK-rearrangement who treated with erlotinib and crizotinib

Abstract Concomitant mutations of echinoderm microtubule-associated protein-like 4 (EML4) anaplastic lymphoma kinase (ALK) translocation and epidermal growth factor receptor (EGFR) can be found rarely in lung adenocarcinoma. We present a case of harboring EML4/ALK rearrangement lung adenocarcinoma who previously received erlotinib. A 42-year-old male who was diagnosed as lung adenocarcinoma and received many series of cytotoxic regimens. A partial tumor response was achieved with crizotinib after failure with erlotinib therapy. After progressive disease, biopsy of new liver lesion showed EML4/ALK rearrangement. Thus crizotinib was administrated. A partial tumor response was achieved with crizotinib after failure with erlotinib therapy and chemotherapy. We conclude that it is important to evaluate for EML4/ALK rearrangement even the patient has EGFR mutation. Concomitant EGFR exon 18 and EML4-ALK mutations can occur in lung adenocarcinoma. EML4/ALK related TKIs may be more effective in these patients.

EML4-ALK fusion variant V3 is a high-risk feature conferring accelerated metastatic spread, early treatment failure and worse overall survival in ALK+ non-small cell lung cancer.

In order to identify anaplastic lymphoma kinase-driven non-small cell lung cancer (ALK+ NSCLC) patients with a worse outcome, who might require alternative therapeutic approaches, we retrospectively analyzed all stage IV cases treated at our institutions with one of the main echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion variants V1, V2 and V3 as detected by next-generation sequencing or reverse transcription-polymerase chain reaction (n = 67). Progression under tyrosine kinase inhibitor (TKI) treatment was evaluated both according to Response Evaluation Criteria in Solid Tumors (RECIST) and by the need to change systemic therapy. EML4-ALK fusion variants V1, V2 and V3 were found in 39%, 10% and 51% of cases, respectively. Patients with V3-driven tumors had more metastatic sites at diagnosis than cases with the V1 and V2 variants (mean 3.3 vs. 1.9 and 1.6, p = 0.005), which suggests increased disease aggressiveness. Furthermore, V3-positive status was associated with earlier failure after treatment with first and second-generation ALK TKI (median progression-free survival [PFS] by RECIST in the first line 7.3 vs. 39.3 months, p = 0.01), platinum-based combination chemotherapy (median PFS 5.4 vs. 15.2 months for the first line, p = 0.008) and cerebral radiotherapy (median brain PFS 6.1 months vs. not reached for cerebral radiotherapy during first-line treatment, p = 0.028), and with inferior overall survival (39.8 vs. 59.6 months in median, p = 0.017). Thus, EML4-ALK fusion variant V3 is a high-risk feature for ALK+ NSCLC. Determination of V3 status should be considered as part of the initial workup for this entity in order to select patients for more aggressive surveillance and treatment strategies.

Oncogene addiction and radiation oncology: effect of radiotherapy with photons and carbon ions in ALK-EML4 translocated NSCLC

BackgroundPatients with Echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) positive lung cancer are sensitive to ALK-kinase inhibitors. TAE684 is a potent second generation ALK inhibitor that overcomes Crizotinib resistance. Radiotherapy is an integral therapeutic component of locally advanced lung cancer. Therefore, we sought to investigate the effects of combined radiotherapy and ALK-inhibition via TAE684 in ALK-positive vs. wild type lung cancer cells.MethodsHuman non-small cell lung cancer (NSCLC) cell lines harboring wild-type ALK (A549), EML4-ALK translocation (H3122) and murine Lewis Lung Cancer (LLC) cells were investigated. Cells were irradiated with 1–4 Gy X-Rays (320 keV) and carbon ions (Spread-out Bragg Peak, SOBP (245.4–257.0 MeV/u)) at Heidelberg Ion Therapy center. TAE684 was administered at the dose range 0–100 nM. Clonogenic survival, proliferation and apoptosis via caspase 3/7 expression level were assessed in all three cell lines using time-lapse live microscopy.ResultsTAE684 inhibited the proliferation of H3122 cells in a dose-dependent manner with a half maximal inhibitory concentration (IC50) of ~ 8.2 nM. However, A549 and LLC cells were relatively resistant to TAE684 and IC50 was not reached at concentrations tested (up to 100 nM) in proliferation assay. The antiproliferative effect of TAE684 was augmented by radiotherapy in H3122 cells. TAE684 significantly sensitized H3122 cells to particle therapy with carbon ions (sensitizer enhancement ratio ~1.61, p < 0.05). Caspase 3/7 activity was evidently enhanced after combination therapy in H3122 cells.ConclusionsThis is the first report demonstrating synergistic effects of combined TAE684 and radiotherapy in EML4-ALK positive lung cancer cells. In addition to conventional photon radiotherapy, ALK-inhibition also enhanced the effects of particle irradiation using carbon ions. Our data indicate beneficial effects of combined ALK-inhibition and radiotherapy in treatment of this distinct subpopulation of NSCLC that warrant further evaluation.

Clinical outcome study of crizotinib in immunohistochemistry-proven echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene among Indian patients with adenocarcinoma lung.

Aims:The anaplastic lymphoma kinase (ALK) Break Apart FISH Probe Kit and Ventana anti-ALK (D5F3) CDx immunohistochemistry (IHC) assay are the Food and Drug Administration-approved companion diagnostic for targeted therapy with the ALK inhibitor crizotinib in lung cancers. The aim of this study was to assess the efficacy and safety of twice daily crizotinib tablet (250 mg) in IHC-proven echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion gene among Indian patients with adenocarcinoma lung in the routine clinical practice.Subjects and Methods:Patients with nonsmall cell lung cancer (NSCLC), adenocarcinoma histology, whose tumors were found to be positive for EML4-ALK fusion gene using IHC, were considered for this study. IHC analysis was performed using a Ventana automated immunostainer (Benchmark XT). Detection was performed using Optiview DAB detection and amplification kit.Results:A total of 25 NSCLC adenocarcinoma patients were included in the study. There were 14 (56%) women and 10 (44%) men with a median age of 53 years. All patients had Stage IV disease at the time of initiation of crizotinib therapy. One patient achieved complete response and 20 achieved response rate (PR) for an overall PR of 84%. The median progression-free survival (PFS) was 11.8 months and median overall survival (OS) was 20.6 months. Two (8%) patients experienced severe hepatotoxicity requiring permanent discontinuation of crizotinib therapy.Conclusions:A very high PR, PFS, and OS achieved in our study population indicates that IHC can accurately identify EML4 ALK fusion gene mutations in lung adenocarcinoma patients who are responsive to ALK inhibitors such as crizotinib. IHC should be considered as a cost-effective alternative to FISH, especially in low-resource countries.