Molecular tumor board: molecularly adjusted therapy upon identification and functional validation of a novel ALK resistance mutation in a case of lung adenocarcinoma.

We report a case of a long-term surviving patient with EML4/ALK translocated non-small cell adenocarcinoma of the lung in UICC8 stage IVA. During recurrence under continuous crizotinib therapy, a hitherto insufficiently characterized missense mutation in the ALK gene (Arg1181His) was identified through targeted sequencing. The aforementioned EML4/ALK translocation could still be detected in this situation. Employing a 3D reconstruction of the ALK tertiary structure, considering its interaction with various ALK inhibitors at the molecular binding site, our analysis indicated the presence of a mutation associated with crizotinib resistance. To validate the biological relevance of this previously unknown mutation, we carried out an in vitro validation approach in cell culture in addition to the molecular diagnostics accompanied by the molecular tumor board. The tumor scenario was mimicked through retroviral transfection. Our comparative in vitro treatment regimen paired with the clinical trajectory of the patient, corroborated our initial clinical and biochemical suspicions. Our approach demonstrates preclinical, in silico, and clinical evidence of a novel crizotinib resistance mutation in ALK as well as sensitivity toward brigatinib and potentially lorlatinib. In future cases, this procedure represents an important contribution to functional diagnostics in the context of molecular tumor boards.

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.

OBJECTIVES: To 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). METHODS: The 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. RESULTS: A 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. CONCLUSIONS: Considering both efficacy and safety, alectinib appears to be the preferable treatment in first-line and second-line, particularly for Asian patients.

Cardiovascular toxicity of anaplastic lymphoma kinase inhibitors for patients with non-small cell lung cancer: a network meta-analysis.

Aim: We conducted network meta-analysis to assess cardiovascular toxicity of anaplastic lymphoma kinase-tyrosine kinase inhibitors (ALK-TKIs).Materials & methods: Eleven articles involving 2855 patients and six interventions including crizotinib, alectinib, ceritinib, lorlatinib, brigatinib and chemotherapy were analyzed.Results: No significant difference was observed in overall cardiovascular risk among ALK-TKIs. Subgroup analysis showed that for cardiac toxicity, crizotinib and alectinib were more likely to cause myocardial rhythm abnormalities. Crizotinib and ceritinib had a higher risk of Q-T prolongation than chemotherapy. For vascular toxicity, crizotinib and ceritinib had a higher risk of thrombotic events than brigatinib. Crizotinib and lorlatinib were more likely to cause blood pressure abnormalities.Conclusion: Clinicians should carefully monitoring cardiovascular events when ALK-TKIs used in NSCLCs patients with baseline cardiovascular diseases.

A network meta-analysis revealed the cardiovascular toxicity caused by ALK-TKIs in non-small cell lung cancer patients.

Pediatric inflammatory myofibroblastic tumor of the bladder with ALK-FN1 fusion successfully treated by alectinib.

An inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm characterized by the proliferation of myofibroblasts and inflammatory cell infiltration. Although radical resection is the only established treatment strategy for IMT, it can cause functional disorders when vital organs are affected. We describe a case of pediatric IMT of the bladder with FN1-ALK (fibronectin 1-anaplastic lymphoma kinase) fusion. Radical resection might lead to urinary disturbance due to the large tumor size at diagnosis. However, the tumor was successfully treated with alectinib, a second-generation ALK inhibitor, followed by transurethral resection of the bladder tumor without any complications.

The role of brain radiotherapy for EGFR- and ALK-positive non-small-cell lung cancer with brain metastases: a review.

Non-small cell lung cancer (NSCLC) is frequently complicated by central nervous system (CNS) metastases affecting patients' life expectancy and quality. At the present clinical trials including neurosurgery, radiotherapy (RT) and systemic treatments alone or in combination have provided controversial results. CNS involvement is even more frequent in NSCLC patients with EGFR activating mutations or ALK rearrangement suggesting a role of target therapy in the upfront treatment in place of loco-regionals treatments (i.e. RT and/or surgery). So far clinical research has not explored the potential role of accurate brain imaging (i.e. MRI instead of the routine total-body contrast CT and/or PET/CT staging) to identify patients that could benefit of local therapies. Moreover, for patients who require concomitant RT there are no clear guidelines on the timing of intervention with respect to innovative precision medicine approaches with Tyrosine Kinase Inhibitors, ALK-inhibitors and/or immuno-oncological therapies. On this basis the present review describes the therapeutic strategies integrating medical and radiation oncology in patients with metastatic NSCLC (mNSCLC) adenocarcinoma with CNS involvement and EGFR activating mutations or ALK rearrangement.

ALK Inhibitors or Chemotherapy for Third Line in ALK-positive NSCLC? Real-world Data.

OBJECTIVES: ALK inhibitors (ALKi) are the standard-of-care treatment for metastatic ALK-rearranged non-small cell lung cancer (NSCLC) in the first- and second-line setting. We conducted a real-world multi-institutional analysis, aiming to compare the efficacy of third-line ALKi versus chemotherapy in these patients. METHODS: Consecutive ALK-positive metastatic NSCLC patients treated with at least one ALKi were identified in the working databases of 7 Israeli oncology centers (the full cohort). Demographic and clinical data were collected. Patients receiving any systemic treatment beyond 2 ALKi comprised the third-line cohort, whether a third ALKi (group A) or chemotherapy (group B). Groups A and B were compared in terms of overall survival (OS) and time-to-next-treatment line (TNT). RESULTS: At a median follow-up of 41 months (95% confidence interval [CI]: 32-55), 80 (47.1%) have died. Median OS (mOS) in the full cohort (n = 170) was 52 months (95% CI: 32-65). Number of ALKi (hazard ratio [HR] 0.765; 95% CI: 0.61-0.95; P = .024) and age (HR 1.02, 95% CI: 1.01-1.04, P = .009) significantly associated with OS in the full cohort. The third-line cohort included 40 patients, of which 27 were treated with third ALKi (group A) and 13 treated with chemotherapy (group B). mOS from third-line initiation was 27 months in group A (95% CI: 13-NR) and 13 months for group B (95% CI: 3-NR); the difference was not significant (NS; P = .12). Chemotherapy as first line (HR 0.17, 95% CI: 0.05-0.52, P = .002) and a higher number of ALKi (HR 0.38, 95% CI: 0.20-0.86, P = .011) associated significantly with longer OS of the third-line cohort. TNT was 10 months for group A (95% CI: 5-19) and 3 months for group B (95% CI: 0-NR); the difference was NS (P = .079). CONCLUSION: We report mature real-world data of more than 4-year mOS in ALK-positive patients. The number of ALKi given was associated with a better outcome. OS and TNT demonstrated a statistically nonsignificant trend for a better outcome in patients receiving a third-line ALKi.

Fragment-based discovery of novel phenyltriazolyl derivatives as allosteric type-I1/2 ALK inhibitors with promising antitumor effects.

Based on the high-throughput screening hit BY-1, a series of phenyltriazolyl derivatives were developed. Satisfyingly, most compounds were detected moderate to excellent antitumor effects against Karpas299 and H2228 cells. Among them, 12k bearing 4­hydroxypiperidinyl group exhibited the optimal activities against tested cells with IC50 values of 51 nM and 175 nM, as well as promising inhibitory effects on ALKWT (3.7 nM) and ALKL1196M (6.8 nM). Unlike the conventional type-I ALK inhibitors, molecular models identified 12k as an allosteric type-I1/2 inhibitor by forming key interactions in both the ATP binding region and the hydrophobic back pocket of ALK. Intriguingly, 12k could dose-dependently induce apoptosis on H2228 cell and inhibit colony formation and tumor cell migration. Taken together, the rationalization of 12k may shed new light on the identification of novel allosteric type-I1/2 ALK inhibitors.

Neuroblastoma Heterogeneity, Plasticity, and Emerging Therapies.

PURPOSE OF REVIEW: The evolving information of the initiation, tumor cell heterogeneity, and plasticity of childhood neuroblastoma has opened up new perspectives for developing therapies based on detailed knowledge of the disease. RECENT FINDINGS: The cellular origin of neuroblastoma has begun to unravel and there have been several reports on tumor cell heterogeneity based on transcriptional core regulatory circuitries that have given us important information on the biology of neuroblastoma as a developmental disease. This together with new insight of the tumor microenvironment which acts as a support for neuroblastoma growth has given us the prospect for designing better treatment approaches for patients with high-risk neuroblastoma. Here, we discuss these new discoveries and highlight some emerging therapeutic options. Neuroblastoma is a disease with multiple facets. Detailed biological and molecular knowledge on neuroblastoma initiation, heterogeneity, and the communications between cells in the tumor microenvironment holds promise for better therapies.

Activity of ALK Inhibitors in Renal Cancer with ALK Alterations: A Systematic Review.

Renal cell carcinoma (RCC) associated with anaplastic lymphoma kinase (ALK) gene rearrangements (ALK-RCC) is currently considered an "emerging or provisional" tumor entity by the last World Health Organization classification published in 2016. Although several studies assessing ALK-RCC's clinical and histological characteristics have been published in recent years, only a few publications have evaluated the activity of ALK inhibitors (ALK-i) in this subgroup of patients. Considering the well-recognized efficacy of this evolving class of targeted therapies in other ALK-positive tumors, we conducted a systematic review to evaluate the reported activity of ALK-i in the ALK-RCC subtype. MEDLINE was searched from its inception to 7 January 2022 for case reports and case series on adult metastatic ALK-RCC patients treated with ALK-i whose therapeutic outcomes were available. A virtual cohort of ALK-RCC patients was created. Our results showed a favorable activity of first- and second-generation ALK-i in pretreated ALK-RCC patients in terms of either radiological response or performance status improvement. We hope that the present work will prompt the creation of large, multi-institutional clinical trials to confirm these promising early data.

Systemic Therapy for Lung Cancer Brain Metastases.

OPINION STATEMENT: Systemic therapy for brain metastases (BM) is quickly moving from conventional cytotoxic chemotherapy toward targeted therapies, that allow a disruption of driver molecular pathways. The discovery of actionable driver mutations has led to the development of an impressive number of tyrosine kinase inhibitors (TKIs), that target the epidermal growth factor receptor (EGFR) mutations, anaplastic-lymphoma-kinase (ALK) rearrangements, and other rare molecular alterations in patients bearing metastatic non-small cell lung cancer (NSCLC) in the brain, with remarkable results in terms of intracranial disease control and overall survival. Moreover, these drugs may delay the use of local therapies, such as stereotactic radiosurgery (SRS) or whole-brain radiotherapy (WBRT). New drugs with higher molecular specificity and ability to cross the CNS barriers (BBB, BTB and blood-CSF) are being developed. Two major issues are related to targeted therapies. First, the emergence of a resistance is a common event, and a deeper understanding of molecular pathways that are involved is critical for the successful development of effective new targeted agents. Second, an early detection of tumor progression is of utmost importance to avoid the prolongation of an ineffective therapy while changing to another drug. In order to monitor over time the treatment to targeted therapies, liquid biopsy, that allows the detection in biofluids of either circulating tumor cells (CTCs) or circulating tumor DNA (ctDNA) or exosomes, is increasingly employed in clinical trials: with respect to BM the monitoring of both blood and CSF is necessary. Also, radiomics is being developed to predict the mutational status of the BM on MRI.For patients without druggable mutations or who do not respond to targeted agents, immunotherapy with checkpoint inhibitors is increasingly employed, alone or in combination with radiotherapy. Pseudoprogression after immunotherapy alone maybe a challenge for several months after the start of treatment, and the same is true for radionecrosis after the combination of immunotherapy and SRS. In this regard, the value of advanced MRI techniques and PET imaging for a better distinction of pseudoprogression/radionecrosis and true tumor progression is promising, but needs validation in large prospective datasets. Last, a new frontier in the near future will be chemoprevention (primary and secondary), but we need to identify among solid tumors those subgroups of patients with a higher risk of relapsing into the brain and novel drugs, active on either neoplastic or normal cells of the microenvironment, that are cooperating in the invasion of brain tissue.

Selected ß2-, ß3- and ß2,3-Amino Acid Heterocyclic Derivatives and Their Biological Perspective.

Heterocyclic moieties, especially five and six-membered rings containing nitrogen, oxygen or sulfur atoms, are broadly distributed in nature. Among them, synthetic and natural alike are pharmacologically active compounds and have always been at the forefront of attention due to their pharmacological properties. Heterocycles can be divided into different groups based on the presence of characteristic structural motifs. The presence of ß-amino acid and heterocyclic core in one compound is very interesting; additionally, it very often plays a vital role in their biological activity. Usually, such compounds are not considered to be chemicals containing a ß-amino acid motif; however, considering them as this class of compounds may open new routes of their preparation and application as new drug precursors or even drugs. The possibility of their application as nonproteinogenic amino acid residues in peptide or peptide derivatives synthesis to prepare a new class of compounds is also promising. This review highlights the actual state of knowledge about ß-amino acid moiety-containing heterocycles presenting antiviral, anti-inflammatory, antibacterial compounds, anaplastic lymphoma kinase (ALK) inhibitors, as well as agonist and antagonists of the receptors.

Crizotinib-induced osteitis mimicking bone metastasis in a stage IV ALK-rearranged NSCLC patient: a case report.

BACKGROUND: Targeted therapies are a standard of care for first-line treatment of Anaplastic lymphoma kinase (ALK)-rearranged non small cell lung cancer (NSCLC). Giving the rapid pace of drug discovery and development in this area, reporting of adverse effects of ALK inhibitors is crucial. Here, we report a case of osteitis induced by an ALK inhibitor mimicking bone metastasis, a previously undescribed side effect of crizotinib. CASE PRESENTATION: A 31-year-old woman with stage IV ALK-rearranged NSCLC presented with back pain after 3 months of crizotinib treatment. Diagnostic work-up showed osteitis on the 4th and 5th thoracic vertebrae, anterior soft tissue infiltration and epiduritis, without any sign of infection. Spinal cord decompression, histological removal and osteosynthesis were performed. Histologic examination showed necrosis with abundant peripheral neutrophils, no microorganism nor malignant cell. Symptoms and Computarized Tomography-abnormalities rapidly diseappeared after crizotinib withdrawal and did not recur after ceritinib onset. CONCLUSIONS: This is the first report of crizotinib-induced osteitis. Crizotinib differs from other ALK inhibitors as it targets other kinases as well, which may have been responsible for the osteitis. Crizotinib can induce rapidly extensive osteitis, which can mimic tumor progression.

Novel Multitarget Therapies for Lung Cancer and Respiratory Disease.

In recent years, multitarget drugs for neurological diseases such as Alzheimer's disease have been developed and well researched. Many studies have revealed that multitarget drugs are also useful for lung cancer and respiratory diseases. Pemetrexed is a multitargeted antifolate with strong antitumor activity against mesothelioma and lung adenocarcinoma. Crizotinib is an ATP-competitive tyrosine kinase inhibitor that targets c-MET, ROS1, and ALK. Alectinib is known as an ALK inhibitor but also targets LTK, CHEK2, FLT3, PHKG2, and RET. Sorafenib is a tyrosine kinase inhibitor that targets RAF kinase, KIT, VEGFR, PDGFR1ß, FLT3, and RET. Nintedanib is a multiple tyrosine kinase inhibitor that targets FGFR, PDGFR, and VEGFR. In this review, we summarize the mechanisms of action of multitarget therapies and report the results of the latest clinical trials.

Sarcoid-like reaction mimicking disease progression in an ALK-positive lung cancer patient receiving lorlatinib.

The administration of target inhibitors is paramount to grant the longest survival in patients with ALK-positive non-small cell lung cancer (NSCLC). The eventual resistance to tyrosine kinase inhibitors (TKI) is monitored clinically and radiologically for prompt molecule shift to further generation TKI, if available. However, the early radiological detection of progression pattern (e.g. nodule onset) should be regarded with caution because overlaps exist with non-tumor cell proliferation and/or accumulation. Here we report the case of a stage IV ALK-rearranged NSCLC patient exposed to serial crizotinib, brigatinib, ceritinib, and lorlatinib (this latter brought to complete brain and leptomeningeal disease response), in a period of more than five years. During lorlatinib, the appearance of solid pulmonary nodules was obviously interpreted as disease progression. However, surgical biopsies of the pulmonary nodules revealed features of sarcoid-like granulomatous lymphadenitis, namely without tumor cell. This invasive approach, besides documenting for the first time a sarcoid-like reaction to ALK inhibitors, allowed to revert the radiological diagnosis and maintain lorlatinib, for the best patient outcome. The pragmatic relevance of these findings suggests a careful attitude towards the interpretation of radiologic patterns of disease progression in patients under TKI.

Anaplastic Large Cell Lymphoma: Contemporary Concepts and Optimal Management.

Anaplastic Large Cell Lymphomas (ALCL) are clinically aggressive and pathologically distinct lymphoid neoplasms that originate from a mature post-thymic T-cell. The contemporary World Health Organization (WHO) Classification of Haematologic Malignancies recognizes two distinct subtypes of systemic ALCL: Anaplastic Lymphoma Kinase (ALK)-negative, and ALK-positive. An additional unique subtype of ALCL is known to arise after prolonged exposure to breast implants, known as Breast Implant Associated ALCL (BIALCL). While histologic features of ALCL subtypes have significant overlap, genomic studies suggest the unique pathophysiology and molecular events of tumorigenesis. As a group, ALCLs are rare among non-Hodgkin lymphomas comprising 1-3% overall. There seems to be age and geographic predilection with ALK-positive ALCL affecting younger individuals and being diagnosed more frequently in North America than Europe. Both subtypes are quite uncommon in Hispanic and Asian populations. ALK-positive ALCL patients have a better overall prognosis than those with ALK-negative ALCL, and clinical features at presentation (i.e., International Prognostic Index, IPI) define the outcome in both subtypes. Molecular events affecting DUSP22 and TP63 have been reported to predict survival outcomes as well, with former being favorable, and the latter an unfavorable prognostic marker. Multiagent CHOP-like chemotherapy remains a standard of care for newly diagnosed ALCL patients treated with curative intent and provide a chance of cure for the majority of ALK-positive ALCL patients, and at least half of the ALK-negative ALCL patients. The role of consolidative high-dose therapy and autologous hematopoietic stem cell transplantation remains unclear. Novel targeted agents are actively being investigated for their role in initial therapy. New immunoconjugates, targeted kinase inhibitors, and transgenic autologous T-cells are being studied in patients with relapsed and refractory disease. This review will discuss contemporary concepts in pathogenesis and management of systemic ALCL. The biology and management of primary cutaneous ALCL will be discussed elsewhere.

ALK inhibition in two emblematic cases of pediatric inflammatory myofibroblastic tumor: Efficacy and side effects.

There is an increasing interest for anaplastic lymphoma kinase (ALK) inhibitors in pediatric oncology for specific entities such as ALK-driven inflammatory myofibroblastic tumor (IMT). IMT treatment can be challenging due to localization of the tumor and in rare cases of metastasis. When standard surgical treatment is not feasible, ALK inhibitors may play an important role, as recently reported for the first-generation ALK inhibitors (crizotinib). However, data on the second-generation ALK inhibitors are limited. We report two emblematic cases of IMT in pediatric patients, treated with the second-generation ALK inhibitor ceritinib in the context of a clinical trial (NCT01742286).

Ocular and orbital side effects of ALK inhibitors: a review article.

ALK inhibitors are a new group of tyrosine kinase inhibitors, highly efficient in the treatment of non-small-cell lung carcinoma. However, these targeted therapies can induce various adverse effects, including ocular toxicity. To date, few articles reporting ophthalmological side effects of ALK inhibitors have been published. In this review, we aim to describe the different side effects and to collect information regarding the causes behind the discrepancy between the reported rates of visual disorders. Frequent ocular side effects of ALK inhibitors included flashes, post-flashbulb effect, stripes, photopsia, accommodation disorder, presbyopia, reduced visual acuity and blurred vision. Optic neuropathy, vitreous floaters, diplopia, cataract and macular edema were also reported.

A case report: Pharmacology and resistance patterns of three generations of ALK inhibitors in metastatic inflammatory myofibroblastic sarcoma.

BACKGROUND: Little exists currently in research about the mechanisms of resistance of ALK inhibitors in inflammatory myofibroblastic sarcoma. It is known, however, that ALK gene rearrangements are common in inflammatory myofibroblastic tumors, similar to non-small cell lung cancer. In roughly 50% of inflammatory myofibroblastic tumors, gene rearrangement has been found to occur on chromosome 2 at band 2p23. In non-small cell lung cancer, it has been shown that about a third of patients who progress on the first generation ALK inhibitor, crizotinib develops mutations in the ALK kinase domain. The remaining two-thirds of patients tend to develop amplification of ALK or activation of alternative signaling pathways. Chromoplexy has also been described as a mechanism of resistance, where multiple closed chain rearrangements cause loss-of-function of tumor suppressor genes and gain-in-function of oncogenic fusions. Partner genes that have been identified in IMTs are tropomyosin 3 (TPM3), tropomyosin 4 (TPM4), clathrin heavy chain (CLTC), Ran-binding protein 2 (RANBP2), cysteinyl-tRNA synthetase (CARS), 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (ATIC), and SEC31L1. All are active promoters for the fusion gene, in response to NPM binding. Several inflammatory myofibroblastic tumor case reports indicated that fusion of ALK and RANBP2 led to a more aggressive clinical course. Although the majority of inflammatory myofibroblastic tumor case reports have utilized first and second generation ALK inhibitors, all generations of ALK inhibitors have demonstrated some ability to impair disease progression and extend life expectancy. However, at some point in the course of therapy with each generation of ALK inhibitor, resistance ultimately developed. In order to better understand the pharmacology and resistance patterns behind three generations of ALK inhibitors, we sought to examine a patient with metastatic anaplastic lymphoma kinase-1-rearranged inflammatory myofibroblastic sarcoma to the brain. We also explored the similarities and differences of this clinical case to other inflammatory myofibroblastic sarcoma case reports involving the use of ALK inhibitors. CASE REPORT: A rare case of pulmonary IMS with ALK-1 gene rearrangement and multiple brain metastases responded to three generations of ALK inhibitors. However, similar to other case reports, due to the development of resistance and recurrence, the patient eventually succumbed to the disease. CONCLUSIONS: ALK inhibitors are beneficial in the temporary prevention of progression of disease in patients with inflammatory myofibroblastic tumors. In this case, due to the inability to reveal the fusion partner in this patient via DNA sequencing, it is unknown exactly if that partner was RANBP2 or another ALK partner gene. Brain biopsy tissue was also unobtainable during sequence of ALK due to risk versus benefit, which would have provided insight as which type of ALK resistance mutations the patient was developing. It is likely that this patient had some form of chromoplexy occurring.

Highly sensitive detection of ALK resistance mutations in plasma using droplet digital PCR.

BACKGROUND: On-target resistance mechanisms found in one-third of patients receiving anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) are secondary ALK mutations in ALK-rearranged non-small cell lung cancer (NSCLC). There are large variations in the resistant mutations, unlike the epithelial growth factor receptor (EGFR) T790 M seen with the use of EGFR-TKIs. Liquid biopsy approaches using cell-free DNA (cfDNA) are used for screening and monitoring of mutations in NSCLC. However, feasible protocol for the simultaneous detection of multiple secondary ALK mutations using droplet digital PCR (ddPCR) has not been developed. An efficient strategy using cfDNA in cancer diagnostics, the development of more accurate and cost-effective tools to identify informative multiple secondary ALK mutations is clinically required. METHODS: To establish a feasible assay to monitor ALK-TKI resistance mutations, we first evaluated the feasibility of ddPCR-based screening for cfDNA mutation detection of 10 distinct secondary ALK mutations. Positive samples were then re-analyzed using mutation-specific probes to track the growth of mutation clones with a high sensitivity. RESULTS: Blood samples from seven ALK-positive patients were analyzed using the ddPCR protocol. Secondary G1202R ALK mutations were identified in 2 of 7 patients by the screening assay. Using the mutation-specific probes, monitoring the resistant clone during the clinical course of the disease was well demonstrated in each of the patients. CONCLUSION: The protocol for ddPCR-based liquid biopsy has a feasibility for the screening of secondary ALK-TKI resistance mutations and offers a tool for a cost-effective monitoring of progression in NSCLC.

Evolution in the treatment landscape of non-small cell lung cancer with ALK gene alterations: from the first- to third-generation of ALK inhibitors.

INTRODUCTION: The medical treatment of non-small cell lung cancer (NSCLC) has radically changed over the last 10 years thanks to new molecular-targeted drugs able to act on biological mechanisms involved in tumor development. One such mechanism is the aberrant anaplastic lymphoma kinase (ALK) activation: patients with ALK-driven NSCLC benefit from treatments that selectively inhibit its pathogenetic mechanism. Areas covered: The first-generation ALK inhibitor is crizotinib, initially used in Europe as second-line treatment for ALK-positive metastatic NSCLC patients, then approved as the standard first-line (already approved in the USA as front-line therapy). However, most patients eventually experience disease progression due to the emergence of secondary resistance, partly linked to ALK-dependent mechanisms, hence the development of second- and third-generation ALK inhibitors: ceritinib, alectinib, and brigatinib are approved for ALK-positive NSCLC, lorlatinib is currently being evaluated while others are under development. Expert opinion: Despite the considerable responses to these new inhibitors, however, resistance mechanisms are described. Thus, while the therapeutic scenario of NSCLC has been soon revolutionized introducing next-generation ALK inhibitors in the first-line setting, future research should identify combined therapies or new generation drugs overcoming resistance in pretreated patients.