Anaplastic Lymphoma Kinase Kinase Research Articles

Population modeling analyses of crizotinib in pediatric patients with ALK-positive advanced cancers.

Alterations in the ALK (anaplastic lymphoma kinase) gene play a critical role in pathogenesis of anaplastic large cell lymphoma (ALCL). Crizotinib is a small molecule competitive inhibitor of ALK, ROS1, and MET kinases and was approved for pediatric patients with ALK-positive relapsed or refractory, systemic ALCL, and ALK-positive unresectable, recurrent, or refractory inflammatory myofibroblastic tumors (IMT). Crizotinib data from pediatric patients with relapsed or refractory solid tumors, IMT, or ALCL were included in the analyses. All patients received crizotinib orally at doses ranging from 100 to 365mg/m2 twice daily (BID). PopPK analyses were conducted to characterize crizotinib disposition in pediatric patients. Exposure-response (ER) safety and antitumor analyses were conducted to characterize relationships between crizotinib dose or exposure with safety and antitumor activity endpoints of interest. The population pharmacokinetic (popPK), ER safety, and ER antitumor analysis included 98, 110, and 36 pediatric patients, respectively. A one-compartment pharmacokinetic model with allometric scaling, first-order elimination, and first-order absorption with lag time adequately described the data. Natural log-transformed model-predicted crizotinib AUCss (steady-state area under the concentration-time curve) demonstrated a significant, positive relationship with Grade ≥3 NEUTROPENIA and Any Grade VISION DISORDER. Crizotinib dose demonstrated a positive relationship with objective response rate. No significant differences in PK were identified across a wide range of ages or across tumor types, suggesting body surface area (BSA)-based dosing adequately adjusted for differences in patient size to achieve similar systemic crizotinib exposures across young children and adolescent pediatric patients. None of the myelosuppressive events except Grade ≥3 NEUTROPENIA had significant relationships identified with crizotinib dose or exposure, suggesting crizotinib is a tolerable treatment with less hematological toxicity than traditional chemotherapy regimens for pediatric patients with ALK-mutated cancers. Results from the presented analyses support the pediatric dosing recommendations in the product label.

Discovery and efficacy study of an ALK inhibitor AMX6001 in anaplastic large cell lymphoma Karpas299 mice models

Anaplastic lymphoma kinase (ALK) is an attractive therapeutic target for the treatment of anaplastic large cell lymphoma (ALCL). We identified novel deuterated 2,4-diarylamino pyrimidine compounds as potent ALK inhibitors. The compound 9 (AMX6001) showed better in vitro activity against ALK and NPM-ALK kinase and significantly inhibited proliferation of Karpas299 and SU-DHL-1 cell lines. In vivo efficacy of compound 9 was better than reference standard ceritinib in ALCL Karpas299 mice models. Daily oral treatment of compound 9 (25 mg/kg) induced tumor suppression TGI up to 95.8 % in ALCL models.

Antineoplastic Effect of ALK Inhibitor Crizotinib in Primary Human Anaplastic Thyroid Cancer Cells with STRN-ALK Fusion In Vitro.

Anaplastic thyroid cancer (ATC) is one of the deadliest human cancers and represents <2% of thyroid carcinomas. A therapeutic target for ATC is represented by anaplastic lymphoma kinase (ALK) rearrangements, involved in tumor growth. Crizotinib is an oral small-molecule tyrosine kinase inhibitor of the ALK, MET, and ROS1 kinases, approved in ALK-positive non-small cell lung cancer. Until now, the effect of crizotinib in "primary human ATC cells" (pATCs) with transforming striatin (STRN)-ALK fusion has not been reported in the literature. In this study, we aimed to obtain pATCs with STRN-ALK in vitro and evaluate the in vitro antineoplastic action of crizotinib. Thyroid surgical samples were obtained from 12 ATC patients and 6 controls (who had undergone parathyroidectomy). A total of 10/12 pATC cultures were obtained, 2 of which with transforming STRN-ALK fusion (17%). Crizotinib inhibited proliferation, migration, and invasion and increased apoptosis in 3/10 pATC cultures (2 of which with/1 without STRN-ALK), particularly in those with STRN-ALK. Moreover, crizotinib significantly inhibited the proliferation of AF cells (a continuous cell line obtained from primary ATC cells). In conclusion, the antineoplastic activity of crizotinib has been shown in human pATCs (with STRN-ALK) in preclinical studies in vitro, opening the way to future clinical evaluation in these patients.

Abstract 1657: Microfluidics-based screening platform identifies a novel therapeutic approach to targeting EML4-ALK driven cancers

Abstract To achieve proliferative dysregulation, a hallmark of cancer, tumor cells utilize a variety of mechanisms to maintain constitutive oncogenic signaling in the absence of extracellular cues. One such mechanism occurs in cells expressing the EML4-ALK fusion protein. This fusion, found in about 4% of non-small cell lung cancer (NSCLC), is a result of an inversion within chromosome 2, placing the 3’ end of the ALK (anaplastic lymphoma kinase) gene downstream of the 5’ end of the EML4 (echinoderm microtubule associated protein-like 4) gene. The resulting fusion protein contains the oligomerization domain and additional disordered sequence elements of EML4 upstream of a functional ALK kinase domain. EML4-ALK is a critical driver for these tumors, promoting aberrant ALK-dependent oncogenic signaling. While tumors harboring the EML4-ALK fusion initially respond to ALK tyrosine kinase inhibitors (TKIs), resistance remains a significant clinical challenge requiring new therapeutic approaches. Recently, it has come to be understood that rather than responding through extracellular proliferative cues, the EML4-ALK fusion protein elicits constitutive ALK signaling through the formation of cytoplasmic biomolecular condensates. These condensates are the result of phase separation and have been shown to be causal for disease phenotypes in cell and animal models driven by EML4-ALK, establishing condensate modulation as a novel means by which to treat TKI-resistant tumors. Here, we have developed a novel proprietary microfluidics-based high throughput screening platform (termed PhaseScanTM) to identify small-molecule modulators of EML4-ALK condensates. Using this technology, we identified compounds that disrupt EML4-ALK condensates in vitro and in cells through a novel mechanism, distinct from that of known ALK TKIs, providing utility in both TKI-resistant as well as TKI-naïve tumors. Further profiling of the mechanism of action (MoA) revealed specific modification within the disordered region of EML4, disruption of EML4 oligomerization, and defective ALK signaling in cancer cells. Thus, our PhaseScanTM methodology enabled the identification of novel, functionally active chemical matter that would have otherwise been challenging to identify utilizing any conventional hit identification methodology. Citation Format: Richard C. Centore, Matthew Watson, Julia Doh, Jerome Cattin, Cinzia Sgambato, Amal Alex, Janhavi Sawant, Prathima Radhakrishnan, Jasmine Cornish, Alex Howarth, Nagakumar Bharatham, William E. Arter, Seema Qamar, Kadi L. Saar, Douglas Williamson, Andrew Seeber, Neils Groenewegen, Magdalena Czekalska, Tadas Kartanas, Niklas Ermann, Ahmed Taher, Tuomas Knowles, Shilpi Arora. Microfluidics-based screening platform identifies a novel therapeutic approach to targeting EML4-ALK driven cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1657.

ALK F1174S mutation impairs ALK kinase activity in EML4-ALK variant 1 and sensitizes EML4-ALK variant 3 to crizotinib.

To assess the influence of F1174S mutation on kinase activity and drug sensitivity of the echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) fusion (EML4-ALK) variants 1 and 3. We constructed mammalian expression plasmids of both wildtype and F1174 mutant EML4-ALK variants 1 and 3, and then characterized them with cell models by performing immunoblotting, neurite outgrowth assay, focus formation assay as well as protein stability assay. Drug sensitivity to ALK tyrosine kinase inhibitors was also compared between wildtype and F1174 mutant EML4-ALK fusions. In addition, we characterized the effect of different F1174 kinase domain mutations in the context of EML4-ALK fusions. In contrast to the oncogenic ALK-F1174S mutation that has been reported to be activating in the context of full-length ALK in neuroblastoma, EML4-ALK (F1174S) variant 1 exhibits impaired kinase activity leading to loss of oncogenicity. Furthermore, unlike the previously reported F1174C/L/V mutations, mutation of F1174 to S sensitizes EML4-ALK variants 3a and 3b to crizotinib. These findings highlight the complexity of drug selection when treating patients harboring resistance mutations and suggest that the F1174S mutation in EML4-ALK variant 1 is likely not a potent oncogenic driver. Additional oncogenic driver or other resistance mechanisms should be considered in the case of EML4-ALK variant 1 with F1174S mutation.

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.

Strategy for Pediatric Patients with Relapsed or Refractory Anaplastic Lymphoma Kinase-Positive Anaplastic Large Cell Lymphoma: A Review.

Anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) is an aggressive T-cell lymphoma characterized by large T-cells with strong CD30 and ALK expression. Although conventional chemotherapy is effective in most patients, approximately 30% experience a relapse or refractory disease and have a poor prognosis. Several risk factors associated with poor prognosis have been identified in pediatric ALK-positive ALCL. These include morphological patterns with the small cell variant or lymphohistiocytic variant, leukemic presentation, the presence of minimal disseminated disease, or involvement of the central nervous system. Relapsed or refractory ALK-positive ALCL is often resistant to conventional chemotherapy; therefore, salvage therapy is required. In recent years, targeted therapies such as ALK inhibitors and brentuximab vedotin (BV) have been developed. ALK inhibitors block the continuous activation of ALK kinase, a driver mutation that leads to cell proliferation in ALK-positive ALCL. Additionally, BV is an antibody-drug conjugate that targets CD30-positive cells. Both ALK inhibitors and BV have displayed dramatic effects in chemoresistant ALK-positive ALCL. Weekly vinblastine treatment and hematopoietic stem cell transplantation have also been reported to be effective therapies. This article reviews pediatric ALK-positive ALCL, focusing on risk factors and treatment strategies for pediatric patients with relapsed or refractory ALK-positive ALCL.

Preliminary Results of Phase 2 Open Label Study of Lorlatinib Monotherapy in Relapsed/Refractory ALK + Lymphomas Previously Treated with Other Tyrosine Kinase Inhibitors

Introduction: Both aggressive T and B cell lymphoma may harbour Anaplastic Lymphoma Kinase (ALK) translocations: ALK+ Anaplastic Large Cell lymphoma (ALCL) offer a good outcome with first line therapy with 5-year survival of 79%, but relapses occur in half of the patients (pts) and salvage therapy still represents a challenge for clinicians; ALK+ large B cell lymphoma (LBCL) are very rare cases but with dismal prognosis. In addition other hematologic neoplasms can be caused by ALK fusions. Crizotinib, an ALK/MET tyrosine kinase inhibitor (TKI), provides long-term response in up to 70% relapsed/refractory (R/R) ALK+ ALCL and can obtain a similar but less durable response rates in ALK+ LBCL. In both cases the loss of response to crizotinib is frequently a fatal event. Lorlatinib, a selective ALK and ROS1 TKI, demonstrated preclinical inhibition of all reported ALK kinase domain mutations responsible for resistance to Crizotinib. Methods: From 2019 to 2022 six relapsed/refractory ALK + neoplasm pts previously treated with at least one ALK-inhibitor were enrolled in a phase 2 open label monocentric study with lorlatinib monotherapy (EudraCT2016-003970-41): Three patients had diagnosis of ALK+ LBCL (# 1, 2, 3) and 2 (#5 and #6) had ALK+ ALCL. One patient (#4) with an ALK+ histiocytosis was also included. Median age was 22 years (range 19-57), Ratio M/F was 1, all pts were in stage IV. Median prior therapy lines was 3 (range 2-5); all pts previously received Crizotinib, two pts received also Alectinib and 1 Ceritinib as TKI treatment. Lorlatinib was administered daily at dose of 100 mg. Clinical, laboratory, radiological and molecular data were collected at screening and during scheduled follow-up. Response was evaluated with 18F-FDG PET/CT (and with contrast enhanced (ce) CT scan) according Lugano Classification, and with ALK RT-PCR on peripheral blood and bone marrow. Side effects were classified according to CTCAEv4.03. PFS and OS were determined from Lorlatinib start to relapse and/or death. The primary endpoint was the evaluation of ORR considering 18F-FDG PET/CT scan and ALK- RT-PCR. Secondary endpoints were: PFS, OS, toxicity, QoL. Results: ALK rearrangement fusion pattern was detected in 6/6 pts: 3 pts with LBCL harboured Clathrin-ALK (CTCL::ALK) rearrangement and 2 ALCL pts the ATIC::ALK fusion; the ALK+ histiocytosis patient harbored an EML4::ALK rearrangement. Median follow-up was 13.7 months (IQR 22-55). At month +1 (M1) 3/6 patients had complete response (CR) defined as complete metabolic and complete radiologic response (CMR/CR) according to PET/CT scans and ALK RT-PCR negativity. The remaining 3 pts had a partial response (PR), for an Overall Response Rate (ORR) of 100% (95%CI: 0.6-1.0). One pt is still on treatment and in CR at 45 months, receiving Lorlatinib 100 mg daily with neither toxicities nor need for Allogenic Stem Cell Transplantation (ASCT); 2 CR pts underwent ASCT after 1 month, resumed lorlatinib after ASCT and are still in CR. 2 pts with PR relapsed within month +3: one pt received salvage therapy without benefit, the other one underwent ASCT but progressed 3 months later. Both pts had ALK+ BCL with CTCL-ALK rearrangement. 1 pts in PR AT M1 (ALK+ istiocytosis) obtain CR at M3 after surgical resection of a residual lung mass and is still receiving Lorlatinib at month 36. Median PFS and OS were not reached: PFS at 6 and 12 months is 83% and 62% respectively; OS at 6 and 12 months is 83% and 55%. Safety: 2/6 pts had thrombocytopenia grade 1, whereas 3/6 pts showed grade I-II hypertriglyceridemia/hypercholesterolemia and muscle cramps. Conclusions: Lorlatinib represents a safe and effective salvage therapy for ALK+ Lymphoma patients failing first line TKI treatment. The obtainment of CR at M1 seems to represent a pivotal prognostic factor. Lorlatinib also offers a promising bridging regimen to salvage ASCT especially for ALK+ BCL patients, with high response rates and no additional toxicities, .

Comparative Atomistic Insights on Apo and ATP-I1171N/S/T in Nonsmall-Cell Lung Cancer.

Anaplastic lymphoma kinase (ALK) rearrangements occur in about 5% of nonsmall cell lung cancer (NSCLC) patients. Despite being first recognized as EML4-ALK, fusions with several additional genes have been identified, all of which cause constitutive activation of the ALK kinase and subsequently lead to tumor development. ALK inhibitors first-line crizotinib, second-line ceritinib, and alectinib are effective against NSCLC patients with these rearrangements. Patients progressing on crizotinib had various mutations in the ALK kinase domain. ALK fusion proteins are activated by oligomerization through the fusion partner, which leads to the autophosphorylation of the kinase's domain and consequent downstream activation. The proposed computational study focuses on understanding the activation mechanism of ALK and ATP binding of wild-type (WT) and I1171N/S/T mutations. We analyzed the conformational change of ALK I1171N/S/T mutations and ATP binding using molecular docking and molecular dynamics simulation approaches. According to principal component analysis and free energy landscape, it is clear that I1171N/S/T mutations in Apo and ATP showed different energy minima/unstable structures compared to WT-Apo. The results revealed that I1171N/S/T mutations and ATP binding significantly supported a change toward an active-state conformation, whereas WT-Apo remained inactive. We demonstrated that I1171N/S/T mutations are persistent in an active state and independent of ATP. The I1171S/T mutations showed greater intermolecular H-bonds with ATP than WT-ATP. The molecular mechanics Poisson-Boltzmann surface area analysis revealed that the I1171N/S/T mutation binding energy was similar to that of WT-ATP. This study shows that I1171N/S/T can form stable bonds with ATP and may contribute to a constitutively active kinase. Based on the Y1278-C1097 H-bond and E1167-K1150 salt bridge interaction, I1171N strongly promotes the constitutively active kinase independent of ATP. This structural mechanism study will aid in understanding the oncogenic activity of ALK and the basis for improving the ALK inhibitors.

Molecular heterogeneity and co-altered genes in MET-amplified ALK-positive lung cancer: Implications for MET targeted therapy

ObjectivesMET amplification is a common mechanism of resistance to second- and third-generation anaplastic lymphoma kinase (ALK) inhibitors. In case series of MET-amplified ALK-rearranged (ALK + ) lung cancer, durability of responses to combinations targeting ALK and MET is variable, suggesting heterogeneity across tumors. However, little is known about the molecular composition of this subset of ALK-rearranged (ALK + ) NSCLC. Materials and methodsWe queried tissue and plasma databases to compile a group of > 50 specimens with ALK rearrangements and concurrent MET amplification. Fluorescence in-situ hybridization (FISH) and next-generation sequencing (NGS) were utilized to quantify the range of MET copies and describe the global molecular landscape of co-altered genes. ResultsBy FISH, high-level amplification (overall MET/centromere 7 probe ratio ≥ 5) was detected in 75 % of MET-amplified ALK + NSCLC tissue specimens. Intralesional heterogeneity of MET copies was observed, with high-level amplification identified even in cells from tumors with overall low-level MET amplification. Analysis of 48 MET-amplified ALK + NSCLC plasma specimens suggested that high-level amplification is rarely (17 %) detected in plasma. In both tissue and plasma, EML4-ALK variant 1 was the predominant variant (51 %) identified in MET-amplified specimens. ALK kinase domain mutations were only present in a minority of MET-amplified ALK + NSCLCs. MET-amplified ALK + NSCLC plasma specimens were enriched for TP53 mutations (81 % vs 45 %, p = 0.002), EGFR amplification (17 % vs 4 %, p < 0.001), and MYC amplification (21 % vs 3 %, p < 0.001) compared to ALK + NSCLC specimens lacking MET amplification. ConclusionsMET-amplified, ALK + NSCLC often presents with high-level and heterogeneous amplification in tissue, seldom overlaps with ALK mutations, and frequently co-occurs with alterations associated with aggressive tumor biology.

Abstract 3884: Targeting the ARID1A mutations overcomes primary resistance to ALK inhibitors in EML4-ALK positive NSCLC

Abstract Introduction: Anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitors (TKIs) have improved an initial clinical response of non-small-cell lung cancer (NSCLC) patients with ALK-rearrangements. However, a subset of patients shows a poor response to ALK-TKIs. Here, we aimed to identify novel mechanism of primary resistance in preclinical model from a patient who presented an impressive resistance to sequential treatment with ALK TKIs. Experimental design: The PDC YU-1076 cells were established from pleural effusion of the patient at the time he was receiving chemotherapy and radiotherapy after failure of ALK-TKI treatment. Sanger sequencing confirmed ML4-ALK variant 1 detected at the initial diagnosis. No resistance mutations in the ALK kinase domain were detected. To investigate co-occurring genetic alterations, we performed whole exome sequencing (WES) on YU-1076 cells and the matched blood sample. We further investigated the molecular profile of YU-1076 cells using RNA-sequencing analysis. Results: YU-1076 cells exhibited cross-resistance to clinically available ALK-TKIs including crizotinib, ceritinib, alectinib, and lorlatinib. However, immunoblot analysis of YU-1076 cells treated with incremental doses of TKIs unexpectedly revealed an effective reduction of ALK activity and downstream signals. We noticed that YU-1076 cells gradually changed from a small, round shape to a fibroblast-like shape following the treatment of ALK-TKIs. Transcriptome analysis confirmed enrichment for gene signatures related epithelial-to-mesenchymal transition (EMT) in ALK TKI-treated YU-1076 cells, suggesting that ALK-TKIs treatment promotes YU-1076 cells toward a more mesenchymal phenotype. WES analysis identified a major chromatin remodeling complex subunit, AT-rich interacting domain 1A (ARID1A), as well as MYC amplification, CDKN2A loss, and TP53 mutations. We focused on a synthetic lethal strategies using the SFK inhibitor dasatinib and the EZH2 inhibitor GSK126 in ARID1A mutant cancers. The combination of dasatinib with ALK-TKIs restored the sensitivity to the ALK TKIs in YU-1076 cells, accompanied by suppression of EMT marker genes VIM and CDH2 and increase of apoptotic markers BIM, PARP, and CAS3. Congruently, dasatinib significantly impaired tumor growth in YU-1076-xenografts. GSK126 also induced synergistic inhibition of cell growth with upregulation of apoptosis marker genes in YU-1076 cells, but did not affect the expression of EMT marker genes. Conclusion: Our data indicate that ARID1A could be potentially used as a predictive biomarker for unfavorable ALK-TKI response. In this context, a combination strategy of ALK TKI with dasatinib may be effective in overcoming primary resistance. Citation Format: Seung Yeon Oh, You Won Lee, Eun Ji Lee, Ju Young Kim, Sewon Park, Ju Yeon Park, Su-Jin Choi, Mi Ra Yu, Sowon Aum, Jiyun Lee, Chang Gon Kim, Jii Bum Lee, Sun Min Lim, Min Hee Hong, Mi Ran Yun, Byoung Chul Cho. Targeting the ARID1A mutations overcomes primary resistance to ALK inhibitors in EML4-ALK positive NSCLC. [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 3884.

Effective and Safe Immune Checkpoint Blockade Induces Complete Responses in Murine PTCL Model of ALCL

Anaplastic large cell lymphoma (ALCL) is a rare T-cell non-Hodgkin lymphoma. In the majority of cases the disease is driven by a chromosomal translocation t(2;5)(p23;35) leading to the fusion of the anaplastic lymphoma kinase (ALK) gene with the nucleophosmin gene (NPM), constitutively activating ALK kinase. In the last decade immunotherapy turned out to be a real game-changer in cancer treatment, especially in the field of solid tumors. Regarding T-cell lymphomas (TCL), the significance of immune checkpoint inhibition is still highly debated. The outcomes in preclinical models as well as clinical trials are ranging from response to hyperprogression. Consequently, to provide a better understanding of the role and underlying mechanisms of targeting immune checkpoint axes, preclinical models of TCL are urgently needed to identify patients that benefit from immunotherapy as well as potential biomarkers. To examine disease biology and therapy effects of ALCL in vivo, we use a syngeneic retroviral bone marrow transplantation mouse model of ALK+ ALCL that closely resembles the disease in humans. In order to study the effect of blocking the PD-1/PD-L1-axis in ALCL in vivo, serial transplantations of lymphoma cells from a murine thymus were performed. We further investigated both spontaneous and immunotherapy-induced immune responses and characterized the interaction of innate and adaptive immune master players with flow cytometry, cytokine analysis, histology and transcriptome analysis. In our mouse model of ALK+ ALCL we confirmed the upregulation of PD-L1 on ALK+ lymphoma cells in vivo. Immune checkpoint inhibition of PD-L1 in vivo leads to high complete response rates, prolonged survival and significantly reduced lymphoma burden of treated animals. Flow cytometry analysis revealed that PD-L1 blockade reverses Treg-mediated immunosuppression and causes augmented circulation of CD8+ effector T-lymphocytes. Treatment with depletion antibodies of lymphocyte subpopulations unveils CD4+ T-cells and NK-cells but not CD8+ T-cells as master players of checkpoint-mediated immune response to ALK+ ALCL. Accordingly, we identified exhausted CD4+ T-cells in non-responders to checkpoint inhibition underlining the central role of CD4+ T-cells in ALCL immune surveillance and response. These results are contributing to a broader understanding of the immune surveillance and response in ALCL, with the outmost goal of better identifying patients that benefit from immunotherapy.

Discovery of Novel α-Carboline Inhibitors of the Anaplastic Lymphoma Kinase.

The anaplastic lymphoma kinase (ALK) is abnormally expressed and hyperactivated in a number of tumors and represents an ideal therapeutic target. Despite excellent clinical responses to ALK inhibition, drug resistance still represents an issue and novel compounds that overcome drug-resistant mutants are needed. We designed, synthesized, and evaluated a large series of azacarbazole inhibitors. Several lead compounds endowed with submicromolar potency were identified. Compound 149 showed selective inhibition of native and mutant drug-refractory ALK kinase in vitro as well as in a Ba/F3 model and in human ALK+ lymphoma cells. The three-dimensional (3D) structure of a 149:ALK-KD cocrystal is reported, showing extensive interaction through the hinge region and the catalytic lysine 1150.

Targeted therapy for advanced anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer.

Targeted therapy for advanced anaplastic lymphoma kinase (<I>ALK</I>)-rearranged non-small cell lung cancer.

Deciphering the Mechanism of Gilteritinib Overcoming Lorlatinib Resistance to the Double Mutant I1171N/F1174I in Anaplastic Lymphoma Kinase.

Anaplastic lymphoma kinase (ALK) is validated as a therapeutic molecular target in multiple malignancies, such as non-small cell lung cancer (NSCLC). However, the feasibility of targeted therapies exerted by ALK inhibitors is inevitably hindered owing to drug resistance. The emergence of clinically acquired drug mutations has become a major challenge to targeted therapies and personalized medicines. Thus, elucidating the mechanism of resistance to ALK inhibitors is helpful for providing new therapeutic strategies for the design of next-generation drug. Here, we used molecular docking and multiple molecular dynamics simulations combined with correlated and energetical analyses to explore the mechanism of how gilteritinib overcomes lorlatinib resistance to the double mutant ALK I1171N/F1174I. We found that the conformational dynamics of the ALK kinase domain was reduced by the double mutations I1171N/F1174I. Moreover, energetical and structural analyses implied that the double mutations largely disturbed the conserved hydrogen bonding interactions from the hinge residues Glu1197 and Met1199 in the lorlatinib-bound state, whereas they had no discernible adverse impact on the binding affinity and stability of gilteritinib-bound state. These discrepancies created the capacity of the double mutant ALK I1171N/F1174I to confer drug resistance to lorlatinib. Our result anticipates to provide a mechanistic insight into the mechanism of drug resistance induced by ALK I1171N/F1174I that are resistant to lorlatinib treatment in NSCLC.

ALK Inhibitor Plus Vinblasitine for Refractory/Relapsed Pediatric ALK+ Anaplastic Large Cell Lymphoma: A Prospective, One-Arm, Open-Label Real-World Study

Background: Refractory and relapsed (r/r) anaplastic lymphoma kinase (ALK)-positive anaplastic large cell Lymphoma(ALK+ALCL) have a poor prognosis. Studies had confirmed vinblastine (VBL) may be an effective treatment for relapsed ALCL and ALK inhibitors may have high efficacy and tolerability in patients carrying ALK fusions. Therefore, we put forward a hypothesis that for those r/r ALK+ALCL patients with poor chemotherapy tolerance and effect, combining ALK inhibitors with vinblastine may have a sustained anti-tumor effect and good tolerance.Aims: To assess the efficacy and safety of ALK inhibitors combined with VBL in pediatric relapsed/refractory (r/r) ALK+ ALCL.Methods: Patients aged between 0 and 18 years with r/r ALK+ ALCL were included in this trial. ALK inhibitors are given orally with a converted dosage according to body surface areaand VBL was given with injection once a week at 4-6 mg/(m2.week). And no intensive chemotherapy and hematopoietic stem cell transplantation will be in our study.We may decrease the dosage of VBL or delete VBL if patients suffer severe bone marrow suppression, repeated infections, and peripheral neuritis and other VBL-related toxicities. Available ALK inhibitors included crizotinib(CZ), alectinib(AL) and ceritinib(CER). Patients without CNS involvement took CZ, and patients with CNS involvement took AL or CER. A cycle of therapy is 28 days. Evaluation for responses toxicities were monitored and recorded.Results:27 patients were enrolled in this trial between April 2018 and April 2021. The median age was 8.3 years old(ranging from 0.75 to 16), male/female ratio is19:8. By St.jude's staging, 20 cases were in stage III (74.1%), 7 cases in stage IV (25.9%) including 3 cases (11.1%) with CNS involvement at initial diagnosis. Before being enrolled in our study, 6 patient (22.2%) failed to achieve CR with prior 4-10 chemotherapy regimens, 21 patients (77.8%) relapsed after an average of 5-16 courses of standard pulse chemotherapy regimens. After 1st cycle of treatments, 62.9%(17/26) achieved comlpele remission(CR) without measurable tumors and ALK gene transcription, no progressed cases. Additional 6 case got CR after 2-10 month(23.1%). In general, 7 patients withdraw due to death, progress, ineffectiveness, economics, adverse reactions. The treatment retention rate was ,7.1%（20/7），objective response rate (ORR) was 85.2%(23/27), best complete remission rate(CRR) was 85.2%(23/27), disease control rate(DCR) was 92.5%(25/27), average duration of CR was 14.85 months(0-36months).Toxicities included nausea and vomiting, stomachache, diarrhea(81.5%,22/27, one or more above toxicities), neutropenia (27/27), pneumonia(7.4%, 2/27), sepsis(7.4%, 2/27), creatine kinase-MB elevation (81.5%,22/27,all are in crizotinib group including 2 abnormal ECG cases), liver enzyme elevation (63.%,17//27), intestinal obstruction(7.4%, 2/26). 2 cases relapsed because of the treatment discontinuation due to severe elevated liver enzymes.Summary/Conclusion: ALK inhibitors combined with VBL may rapidly induce the tumor remission of r/r ALK+ALCL and the tolerance is good. Combination therapy may induce a more lasting remission in for patients without BM involvement. Patients with BM involvement are more likely to fail treatment. Sequential use of ALK kinase inhibitors may be an efficient strategy to counter drug resistance.More data and longer follow-up time are needed to support our study. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Phase-separated foci of EML4-ALK facilitate signalling and depend upon an active kinase conformation.

Variants of the oncogenic EML4‐ALK fusion protein contain a similar region of ALK encompassing the kinase domain, but different portions of EML4. Here, we show that EML4‐ALK V1 and V3 proteins form cytoplasmic foci that contain components of the MAPK, PLCγ and PI3K signalling pathways. The ALK inhibitors ceritinib and lorlatinib dissolve these foci and EML4‐ALK V3 but not V1 protein re‐localises to microtubules, an effect recapitulated in a catalytically inactive EML4‐ALK mutant. Mutations that promote a constitutively active ALK stabilise the cytoplasmic foci even in the presence of these inhibitors. In contrast, the inhibitor alectinib increases foci formation of both wild‐type and catalytically inactive EML4‐ALK V3 proteins, but not a Lys‐Glu salt bridge mutant. We propose that EML4‐ALK foci formation occurs as a result of transient association of stable EML4‐ALK trimers mediated through an active conformation of the ALK kinase domain. Our results demonstrate the formation of EML4‐ALK cytoplasmic foci that orchestrate oncogenic signalling and reveal that their assembly depends upon the conformational state of the catalytic domain and can be differentially modulated by structurally divergent ALK inhibitors.

Development of a novel ALK rearrangement screening test for non-small cell lung cancers.

Approximately 5–7% of non–small cell lung cancer (NSCLC) cases harbor an anaplastic lymphoma kinase (ALK) fusion gene and may benefit from ALK inhibitor therapy. To detect ALK fusion genes, we developed a novel test using reverse transcription polymerase chain reaction (RT-PCR) for the ALK kinase domain (KD). Since ALK expression is mostly silenced in the adult with the exception of neuronal tissue, the normal lung tissue, mesothelial lining, and inflammatory cells are devoid of ALK transcript, making ALK KD RT-PCR an ideal surrogate test for ALK fusion transcripts in lung or pleural effusion. The test was designed with a short PCR product (197 bp) to work for both malignant pleural effusion (MPE) and formalin-fixed, paraffin-embedded (FFPE) NSCLC samples. Using ALK IHC as a reference, the sensitivity of the test was 100% for both MPE and FFPE. The specificity was 97.6% for MPE and 97.4% for FFPE. Two false positive cases were found. One was a metastatic brain lesion which should be avoided in the future due to intrinsic ALK expression in the neuronal tissue. The other one resulted from ALK gene amplification. Due to potential false positivity, subsequent confirmation tests such as fluorescence in situ hybridization or multiplex PCR would be preferable. Nevertheless, the test is simple and inexpensive with no false negativity, making it a desirable screening test. It also offers an advantage over multiplex RT-PCR with the capability to detect novel ALK fusions. Indeed through the screening test, we found a novel ALK fusion partner (sperm antigen with calponin homology and coiled-coil domains 1 like gene, SPECC1L) with increased sensitivity to crizotinib in vitro. In summary, a novel RNA-based ALK KD analysis was developed for ALK rearrangement screening in MPE and FFPE specimens of NSCLC. This simple inexpensive test can be implemented as routine diagnostics.

Testing for EGFR Mutations and ALK Rearrangements in Advanced Non-Small-Cell Lung Cancer: Considerations for Countries in Emerging Markets.

The treatment of patients with advanced non-small-cell lung cancer (NSCLC) in recent years has been increasingly guided by biomarker testing. Testing has centered on driver genetic alterations involving the epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) rearrangements. The presence of these mutations is predictive of response to targeted therapies such as EGFR tyrosine kinase inhibitors (TKIs) and ALK TKIs. However, there are substantial challenges for the implementation of biomarker testing, particularly in emerging countries. Understanding the barriers to testing in NSCLC will be key to improving molecular testing rates worldwide and patient outcomes as a result. In this article, we review EGFR mutations and ALK rearrangements as predictive biomarkers for NSCLC, discuss a selection of appropriate tests and review the literature with respect to the global uptake of EGFR and ALK testing. To help improve testing rates and unify procedures, we review our experiences with biomarker testing in China, South Korea, Russia, Turkey, Brazil, Argentina and Mexico, and propose a set of recommendations that pathologists from emerging countries can apply to assist with the diagnosis of NSCLC.

Concomitance of a novel RMDN2-ALK fusion and an EML4-ALK fusion in a lung adenocarcinoma

The anaplastic lymphoma kinase (ALK) fusions/rearrangements in non-small cell lung cancer (NSCLC) act as oncogenic driver mutations. ALK tyrosine kinase inhibitors have anti-tumor activities in ALK-positive NSCLC. Although the EML4-ALK fusion is common in NSCLC, concomitance of an additional ALK fusion together with an EML4-ALK fusion is not common. Here, we present a lung adenocarcinoma with two ALK fusions, a novel RMDN2-ALK fusion accompanied by an EML4-ALK fusion, detected by a targeted next generation sequencing assay. The genomic translocation breakpoints of the RMDN2-ALK fusion were mapped to intron 2 for RMDN2 and exon 15 for ALK, and EML4-ALK breakpoints were mapped to intron 13 for EML4 and intron 19 for ALK. ALK break-apart FISH detected multiple ALK rearrangements, a gene fusion panel (NanoString) test confirmed the EML4-ALK fusion, and RNA-sequencing revealed two ALK fusions. The RMDN2 gene locates at the short arm of chromosome 2 between ALK and EML4 genes. The intact ALK kinase domain fused to RMDN2. Genome-wide copy number variants were found in multiple chromosome arms and the short arm of chromosome 2, suggestive of complex rearrangements. Further detailed analyses of breakpoints and copy number variants may shed light on mechanisms of their formation and pathogenesis in lung malignancies.