Anaplastic Lymphoma Kinase Inhibitors Research Articles

Discovery of novel anaplastic lymphoma kinase (ALK) and histone deacetylase (HDAC) dual inhibitors exhibiting antiproliferative activity against non-small cell lung cancer

A series of novel benzimidazole derivatives were designed and synthesised based on the structures of reported oral available ALK inhibitor and HDAC inhibitor, pracinostat. In enzymatic assays, compound 3b, containing a 2-acyliminobenzimidazole moiety and hydroxamic acid side chain, could inhibit both ALK and HDAC6 (IC50 = 16 nM and 1.03 µM, respectively). Compound 3b also inhibited various ALK mutants known to be involved in crizotinib resistance, including mutant L1196M (IC50, 4.9 nM). Moreover, 3b inhibited the proliferation of several cancer cell lines, including ALK-addicted H2228 cells. To evaluate its potential for treating cancers in vivo, 3b was used in a human A549 xenograft model with BALB/c nude mice. At 20 mg/kg, 3b inhibited tumour growth by 85% yet had a negligible effect on mean body weight. These results suggest a attracting route for the further research and optimisation of dual ALK/HDAC inhibitors.

Formation and characterization of charge transfer complex between alectinib and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone: Application to development of microwell spectrophotometric method

Alectinib (ALC) is a novel highly selective anaplastic lymphoma kinase (ALK) inhibitor that is effective in the treatment of patients with advanced ALK-positive non-small cell lung cancer and lymphomas. This study, describes, for the first time, the formation of a charge transfer complex (CTC) between ALC with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The CTC was characterized using different spectrophotometric and computational techniques. UV–visible spectrophotometry ascertained the formation of the CTC in methanol via the formation of a new broad absorption band with a maximum absorption peak (λmax) at 505 nm. The molar absorptivity (ε) of the complex was 2.72 × 103 L mol−1 cm−1 and its band gap energy was 1.94 eV. The stoichiometric ratio of ALC:DDQ was found to be 1:1. The association constant of the complex was 9.6 × 102 L mol−1, and its standard free energy was −16.98 J mol−1. Computational calculations were conducted using different calculation tools. The computed geometrical parameters, specifically bond lengths, exhibited variations in the CTC compared to the individual reactants (ALC and DDQ). The Mulliken atomic charge analysis indicated increased values for DDQ (the acceptor) and decreased values for ALC (the donor) in the CTC, confirming the formation of a CTC. The reaction was employed as a basis for a novel microwell spectrophotometric method for the quantification of ALC in its bulk form, capsule content, and uniformity testing. This greenness and high throughput of the method was documented. The method represents a valuable tool for routine use in quality control laboratories for analysis of ALC's bulk form and capsules.

Case report: A patient with ALK-positive large B-cell lymphoma benefited from myeloma-like treatment combined with the ALK inhibitor lorlatinib

Case report: A patient with ALK-positive large B-cell lymphoma benefited from myeloma-like treatment combined with the ALK inhibitor lorlatinib

The mesenchymal morphology of cells expressing the EML4–ALK V3 oncogene is dependent on phosphorylation of Eg5 by NEK7

Echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) oncogenic fusion proteins are found in approximately 5% of non-small cell lung cancers. Different EML4-ALK fusion variants exist with variant 3 (V3) being associated with a significantly higher risk than other common variants, such as variant 1 (V1). Patients with V3 respond less well to targeted ALK inhibitors, have accelerated rates of metastasis, and have poorer overall survival. A pathway has been described downstream of EML4-ALK V3 that is independent of ALK catalytic activity but dependent on the NEK9 and NEK7 kinases. It has been proposed that assembly of an EML4-ALK V3-NEK9-NEK7 complex on microtubules leads to cells developing a mesenchymal-like morphology and exhibiting enhanced migration. However, downstream targets of this complex remain unknown. Here, we show that the microtubule-based kinesin, Eg5, is recruited to interphase microtubules in cells expressingEML4-ALK V3, whereas chemical inhibition of Eg5 reverses the mesenchymal morphology of cells. Furthermore, we show that depletion of NEK7 interferes withEg5 recruitment to microtubules in cells expressing EML4-ALK V3 and cell length is reduced, but this is reversed by coexpression of a phosphomimetic mutant of Eg5, in a site, S1033, phosphorylated by NEK7. Intriguingly, we also found that expression of Eg5-S1033D led to cells expressing EML4-ALK V1 adopting a more mesenchymal-like morphology. Together, we propose that Eg5 acts as a substrate of NEK7 in cells expressing EML4-ALK V3 andEg5 phosphorylation promotes the mesenchymal morphology typical of these cells.

Advancements in the Detection and Treatment of Rare ALK Fusion Mutations in Hepatocellular Carcinoma: A Case Report and Literature Review

This case report and comprehensive literature review highlights the significance of advanced molecular diagnostic techniques, particularly next-generation sequencing (NGS), in the identification and treatment of rare ALK fusion mutations in hepatocellular carcinoma (HCC). Through a detailed analysis of a single patient case, accompanied by a review of existing literature, we underscore the diagnostic challenges and therapeutic potential associated with rare ALK fusions in HCC. Our findings demonstrate the superior capability of NGS, both DNA-based and RNA-based, in detecting these mutations, leading to targeted treatment approaches with ALK inhibitors. The case report illustrates the practical application of precision oncology in HCC, showcasing significant clinical benefit and improved treatment outcomes with the use of ALK inhibitors for rare fusion types. This study not only contributes to the existing body of knowledge by documenting a rare instance of ALK fusion in HCC but also advocates for the integration of comprehensive molecular profiling into standard clinical practice to enhance personalized treatment strategies and patient care.

Insight into systematic development of ALK (anaplastic lymphoma kinase) inhibitors towards NSCLC treatment

Among cancer-related disorders, lung carcinoma is one of the leading causes of mortality. Anaplastic lymphoma kinase (ALK) belongs to tyrosine kinase receptor family and exhibits similar characteristics to insulin type receptors. The treatment of advanced non-small cell lung cancer (NSCLC) associates with ALK gene rearrangement has significantly improved since the approval of Crizotinib in 2011 as the first generation ALK inhibitor. In continuation, the second-generation drugs like ceritinib, alectinib, and brigatinib were developed to address and counteract resistance that was associated with the first-generation agents. However, resistance can develop over time, necessitating ongoing research to enhance their effectiveness. Therefore, the third-generation drug lorlatinib, which has demonstrated broad-spectrum potency against the majority of known resistance mutations and better lipophilicity, has been developed. According to current reports, the USFDA has approved five ALK-TKIs crizotinib, ceritinib, alectinib, brigatinib, and lorlatinib for ALK-associated lung cancer. Currently, several clinical trials are underway in search of better ALK inhibitors. Trials such as TPX-0131 and NVL-655 are considered fourth-generation ALK inhibitors for the treatment of patients with advanced ALK-positive or metastatic NSCLC. This review aims to provide specifics information on research works involving various ALK tyrosine kinase inhibitors, clinical studies, and the development of ALK TKIs. Additionally, we suggest potential future strategies involving sequential therapy and combination techniques for managing non-small cell carcinoma.

Anaplastic Lymphoma Kinase (ALK) Inhibitors Show Activity in Colorectal Cancer With ALK Rearrangements: Case Series and Literature Review.

Anaplastic lymphoma kinase (ALK) rearrangement is a well-known driver oncogene detected in approximately 5% of non-small cell lung cancer. However, ALK rearrangement is much less frequent in other solid tumors outside the lungs, such as colorectal cancer (CRC); thus, the optimal management of CRC with ALK rearrangements has yet to be established. In this report, we describe 2 cases of ALK-positive CRC, both of which benefited from ALK tyrosine kinase inhibitor (ALK-TKI) therapy. Case 1 was a postoperative patient with poorly differentiated colon adenocarcinoma, who was diagnosed with metastatic relapse shortly after surgery. Both fluorouracil, leucovorin, and oxaliplatin (FOLFOX) and bevacizumab combined with 5-fluorouracil, l-leucovorin, and irinotecan (FOLFIRI) proved ineffective against the disease. The patient was then treated with ensartinib, as the CAD-ALK fusion gene was detected by genomic analysis. The patient was initially treated with ensartinib monotherapy for 9 months, then with ensartinib combined with local radiotherapy and fruquintinib for another 4 months for isolated hilar hepatic lymph node metastasis. The patient experienced disease progression with an acquired ALK G1202R resistance mutation that responded well to lorlatinib. Case 2 involved a 72-year-old man with advanced colon cancer (pT4bN2aM1b, stage IV) harboring an EML4-ALK fusion. The patient underwent resection of the right colon tumor due to intestinal obstruction, but the disease continued to progress after 12 courses of FOLFIRI and bevacizumab chemotherapy. However, the patient responded remarkably well to alectinib. Our report emphasizes the importance of gene detection in the treatment of malignant tumors, and the significance of ALK mutations in CRC.

Concomitant double-fusion of PLEKHA7-ALK and INPP5D-ALK reveals favorable alectinib sensitivity in lung adenocarcinoma: a case report and literature review

Anaplastic lymphoma kinase (ALK) gene fusion is a classic driver mutation in non-small cell lung cancer (NSCLC); however, ALK double-fusion variants in NSCLC have rarely been reported. In this study, we reported a case with extremely uncommon ALK double-fusion variants. A 32-year-old female diagnosed with lung adenocarcinoma, who had developed multiple intrapulmonary and brain metastases, experienced worsening of her condition despite undergoing prior chemotherapy. Subsequent testing using next-generation sequencing (NGS) detected the presence of PLEKHA7-ALK and INPP5D-ALK double-fusion. The prescription of alectinib revealed potent efficacy and resulted in an increase in the survival rate. This case presented two uncommon and concomitant ALK fusion partners in NSCLC; more importantly, the INPP5D-ALK subtype has not been reported, therefore this study broadens the spectrum of ALK double-fusion variants and provides insight into the use of ALK inhibitors for the treatment of NSCLC in patients with double ALK fusions.

Mutant anaplastic lymphoma kinase inhibitor identification by integrated in silico approaches

ABSTRACT Non-small-cell lung cancer (NSCLC) is the primary form of lung cancer globally and remains a leading cause of mortality. Anaplastic lymphoma kinase (ALK) mutations, such as I1171N + L1198H, have been discovered to confer resistance to current ALK inhibitors, reducing their therapeutic effectiveness. Addressing drug resistance necessitates exploring selective inhibitors for innovative therapeutic approaches. In this study, a structure-based pharmacophore model, using ALK-approved inhibitors, was developed to screen an In-house database for potential mutant ALK inhibitors. Compounds with requisite pharmacophoric features were evaluated for binding potential against the I1171N + L1198H ALK mutant phenotype. Selected hits underwent assessment for chemical reactivity, and dynamics stability. The study identified five chemical scaffolds (NS1-5) with favorable binding modes and pharmacokinetic properties. The conformational ensembles featured the average RMSD values, ranging from 0.4 to 0.6 nm. RMSF analysis revealed consistent side chain fluctuations with reduced flexibility, while Rog analysis indicated convergence of most complexes. NS1 and NS5, in particular emerged as promising candidates, exhibiting remarkable performance than others, with binding free energies of −210.12 ± 9.94 and −163.68 ± 11.14 kcal/mol, respectively. These findings thus suggest further exploration and optimisation of NS1 and NS5 for mutant ALK inhibitors for the treatment of NSCLC.

Inflammation-related molecular signatures involved in the anticancer activities of brigatinib as well as the prognosis of EML4-ALK lung adenocarcinoma patient.

Although ALK tyrosine kinase inhibitors (ALK-TKIs) have shown remarkable benefits in EML4-ALK positive NSCLC patients compared to conventional chemotherapy, the optimal sequence of ALK-TKIs treatment remains unclear due to the emergence of primary and acquired resistance and the lack of potential prognostic biomarkers. In this study, we systematically explored the validity of sequential ALK inhibitors (alectinib, lorlatinib, crizotinib, ceritinib and brigatinib) for a heavy-treated patient with EML4-ALK fusion via developing an in vitro and in vivo drug testing system based on patient-derived models. Based on the patient-derived models and clinical responses of the patient, we found that crizotinib might inhibit proliferation of EML4-ALK positive tumors resistant to alectinib and lorlatinib. In addition, NSCLC patients harboring the G1269A mutation, which was identified in alectinib, lorlatinib and crizotinib-resistant NSCLC, showed responsiveness to brigatinib and ceritinib. Transcriptomic analysis revealed that brigatinib suppressed the activation of multiple inflammatory signaling pathways, potentially contributing to its anti-tumor activity. Moreover, we constructed a prognostic model based on the expression of IL6, CXCL1, and CXCL5, providing novel perspectives for predicting prognosis in EML4-ALK positive NSCLC patients. In summary, our results delineate clinical responses of sequential ALK-TKIs treatments and provide insights into the mechanisms underlying the superior effects of brigatinib in patients harboring ALKG1269A mutation and resistant towards alectinib, lorlatinib and crizotinib. The molecular signatures model based on the combination of IL6, CXCL1 and CXCL5 has the potential to predict prognosis of EML4-ALK positive NSCLC patients.

Expansion of targeted degradation by Gilteritinib-Warheaded PROTACs to ALK fusion proteins

Proteolysis targeting chimeras (PROTACs) induce the ubiquitination and subsequent proteasomal degradation of targeted proteins. Numerous PROTACs have emerged as promising drug candidates for various disease-related proteins. This study investigates PROTACs targeted to degrade anaplastic lymphoma kinase (ALK) fusion proteins, which are implicated in diseases such as anaplastic large cell lymphoma and non-small cell lung cancer. We recently reported the development of a gilteritinib-warheaded PROTAC to target and degrade the Fms-like tyrosine kinase 3 (FLT3) protein. Gilteritinib is a tyrosine kinase inhibitor that targets FLT3, and recent studies have revealed that it also functions as an ALK inhibitor. We conducted a structure–activity relationship (SAR) study and expanded the range of target proteins for gilteritinib-warheaded PROTACs to include echinoderm microtubule-associated protein-like 4 (EML4)-ALK and nucleophosmin (NPM)-ALK, in addition to FLT3. Our SAR study utilized three types of ligands for E3 ligase— inhibitor of apoptosis protein (IAP), cereblon (CRBN), and von Hippel-Lindau (VHL)— in the PROTAC designs and we observed varied efficacy in the degradation of target proteins. The CRBN-based PROTAC effectively reduced the protein expression of FLT3, EML4-ALK, and NPM-ALK. The IAP-based PROTAC reduced expression of both FLT3 and EML4-ALK proteins but not that of NPM-ALK, while the VHL-based PROTAC was ineffective against all target proteins. Several ALK-targeted PROTACs have already been developed using CRBN or VHL as E3 ligase, but this is the first report of an IAP-based ALK degrader. The length of the linker structure utilized in PROTAC also had a significant effect on their efficacy and activity. PROTACs formed with shorter linkers demonstrated an enhanced degradation activity to target proteins compared with those formed with longer linkers. These findings provide valuable insight for the development of effective PROTACs to target and degrade ALK fusion proteins.

A199 ALKAL2/ALK AXIS PROMOTE PERSISTENT VISCERAL PAIN

Abstract Background Long-lasting changes in neural pain circuits precipitate the transition from acute to chronic pain in patients living with inflammatory bowel diseases (IBDs). While significant improvement in IBD therapy has been made to reduce inflammation, a large subset of patients continues to suffer throughout quiescent phases of the disease. Peripheral and central mechanisms contribute to the transition from acute to chronic pain during clinical remission. In the search of new treatments, we previously found that targeting the anaplastic lymphoma kinase (ALK) receptor could have therapeutic value for persistent pain conditions. Aims Here we investigated whether ALKAL2 (ALK ligand) /ALK signaling axis regulates chronic visceral pain. Methods We used the post-inflammatory dextran sodium sulfate (DSS) mouse model of colitis as a well-established rodent model of chronic visceral pain, in which animals display increased VHS 5 weeks after DSS administration in the absence of inflammation as described in IBD patients. To assess the role of ALKAL2/ALK signalling in chronic visceral pain, we pharmacologically blocked ALK receptor using clinically available compound Lorlatinib in the postcolitis model. Moreover we genetically depleted ALKAL2 in gut-innervating nociceptors that express the heat sensitive transient receptor potential vanilloid type 1 (TRPV1) channel, using shRNA vectorized in cell type specific Adeno-associated Viruses. Results We showed that ALKAL2 expression was significatively enhanced in lumbosacral (LS) dorsal root ganglia (DRG) sensory neurons in the post-colitis model. In naïve mice, ALKAL2 administration induced visceral hypersensitivity in an ALK dependant manner. In addition, depletion of ALKAL2 in TRPV1 nociceptors or blocking ALK with the clinically available compound Lorlatinib, reversed visceral hypersensitivity in the post-colitis model. Accordingly, phosphorylation of ALK receptor occurring at the LS of the spinal dorsal horn was reduced. Conclusions Overall, these findings provide novel insights into the mechanisms underlying the transition from acute to chronic visceral pain in IBD. Our work could generate a portfolio of clinically available anti-cancer drugs, including Lorlatinib, as novel pain therapeutics. Repurposed ALK inhibitor could facilitate pain management in in individuals with IBD. Funding Agencies CIHR

Neuro-ophthalmic complications of modern anti-cancer drugs

PurposeTargeted cancer therapies have been responsible for a dramatic shift in treatment strategies for cancer, and the number of drugs, classes, and indications are continually growing. Neuro-ophthalmic complications of these medications are an uncommon but important subset of adverse events which profoundly impact vision. This review aims to collate studies and reports of known neuro-ophthalmic complications of targeted therapies and describe their management.MethodsThe anti-cancer drugs included in the review were any drugs targeting specific molecules involved in the cancer disease process. PubMed, EMBASE, and Web of Science were searched using the generic names of each drug and keywords of neuro-ophthalmic conditions. The prescribing information published by the US Food and Drug Administration (FDA) for each drug was also reviewed.ResultsSeveral classes of targeted anti-cancer drugs were found to cause neuro-ophthalmic adverse effects. Immune checkpoint inhibitors are responsible for a raft of immune-related adverse events such as optic neuritis, ischemic optic neuropathy, PRES, and myasthenia gravis. Therapies with anti-VEGF activity can provoke posterior reversible leukoencephalopathy, which commonly presents with visual loss and can be fatal if not treated promptly. Inhibitors of BCR-ABL1, VEGF, ALK, and proteasomes have all been linked to optic nerve disorders which can have debilitating consequences for vision.ConclusionThe neuro-ophthalmic complications of modern anti-cancer drugs can limit or necessitate the withdrawal of these life-prolonging medications. Ophthalmologists should be alert for neuro-ophthalmic complications in these medications to facilitate prompt diagnosis and treatment and reduce the risk of severe and permanent consequences.

Identifying optimal ALK inhibitors in first- and second-line treatment of patients with advanced ALK-positive non-small-cell lung cancer: a systematic review and network meta-analysis

ObjectivesTo compare the efficacy, safety and effects on quality of life of different ALK-inhibitors for global and Asian patients with advanced ALK-positive non-small-cell lung cancer (NSCLC).MethodsThe included RCTs were identified through a systematic search of PubMed, EMBASE, Cochrane Library, Clinical Trials.gov, and major cancer conferences. The assessment of progression-free survival (PFS), intracranial PFS, overall survival (OS), and patient-reported outcomes (PROs) was carried out using restricted mean survival time (RMST) model, fractional polynomial model and Royston-Parmar model. Time-invariant hazard ratio (HR) models were also used to validate and supplement the primary analysis. Objective response rate (ORR) and adverse events with any grade, grade 3–5 were assessed through a Bayesian network meta-analysis. The primary measures for OS, PFS, and PROs were HR and RMST. The odds ratio was the metric for evaluating safety, ORR, 12-month PFS rate, 24-month OS rate, and the 12-month non-deterioration rate of PROs. Subgroup analyses based on patient characteristics were performed.ResultsA total of fourteen studies (ten for first-line, four for second-line) consisting of nine treatments (chemotherapy, crizotinib, alectinib [600mg BID], low-dose alectinib [300mg BID], brigatinib, ceritinib, ensartinib, envonalkib, and lorlatinib) were included. In the first-line setting, alectinib showed a significant advantage over crizotinib and had the longest OS among all ALK-inhibitors. Compared to crizotinib, lorlatinib had the best efficacy regarding PFS for global patients, followed closely by alectinib and brigatinib. For Asian patients, alectinib significantly improved PFS compared to other treatments. In second-line, alectinib had the highest PFS for patients pretreated with crizotinib, followed by brigatinib, ceritinib and chemotherapy. Alectinib, irrespective of the dose, was the safest first-line option, whereas lorlatinib, brigatinib, and ceritinib showed poorer safety profiles. Alectinib was also the safest ALK-inhibitor for crizotinib-resistant patients. Brigatinib had the best performance in terms of PROs.ConclusionsConsidering both efficacy and safety, alectinib appears to be the preferable treatment in first-line and second-line, particularly for Asian patients.

Mitoxantrone and abacavir: An ALK protein-targeted in silico proposal for the treatment of non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is a type of lung cancer associated with translocation of the EML4 and ALK genes on the short arm of chromosome 2. This leads to the development of an aberrant protein kinase with a deregulated catalytic domain, the cdALK+. Currently, different ALK inhibitors (iALKs) have been proposed to treat ALK+ NSCLC patients. However, the recent resistance to iALKs stimulates the exploration of new iALKs for NSCLC. Here, we describe an in silico approach to finding FDA-approved drugs that can be used by pharmacological repositioning as iALK. We used homology modelling to obtain a structural model of cdALK+ protein and then performed molecular docking and molecular dynamics of the complex cdALK+-iALKs to generate the pharmacophore model. The pharmacophore was used to identify potential iALKs from FDA-approved drugs library by ligand-based virtual screening. Four pharmacophores with different atomistic characteristics were generated, resulting in six drugs that satisfied the proposed atomistic positions and coupled at the ATP-binding site. Mitoxantrone, riboflavin and abacavir exhibit the best interaction energies with 228.29, 165.40 and 133.48 KJoul/mol respectively. In addition, the special literature proposed these drugs for other types of diseases due to pharmacological repositioning. This study proposes FDA-approved drugs with ALK inhibitory characteristics. Moreover, we identified pharmacophores sites that can be tested with other pharmacological libraries.

Targeting ALK averts ribonuclease 1-induced immunosuppression and enhances antitumor immunity in hepatocellular carcinoma

Tumor-secreted factors contribute to the development of a microenvironment that facilitates the escape of cancer cells from immunotherapy. In this study, we conduct a retrospective comparison of the proteins secreted by hepatocellular carcinoma (HCC) cells in responders and non-responders among a cohort of ten patients who received Nivolumab (anti-PD-1 antibody). Our findings indicate that non-responders have a high abundance of secreted RNase1, which is associated with a poor prognosis in various cancer types. Furthermore, mice implanted with HCC cells that overexpress RNase1 exhibit immunosuppressive tumor microenvironments and diminished response to anti-PD-1 therapy. RNase1 induces the polarization of macrophages towards a tumor growth-promoting phenotype through activation of the anaplastic lymphoma kinase (ALK) signaling pathway. Targeting the RNase1/ALK axis reprograms the macrophage polarization, with increased CD8+ T- and Th1- cell recruitment. Moreover, simultaneous targeting of the checkpoint protein PD-1 unleashes cytotoxic CD8+ T-cell responses. Treatment utilizing both an ALK inhibitor and an anti-PD-1 antibody exhibits enhanced tumor regression and facilitates long-term immunity. Our study elucidates the role of RNase1 in mediating tumor resistance to immunotherapy and reveals an RNase1-mediated immunosuppressive tumor microenvironment, highlighting the potential of targeting RNase1 as a promising strategy for cancer immunotherapy in HCC.

Aggressive T-cell lymphomas: 2024: Updates on diagnosis, risk stratification, and management.

Aggressive T-cell lymphomas continue to have a poor prognosis. There are over 30 different subtypes of peripheral T-cell lymphoma (PTCL), and we are now beginning to understand the differences between the various subtypes beyond histologic variations. Gene expression profiling and other molecular techniques have enabled deeper understanding of differences in various subtypes as reflected in the latest 5th WHO classification of PTCL. It is becoming increasingly clear that therapeutic approaches that target specific cellular pathways are needed to improve the clinical outcomes of PTCL. There are many targeted agents currently in various stages of clinical trials for PTCL that take advantage of the differential expression of specific proteins or receptors in PTCL tumors. This includes the CD30 directed antibody drug conjugate brentuximab vedotin. Other notable targets are phosphatidylinositol 3-kinase inhibitors, histone deacetylase inhibitors, CD25, and chemokine receptor 4. Anaplastic lymphoma kinase (ALK) inhibitors are promising for ALK expressing tumors. Allogeneic stem cell transplant continues to be the curative therapy for most aggressive subtypes of PTCL. The use of checkpoint inhibitors in the treatment of PTCL is still controversial, with best results seen in cases of extranodal natural killer cell/T-cell lymphoma. Bispecific antibody-based treatments and chimeric antigen receptor cell-based therapies are in clinical trials.

Anaplastic Lymphoma Kinase (ALK) in Posterior Cranial Fossa Tumors: A Scoping Review of Diagnostic, Prognostic, and Therapeutic Perspectives

Anaplastic Lymphoma Kinase (ALK) has been implicated in several human cancers. This review aims at mapping the available literature on the involvement of ALK in non-glial tumors localized in the posterior cranial fossa and at identifying diagnostic, prognostic, and therapeutic considerations. Following the PRISMA-ScR guidelines, studies were included if they investigated ALK’s role in primary CNS, non-glial tumors located in the posterior cranial fossa. A total of 210 manuscripts were selected for full-text review and 16 finally met the inclusion criteria. The review included 55 cases of primary, intracranial neoplasms with ALK genetic alterations and/or protein expression, located in the posterior fossa, comprising of medulloblastoma, anaplastic large-cell lymphoma, histiocytosis, inflammatory myofibroblastic tumors, and intracranial myxoid mesenchymal tumors. ALK pathology was investigated via immunohistochemistry or genetic analysis. Several studies provided evidence for potential diagnostic and prognostic value for ALK assessment as well as therapeutic efficacy in its targeting. The available findings on ALK in posterior fossa tumors are limited. Nevertheless, previous findings suggest that ALK assessment is of diagnostic and prognostic value in medulloblastoma (WNT-activated). Interestingly, a substantial proportion of ALK-positive/altered CNS histiocytoses thus far identified have been localized in the posterior fossa. The therapeutic potential of ALK inhibition in histiocytosis warrants further investigation.

HER3 overexpression: a predictive marker for poor prognosis in advanced ALK-positive non-small cell lung cancer treated with ALK inhibitors.

Anaplastic lymphoma kinase (ALK)-targeted tyrosine kinase inhibitors (TKIs) improve patient survival; however, some patients develop ALK-TKI resistance with unidentified mechanisms. We investigated ErbB family and c-MET expression in patients with ALK-positive non-small cell lung cancer (NSCLC) to understand their roles in the ALK-TKI response. We studied 72 patients with advanced ALK-positive NSCLC with EML4-ALK fusion variant subtyping and immunostaining for c-MET, EGFR, HER2, and HER3 on tissue specimens both pre- (primary) and post-treatment (secondary) with ALK-TKI. We investigated the association of their expression with survival outcomes and assessed the effectiveness of combining ALK and EGFR inhibitors in ALK-positive NSCLC cell lines stimulated with the HER3-specific ligand HRG1. High expression of c-MET, EGFR, HER2, and HER3 was observed in 4.9%, 18.0%, 1.6%, and 25.8% of primary tumors, respectively, and 18.5%, 37.0%, 10.7%, and 35.7% of secondary tumors, respectively. HER3 overexpression in primary tumors showed inferior survival (P=0.132). In the subgroup with EML4-ALK variant 1/2 (V1/V2), HER3 overexpression was significantly associated with inferior survival in both primary and secondary tumors (P=0.022 and P=0.004, respectively). Combination treatment with lorlatinib and erlotinib significantly reduced HRG1-induced activation of RTK signaling in ALK-positive NSCLC cells. HER3 overexpression has potential as a prognostic marker in ALK-positive NSCLCs, including ALK-TKI naïve and treated cases, especially those with EML4-ALK V1/V2. Assessing HER3 expression may be crucial for treatment planning and outcome prediction in these patients.

Abstract A016: Positive ecological interaction between therapy-resistant and sensitive cells, mediated by stromal niche, slows the expansion of resistant subpopulations and promotes tumor heterogeneity

Abstract Despite strong initial responses, advanced cancers inevitably develop resistance to pharmacological inhibitors of mutant tyrosine kinases, including EML4-ALK fusion, which drives neoplastic transformation in a subset of lung cancers. Whereas the main thrust of research and development efforts to tackle the issue of resistance is directed toward identification and targeting specific molecular mechanisms, there is also a growing interest in developing strategies to suppress the ability of neoplastic populations to evolve resistance. The success of these strategies is contingent on the accuracy of the basic assumptions on how resistance arises. One of the key issues is the uncertainty over whether the acquired resistance reflects an expansion of pre-existing fully resistant populations or develops de novo from weakly resistant cells initially capable of only narrowly avoiding elimination. To elucidate this question, we decided to examine the impact of a minor subpopulation of resistant cells on the evolutionary dynamics of therapy responses to ALK inhibitors. To this end, we used an integration of experimental studies in mouse xenograft models of ALK+ lung cancers with agent-based in silico modeling approaches. We found that therapy induces a rapid expansion of pre-existing subpopulations, leading to a quick transition toward relapse. Surprisingly, resistant cells modulated the dynamics of sensitive cells, preserving the survival and expansion of their sensitive competitors, indicating a positive ecological interaction. Spatial histological analyses revealed that this positive interaction was mediated by the preservation and expansion of stromal niches that both boosted the competitive fitness of therapy-sensitive cells and promoted their adaptation, thus facilitating tumor heterogeneity. Whereas this effect inhibited the competitive expansion of resistant cells and tumor relapse, our analyses suggest that pre-existing resistance is incompatible with long remissions observed in a large subset of patients treated with advanced ALK inhibitors. In summary, our results challenge a common assumption of the pre-existence of full resistance prior to therapy and highlight the essentiality of considering ecological factors in understanding the evolutionary dynamics of therapy responses. Citation Format: Bina Desai, Mark Robertson-Tessi, Robert Vander Velde, Tatiana Miti, Sagnik Yarlagadda, Rishi Shah, Daria Miroshnychenko, David Basanta, Alexander Anderson, Andriy Marusyk. Positive ecological interaction between therapy-resistant and sensitive cells, mediated by stromal niche, slows the expansion of resistant subpopulations and promotes tumor heterogeneity [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Cancer Evolution and Data Science: The Next Frontier; 2023 Dec 3-6; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_2):Abstract nr A016.