Mechanisms of acquired crizotinib resistance in ALK-rearranged lung Cancers

Novel ALK mutation with durable response to brigatinib-a case report

Anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors are the preferred initial treatment for ALK rearranged non-small cell lung cancer (NSCLC). While initial responses to next-generation inhibitors are robust, acquired resistance is expected for nearly all patients. Resistance is often mediated by point mutations along the solvent front. Use of the acquired mutational profile to guide therapy is still investigational and largely based on preclinical data demonstrating sensitivity of resistant cell lines to available kinase inhibitors. Here, we describe outcomes after development of an ALK L1196Q mutation. We present a patient with stage IV ALK rearranged lung cancer received who received first line crizotinib at 250 mg twice daily, then at progression, second line alectinib at 600 mg twice daily. When radiographic evidence of progression was noted, a biopsy was performed. Next generation sequencing (NGS) identified an acquired ALK L1196Q mutation. The patient was treated with third line brigatinib, at 90 mg daily and escalating to 180 mg daily, and achieved a partial response that is still ongoing, one year later. We highlight false-negative ALK mutation results when only plasma is used, particularly in early metastatic disease. We also discuss how the use of specific ALK resistance mutations to guide therapy is clinically relevant is being investigated.

Inflammatory Myofibroblastic Tumor of the Bladder With FN1-ALK Gene Fusion: Different Response to ALK Inhibition

Inflammatory myofibroblastic tumors are rare tumors with an ALK (anaplastic lymphoma kinase) gene rearrangement in up to 65% of all cases. In our patient, the tumor was not primary resectable due to its extension. Under neoadjuvant treatment with the first generation ALK inhibitor crizotinib no tumor response was seen, but the following therapy with the next generation ALK inhibitor lorlatinib led to a rapid and deep response, enabling a complete tumor resection by partial cystectomy. Our case indicates that ALK positive inflammatory myofibroblastic tumors which do not respond to ALK inhibition with crizotinib can be successfully treated with newer agents.

Brigatinib in ALK-positive non-small cell lung cancer: real-world data in the Latin American population (Bri-world extend CLICaP)

Background: Brigatinib has demonstrated its efficacy as first-line therapy and in further lines for ALK-positive non-small cell lung cancer (NSCLC) patients; however, real-world data in Latin America are scarce. Methods: From January 2018 to March 2020, 46 patients with advanced ALK-positive NSCLC received brigatinib as second or further line of therapy in Mexico and Colombia. The primary end point was progression-free survival (PFS); secondary end point was time to treatment discontinuation (TTD). Results: At a median follow-up of 9.3 months, the median PFS was 15.2 months (95% CI: 11.6-18.8), and TTD was 18.46 months (95% CI: 9.54-27.38). The estimated overall survival at 12 months was 80%. Safety profile was consistent with previously published data. Conclusion: Brigatinib is an effective treatment for previously treated ALK-positive NSCLC patients in a real-world setting.

Molecular Mechanisms and Targeted Therapies Including Immunotherapy for Non-Small Cell Lung Cancer

Lung cancer is the leading cause of cancer death worldwide. Molecular targeted therapy has greatly advanced the field of treatment for non-small cell lung cancer (NSCLC), which accounts for the majority of lung cancers. Indeed, gefitinib, which was the first molecular targeted therapeutic agent, has actually doubled the survival time of NSCLC patients. Vigorous efforts of clinicians and researchers have revealed that lung cancer develops through the activating mutations of many driver genes including the epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1), v-Raf murine sarcoma viral oncogene homolog B (BRAF), and rearranged during transfection (RET) genes. Although ALK, ROS1, and RET are rare genetic abnormalities, corresponding tyrosine kinase inhibitors (TKIs) can exert dramatic therapeutic effects. In addition to anticancer drugs targeting driver genes, bevacizumab specifically binds to human vascular endothelial growth factor (VEGF) and blocks the VEGF signaling pathway. The VEGF signal blockade suppresses angiogenesis in tumor tissues and inhibits tumor growth. In this review, we also explore immunotherapy, which is a promising new NSCLC treatment approach. In general, antitumor immune responses are suppressed in cancer patients, and cancer cells escape from the immune surveillance mechanism. Immune checkpoint inhibitors (ICIs) are antibodies that target the primary escape mechanisms, immune checkpoints. Patients who respond to ICIs are reported to experience longlasting therapeutic effects. A wide range of clinical approaches, including combination therapy involving chemotherapy or radiation plus adjuvant therapy, are being developed.

Treatment of ALK-rearranged non-small-cell lung cancer with brigatinib as second or later lines: real-world observations from a single institution

The second-generation ALK tyrosine kinase inhibitor brigatinib has recently been approved in the European Union for use after crizotinib treatment in patients with EML4-ALK-rearranged lung cancer. In the current study, brigatinib was investigated as second-line or later-line treatment in 35 patients who had developed resistance to crizotinib, ceritinib, or alectinib. Most patients (68.6%) received brigatinib as second or third line (range: second to 12th line). In the total cohort, complete and partial responses were obtained for 9.1 and 75.8%, respectively. Overall median progression-free survival was 9.9 months, whereas the largest treatment cohort (brigatinib after crizotinib failure) showed a median progression-free survival of 8.4 months. Fifty-four percent of patients with baseline brain metastases responded to brigatinib treatment. Brigatinib was highly effective after crizotinib and ceritinib failure. Six patients had received alectinib as monotherapy, second-line, or third line before brigatinib; of these, four experienced partial responses and two progressed responses. Brigatinib treatment was well tolerated.

Emerging MET tyrosine kinase inhibitors for the treatment of non-small cell lung cancer

Introduction MET aberrations, including MET exon 14 skipping mutation and amplification, are present in ~5% of non-small cell lung cancer (NSCLC) cases, and these levels are comparable to the frequency of ALK fusion. MET amplification also occurs as an acquired resistance mechanism in EGFR-mutated NSCLC after EGFR tyrosine kinase inhibitors (TKI) treatment failure. Therefore, the development of therapies for activated MET is urgently needed. Areas covered This review summarizes (1) the mechanisms and frequencies of MET aberrations in NSCLC, (2) the efficacies and toxicities of MET-TKIs under clinical development and (3) the mechanisms of inherent and acquired resistance to MET-TKIs. Expert opinion Type Ia, Ib and II MET-TKIs are currently under clinical development, and phase I/II studies have shown the potent activities of tepotinib, capmatinib and savolitinib; in fact, tepotinib and capmatinib were approved for use by health authorities. However, inherent and acquired resistance through on- and off-target mechanisms has been detected, and strategies to overcome this resistance are being developed.

Molecular Pathology of Primary Non-small Cell Lung Cancer

Lung carcinoma is one of the most common human cancers and is estimated to have an incidence of approximately 2 million new cases per year worldwide with a 20% mortality rate. Lung cancer represents one of the leading causes of cancer related death in the world. Of all cancer types to affect the pulmonary system, non-small cell lung carcinoma comprises approximately 80-85% of all tumors. In the past few decades cytogenetic and advanced molecular techniques have helped define the genomic landscape of lung cancer, and in the process, revolutionized the clinical management and treatment of patients with advanced non-small cell lung cancer. The discovery of specific, recurrent genetic abnormalities has led to the development of targeted therapies that have extended the life expectancy of patients who develop carcinoma of the lungs. Patients are now routinely treated with targeted therapies based on identifiable molecular alterations or other predictive biomarkers which has led to a revolution in the field of pulmonary pathology and oncology. Numerous different testing modalities, with various strengths and limitations now exist which complicate diagnostic algorithms, however recently emerging consensus guidelines and recommendations have begun to standardize the way to approach diagnostic testing of lung carcinoma. Herein we provide an overview of the molecular genetic landscape of non-small cell lung carcinoma, with attention to those clinically relevant alterations which drive management, as well as review current recommendations for molecular testing.

Making NSCLC Crystal Clear: How Kinase Structures Revolutionized Lung Cancer Treatment

The parallel advances of different scientific fields provide a contemporary scenario where collaboration is not a differential, but actually a requirement. In this context, crystallography has had a major contribution on the medical sciences, providing a “face” for targets of diseases that previously were known solely by name or sequence. Worldwide, cancer still leads the number of annual deaths, with 9.6 million associated deaths, with a major contribution from lung cancer and its 1.7 million deaths. Since the relationship between cancer and kinases was unraveled, these proteins have been extensively explored and became associated with drugs that later attained blockbuster status. Crystallographic structures of kinases related to lung cancer and their developed and marketed drugs provided insight on their conformation in the absence or presence of small molecules. Notwithstanding, these structures were also of service once the initially highly successful drugs started to lose their effectiveness in the emergence of mutations. This review focuses on a subclassification of lung cancer, non-small cell lung cancer (NSCLC), and major oncogenic driver mutations in kinases, and how crystallographic structures can be used, not only to provide awareness of the function and inhibition of these mutations, but also how these structures can be used in further computational studies aiming at addressing these novel mutations in the field of personalized medicine.

Brigatinib Versus Crizotinib in Advanced ALK Inhibitor-Naive ALK-Positive Non-Small Cell Lung Cancer: Second Interim Analysis of the Phase III ALTA-1L Trial

Brigatinib, a next-generation anaplastic lymphoma kinase (ALK) inhibitor, demonstrated superior progression-free survival (PFS) and improved health-related quality of life (QoL) versus crizotinib in advanced ALK inhibitor–naive ALK-positive non–small cell lung cancer (NSCLC) at first interim analysis (99 events; median brigatinib follow-up, 11.0 months) in the open-label, phase III ALTA-1L trial (ClinicalTrials.gov identifier: NCT02737501). We report results of the second prespecified interim analysis (150 events).

Squamous Cell Transformation of Primary Lung Adenocarcinoma in a Patient With EML4-ALK Fusion Variant 5 Refractory to ALK Inhibitors

Histologic transformation from adenocarcinoma to squamous cell carcinoma in lung cancer has not been reported as a mechanism of resistance to ALK inhibition. This report describes the clinical course of a female former light smoker with metastatic lung adenocarcinoma whose tumor underwent histologic transformation from a well-differentiated lung adenocarcinoma to a well-differentiated lung squamous cell carcinoma in the same location at the left mainstem bronchus while maintaining the ALK fusion oncogene without any resistance mutations. After experiencing disease progression while on crizotinib, the patient participated in clinical trials that provided early access to the novel ALK inhibitors ceritinib and alectinib before they were commercially available. Tumor recurrence occurred at the primary and metastatic central nervous system sites (ie, brain and spine). At tumor progression, liquid biopsy and tumor genomic profiling of plasma cell-free DNA next-generation sequencing (NGS) provided an accurate diagnosis with a short turnaround time compared with the tissue-based targeted capture NGS. The patient received several courses of radiation primarily to the brain and spine during her disease course. Her disease did not respond to the immune checkpoint inhibitor nivolumab, and she died on home hospice approximately 4 years after diagnosis. This case supports the importance of both histopathologic assessment and comprehensive genomic profiling in selecting appropriate treatment for patients with refractory, metastatic, ALK oncogene-driven non-small cell lung cancer. Use of symptom-directed radiation in tandem with ALK inhibitors contributed to the disease and symptomatic control and prolonged survival in this patient.

Applications of liquid biopsies for cancer

Liquid biopsies have the potential to detect, characterize, and monitor cancers earlier than is possible with conventional approaches.

Chemical strategies to overcome resistance against targeted anticancer therapeutics

Emergence of resistance is a major factor limiting the efficacy of molecularly targeted anticancer drugs. Understanding the specific mutations, or other genetic or cellular changes, that confer drug resistance can help in the development of therapeutic strategies with improved efficacies. Here, we outline recent progress in understanding chemotype-specific mechanisms of resistance and present chemical strategies, such as designing drugs with distinct binding modes or using proteolysis targeting chimeras, to overcome resistance. We also discuss how targeting multiple binding sites with bifunctional inhibitors or identifying collateral sensitivity profiles can be exploited to limit the emergence of resistance. Finally, we highlight how incorporating analyses of resistance early in drug development can help with the design and evaluation of therapeutics that can have long-term benefits for patients.

Vulnerability of drug-resistant EML4-ALK rearranged lung cancer to transcriptional inhibition

A subset of lung adenocarcinomas is driven by the EML4-ALK translocation. Even though ALK inhibitors in the clinic lead to excellent initial responses, acquired resistance to these inhibitors due to on-target mutations or parallel pathway alterations is a major clinical challenge. Exploring these mechanisms of resistance, we found that EML4-ALK cells parental or resistant to crizotinib, ceritinib or alectinib are remarkably sensitive to inhibition of CDK7/12 with THZ1 and CDK9 with alvocidib or dinaciclib. These compounds robustly induce apoptosis through transcriptional inhibition and downregulation of anti-apoptotic genes. Importantly, alvocidib reduced tumour progression in xenograft mouse models. In summary, our study takes advantage of the transcriptional addiction hypothesis to propose a new treatment strategy for a subset of patients with acquired resistance to first-, second- and third-generation ALK inhibitors.

Treatment Sequencing in Patients with Anaplastic Lymphoma Kinase-Positive Non-Small Cell Lung Cancer in Japan: A Real-World Observational Study

INTRODUCTION

The anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI) alectinib was approved in Japan in 2014 for the treatment of ALK fusion gene-positive advanced non-small cell lung cancer (NSCLC). With the approvals of crizotinib in 2012 and ceritinib in 2017, Japan became the first country with multiple ALK TKIs available for first-line or later use in patients with ALK-positive advanced NSCLC. Here, we collected and evaluated real-world data on ALK TKI clinical usage patterns and sequencing in patients with ALK-positive NSCLC in Japan.

METHODS

This retrospective observational study used the Japanese Medical Data Vision database to analyze data from patients with a confirmed diagnosis of lung cancer who visited a healthcare facility in the database between April 2010 and March 2017, underwent an ALK test, received a prescription for an ALK TKI, and were at least 18 years old as of the date of the first ALK TKI prescription. There were no exclusion criteria. Descriptive analyses of demographics, baseline characteristics, ALK TKI treatment patterns and sequences, non-ALK TKI treatments received before, during, and after ALK TKI treatment, and treatment durations were reported.

RESULTS

A total of 378 patients met the inclusion criteria and were evaluated in mutually exclusive groups of patients receiving one, two, or three ALK TKIs. The initial ALK TKI prescribed was crizotinib for 52.1% of patients and alectinib for 47.9% of patients; however, the proportion of patients receiving alectinib as the initial ALK TKI increased over time following the Japanese approval of alectinib in 2014. Of the 117 patients who received two or three ALK TKIs, 106 received crizotinib as the first ALK TKI and 11 received alectinib. Before the date of the patient's first ALK TKI prescription, 153 of 378 patients (40.5%) had received chemotherapy. Of 104 patients who discontinued ALK therapy, 46.2% received chemotherapy and 5.8% received immunotherapy as their next treatment.

CONCLUSION

At the time of this analysis, most patients who received more than one ALK TKI received crizotinib as the initial ALK TKI. Additional ALK TKIs have since been approved in Japan as first-line or later therapeutic options for patients with ALK-positive NSCLC, but the optimal sequence of ALK TKI usage remains undetermined. As new data continue to emerge, additional research will be warranted to evaluate ALK TKI sequences that do not include crizotinib as the first therapy in this patient population.

Non-Small Cell Lung Cancer from Genomics to Therapeutics: A Framework for Community Practice Integration to Arrive at Personalized Therapy Strategies

Non-small cell lung cancer (NSCLC) is a heterogeneous disease, and therapeutic management has advanced with the identification of various key oncogenic mutations that promote lung cancer tumorigenesis. Subsequent studies have developed targeted therapies against these oncogenes in the hope of personalizing therapy based on the molecular genomics of the tumor. This review presents approved treatments against actionable mutations in NSCLC as well as promising targets and therapies. We also discuss the current status of molecular testing practices in community oncology sites that would help to direct oncologists in lung cancer decision-making. We propose a collaborative framework between community practice and academic sites that can help improve the utilization of personalized strategies in the community, through incorporation of increased testing rates, virtual molecular tumor boards, vendor-based oncology clinical pathways, and an academic-type singular electronic health record system.

Technology-enabled assessments to enhance multiple sclerosis clinical care and research

BACKGROUND

Comprehensive and efficient assessments are necessary for clinical care and research in chronic diseases. Our objective was to assess the implementation of a technology-enabled tool in MS practice.

METHOD

We analyzed prospectively collected longitudinal data from routine multiple sclerosis (MS) visits between September 2015 and May 2018. The MS Performance Test, comprising patient-reported outcome measures (PROMs) and neuroperformance tests (NPTs) self-administered using a tablet, was integrated into routine care. Descriptive statistics, Spearman correlations, and linear mixed-effect models were used to examine the implementation process and relationship between patient characteristics and completion of assessments.

RESULTS

A total of 8022 follow-up visits from 4199 patients (median age 49.9 [40.2-58.8] years, 32.1% progressive course, and median disease duration 13.6 [5.9-22.3] years) were analyzed. By the end of integration, the tablet version of the Timed 25-Foot Walk was obtained in 89.0% of patients and the 9-Hole Peg Test in 94.8% compared with 74.2% and 64.3%, respectively before implementation. The greatest increase in data capture occurred in processing speed and low-contrast acuity assessments (0% prior vs 78.4% and 36.7%, respectively, following implementation). Four PROMs were administered in 41%-98% of patients compared with a single depression questionnaire with a previous capture rate of 70.6%. Completion rates and time required to complete each NPT improved with subsequent visits. Younger age and lower disability scores were associated with shorter completion time and higher completion rates.

CONCLUSIONS

Integration of technology-enabled data capture in routine clinical practice allows acquisition of comprehensive standardized data for use in patient care and clinical research.

Consensus Recommendations for Management and Counseling of Adverse Events Associated With Lorlatinib: A Guide for Healthcare Practitioners

Resistance to first- and second-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) and development and progression of central nervous system metastases remain significant issues in the treatment of ALK-positive non-small-cell lung cancer. Lorlatinib is a novel third-generation ALK TKI that is able to penetrate the blood-brain barrier and has broad-spectrum potency against most known resistance mutations that can develop during treatment with crizotinib and second-generation ALK TKIs. The safety profile of lorlatinib is distinct from those of other ALK TKIs. Adverse events are typically mild to moderate in severity, seldom result in permanent discontinuations, and are generally manageable through lorlatinib dose modifications and/or standard medical therapy. This article provides guidance to advanced practice providers (e.g., nurses, nurse practitioners, physician assistants) and oncology pharmacists for the clinical management of key lorlatinib-emergent adverse reactions (i.e., hyperlipidemias, central nervous system effects, bodyweight increase, edema, and peripheral neuropathy). As lorlatinib is both a substrate and inducer of the CYP3A enzyme system and is contraindicated with strong CYP3A inducers, relevant drug-drug interactions are also highlighted.

BRAF V600E mutation and MET amplification as resistance pathways of the second-generation anaplastic lymphoma kinase (ALK) inhibitor alectinib in lung cancer

BACKGROUND

Anaplastic lymphoma kinase (ALK) targeted therapies have demonstrated remarkable efficacy in ALK-positive lung adenocarcinomas. However, patients inevitably develop resistance to such therapies. To investigate novel mechanisms of resistance to second generation ALK inhibitors, we characterized and modeled ALK inhibitor resistance of ALK-positive patient-derived xenograft (PDX) models established from advanced-stage lung adenocarcinoma patients who have progressed on one or more ALK inhibitors.

METHODS

Whole exome sequencing was performed to identify resistance mechanisms to ALK inhibitors in PDXs generated from biopsies at the time of relapse. ALK fusion status was confirmed using fluorescent in situ hybridization, immunohistochemistry, RNA-sequencing, RT-qPCR and western blot. Targeted therapies to overcome acquired resistance were then tested on the PDX models.

RESULTS

Three PDX models were successfully established from biopsies of two patients who had progressed on crizotinib and/or alectinib. The PDX models recapitulated the histology and ALK status of their patient tumors, as well as their matched patients' clinical treatment outcome to ALK inhibitors. Whole exome sequencing identified MET amplification and previously unreported BRAF V600E mutation as independent mechanisms of resistance to alectinib. Importantly, PDX treatment of inhibitors specific for these targets combined with ALK inhibitor overcame resistance.

CONCLUSIONS

Bypass signaling pathway through c-MET and BRAF are independent mechanisms of resistance to alectinib. Individualized intervention against these resistance pathways could be viable therapeutic options in alectinib-refractory lung adenocarcinoma.

RET kinase alterations in targeted cancer therapy

The rearranged during transfection (RET) gene encodes a protein tyrosine kinase. RET alterations by point mutations and gene fusions were found in diverse cancers. RET fusions allow abnormal expression and activation of the oncogenic kinase, whereas only a few of RET point mutations found in human cancers are known oncogenic drivers. Earlier studies of RET-targeted therapy utilized multi-targeted protein tyrosine kinase inhibitors (TKIs) with RET inhibitor activity. These multi-targeted TKIs often led to high-grade adverse events and were subject to resistance caused by the gatekeeper mutations. Recently, two potent and selective RET TKIs, pralsetinib (BLU-667) and selpercatinib (LOXO-292), were developed. High response rates to these selective RET inhibitors across multiple forms of RET alterations in different types of cancers were observed in clinical trials, demonstrating the RET dependence in human cancers harboring these RET lesions. Pralsetinib and selpercatinib were effective in inhibiting RETV804L/M gatekeeper mutants. However, adaptive mutations that cause resistance to pralsetinib or selpercatinib at the solvent front RETG810 residue have been found, pointing to the need for the development of the next-generation of RET TKIs.

The Genomic Characteristics of ALK Fusion Positive Tumors in Chinese NSCLC Patients

Anaplastic lymphoma kinase (ALK) fusion events account for ~3–7% genetic alterations in patients with non-small cell lung cancer (NSCLC). In this study, we identified the ALK fusion patterns and a novel ALK fusion partner in 44 ALK positive NSCLC patients using a customized HapOncoCDx panel, and identified ALK fusion partners. The most common partner is EML4, forming the variant 1 (v1, E13:A20, 18/44), variant 2 (v2, E20:A20, 5/44), and variant 3 (v3, E6:A20, 13/44). Moreover, we detected a new ALK fusion partner HMBOX1. At the mutation level, TP53 is the most frequently mutated gene (24%), followed by ALK (12%) and STED2 (12%). The median tumor mutation burden (TMB) of these samples is 2.29 mutations/Mb, ranging from 0.76 mut/Mb to 16.79 muts/Mb. We further elaborately portrayed the TP53 mutation sites on the peptide sequence of the encoded protein by lollipop. The mutational signature and copy number alterations (CNAs) of the samples were also analyzed. The CNA events were found in 13 (13/44) patients, and the most commonly amplified genes were MDM2 (n = 4/13) and TERT (n = 4/13). Together, these results may guide personalized clinical management of patients with ALK fusion in the era of precision medicine.

Targeting the HGF/MET Axis in Cancer Therapy: Challenges in Resistance and Opportunities for Improvement

Among hundreds of thousands of signal receptors contributing to oncogenic activation, tumorigenesis, and metastasis, the hepatocyte growth factor (HGF) receptor - also called tyrosine kinase MET - is a promising target in cancer therapy as its axis is involved in several different cancer types. It is also associated with poor outcomes and is involved in the development of therapeutic resistance. Several HGF/MET-neutralizing antibodies and MET kinase-specific small molecule inhibitors have been developed, resulting in some context-dependent progress in multiple cancer treatments. Nevertheless, the concomitant therapeutic resistance largely inhibits the translation of such targeted drug candidates into clinical application. Until now, numerous studies have been performed to understand the molecular, cellular, and upstream mechanisms that regulate HGF/MET-targeted drug resistance, further explore novel strategies to reduce the occurrence of resistance, and improve therapeutic efficacy after resistance. Intriguingly, emerging evidence has revealed that, in addition to its conventional function as an oncogene, the HGF/MET axis stands at the crossroads of tumor autophagy, immunity, and microenvironment. Based on current progress, this review summarizes the current challenges and simultaneously proposes future opportunities for HGF/MET targeting for therapeutic cancer interventions.

Molecular mechanisms of resistance to BRAF and MEK inhibitors in BRAFV600E non-small cell lung cancer

INTRODUCTION

BRAF is a confirmed therapeutic target in non-small cell lung cancer (NSCLC), as the BRAF inhibitor dabrafenib, in combination with the MEK inhibitor trametinib, is approved for the treatment of NSCLC harbouring BRAF V600E mutation. Scant evidence is available concerning the mechanisms of resistance to BRAF/MEK inhibitors in BRAF^V600E NSCLC.

PATIENTS AND METHODS

Patients with BRAF^V600E NSCLC with acquired resistance to BRAF/MEK inhibitors were included in the institutional, prospective MATCH-R (from "Matching Resistance") trial and underwent tumour and liquid biopsies at the moment of radiological progression. Extensive molecular analyses were performed, including targeted next-generation sequencing (NGS), whole-exome sequencing (WES), RNA sequencing and comparative genomic hybridisation (CGH) array.

RESULTS

Of the 11 patients included, eight had progressed on dabrafenib-trametinib combination, two on dabrafenib monotherapy and one on vemurafenib (BRAF inhibitor). Complete molecular analyses were available for seven patients, whereas an additional case had only targeted NGS and CGH array data. Among these eight patients, acquired molecular events potentially responsible for resistance were detected in three who progressed on dabrafenib-trametinib combination, that is, MEK1 K57N, RAS viral (v-ras) oncogene homolog (NRAS) Q61R and rat sarcoma viral oncogene homolog (KRAS) Q61R mutations. One patient progressing on dabrafenib monotherapy developed a PTEN frameshift mutation. No molecular hints addressing resistance emerged in the remaining four patients with analyses performed. Tumour mutational burden, evaluated by WES in seven patients, was low (median = 2.06 mutations/megabase, range = 1.57-3.75 mut/Mb).

CONCLUSIONS

Novel resistance mechanisms to BRAF/MEK inhibitors in BRAF^V600E NSCLC were identified, pointing out the recurring involvement of the MAPK pathway and guiding the development of new treatment strategies.

Efficacy and safety of ceritinib in anaplastic lymphoma kinase-rearranged non-small cell lung cancer: A systematic review and meta-analysis

What is known and objective

Ceritinib is a new, oral, potent and selective second‐generation anaplastic lymphoma kinase (ALK) inhibitor approved by the Food and Drug Administration of the United States in April 2014. It is active in crizotinib‐resistant patients, especially in patients with non‐small cell lung cancer (NSCLC) and brain metastasis. The aim of this study was to analyse the effects and side effects of ceritinib in ALK‐rearranged NSCLC.

Methods

We searched articles published from January 1980 to March 2019 in PubMed, EMBASE, Cochrane Library and Web of Science. The pooled estimate and 95% CI were calculated with DerSimonian‐Laird method and the random effect model.

Results and discussion

From 15 articles, 2,598 patients were included in the meta‐analysis. Eleven studies reported the ORR, and the DCR was presented in 10 studies. The ORR and DCR of ceritinib were 0.48 (95% CI, 0.39‐0.57) and 0.76 (95% CI, 0.69‐0.82), respectively. The PFS and OS were presented in nine and three eligible studies, respectively. The PFS and OS of ceritinib were 7.26 months (95% CI, 5.10‐9.43) and 18.73 months (95% CI; 14.59‐22.87). These results suggested that ceritinib can effectively treat patients with ALK‐rearranged NSCLC. Diarrhoea, nausea and vomiting were the three most common AEs and occurred in 69% (95% CI 51.7‐87.1%), 66% (95% CI 47.0‐85.8%) and 51% (95% CI 35.9‐66.8%) of patients, respectively. Considering serious gastrointestinal AEs, antiemetic and antidiarrhoeal drugs should be considered to improve a patient's tolerance to ceritinib.

What is new and conclusion

Ceritinib is effective in the treatment of patients with ALK‐rearranged NSCLC with crizotinib resistance. The DCR was up to 76%, and PFS was extended to 7.6 months. The AEs were acceptable.

Real-world treatment duration in ALK-positive non-small-cell lung cancer patients receiving brigatinib through the early access program

Aim: To assess time-to-treatment discontinuation (TTD) of brigatinib following treatment with ALK tyrosine kinase inhibitor(s) (TKIs) in patients with ALK-positive (ALK+) non-small-cell lung cancer (NSCLC) receiving brigatinib through the international early access program. Patients & analysis: Analysis was performed for patients with ALK+ NSCLC treated with prior ALK TKIs, including next-generation ALK TKIs. Results: Data for 604 patients (21 countries), including patients with prior next-generation ALK TKIs, were reported. The median TTD of brigatinib in patients with prior crizotinib, alectinib, ceritinib or lorlatinib was 10.0, 8.7, 10.3 and 7.5 months, respectively. Conclusion: Brigatinib appears to be effective and tolerable in real-world clinical practice regardless of prior treatment with first or NG ALK TKIs.

Revealing Acquired Resistance Mechanisms of Kinase-Targeted Drugs Using an on-the-Fly, Function-Site Interaction Fingerprint Approach

Although kinase-targeted drugs have achieved significant clinical success, they are frequently subject to the limitations of drug resistance, which has become a primary vulnerability to targeted drug therapy. Therefore, deciphering resistance mechanisms is an important step in designing more efficacious, antiresistant drugs. Here we studied two FDA-approved kinase drugs: Crizotinib and Ceritinib, which are first- and second-generation anaplastic lymphoma kinase (ALK) targeted inhibitors, to unravel drug-resistance mechanisms. We used an on-the-fly, function-site interaction fingerprint (on-the-fly Fs-IFP) approach, combining binding free-energy surface calculations with the Fs-IFPs. Establishing the potentials of mean force and monitoring the atomic-scale protein-ligand interactions, before and after L1196M-induced drug resistance, revealed insights into drug-resistance/antiresistant mechanisms. Crizotinib prefers to bind the wild-type ALK kinase domain, whereas Ceritinib binds more favorably to the mutated ALK kinase domain, in agreement with experimental results. We determined that ALK kinase-drug interactions in the region of the front pocket are associated with drug resistance. Additionally, we find that the L1196M mutation does not simply alter the binding modes of inhibitors but also affects the flexibility of the entire ALK kinase domain. Our work provides an understanding of the mechanisms of ALK drug resistance, confirms the usefulness of the on-the-fly Fs-IFP approach, and provides a practical paradigm to study drug-resistance mechanisms in prospective drug discovery.

ALK Inhibitors-Induced M Phase Delay Contributes to the Suppression of Cell Proliferation

Anaplastic lymphoma kinase (ALK), a receptor-type tyrosine kinase, is involved in the pathogenesis of several cancers. ALK has been targeted with small molecule inhibitors for the treatment of different cancers, but absolute success remains elusive. In the present study, the effects of ALK inhibitors on M phase progression were evaluated. Crizotinib, ceritinib, and TAE684 suppressed proliferation of neuroblastoma SH-SY5Y cells in a concentration-dependent manner. At approximate IC₅₀ concentrations, these inhibitors caused misorientation of spindles, misalignment of chromosomes and reduction in autophosphorylation. Similarly, knockdown of ALK caused M phase delay, which was rescued by re-expression of ALK. Time-lapse imaging revealed that anaphase onset was delayed. The monopolar spindle 1 (MPS1) inhibitor, AZ3146, and MAD2 knockdown led to a release from inhibitor-induced M phase delay, suggesting that spindle assembly checkpoint may be activated in ALK-inhibited cells. H2228 human lung carcinoma cells that express EML4-ALK fusion showed M phase delay in the presence of TAE684 at about IC₅₀ concentrations. These results suggest that ALK plays a role in M phase regulation and ALK inhibition may contribute to the suppression of cell proliferation in ALK-expressing cancer cells.

HDAC inhibition synergizes with ALK inhibitors to overcome resistance in a novel ALK mutated lung adenocarcinoma model

OBJECTIVES

Somatic chromosomal rearrangements resulting in ALK fusion oncogenes are observed in 3-7 % of lung adenocarcinomas. ALK tyrosine kinase inhibitors (ALKi) induce initially response, however, various resistance mechanisms limit their efficacy. Novel therapeutic approaches are of utmost importance to tailor these targeted therapies.

MATERIALS AND METHODS

A synchronous ALK-rearranged and mutated lung cancer cell line pair was established from malignant pleural effusion (PF240-PE) and carcinosis (PF240-PC) at time of ALKi resistance. Immunohistochemistry, FISH and sequencing were performed in pre- and post-treatment tumors and in both cell lines. Differentiation markers were measured by immunoblot. Viability was tested following treatment with ALKi and/or a pan-HDAC inhibitor. Additionally, a novel treatment-naïve ALK-rearranged cell line served as control. In vivo tumorigenicity was evaluated in subcutaneous xenografts.

RESULTS

Two distinct resistance mutations were identified in different carcinosis tissues at time of resistance, the previously described resistance mutation L1152R and the hitherto uncharacterized E1161K. Strikingly, PF240-PC cells carried E1161K and PF240-PE cells harbored L1152R. Immunohistochemistry and immunoblot identified epithelial-to-mesenchymal transition markers upregulated following ALKi resistance development both in carcinosis tissues and cell lines. While both lines grew as xenografts, they differed in morphology, migration, in vivo growth and sensitivity to ALKi in vitro. Strikingly, the combination of ALKi with SAHA yielded strong synergism.

CONCLUSION

Using a patient-derived ALKi resistant lung cancer model we demonstrated the synergism of HDAC and ALK inhibition. Furthermore, our findings provide strong evidence for intratumoral heterogeneity under targeted therapy and highlight the importance of site-specific mutational analysis.

Prognostic value of TP53 concurrent mutations for EGFR- TKIs and ALK-TKIs based targeted therapy in advanced non-small cell lung cancer: a meta-analysis

Background

The prognostic significance of TP53 concurrent mutations in patients with epidermal growth factor receptor (EGFR)- or anaplastic lymphoma kinase (ALK)- mutated advanced non–small-cell lung cancer (NSCLC) who received EGFR-tyrosine kinase inhibitors (TKIs) or ALK-TKIs based targeted therapy remains controversial. Therefore, the present meta-analysis was performed to investigate the association between TP53 concurrent mutations and prognosis of patients with advanced NSCLC undergoing EGFR-TKIs or ALK-TKIs treatments.

Methods

Eligible studies were identified by searching the online databases PubMed, Embase, Medline, The Cochrane library and Web of Science. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to clarify the correlation between TP53 mutation status and prognosis of patients. This meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results

In total, 15 studies with 1342 patients were included for final analysis. Overall, concurrent TP53 mutation was associated with unfavorable progression-free survival (PFS) (HR = 1.88, 95%CI: 1.59–2.23, p < 0.001, I² = 0.0%, P = 0.792) and overall survival (OS) (HR = 1.92, 95%CI: 1.55–2.38, p < 0.001, I² = 0.0%, P = 0.515). Subgroup analysis based on type of targeted therapy (EGFR-TKIs or ALK-TKIs, pathological type of cancer (adenocarcinoma only or all NSCLC subtypes) and line of treatment (first-line only or all lines) all showed that TP53 mutations was associated with shorter survivals of patients with EGFR-TKIs or ALK-TKIs treatments. Particularly, in patients with first-line EGFR-TKIs treatment, significantly poorer prognosis was observed in patients with TP53 concurrent mutations (pooled HR for PFS: 1.69, 95% CI 1.25–2.27, P < 0.001, I² = 0.0%, P = 0.473; pooled HR for OS: 1.94, 95% CI 1.36–2.76, P < 0.001, I² = 0.0%, P = 0.484). Begg’s funnel plots and Egger’s tests indicated no significant publication bias in this study.

Conclusions

This meta-analysis indicated that concurrent TP53 mutations was a negative prognostic factor and associated with poorer outcomes of patients with EGFR-TKIs or ALK-TKIs treatments in advanced NSCLC. In addition, our study provided evidence that TP53 mutations might be involved in primary resistance to EGFR-TKIs treatments in patients with sensitive EGFR mutations in advanced NSCLC.

Inhibition of Mitogen-Activated Protein Kinase Kinase Alone and in Combination with Anaplastic Lymphoma Kinase (ALK) Inhibition Suppresses Tumor Growth in a Mouse Model of ALK-Positive Lung Cancer

Anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer most commonly arises through EML4 (Echinoderm Microtuble Like 4)-ALK chromosomal fusion. We have previously demonstrated that combination of the ALK inhibitor crizotinib with the MEK inhibitor selumetinib was highly effective at reducing cell viability of ALK-positive non-small-cell lung cancer (H3122) cells. In this study, we further investigated the efficacy of crizotinib and selumetinib combination therapy in an in vivo xenograft model of ALK-positive lung cancer. Crizotinib decreased tumor volume by 52% compared with control, and the drug combination reduced tumor growth compared with crizotinib. In addition, MEK inhibition alone reduced tumor growth by 59% compared with control. Crizotinib and selumetinib alone and in combination were nontoxic at the dose of 25 mg/kg, with values for ALT (<80 U/l) and creatinine (<2 mg/dl) within the normal range. Our results support the combined use of crizotinib with selumetinib in ALK-positive lung cancer but raise the possibility that a sufficient dose of an MEK inhibitor alone may be as effective as adding an MEK inhibitor to an ALK inhibitor. SIGNIFICANCE STATEMENT: This study contains in vivo evidence supporting the use of combination MEK inhibitors in ALK+ lung cancer research, both singularly and in combination with ALK inhibitors. Contrary to previously published reports, our results suggest that it is possible to gain much of the benefit from combination treatment with an MEK inhibitor alone, at a tolerable dose.

Genomic Profiling of Circulating Tumor DNA Predicts Outcome and Demonstrates Tumor Evolution in ALK-Positive Non-Small Cell Lung Cancer Patients

With the rapid development of targeted therapies for the treatment of cancer, methods for predicting response and outcome are in high demand. Non-small cell lung cancer driven by genomic rearrangements of the anaplastic lymphoma kinase (ALK) gene can be successfully treated with ALK-targeted therapy. Unfortunately, a subset of patients does not respond, and all patients ultimately acquire resistance, highlighting the need for better clinical tools to manage these patients. Here, we performed targeted next-generation sequencing on plasma circulating tumor DNA (ctDNA) from 24 patients to assess the clinical utility of ctDNA genomic profiling. Patients with detectable ctDNA prior to treatment had worse progression-free survival (PFS) than those without (median 8.7 vs. 15.2 months, p = 0.028). In addition, the presence of ctDNA within two months after treatment initiation predicted inferior PFS (median 4.6 vs. 14.5 months, p = 0.028). Longitudinal monitoring of ctDNA with droplet digital PCR during treatment reflected the radiological response and revealed potential acquired resistance mutations. Interestingly, an increase in the ctDNA concentration was evident prior to the determination of progressive disease by conventional radiological imaging, with a median lead time of 69 days (range 30-113). Genomic profiling of ctDNA is a promising tool for predicting outcome and monitoring response to targeted therapy.

Secondary Resistant Mutations to Small Molecule Inhibitors in Cancer Cells

Secondary resistant mutations in cancer cells arise in response to certain small molecule inhibitors. These mutations inevitably cause recurrence and often progression to a more aggressive form. Resistant mutations may manifest in various forms. For example, some mutations decrease or abrogate the affinity of the drug for the protein. Others restore the function of the enzyme even in the presence of the inhibitor. In some cases, resistance is acquired through activation of a parallel pathway which bypasses the function of the drug targeted pathway. The Catalogue of Somatic Mutations in Cancer (COSMIC) produced a compendium of resistant mutations to small molecule inhibitors reported in the literature. Here, we build on these data and provide a comprehensive review of resistant mutations in cancers. We also discuss mechanistic parallels of resistance.

Efficacy of Immune Checkpoint Inhibitor Monotherapy for Advanced Non-Small-Cell Lung Cancer with ALK Rearrangement

Programmed death-ligand 1 (PD-L1) expression is a predictor of immune checkpoint inhibitor (ICI) treatment efficacy. The clinical efficacy of ICIs for non-small-cell lung cancer (NSCLC) patients harboring major mutations, such as EGFR or ALK mutations, is limited. We genotyped 190 patients with advanced lung adenocarcinomas who received nivolumab or pembrolizumab monotherapy, and examined the efficacy in NSCLC patients with or without major mutations. Among the patients enrolled in the genotyping study, 47 patients harbored EGFR mutations, 25 patients had KRAS mutations, 5 patients had a HER2 mutation, 6 patients had a BRAF mutation, and 7 patients had ALK rearrangement. The status of PD-L1 expression was evaluated in 151 patients, and the rate of high PD-L1 expression (≥50%) was significantly higher in patients with ALK mutations. The progression-free survival was 0.6 (95% CI: 0.2–2.1) months for ALK-positive patients and 1.8 (95% CI: 1.2–2.1) months for EGFR-positive patients. All patients with ALK rearrangement showed disease progression within three months from the initiation of anti-PD-1 treatment. Our data suggested that ICI treatment was significantly less efficacious in patients with ALK rearrangement than in patients with EGFR mutations, and PD-L1 expression was not a critical biomarker for ICI treatment for patients with one of these mutations.

The Evolving Diagnostic and Treatment Landscape of NTRK-Fusion-Driven Pediatric Cancers

The neurotrophin receptor tyrosine kinase (NTRK1-3) genes have been identified as key fusion partners in a range of pediatric cancers. In childhood cancers, ETV6-NTRK3 fusions are found in the majority of infantile fibrosarcomas and congenital mesoblastic nephromas. NTRK fusions are also found in mammary analog secretory carcinomas (MASC), secretory breast carcinomas, and with modest frequency in high-grade gliomas in very young children. While there are a range of multi-receptor tyrosine kinase inhibitors that show efficacy against TRK kinases, there are now multiple highly selective TRK inhibitors in clinical evaluation. Entrectinib and larotrectinib have been evaluated in early-phase clinical trials for children and demonstrated high response rates with good durability of response. Both agents are now approved in the United States in an age and histology agnostic manner for children (age > 12 years for entrectinib; all ages for larotrectinib) for the treatment of solid tumors harboring NTRK fusions without an option for complete surgical resection, with relapsed disease, or without a viable alternative systemic option. More recently, two second-generation TRK inhibitors, selitrectinib and repotrectinib, have been developed and are currently being evaluated in pediatric early phase trials. The Children's Oncology Group has also launched a phase II trial of larotrectinib as a neoadjuvant agent for patients with newly diagnosed infantile fibrosarcoma. While the clinical use of these agents has developed rapidly, many questions remain in terms of duration of therapy, treatment of CNS disease, and long-term toxicities. Further development of this class of agents will continue to require multi-center trials for these rare tumors. Tumor sequencing and potentially sequencing of circulating tumor DNA will improve our understanding of patterns of resistance and the most effective treatment strategies for these patients.

Next-generation sequencing to dynamically detect mechanisms of resistance to ALK inhibitors in ALK-positive NSCLC patients: a case report

Tyrosine kinase inhibitors (TKIs) of the anaplastic lymphoma kinase gene (ALK) have significantly improved the quality of life and survival of non-small cell lung cancer (NSCLC) patients whose tumors harbor an ALK translocation. However, most of these patients relapse within 2 to 3 years as the tumor acquires resistance mutations. Unlike beaming and digital PCR (dPCR), which only allow a few mutations to be analyzed, next-generation sequencing (NGS) approaches enable the simultaneous screening of multiple genetic alterations even when the frequencies of the variants are very low. We present the case of a 52-year-old man who was diagnosed with an ALK-positive NSCLC and was treated with crizotinib and, subsequently, ceritinib. The analysis of serial liquid biopsies by NGS detected two asynchronous mutations arising in the ALK locus during disease progression, namely p.Gly1269Ala (c.3806G>C) and p.Gly1202Arg (c.3604G>A), that conferred resistance to crizotinib and ceritinib, respectively. The resistance mutations were detected independently at different times, and could be imputed to different metastatic lesions, thereby highlighting the importance of heterogeneity in advance disease. Plasma levels of ALK resistance mutations correlated well with tumor responses assessed by CT scans and bone scintigraphy, demonstrating that non-invasive tumor molecular profiling by NGS allows the efficient dynamic monitoring of ALK-positive NSCLC patients, and outperforms dPCR and beaming because more somatic mutations can be tracked over the course of the treatment. In conclusion, this case report illustrates the usefulness NGS to guide therapeutic decisions in ALK-positive NSCLC patients based tumor molecular profile upon disease progression.

Lorlatinib for the treatment of ALK-positive metastatic non-small cell lung cancer

Introduction: The treatment of lung cancer has changed dramatically with the development of tyrosine kinase inhibitors (TKIs) that target sensitizing somatic (gene) activations including anaplastic lymphoma kinase (ALK)-rearrangements. Despite remarkable initial responses, patients develop progressive disease via various resistance mechanisms, some of which are ALK dependent. Various next-generation ALK TKIs have been developed to improve on central nervous system (CNS) activity and also target the multitude of acquired resistance mechanisms. Of these, lorlatinib has the greatest spectrum of clinical activity against multiple ALK resistance mutations and has also demonstrated promising efficacy in patients with known brain metastases.Areas covered: We discuss the structure, pharmacology and efficacy of lorlatinib and also provide future perspectives in the management of patients with ALK-rearranged non-small cell lung cancer (NSCLC).Expert opinion: Patients invariably develop resistance during treatment with lorlatinib. Unique combinations of ALK resistance mutations may confer sensitivity to alternate ALK TKIs. There is a move toward individualized biomarker-driven treatment strategies to identify the select group of candidates that can benefit from existing therapies.

Single-center study to determine the safety and efficacy of CT-707 in Chinese patients with advanced anaplastic lymphoma kinase-rearranged non-small-cell lung cancer

Introduction

It has been proven that ALK‐rearranged non‐small cell lung cancer (NSCLC) is sensitive to ALK inhibitors while the chemotherapy resistance is unavoidable. In this study, safety and antitumor activity of the novel ALK inhibitor (ALKi) CT‐707 were evaluated in Chinese patients with advanced ALK‐rearranged NSCLC.

Methods

This single‐center, open‐label phase I study recruited adult patients with ALK‐rearrangement (confirmed by fluorescence in situ hybridization and/or immunohistochemistry) of locally advanced/metastatic malignancies including NSCLC. This study consisted of two parts: dose escalation and dose expansion. CT‐707 was administered orally once a day for 21 days.

Results

A total of 13 patients who were treated with CT‐707 from 450 to 600 mg (in the dose increasing phase) were enrolled in this trial (two patients were previously treated with crizotinib). There were 12 patients diagnosed with lung adenocarcinoma and one patient with malignant pleural mesothelioma. After treatment, grade 3 diarrhea (600 mg once a day) was found as dose‐limiting toxicity (DLT).The most common adverse events included diarrhea (92%), elevated aspartate aminotransferase (61%), elevated alanine aminotransferase (54%), hair loss (38%), and vomiting (31%). The overall response rate was 77% (10/13). Among all patients, four of the five patients who did not receive any treatment, one of the two patients who had received treatments with crizotinib, and five of the six patients who received standard chemotherapy achieved partial response (PR). One patient reached a complete remission (CR).

Conclusions

This study indicated that CT‐707 is clinically effective as a new antitumor drug for Chinese lung adenocarcinoma patients with ALK rearrangement. It is safe and reliable and the dose‐expansion phase recruitment has started.

Real world experience of treatment and outcome in ALK-rearranged metastatic nonsmall cell lung cancer: A multicenter study from India

BACKGROUND

Anaplastic lymphoma kinase (ALK) rearranged metastatic non-small cell lung cancer (NSCLC) comprises 5%-7% of all lung cancer and carries a good prognosis with available ALK-inhibitors. Majority of registration trials in ALK-inhibitors did not include Indian patients. Hence, this study was planned to analyze the outcome of Indian patients treated with ALK-inhibitors and associated challenges.

METHODS

This is a multi-center study in 5 major tertiary care cancer centers across India treating ALK-rearranged NSCLC patients from April 2013 to April 2019. ALK rearrangement was determined by Ventana immunohistochemistry with D5F3 clone and/or by break-apart FISH. Patients treated with ALK-inhibitors in any lines of treatment were included in this study. Patients were evaluated for clinicopathologic features, patterns of ALK-inhibitors use and outcome. Progression free-survival (PFS) and overall survival (OS) were calculated and data were censored on April 30, 2019.

RESULTS

A total of 274 patients were studied, out of which 250 patients received ALK inhibitor and were analyzed further for outcome. The median age was 50 years (range: 24-82) and male to female ratio of 1.17:1. ALK was evaluated by immunohistochemistry in majority of patients (97%), 3 patients by FISH and 3 more patients were evaluated by both methods. Sixty-five percent (n = 162) of the patients received ALK-inhibitor as first line therapy, 51 patients received ALK-inhibitor as switch maintenance therapy after initial chemotherapy. Crizotinib and Ceritinib were used in 88% and 12%, respectively. One patient received Alectinib. Forty-one percent of patients had CNS progression. After median follow up of 27 months (1-72 months), the median OS was 24.7 months with OS rate of 72%, 51%, and 18% at 1, 2, and 4-years respectively. Median OS was 21.2, 26, and 38 months in the first line ALK-inhibitors use (n = 162), switch maintenance group (n = 51) and second line ALK-inhibitors use (postchemotherapy progression) (n = 33), respectively. No baseline variable predicted PFS. Presence of brain metastasis (P = 0.039) and first line ALK-inhibitors use (P = 0.032) emerged as poor prognostic factor for OS on multivariate analysis. PFS rate was 70%, 47%, and 31% at 6, 12, and 18 months respectively.

CONCLUSION

This is one of the largest real-world data on outcome of ALK inhibitors in ALK-rearranged NSCLC from Asia. In absence of second line ALK inhibitor, initial chemotherapy followed by ALK-inhibitors (switch maintenance) had better outcome. This fact may be studied in individual patient data meta-analysis. Poor performance status and brain metastases at presentation are poor prognostic factors for overall survival. Second-line ALK inhibitor use crucial for better outcome and access to clinical trials are much needed in Indian patients.

Alteration in the sensitivity to crizotinib by Na+/H+ exchanger regulatory factor 1 is dependent to its subcellular localization in ALK-positive lung cancers

Background

Na⁺/H⁺ exchanger regulatory factor 1 (NHERF1) is an important scaffold protein participates in the modulation of a variety of intracellular signal pathways. NHERF1 was able to enhance the effects of chemo-drugs in breast and cervical cancer cells. Anaplastic lymphoma kinase (ALK) fusion mutations are validated molecules targeted therapy in lung cancers, where crizotinib can be used as the specific inhibitor to suppress tumor progression. However, due to the less frequent occurrence of ALK mutations and the complexity for factors to determine drug responses, the genes that could alter crizotinib sensitivity are unclear.

Methods

Both ALK-translocated and ALK-negative lung adenocarcinoma specimens in tissue sections were collected for immunohistochemistry. The possible mechanisms of NHERF1 and its role in the cell sensitivity to crizotinib were investigated using an ALK-positive and crizotinib-sensitive lung adenocarcinoma cell line H3122. Either a NHERF1 overexpression vector or agents for NHERF1 knockdown was used for crizotinib sensitivity measures, in association with cell viability and apoptosis assays.

Results

The expression level of NHERF1 in ALK-translocated NSCLC was significantly higher than that in other lung cancer tissues. NHERF1 expression in ALK positive lung cancer cells was regulated by ALK activities, and was in return able to alter the sensitivity to crizotinib. The function of NHERF1 to influence crizotinib sensitivity was depending on its subcellular distribution in cytosol instead of its nucleus localized form.

Conclusion

Ectopically overexpressed NHERF1 could be a functional protein for consideration to suppress lung cancers. The determination of NHERF1 levels in ALK positive NSCLC tissues might be useful to predict crizotinib resistance, especially by distinguishing cytosolic or nuclear localized NHERF1 for the overexpressed molecules.

Acquired resistance to targeted therapies in NSCLC: Updates and evolving insights

While significant advancements have been made in the available therapies for metastatic non-small cell lung cancer (NSCLC), acquired resistance remains a major barrier to treatment. We have not yet achieved the ability to cure advanced NSCLC with systemic therapy, despite our growing understanding of many of the oncogenic drivers of this disease. Rather, the emergence of drug-tolerant and drug-resistant cells remains the rule, even in the face of increasingly potent targeted therapies. In this review, we provide a broad overview of the mechanisms of resistance to targeted therapy that have been demonstrated across molecular subtypes of NSCLC, highlighting the dynamic interplay between driver oncogene, bypass signaling pathways, shifting cellular phenotypes, and surrounding tumor microenvironment.

Anaplastic Lymphoma Kinase Mutation-Positive Non-Small Cell Lung Cancer

The treatment of patients with advanced non-small cell lung cancer with anaplastic lymphoma kinase chromosomal rearrangements has been revolutionized by the development of tyrosine kinase inhibitors (TKIs). Excellent progress has been made over the past decade, with 4 TKIs now approved in the front-line setting. Alectinib is the preferred first-line option based on its efficacy and side-effect profile. The central nervous system (CNS) activity of alectinib and brigatinib has allowed for treatment of CNS metastases with TKI therapy. Once resistance inevitably develops, newer therapies such as lorlatinib can be considered.

CT-Based Radiomic Signature as a Prognostic Factor in Stage IV ALK-Positive Non-small-cell Lung Cancer Treated With TKI Crizotinib: A Proof-of-Concept Study

Objectives: To identify a computed tomography (CT)-based radiomic signature for predicting progression-free survival (PFS) in stage IV anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer (NSCLC) patients treated with tyrosine kinase inhibitor (TKI) crizotinib. Materials and Methods: This retrospective proof-of-concept study included a cohort of 63 stage IV ALK-positive NSCLC patients who had received TKI crizotinib therapy for model construction and validation. Another independent cohort including 105 stage IV EGFR-positive NSCLC patients was also used for external validation in EGFR-TKI treatment. We initially extracted 481 quantitative three-dimensional features derived from manually segmented tumor volumes of interest. Pearson's correlation analysis along with the least absolute shrinkage and selection operator (LASSO) penalized Cox proportional hazards regression was successively performed to select critical radiomic features. A CT-based radiomic signature for PFS prediction was obtained using multivariate Cox regression. The performance evaluation of the radiomic signature was conducted using the concordance index (C-index), time-dependent receiver operating characteristic (ROC) analysis, and Kaplan-Meier survival analysis. Results: A radiomic signature containing three features showed significant prognostic performance for ALK-positive NSCLC patients in both the training cohort (C-index, 0.744; time-dependent AUC, 0.895) and the validation cohort (C-index, 0.717; time-dependent AUC, 0.824). The radiomic signature could significantly risk-stratify ALK-positive NSCLC patients (hazard ratio, 2.181; P < 0.001) and outperformed other prognostic factors. However, no significant association with PFS was captured for the radiomic signature in the EGFR-positive NSCLC cohort (log-rank tests, P = 0.41). Conclusions: The CT-based radiomic features can capture valuable information regarding the tumor phenotype. The proposed radiomic signature was found to be an effective prognostic factor in stage IV ALK mutated nonsynchronous nodules in NSCLC patients treated with a TKI.

Drug resistance mechanisms in Japanese anaplastic lymphoma kinase-positive non-small cell lung cancer and the clinical responses based on the resistant mechanisms

The treatment for anaplastic lymphoma kinase (ALK)-positive lung cancer has been rapidly evolving since the introduction of several ALK tyrosine kinase inhibitors (ALK-TKI) in clinical practice. However, the acquired resistance to these drugs has become an important issue. In this study, we collected a total of 112 serial biopsy samples from 32 patients with ALK-positive lung cancer during multiple ALK-TKI treatments to reveal the resistance mechanisms to ALK-TKI. Among 32 patients, 24 patients received more than two ALK-TKI. Secondary mutations were observed in 8 of 12 specimens after crizotinib failure (G1202R, G1269A, I1171T, L1196M, C1156Y and F1245V). After alectinib failure, G1202R and I1171N mutations were detected in 7 of 15 specimens. G1202R, F1174V and G1202R, and P-gp overexpression were observed in 3 of 7 samples after ceritinib treatment. L1196M + G1202R, a compound mutation, was detected in 1 specimen after lorlatinib treatment. ALK-TKI treatment duration was longer in the on-target treatment group than that in the off-target group (13.0 vs 1.2 months). In conclusion, resistance to ALK-TKI based on secondary mutation in this study was similar to that in previous reports, except for crizotinib resistance. Understanding the appropriate treatment matching resistance mechanisms contributes to the efficacy of multiple ALK-TKI treatment strategies.

Frontiers of ctDNA, targeted therapies, and immunotherapy in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC), a main subtype of lung cancer, is one of the most common causes of cancer death in men and women worldwide. Circulating tumor DNA (ctDNA), tyrosine kinase inhibitors (TKIs) and immunotherapy have revolutionized both our understanding of NSCLC, from its diagnosis to targeted NSCLC therapies, and its treatment. ctDNA quantification confers convenience and precision to clinical decision making. Furthermore, the implementation of TKI-based targeted therapy and immunotherapy has significantly improved NSCLC patient quality of life. This review provides an update on the methods of ctDNA detection and its impact on therapeutic strategies; therapies that target epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) using TKIs such as osimertinib and lorlatinib; the rise of various resistant mechanisms; and the control of programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1), and cytotoxic T-lymphocyte antigen-4 (CTLA-4) by immune checkpoint inhibitors (ICIs) in immunotherapy; blood tumor mutational burden (bTMB) calculated by ctDNA assay as a novel biomarker for immunotherapy. However, NSCLC patients still face many challenges. Further studies and trials are needed to develop more effective drugs or therapies to treat NSCLC.

KRCA-0008 suppresses ALK-positive anaplastic large-cell lymphoma growth

Anaplastic lymphoma kinase (ALK), which belongs to the insulin receptor tyrosine kinase superfamily, plays an important role in nervous system development. Due to chromosomal translocations, point mutations, and gene amplification, constitutively activated ALK has been implicated in a variety of human cancers, including anaplastic large-cell lymphoma (ALCL), non-small cell lung cancer, and neuroblastoma. We evaluated the anti-cancer activity of the ALK inhibitor KRCA-0008 using ALCL cell lines that express NPM (nucleophosmin)-ALK. KRCA-0008 strongly suppressed the proliferation and survival of NPM-ALK-positive ALCL cells. Additionally, it induced G0/G1 cell cycle arrest and apoptosis by blocking downstream signals including STAT3, Akt, and ERK1/2. Tumor growth was strongly suppressed in mice inoculated with Karpas-299 tumor xenografts and orally treated with KRCA-0008 (50 mg/kg, BID) for 2 weeks. Our results suggest that KRCA-0008 will be useful in further investigations of ALK signaling, and may provide therapeutic opportunities for NPM-ALK-positive ALCL patients.

Overcoming resistance by ALK compound mutation (I1171S + G1269A) after sequential treatment of multiple ALK inhibitors in non-small cell lung cancer

Background

Anaplastic lymphoma kinase (ALK) fusion genes are found in 3%–5% of non‐small cell lung cancers (NSCLCs). ALK inhibitors show a very high response rate to ALK‐positive NSCLCs. However, the emergence of acquired resistance is inevitable. In this study, we investigated the drugs for overcoming resistance especially compound mutations after sequential treatment with crizotinib, alectinib, and lorlatinib.

Method

Next‐generation sequencing (NGS) and Sanger sequencing were performed on a liver biopsy tissue obtained from a clinical case. Ba/F3 cells in which mutant EML4‐ALK were overexpressed were prepared, and cell viability assay and immunoblotting were performed to check the sensitivity of five independent ALK inhibitors.

Results

I1171S + G1269A double mutation was identified by NGS and Sanger sequencing on a liver biopsy tissue from a patient who relapsed on lorlatinib treatment. Ceritinib and brigatinib—but not other ALK inhibitors—were active against the compound mutations in the cell line model.

Conclusions

With the sequential ALK inhibitors treatment, cancer cells accumulate new mutations in addition to mutations acquired previously. The identified compound mutation (I1171S + G1269A) was found to be sensitive to ceritinib and brigatinib, and indeed the patient's tumor partially responded to ceritinib.

Key points

ALK compound mutation was found in a clinical sample that was resistant to lorlatinib after sequential ALK‐tyrosine kinase inhibitor (TKI) treatment.

Ceritinib and brigatinib are potential overcoming drugs against ALK I1171S + G1269A double mutation.

Tumor-educated platelet as liquid biopsy in lung cancer patients

Lung cancer is the most frequent cancer for males and third most frequent cancer for females. Targeted therapy drugs based on molecular alterations, such as angiogenesis inhibitors, epidermal growth factor receptor (EGFR) inhibitors, and anaplastic lymphoma kinase (ALK) inhibitors are important part of treatment of NSCLC. However, the quality of the available tumor biopsy and/or cytology material is sometimes not adequate to perform the necessary molecular testing, which has prompted the search for alternatives. This review examines the use of tumor-educated platelet (TEP) as a liquid biopsy in lung cancer patients. The development of sensitive and accurate techniques have made it possible to detect the specific genetic alterations for which targeted therapies are already available. Liquid biopsy offers opportunities to detect resistance mechanisms at an early stage. To conclude, tumor-educated platelet has the potential to be used as liquid biopsy for a variety of clinical and investigational applications.

Mechanisms of suppression of cell growth by dual inhibition of ALK and MEK in ALK-positive non-small cell lung cancer

Anaplastic lymphoma kinase (ALK) rearrangement, a key oncogenic driver in a small subset of non-small cell lung cancers, confers sensitivity to ALK tyrosine kinase inhibitors (TKIs). Crizotinib, a first generation ALK-TKI, has superiority to standard chemotherapy with longer progression-free survival and higher objective response rate. However, clinical benefit is limited by development of resistance, typically within a year of therapy. In this study the combined effect of crizotinib and the MEK inhibitor selumetinib was investigated in both crizotinib naïve (H3122) and crizotinib resistant (CR-H3122) ALK-positive lung cancer cells. Results showed that combination treatment potently inhibited the growth of both H3122 and CR-H3122 cells, resulting from increased apoptosis and decreased cell proliferation as a consequence of suppressed downstream RAS/MAPK signalling. The drug combination also elicited a greater than 3-fold increase in Bim, a mediator of apoptosis, and p27, a cyclin dependent kinase inhibitor compared to crizotinib alone. The results support the hypothesis that combining MEK inhibitors with ALK inhibitor can overcome ALK inhibitor resistance, and identifies Bim, PARP and CDK1 as druggable targets for possible triple drug therapy.

Interpretation of ceritinib clinical trial results and future combination therapy strategies for ALK-rearranged NSCLC

Introduction: Lung cancer is the leading cause of cancer-related deaths, with non-small cell lung cancer (NSCLC) accounting for approximately 85% of all lung cancer cases. The continued advancement of DNA sequencing technology and the discovery of multiple specific driver mutations underlying many cases of NSCLC are moving clinical intervention toward a more targeted approach. Here we focus on anaplastic lymphoma kinase (ALK), a member of the receptor tyrosine kinase family, as an oncogenic driver in NSCLC. The ALK gene is rearranged in 3-7% of NSCLCs, and targeted inhibition of ALK is a viable therapy option.Areas covered: We discuss the available treatment options for ALK-positive NSCLC with an emphasis on the second-generation ALK inhibitor ceritinib. We also discuss practical treatment strategies and possible strategies to overcome or delay resistance to ALK inhibitors.Expert opinion: With a robust treatment armamentarium for patients with ALK-positive NSCLC, emphasis has shifted to optimizing individualized treatment strategies to further enhance outcomes for these patients.