Anaplastic Lymphoma Kinase Aberrations Research Articles

Abstract LB414: Novel ALK/PIK3CA cooperativity in head and neck squamous cell carcinoma (HNSCC) progression

Abstract Recent genomic characterization studies have demonstrated the genetic heterogeneity of head and neck squamous cell carcinoma (HNSCC). Yet, most of these genetic aberrations remain undruggable. Anaplastic Lymphoma Kinase (ALK) is somatically mutated in ~3.6% of HNSCC (18/504 cases, TCGA-HNSCC Firehose cohort, USA), and the majority of these ALK-mutated HNSCC cases are of advanced stage diseases. Here, we hypothesized that ALK mutations might plausibly contribute to HNSCC progression and could be potentially druggable. Unexpectedly, analysis of HNSCC genomic events revealed a novel co-occurrence relationship between ALK and PIK3CA genomic aberrations in TCGA-HNSCC Firehose cohort (Odds Ratio=2.41; N=522 samples with CNV data), with subsequent validation in an independent metastatic MSK-MetTropism HNSCC cohort (Odds Ratio=5.12; N=412). Consistent with this newly identified co-occurrence relationship, we showed that all 7 HNSCC-relevant ALK point mutations were potent drivers for HNSCC invasiveness and clonogenic growth only in corroboration with PIK3CA aberrations in HNSCC cell models, highlighting the functional importance of this novel ALK/PIK3CA cooperativity in HNSCC, likely reminiscent of ALK/MYCN cooperativity in neuroblastoma. Further, by clonogenic assay, we demonstrated pharmacologic vulnerabilities of all 7 ALK point mutations (including extracellular domain mutations) to ALK targeting by ceritinib in FaDu cell background with endogenous PIK3CA amplification. Strikingly, we were able to capture, for the first time, spontaneous emergence of a druggable ALK somatic mutation directly from a PIK3CA-altered HNSCC patient-derived culture (PDC) upon forced acquisition of anoikis-resistance ex vivo (PDC-25-AR), demonstrating co-evolution of ALK/PIK3CA aberrations in HNSCC likely associated with cancer progression. Patient-derived culture-xenograft (PDCx) of PDC-25-AR displayed remarkable sensitivity to ALK targeting, PI3K targeting, as well as their combination, with induction of apoptosis in these tumors compared to vehicle control. In conclusion, ALK aberrations corroborate with PIK3CA aberrations to promote HNSCC progression, yet, these events are potentially druggable in advanced HNSCC. Citation Format: Lan Wang, Helen Hoi-Yin Chan, Angel Yee Lok Fung, Yuen-Keng Ng, Patrick Kwok-Shing Ng, Yuxiong Su, Jason Ying Kuen Chan, Peony Hiu Yan Poon, Thomas Chun Kit Yeung, Chi Man Tsang, Hoi-Lam Ngan, Wenying Piao, Yuchen Liu, Jack Nimitz Smith, Tin Yu Samuel Law, Ee Ling Kong, Melissa Sue Ann Chan, Chun Ho Law, Sze-Man Chan, Zoey Wing Yee Liu, Joshua Chung-Hymn Ng, Gordon B. Mills, Vivian W.Y. Lui. Novel ALK/PIK3CA cooperativity in head and neck squamous cell carcinoma (HNSCC) progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB414.

Therapeutic benefit of the dual ALK/FAK inhibitor ESK440 in ALK-driven neuroblastoma

Neuroblastoma (NB) is a predominantly pediatric cancer with greater than 90% of cases arising in children under the age of five. More than half of patients have metastases detected at diagnosis, and high-risk disease is associated with five-year survival rates of only 50–60 %. Standard therapy involves highly toxic chemotherapy, surgery, radiation, and immunotherapy, and less toxic, more specific targeted therapies are urgently needed. Genomic studies have identified common driver aberrations in high-risk NB, such as MYCN amplification. In addition, a proportion of high-risk patients harbor amplification or activating mutations in anaplastic lymphoma kinase (ALK), and co-occurrence of ALK mutations and MYCN amplification have been associated with aggressive disease. In this study, we analyzed the efficacy of a Phase Ia-cleared, orally bioavailable dual ALK and focal adhesion kinase (FAK) inhibitor, ESK440, in multiple preclinical NB models. ESK440 potently inhibited proliferation of NB cell lines, with increased sensitivity in cell lines harboring ALK aberrations. ALK, FAK, and downstream target activation were rapidly decreased upon ESK440 treatment, and this was associated with impaired cellular migration and invasion. Importantly, ESK440 treatment also decreased MYCN levels. NB cell line and patient-derived xenograft studies showed significant reduction in tumor growth in ESK440-treated mice with no signs of toxicity. In certain NB models, ESK440 showed comparable or enhanced efficacy to lorlatinib, another clinical ALK inhibitor, and a lorlatinib-resistant cell line (COG-N-561 LR) retained sensitivity to ESK440. These preclinical results indicate that ESK440 is a promising targeted agent for ALK-driven NB and support future clinical studies to evaluate its efficacy in NB patients.

Abstract 1201: ALK amplification and rearrangements are recurrent targetable events in congenital and adult glioblastoma

Abstract Purpose: Anaplastic Lymphoma Kinase (ALK) aberrations have been identified in pediatric type infant gliomas, but their occurrence across age groups, functional effects, and treatment response have not been broadly established. Experimental Design: We performed a comprehensive analysis of ALK expression and genomic aberrations in both newly-generated and retrospective data from 371 glioblastomas (156 adult, 205 infant/pediatric and 10 congenital) with in vitro and in vivo validation of aberrations. Results: ALK aberrations at the protein or genomic level were detected in 12% of gliomas (45/371) in a wide age range (0-80 years). Recurrent as well as novel ALK fusions (LRRFIP1-ALK, DCTN1-ALK, PRKD3-ALK) were present in 50% (5/10) of congenital/infant, 1.4% (3/205) of pediatric, and 1.9% (3/156) of adult GBMs. ALK fusions were present as the only candidate driver in congenital/infant GBMs, and were sometimes focally amplified. In contrast, adult ALK fusions co-occurred with other oncogenic drivers. No activating ALK mutations were identified in any age group. Novel and recurrent ALK rearrangements promoted STAT3 and ERK1/2 pathways and transformation in vitro and in vivo. ALK-fused GBM cellular and mouse models were responsive to ALK inhibitors, including in patient cells derived from a congenital GBM. Relevant to treatment of infant gliomas, we showed that ALK protein appears minimally expressed in the forebrain at perinatal stages and no gross effects on perinatal brain development was seen in pregnant mice treated with the ALK inhibitor ceritinib. Conclusions: These findings support expanded evaluation of brain-penetrant ALK inhibitors in clinical trials across infant, pediatric, and adult GBMs. Citation Format: Anne-Florence Blandin, Ross Giglio, Maya Srikanth Graham, Guadalupe Garcia, Seth Malinowski, Jared K. Woods, Shakti Ramkissoon, Lori Ramkissoon, Frank Dubois, Kate Schoolcraft, Jessica W. Tsai, Dayle K. Wang, Robert Jones, Jayne Vogelzang, Kristine Pelton, Sarah Becker, Fiona Watkinson, Claire Sinai, Elizabeth Cohen, Matthew Booker, Michael Tolstorukov, Veerle Haemels, Liliana Goumnerova, Karen Wright, Mark Kieran, Katie Fehnel, David Reardon, Arnault Tauziede-Espariat, Rishi Lulla, Benjamin Carcamo, Stanley Chaleff, Alain Charest, Frederik De Smet, Azra H. Ligon, Adrian Dubuc, Melanie Pagès, Pascale Varlet, Patrick Wen, Brian Alexander, Susan Chi, Sanda Alexandrescu, Ralf Kittler, Robert Bachoo, Rameen Beroukhim, Pratiti Bandopadhayay, Keith L. Ligon. ALK amplification and rearrangements are recurrent targetable events in congenital and adult glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1201.

Abstract 2422: Genetic aberrations of Anaplastic Lymphoma Kinase (ALK) are functional drivers in head and neck squamous cell carcinoma (HNSCC)

Abstract Head and neck squamous carcinoma (HNSCC) is a cancer with high genetic heterogeneity. Fusions of Anaplastic Lymphoma Kinase (ALK) have been widely described as a functional driver for lung cancer. Yet, mutations and amplification of ALK are found in HNSCC as well as many other human cancers. Their biological impacts on cancer cell growth are underexplored. Using the Cancer Genome Atlas (TCGA) HNSCC dataset (Firehose Legacy; N=510), we identified a subset of HNSCC patients harboring ALK aberrations (4%), including 0.4% cases with gene amplification and 3.5% with somatic mutations. Transcriptome analysis showed significant tumor-specific ALK upregulation in 43 adjacent normal-HNSCC tumor pairs (2-fold, p=0.001***, TCGA HNSCC Firehose Legacy). Interestingly, clinical analysis revealed that ~94% HNSCC patients with ALK amplification and mutations have advanced diseases (stage III or IV). Among the HNSCC-associated ALK aberrations, ALK amplification, as well as ALK p.R401L mutations are recurrent events. Thus, we sought to investigate their biological functions by ectopic expressions into an HNSCC cell line, FaDu, via retroviral infection. We found that overexpression of ALK WT gene (mimicking gene amplification) and ALK p.R401L significantly promoted cell proliferation vs. EGFP-control (p=0.0004***, 0.01*, respectively). Clonogenic assay also demonstrated both events to be drivers for colony survival vs. EGFP-control by 120%, 150% (p=0.02*, 0.0025**, respectively). Lastly, both events markedly increase FaDu cells invasiveness by Matrigel invasion assay by 67%, 58% (vs. EGFP-control, p<0.0001****, 0.0001****, respectively). In conclusion, ALK aberrations are functional drivers promoting HNSCC aggressiveness. Acknowledgements: This study is funded by General Research Fund, Research Grant Council, Hong Kong Government, Hong Kong SAR (#17121616 ). VWYL also receives funding supports from General Research Fund, Research Grant Council, Hong Kong Government, Hong Kong SAR (#17121616, #14168517), Research Impact Fund (#R4015-19F, R4017-18), the Health and Medical Research Fund (HMRF#15160691) from the Health and Medical Research Fund, the Food and Health Bureau, the Government of the Hong Kong Special Administrative Region), University-Industry Collaboration Programme (UIM/329; Innovation and Technology Fund, Hong Kong Government, Hong Kong SAR), and the Hong Kong Cancer Fund, Hong Kong SAR. Citation Format: Lan Wang, Thomas Chun Kit Yeung, Hoi-Lam Ngan, Peony Hiu Yan Poon, Vivian Wai Yan Lui. Genetic aberrations of Anaplastic Lymphoma Kinase (ALK) are functional drivers in head and neck squamous cell carcinoma (HNSCC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2422.

Immunotherapy for ALK-Rearranged Non-Small Cell Lung Cancer: Challenges Inform Promising Approaches.

Simple SummaryNon-small cell lung cancer is the most common type of lung cancer. Anaplastic Lymphoma Kinase (ALK) rearrangements have been found in 5–6% of non-small cell lung cancers. While ALK rearranged non-small cell lung cancer is exquisitely sensitive to ALK directed targeted therapies, it is generally resistant to immune-based therapies. We aim to describe the mechanisms by which ALK-rearranged non-small cell lung cancers escape host immunity and are thereby unresponsive to immunotherapies. Furthermore, we describe new immunotherapy strategies and the promises and challenges in incorporating these into clinical practice.Rearrangements in the Anaplastic Lymphoma Kinase (ALK) gene have been implicated in 5–6% of all non-small cell lung cancers. ALK-rearranged non-small cell lung cancers are sensitive to ALK-directed tyrosine kinase inhibitors, but generally resistant to single-agent immune checkpoint inhibitors. Here, we aim to describe the mechanisms of ALK aberrations in non-small cell lung cancer by which an immunosuppressed tumor microenvironment is created, leading to host immune evasion. We report pre-clinical and clinical studies evaluating novel immunotherapeutic approaches and describe the promises and challenges of incorporating immune-based treatments for ALK-rearranged non-small cell lung cancer.

Repotrectinib (TPX-0005), effectively reduces growth of ALK driven neuroblastoma cells

Neuroblastoma is the most commonly diagnosed extracranial tumor in the first year of life. Approximately 9% of neuroblastoma patients present germline or somatic aberrations in the gene encoding for anaplastic lymphoma kinase (ALK). This increases in high-risk neuroblastomas, which have a 14% frequency of ALK aberrations at the time of diagnosis and show increasing numbers at relapse. Abrogating ALK activity with kinase inhibitors is employed as clinical therapy in malignancies such as non-small cell lung cancer and has shown good results in pediatric inflammatory myofibroblastic tumors and anaplastic large cell lymphomas. A phase I clinical trial of the first generation ALK inhibitor, crizotinib, in neuroblastoma patients showed modest results and suggested that further investigation was needed. Continuous development of ALK inhibitors has resulted in the third generation inhibitor repotrectinib (TPX-0005), which targets the active kinase conformations of ALK, ROS1 and TRK receptors. In the present study we investigated the effects of repotrectinib in a neuroblastoma setting in vitro and in vivo. Neuroblastoma cell lines were treated with repotrectinib to investigate inhibition of ALK and to determine its effect on proliferation. PC12 cells transfected with different ALK mutant variants were used to study the efficacy of repotrectinib to block ALK activation/signaling. The in vivo effect of repotrectinib was also analyzed in a neuroblastoma xenograft model. Our results show that repotrectinib is capable of inhibiting signaling activity of a range of ALK mutant variants found in neuroblastoma patients and importantly it exhibits strong antitumor effects in a xenograft model of neuroblastoma.

ALKATI interacts with c-Myc and promotes cancer stem cell-like properties in sarcoma.

Soft tissue sarcoma (STS) is a highly malignant tumor with limited targeted therapies. A novel anaplastic lymphoma kinase (ALK) transcript, ALKATI, was identified recently and could be targeted by ALK inhibitors in melanoma. However, the clinical and functional role of aberrant ALKATI expression in STS remains unknown. Here we demonstrate that as a new ALK transcript, ALKATI is frequently found in STS. ALKATI expression correlates with a lower probability of progression-free survival in STS patients. Compared with the other ALK isoforms, ALKATI expresses not only in the cytoplasm, but also in the nucleus of sarcoma cells. Functionally, overexpression of ALKATI promoted cancer stem cell (CSC)-like properties in sarcoma cells by promoting sphere formation and upregulating the expression of stem cell markers. Moreover, the ALK inhibitors not only suppressed the oncogenic functions of ALKATI but also attenuated ALKATI-induced CSC-like properties by reducing the expression of stem cell markers such as c-Myc, ABCG2, BMI1, and OCT4 both in vitro and in vivo. Furthermore, ALKATI interacted with c-Myc and increased the binding of c-Myc to the ABCG2 promoter, resulting in the induction of stem cell-like properties. Together, these findings indicate that ALKATI may be a potential prognostic marker and therapeutic target for STS patients harboring such ALK aberrations.

Identification of Novel Pathways and Small Molecules Able to Down Regulate Oncogenes Expression By Compounds Screening Approaches in Acute Leukemia and Neuroblastoma Cells

Targeting anaplastic lymphoma kinase (ALK), a receptor tyrosine kinase initially identified as a potent oncogenic driver in anaplastic large-cell lymphoma (ALCL) in the form of nucleophosmin (NPM)-ALK fusion protein, using tyrosine kinase inhibitors has shown to be a promising therapeutic approach for ALK-expressing tumors. However, resistance to ALK inhibitors is a ubiquitous problem in ALK-expressing cell lines as well as treated patients. Amplified ALK or mutated ALK was identified in ~14% of neuroblastomas (NB), the most common and aggressive childhood malignancy, and phase I trial of ALK inhibitor such as crizotinib showed a lack of response in patients harboring certain ALK mutations. Previous reports have suggested that mechanism of resistance is mediated by mutations in the ALK kinase domain impairing binding of an inhibitor to an ALK protein. Thus, new treatment modalities are urgently needed to sensitize patients to crizotinib thereby improving the management of hematological or solid malignancies harboring ALK mutations. To identify compounds with the potential of inhibiting oncogenic activity of ALK in NB, we implemented a high throughput chemical screen in 4 NB-derived cell lines, using a curated library of ~450 compounds. In the compounds screening, JAK-STAT kinase inhibitor (cucurbitacin I) was the most discriminatory with regard to sensitivity for ALK-mutated cell lines. Since Gamma cytokine JAK/STAT system as a target in the treatment of T-cell or myeloid malignancies, we analyzed the cytotoxicity of cucurbitacin I antitumor effect using an MTT assay revealed cucurbitacin I to possess potent cytotoxic activity across a broad spectrum of hematopoietic malignancies, with T-acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) being especially responsive. For example, T-ALL cell lines, as well as AML lines, were potently inhibited by cucurbitacin I (IC50values:T-ALL lines, ICH-TALL-UK, 103.2 nM; MOLT-14, 35.6 nM; KCMC-T, 134.2 nM; Jurkat, 77 nM; ICH-TALL-SM, 47.7 nM; MOLT-4, 22.2 nM. AML lines, HEL, 66.7 nM; Kasumi-3, 4.5 nM; KG-1, 53.6 nM; THP-1, 337.2 nM). In an expanded panel of 20 NB cell lines, those with or without MYCN-amplification or 11q loss of heterozygousity which have been identified as two major oncogenic events in NB pathogenesis, especially in the high-risk group were the most sensitive to low nanomolar concentrations of cucurbitacin I. In NB cell lines harboring F1174L or R1275Q-mutated ALK, crizotinib combined with cucurbitacin I enhanced tumor responses and showed synergistic cytotoxicity.Although crizotinib and cucurbitacin I alone or combination therapy (cucurbitacin I + crizotinib) did not result in decreased viability over control compared with vehicle, the combination therapy in all of 6 cell lines with ALK aberrations and 10 of 13 ALK wild-type cell lines with MYCN amplification or 11q LOH was more effective than vehicle, crizotinib alone, and cucurbitacin I alone. Analysis of downstream signalling through MAPK, AKT and STAT3 pathways showed that NIH3T3 cells stably expressed F1174L mutated ALK or TGW cells harboring R1275Q-mutated ALK, expressed lower levels of pERK, pAKT and pSTAT3 in combination therapy compared with cells treated with cucurbitacin I or crizotinib alone. These findings may provide a indication that the combination of low-dose ALK and STAT3 inhibitors may be benefitical for the treatment of NB, by enhancing efficacy while reducing toxicity. In conclusion, our studies suggested that NB, T-ALL or AML cell lines also exhibited potent cytotoxic responses to the cucurbitacin I and the combination of ALK and JAK-STAT inhibitors could be a valuable therapeutic option for ALK mutated malignancies such as high-risk NB with potential clinical application. DisclosuresNo relevant conflicts of interest to declare.

Targeted sequencing and intracranial outcomes of patients with lung adenocarcinoma brain metastases treated with radiotherapy.

Treatment for advanced lung adenocarcinoma (AC) has become increasingly personalized based on molecular results. However, for patients with AC brain metastases (BMs), intracranial outcomes based on molecular subtype and the frequency of molecular aberrations are less well defined. This study sought to report targeted next-generation sequencing results and investigate molecularly based outcomes for patients with AC-BMs treated with radiotherapy. The records of 132 patients with AC-BMs treated at Emory University from September 2008 to August 2016 with successful next-generation sequencing were reviewed. Rates of local disease recurrence, distant brain failure (DBF), and salvage whole-brain radiotherapy (WBRT) were estimated using cumulative incidence with competing risk analysis. Univariate and multivariate analyses were performed. The most common aberrations included tumor protein 53 (TP53) (60%), KRAS (29%), epidermal growth factor receptor (EGFR) (20.5%), phosphatase and tensin homolog (PTEN) loss (15.5%), and MET amplification (13%). The majority of patients (62%) were treated with stereotactic radiosurgery alone. In these patients, KRAS mutation, anaplastic lymphoma kinase (ALK) rearrangement, and having ≥ 6 BMs were associated with an increased risk of salvage WBRT (P < .05). KRAS mutation remained significant for an increased risk of salvage WBRT when compared with EGFR/ALK/KRAS-negative patients (hazard ratio, 5.17; P < .05), despite a similar risk of DBF. PTEN loss was associated with increased risk of DBF (P < .05), whereas EGFR and ALK aberrations were associated with a decreased risk of local disease recurrence (P < .05). The results of the current study quantified the frequency of genetic aberrations in patients with AC-BMs and demonstrated their association with intracranial outcomes. In particular, a cohort of patients with KRAS mutations and ≥6 BMs were identified to be at high risk of requiring salvage WBRT after undergoing upfront stereotactic radiosurgery.

Induction of anaplastic lymphoma kinase (ALK) as a novel mechanism of EGFR inhibitor resistance in head and neck squamous cell carcinoma patient-derived models

Head and neck squamous cell carcinoma (HNSCC) currently only has one FDA-approved cancer intrinsic targeted therapy, the epidermal growth factor receptor (EGFR) inhibitor cetuximab, to which only approximately 10% of tumors are sensitive. In order to extend therapy options, we subjected patient-derived HNSCC cells to small-molecule inhibitor and siRNA screens, first, to find effective combination therapies with an EGFR inhibitor, and second, to determine a potential mechanistic basis for repurposing the FDA approved agents for HNSCC. The combinations of EGFR inhibitor with anaplastic lymphoma kinase (ALK) inhibitors demonstrated synergy at the highest ratio in our cohort, 4/8 HNSCC patients' derived tumor cells, and this corresponded with an effectiveness of siRNA targeting ALK combined with the EGFR inhibitor gefitinib. Co-targeting EGFR and ALK decreased HNSCC cell number and colony formation ability and increased annexin V staining. Because ALK expression is low and ALK fusions are infrequent in HNSCC, we hypothesized that gefitinib treatment could induce ALK expression. We show that ALK expression was induced in HNSCC patient-derived cells both in 2D and 3D patient-derived cell culture models, and in patient-derived xenografts in mice. Four different ALK inhibitors, including two (ceritinib and brigatinib) FDA approved for lung cancer, were effective in combination with gefitinib. Together, we identified induction of ALK by EGFR inhibitor as a novel mechanism potentially relevant to resistance to EGFR inhibitor, a high ratio of response of HNSCC patient-derived tumor cells to a combination of ALK and EGFR inhibitors, and applicability of repurposing ALK inhibitors to HNSCC that lack ALK aberrations.

Aberrant status and clinicopathologic characteristic associations of 11 target genes in 1,321 Chinese patients with lung adenocarcinoma.

The aberrant status of target genes and their associations with clinicopathologic characteristics are still unclear in primary lung adenocarcinoma. The common mutations and translocations of nine target genes were evaluated in 1,247 specimens of surgically-resected primary lung adenocarcinoma. Immunohistochemistry was used to analyze the expressions of programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) in 731 specimens. The frequency of the aberrations and their associations with clinicopathologic characteristics were analyzed. Overall, 952 (76.3%) of 1,247 patients harbored at least one target mutation or translocation: epidermal growth factor receptor (EGFR) (729, 58.5%), v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) (83, 6.7%), human epidermal growth factor receptor 2 (HER2) (82, 6.6%), anaplastic lymphoma kinase (ALK) (23, 1.8%), phosphoinositide-3-kinase catalytic alpha polypeptide (PIK3CA) (20, 1.6%), Ret proto-oncogene RET (15, 1.2%), ROS proto-oncogene 1 receptor tyrosine kinase (ROS1) (12, 1.0%), B-raf proto-oncogene (BRAF) (9, 0.7%), neuroblastoma RAS viral (v-ras) oncogene homolog (NRAS) (3, 0.2%). Fourteen (1.9%) of 731 patients were PD-1 positive and 95 (13.0%) were PD-L1 positive in tumor cells. In men and smokers, there were more frequent KRAS mutations (both P<0.001) and PD-L1 positive tumors (P<0.001, P=0.005, respectively), and less frequent EGFR mutations (P=0.049, <0.001, respectively). In ground-glass opacity (GGO) or ground-glass nodules (GGN), there were more HER2 (P=0.033) but less EGFR (P=0.025) and PIK3CA mutations (P=0.012), and ALK translocations (P=0.014). EGFR (P<0.001), KRAS mutations (P=0.004) and PD-L1 positive tumors (P=0.046) were more frequent in older patients, while HER2 (P<0.001), ALK (P=0.005) and ROS1 aberrations (P=0.044) were less frequent. Invasive mucinous adenocarcinoma was significantly associated with KRAS and ALK aberrations (both P<0.001), while solid predominant adenocarcinoma was associated with ROS1 translocations (P=0.036) and PD-L1 expression (P<0.001). KRAS, HER2, and ALK aberrations were scarce in patients with EGFR mutations (all P<0.001), while PD-L1 positive tumors positively correlated with ALK translocations (P=0.031) and negatively correlated with HER2 mutations (P=0.019). Most patients with primary lung adenocarcinoma harbored target gene aberrations. The frequency of each alteration differed in patients depending on clinicopathologic characteristics.

Abstract LB-A08: ALK and ROS-1 status: A retrospective analysis in solid tumors

Abstract Background: Tyrosine kinase receptors are important regulators of cellular signal transduction pathways that play a crucial role in development of cancer. Among them, Anaplastic Lymphoma Kinase (ALK) and C-Ros Oncogene-1 (ROS-1) are activated by rearrangement in several tumors. Tailored therapies have been developed according to the status of ALK and ROS-1, successfully used in NSCLC and potentially useful in other solid tumors harboring ALK and ROS-1 aberrations. Material and methods: ALK and ROS-1 status was evaluated in 666 and 441 patients with solid tumors, respectively, since 2014 at the Pathology Department. ALK and ROS-1 rearrangement and gene copy number variation (CNV) were assayed by fluorescence in situ hybridization (FISH). Gene copy number gain was defined by 3 to 5 fusion signals on average in ≥10% of cells, with amplification being highlighted by the clusters or 10 to 15 fusion signals in 10% or more tumor cells. Results: ALK status was assessed in 650/666 (97%) cases, while ROS-1 status was evaluable in 426/441 (96%). We identified 15/650 (2.3%) cases with ALK rearrangment, including 13 lung adenocarcinomas (4.1%), 1 colon cancer (0.5%) and 1 myoepithelioma (0.5%). CNV for ALK was documented in 53% lung adenocarcinoma, 50% pancreatic, 41% biliary and 37% colon carcinoma patients. We found 7/426 (1.6%) tumors with ROS-1 rearrangement, corresponding to 5 lung (2.7%) and 2 colon (1.3%) adenocarcinomas. CNV for ROS-1 was more frequent in melanoma (77%), neuroendocrine tumors (39%) and NSCLC (32%, 3/4 cases of ROS-1 amplification were squamous carcinoma). Eight out of the 22 rearranged cases (5 ALK and 3 ROS-1) were tested for both genes: these aberrations were mutually exclusive. Three out of 5 (60%) ALK rearranged tumors showed ROS-1 deletion. No ALK and ROS-1 alterations were documented in 30 pancreatic, 25 H&amp;N, 22 biliary tract, 13 renal, and 13 breast carcinomas, as well as in 13 melanomas and 36 other solid tumors. Conclusions: ALK and ROS-1 rearrangement was found in 4.1% and 2.7% of NSCLC, respectively, in keeping with literature data. In other solid tumors, the percentage of rearrangements is exceedingly low, but melanoma, neuroendocrine tumors, pancreatic and colon cancer may show significant CNV. We speculate that such aberrations of ALK and ROS-1 could act as potential therapy targets, but additional investigation by immunohistochemistry and next generation sequencing is clinically warranted. Citation Format: Maria Silvia Cona, matteo Duca, Adele Testi, Sara Cresta, Katia Fiorella Dotti, Alice Indini, Diego Signorelli, Giuseppe Pelosi, Filippo Guglielmo de Braud, Silvia Damian. ALK and ROS-1 status: A retrospective analysis in solid tumors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr LB-A08.

Abstract 1619: The next-generation ALK inhibitor PF-06463922 overcomes primary resistance to crizotinib in neuroblastoma

Abstract Neuroblastomas (NBs) harboring activating point mutations in the kinase domain of anaplastic lymphoma kinase (ALK) are differentially sensitive to ALK inhibition by crizotinib (Bresler et al. 2011). The F1174L and F1245C amino acid substitutions, which comprise 38.5% (mycancergenome.org) of ALK aberrations in NB, also confer intrinsic resistance to crizotinib and present a significant obstacle in the clinic. Therefore, our goal has been to identify a next-generation ALK inhibitor with improved selectivity and potency to target these resistant mutants effectively. We demonstrate here that PF-06463922 (Pfizer), an ATP-competitive, macrocyclic ALK/ROS1 inhibitor, overcomes crizotinib resistance of these ALK variants in NB, and exerts unprecedented activity as a single agent against the F1174L and F1245C ALK-mutated tumors. At a tenfold lower dose (10 mg/kg) than typically used for crizotinib (100 mg/kg), PF-06463922 induces complete tumor regression in patient-derived (COG-N-426x, F1245C ALK-mutated) and cell line-derived (SY5Y, F1174L ALK-mutated) xenograft mouse models. Whereas crizotinib-treated mice in both models experience rapid tumor growth on therapy, PF-06463922-treated mice showed sustained complete responses for several weeks even after treatment was discontinued. Cell-based and biochemical analyses indicate that the superior activity of PF-06463922 is a function of both higher potency and a broader spectrum of effectiveness across mutants. ATP levels were measured in ten NB cell lines upon treatment with PF-06463922 and crizotinib; at 120 hours post-treatment, PF-06463922 is 26-38 times more effective at inducing growth inhibition in cells with primary resistance than crizotinib. These in vitro and in vivo results are corroborated by our biochemical experiments. In comparative kinase inhibition studies of several next-generation ALK inhibitors, PF-06463922 was most effective against frequently observed ALK variants accounting for approximately 75% of neuroblastoma samples, including those with F1174L mutations. In vitro, PF-06463922 showed at least 3-4 fold higher potency than crizotinib in peptide phosphorylation assays, and its superior inhibition was consistently observed in cellular analysis of transforming ability. Further investigation is necessary to elucidate PF-06463922's mechanism of action and reveal how it induces apoptotic signaling networks without abrogating phospho-ALK. Taken together, these results support the argument that a modified ALK inhibitor may improve outcomes for patients with primary resistance to crizotinib and provide the preclinical basis from which to design a clinical trial for PF-06463922 for the treatment of ALK-mutated NBs. Citation Format: Nicole Infarinato, Jin Park, Renata Sano, Kateryna Krytska, Hannah Ryles, Helen Zou, Nathan Lee, Tod Smeal, Mark A. Lemmon, Yael P. Mosse. The next-generation ALK inhibitor PF-06463922 overcomes primary resistance to crizotinib in neuroblastoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1619. doi:10.1158/1538-7445.AM2015-1619

PD-L1 is highly expressed in lung lymphoepithelioma-like carcinoma: A potential rationale for immunotherapy.

Programmed cell death-ligand 1 (PD-L1) and driver mutations are found in non-small cell lung cancers (NSCLCs) and may be suitable targets for specific therapies, but their roles in lymphoepithelioma-like carcinoma (LELC) of the lung are unclear. Sixty-six patients with pulmonary LELCs were investigated. Paraffin-embedded tumor sections were stained with PD-L1 antibody. Tumors with moderate-to-strong membrane staining in ≥5% of tumor cells were positive for PD-L1 overexpression. The presence of driver mutations in the genes for epidermal growth factor receptor (EGFR), KRAS, and BRAF were examined by direct sequencing. Anaplastic lymphoma kinase (ALK) and ROS1 levels were determined by immunohistochemistry. Correlations of PD-L1 expression and driver mutations with clinicopathologic parameters were analyzed. The overall frequency of PD-L1 overexpression and EGFR mutation was 75.8% and 12.1%, respectively. No KRAS, BRAF, ALK or ROS1 aberrations could be detected. PD-L1 expression was not associated with driver mutations. Multivariate analysis revealed that smoking and advanced stage were independent risk factors for poor overall survival, whereas PD-L1 positivity was not significantly associated with patient outcome. There are high PD-L1 expression and infrequent driver mutations in LELCs compared with conventional NSCLCs. The high expression of PD-L1 in EBV and inflammation associated LELC may provide a rationale for immunotherapy in this subtype of lung cancer.

Frequency of the ALK gene and its prognostic value in neuroblastoma by FISH

Introduction The anaplastic lymphoma kinase (ALK) gene has been identified as a major neuroblastoma (NB) predisposition gene. Furthermore, there are controversies on the correlation between ALK gene aberration and clinical outcome in neuroblastoma (NBL). Materials and methods We evaluated N-MYC/ALK gene copy number by fluorescence in situ hybridization and analyzed 32 bone marrow samples infiltrated by NB and analyzed their association with the clinical outcome of the patients. Results Although an increase in ALK gene aberration is a recurrent genetic abnormality of NB (50%, 16/32), ALK amplification was only present in one NB (3.2%, 1/32). In addition, ALK positivity also significantly correlates with N-MYC gene copy number ( P P Conclusion ALK aberrations in NB were correlated with advanced tumor types and an increase in both N-MYC/ALK gene aberrations. ALK aberrations predict an inferior prognosis, which can be used as a prognostic factor in NB in clinical practice.

ALK gene aberrations and the JUN/JUNB/PDGFR axis in metastatic NSCLC.

Anaplastic lymphoma kinase (ALK) gene aberrations are found in several tumor types including anaplastic large cell lymphoma (ALCL) and non-small cell lung cancer (NSCLC). Crizotinib, an inhibitor of ALK-fusion proteins, has shown clinical activity, but resistance mechanisms limit long-lasting disease control. It has been shown that ALK-NPM fusion upregulates platelet-derived growth factor receptor beta (PDGFRB) via JUN and transcription factor Jun B (JUNB) in ALCL. PDGFRB inhibition has been identified as therapy option for ALK-positive ALCL. Here, we investigated the ALK/JUN/JUNB/transcription factor Jun C (JUNC)/PDGFR axis in metastatic NSCLC with regard to ALK aberrations. We performed immunohistochemical analysis of platelet-derived growth factor receptor alpha (PDGFRA), PDGFRB, JUNB and JUNC expression in formalin-fixed, paraffin-embedded specimens of 15 NSCLC brain metastases (5 ALK translocations, 3 of them involving EML4, 5 ALK amplifications, 5 without ALK aberrations). We did not find a statistically significant difference in expression of PDGFRA, PDGFRB, JUNB or JUNC in tumor samples with normal ALK status, ALK amplification or ALK translocations (Kruskal-Wallis test p>0.05). Interestingly, PDGFRB was not expressed in tumor cells (but in vascular and stromal cells) in any of our cases. Our data argue against PDGFRB activation in association with ALK gene aberrations in metastatic NSCLC and thus seem to imply differential pathobiological roles of ALK alterations in lung cancer and lymphoma, possibly depending on different fusion partner genes. These results may be relevant for targeted therapies, as they indicate that inhibition of PDGFRB in ALK translocated NSCLC seems to be no therapeutic opportunity.

Expression and clinical relevance of MET and ALK in Ewing sarcomas

Because novel therapeutic options are limited in Ewing sarcomas (ES), we investigated the expression, genetic aberrations and clinical relevance of MET and anaplastic lymphoma kinase (ALK) in ES and determined the relevance of targeting these receptors. MET and ALK protein expression was determined immunohistochemically in 31 (50 samples) and 36 (59 samples) ES patients, respectively. Samples included primary tumors, postchemotherapy resections, metastases and relapses. MET and ALK RTK domains were sequenced in respectively 33 and 32 tumors. Five ES cell lines were treated in vitro with the MET/ALK-inhibitor crizotinib, the ALK-inhibitor NVP-TAE684 or the MET-inhibitor cabozantinib and analyzed by MTT assays. Modest to high MET and ALK expression was detected in the majority of ES (86 and 69%, respectively). ALK expression was significantly lower in postchemotherapy resections compared to paired untreated primary tumors (p = 0.031, z = -2.310, n = 11). In primary tumors (n = 20), membranous MET expression significantly correlated with a poor overall survival (OS) (60 vs. 197 months, p = 0.014). There was a trend toward a poor event-free survival (67 vs. 111 months, p = 0.078) and OS (88 vs. 128 months, p = 0.074) in patients with highest ALK levels (n = 29). ALK or MET RTK domain aberrations were demonstrated in 5/32 (16%) and 3/33 (9%) tumors, respectively. Crizotinib (IC50 1.22-3.59 μmol/L), NVP-TAE684 (IC50 0.15-0.79 μmol/L) and cabozantinib (IC50 2.69-8.27 μmol/L) affected ES cell viability in vitro. Altogether, our data suggest that MET and ALK are potential novel therapeutic targets in ES and targeting these receptors may be of great interest to rationally design future studies in ES.

Detection of chromosomal translocations involving ALK gene in anaplastic large cell lymphoma by fluorescence in-situ hybridization and its clinical significance

To investigate clinicopathologic features and clinical value of the chromosomal translocation involving anaplastic lymphoma kinase (ALK) in anaplastic large cell lymphoma (ALCL) by fluorescence in situ hybridization (FISH). A total of 55 cases, including 45 cases of ALCL and 10 reactive lymphoid hyperplasia, were collected during 1999 to 2006 in the Department of Pathology, Fudan University Shanghai Cancer Center, and Xinhua Hospital Affiliated to Shanghai Jiaotong University. All cases were studied by FISH using dual color break apart probes of ALK for detection of chromosomal translocation, compared with the previous results of immunohistochemistry (IHC) and reverse-transcriptase polymerase chain reaction (RT-PCR) for the detection of ALK aberrations. The result of FISH showed that the clear red and green fluorescence signals were detected in 38 cases of ALCL, in which conspicuous split signals were observed in tumor cells in 24 cases (63.2%), suggesting the rearrangement of the ALK locus, with multiple copies of ALK gene in one case. In addition, the rearrangement of the ALK locus was not identified in 14 of 38 cases (36.8%); and the FISH results were unable to be evaluated in 7 cases, because no fluorescent signals involving ALK gene were found or signals were too weak to be analyzed. The concordance for the detection ALK aberrations in ALCL between FISH and RT-PCR, FISH and IHC were both statistically significant (P < 0.01). Chromosomal translocation involving ALK gene was not found in all 10 cases of reactive lymphoid hyperplasia. ALCL is an entity of lymphoma characterized by special clinical presentation, morphology, and ALK aberrations. FISH is helpful for detection of the chromosomal translocations involving ALK in ALCL, however, the detection efficiency by FISH may be affected by storage time of the paraffin-embedded tissue; and therefore combined detection with IHC and RT-PCR could complement each other and help for differential diagnosis of ALK(+)ALCL from ALK(-)ALCL.

Antibody targeting of anaplastic lymphoma kinase induces cytotoxicity of human neuroblastoma

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase aberrantly expressed in neuroblastoma, a devastating pediatric cancer of the sympathetic nervous system. Germline and somatically acquired ALK aberrations induce increased autophosphorylation, constitutive ALK activation and increased downstream signaling. Thus, ALK is a tractable therapeutic target in neuroblastoma, likely to be susceptible to both small-molecule tyrosine kinase inhibitors and therapeutic antibodies-as has been shown for other receptor tyrosine kinases in malignancies such as breast and lung cancer. Small-molecule inhibitors of ALK are currently being studied in the clinic, but common ALK mutations in neuroblastoma appear to show de novo insensitivity, arguing that complementary therapeutic approaches must be developed. We therefore hypothesized that antibody targeting of ALK may be a relevant strategy for the majority of neuroblastoma patients likely to have ALK-positive tumors. We show here that an antagonistic ALK antibody inhibits cell growth and induces in vitro antibody-dependent cellular cytotoxicity of human neuroblastoma-derived cell lines. Cytotoxicity was induced in cell lines harboring either wild type or mutated forms of ALK. Treatment of neuroblastoma cells with the dual Met/ALK inhibitor crizotinib sensitized cells to antibody-induced growth inhibition by promoting cell surface accumulation of ALK and thus increasing the accessibility of antigen for antibody binding. These data support the concept of ALK-targeted immunotherapy as a highly promising therapeutic strategy for neuroblastomas with mutated or wild-type ALK.

Anaplastic Lymphoma Kinase Aberrations in Rhabdomyosarcoma: Clinical and Prognostic Implications

Anaplastic Lymphoma Kinase Aberrations in Rhabdomyosarcoma: Clinical and Prognostic Implications