Differential Crizotinib Response Duration Among ALK Fusion Variants in ALK-Positive Non-Small-Cell Lung Cancer

A Poor Prognostic ALK Phenotype: A Review of Molecular Markers of Poor Prognosis in ALK Rearranged Nonsmall Cell Lung Cancer

BACKGROUND

Patients with nonsmall cell lung cancer with anaplastic lymphoma kinase (ALK) rearrangements derive a significant and durable clinical benefit from tyrosine kinase inhibitors (TKIs). However, early progression/death on treatment occurs in a subset of patients, which we term the poor prognostic ALK phenotype. This review aims to summarize the known molecular mechanisms that underlie this phenotype with a focus on variant 3 and TP53 mutations.

METHODS

A scoping review was performed using scientific databases such as Ovid Medline, Ovid Embase, and Cochrane Central Register of Controlled Trials. Studies included molecular markers of poor prognosis, with a focus on TP53 mutations, variant 3 re-arrangements, and poor clinical response to TKIs.

RESULTS

Of 4371 studies screened, 108 were included. Numerous studies implicated a negative prognostic role of variant 3, likely mediated through the acquisition of on-target resistance mutations and TP53 mutations which are associated with greater chromosomal instability and mutational burden. Co-occurring variant 3 and TP53 mutations were associated with even worse survival. Other mediators of early resistance development include aberrations in cell cycle regulators and mutations in cell signaling pathways. Comprehensive genomic analysis from first-line TKI clinical trial data was unable to identify a singular genomic signature that underlies the poor prognostic phenotype but implicated a combination of pathways.

CONCLUSIONS

This scoping review highlights that the poor prognostic ALK phenotype is likely composed of a heterogeneous variety of genomic factors. There remains an unmet need for a genomic assay to integrate these various molecular markers to predict this ALK phenotype.

The Use of Anaplastic Lymphoma Kinase Inhibitors in Non-Small-Cell Lung Cancer Treatment-Literature Review

Lung cancer is the leading cause of cancer-related morbidity and mortality. The median survival time for patients with advanced non-small-cell lung cancer before the era of molecular-based personalized treatment was 7.9 months. The discovery of predictive factors and the introduction of molecular diagnostics into daily practice made a breakthrough, enabling several years of survival in patients with advanced disease. The discovery of rearrangements in the ALK gene and ALK tyrosine kinase inhibitors has resulted in a dramatic improvement in the prognosis of patients with this subtype of cancer. Currently, three generations of ALK inhibitors differing in activity, toxicity and degree of penetration into the central nervous system are available in clinical practice. The current state of knowledge on ALK inhibitors used in clinical practice is summarised in this research paper. Methods of diagnosis of abnormalities in ALK have been shown, and the review of research that contributed to the development of the next generation of ALK inhibitors has been presented.

Clinical difference on the variants and co-mutation in a Chinese cohort with ALK-positive advanced non-small cell lung cancer

PURPOSE

Despite the generally favourable prognoses observed in patients with ALK-positive non-small cell lung cancer (NSCLC), there remains significant variability in clinical outcomes. The objective of this study is to enhance patient stratification by examining both the specific sites of gene fusion and the presence of co-occurring mutations.

METHODS

We collected retrospective clinical and pathological data on ALK-positive patients with locally advanced or metastatic disease. ALK fusion variants and concomitant mutations were identified through next-generation sequencing technology. We then assessed treatment efficacy via tumor response and survival metrics.

RESULTS

This study included a total of 59 patients, with 49 harboring echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusions and 10 presenting with rare fusions. The median follow-up period was 33 months. Clinical outcomes between non-EML4-ALK and EML4-ALK patients were comparable. Among the EML4-ALK cohort, patients with longer variants (v1, v2, v8) demonstrated superior progression-free survival (PFS) (median PFS: 34 months vs. 11 months; hazard ratio [HR]: 2.28; P = 0.05) compared to those with shorter variants (v3, v5). Furthermore, patients treated with second-generation ALK inhibitors (ALKi) displayed a progression-free survival advantage (median PFS: not reached [NR] vs. 9 months; HR: 5.37; P = 0.013). Baseline TP53 co-mutation were linked with a substantially shorter OS (median OS,37 months vs. NR; HR 2.74; P = 0.047).

CONCLUSIONS

In ALK+ NSCLC, longer EML4-ALK variants correlate with improved prognosis and enhanced response to second-generation ALKi, while TP53 co-mutations indicate a negative prognosis.

Primary lung adenocarcinoma with breast metastasis harboring the EML4‑ALK fusion: A case report

Pulmonary adenocarcinoma with breast metastasis is rarely encountered in clinical practice. Therefore, precise clinical diagnosis of patients with this disease is crucial when selecting subsequent treatment modalities and for overall prognosis assessment. The present study reported on a case of lung cancer with breast metastasis harboring the EML4-ALK fusion. The patient was initially diagnosed with triple-negative breast cancer with lung metastasis, but comprehensive breast cancer treatment was ineffective. Reevaluation of the patient's condition via lung biopsy revealed primary lung adenocarcinoma. In addition, the results of genetic testing revealed the EML4-ALK fusion protein in both lung and breast tissues. After treatment with ALK inhibitors, the patient's symptoms improved rapidly. This case highlights the prolonged diagnostic journey from presentation with a breast mass to ultimately being diagnosed with lung cancer with breast metastasis, underscoring the critical need for heightened awareness among clinicians regarding the possibility of rare metastatic patterns. Timely identification of lung cancer with breast metastasis, facilitated by comprehensive genetic testing, not only refines treatment decisions but also emphasizes the importance of interdisciplinary collaboration in navigating complex clinical scenarios. Such insight contributes to the ongoing development of personalized cancer care that guides clinicians toward more effective and tailored therapeutic strategies for patients with similar diagnostic challenges.

ALK inhibitors in cancer: mechanisms of resistance and therapeutic management strategies

Anaplastic lymphoma kinase (ALK) gene rearrangements have been identified as potent oncogenic drivers in several malignancies, including non-small cell lung cancer (NSCLC). The discovery of ALK inhibition using a tyrosine kinase inhibitor (TKI) has dramatically improved the outcomes of patients with ALK-mutated NSCLC. However, the emergence of intrinsic and acquired resistance inevitably occurs with ALK TKI use. This review describes the molecular mechanisms of ALK TKI resistance and discusses management strategies to overcome therapeutic resistance.

Alk-rearranged lung adenocarcinoma: From molecular genetics to therapeutic targeting

Anaplastic Lymphoma Kinase (ALK) is a potent oncogenic driver of lung adenocarcinoma (LUAD). ALK is constitutively activated by gene fusion events between the ALK and other gene fusion partners in about 2-3% of LUADs, characterized by few other gene alterations. ALK-fusions are a druggable target through potent pharmacological inhibitors of tyrosine kinase activity. Thus, several ALK-TKIs (Tyrosine Kinase Inhibitors) of first-, second- and third-generation have been developed that improved the outcomes of ALK-rearranged LUADs when used as first- or second-line agents. However, resistance mechanisms greatly limit the durability of the therapeutic effects elicited by these TKIs. The molecular mechanisms responsible for these resistance mechanisms have been in part elucidated, but overcoming acquired resistance to ALK-derived therapy remains a great challenge. Some new therapeutic strategies under investigation aim to induce long-term remission in ALK-fusion positive LUADs.

A Novel Intergenic Region (chr2: 30,316,870)-ALK Fusion in a Patient with Lung Adenocarcinoma Responding to Crizotinib Combined with Pemetrexed Treatment: A Case Report

Background

Anaplastic lymphoma kinase (ALK) rearrangements have been reported as an important oncogenic driver in 5-7% non-small cell lung cancer (NSCLC) patients. Reports about the intergenic region (IGR) as an ALK fusion partner are rare. In this study, we report a novel IGR (chr2: 30,316,870)-ALK fusion in an advanced lung adenocarcinoma patient that responded effectively to crizotinib combined with pemetrexed.

Case Presentation

A 68-year-old Chinese female was diagnosed with stage IV right lung adenocarcinoma (cT3N3M1c). The targeted next-generation sequencing (NGS) of 14 cancer-related genes identified an IGR (chr2: 30,316,870)-ALK fusion. Her lung lesions have been successfully converted from a partial response to a complete response after administrating crizotinib for 1 year combined with 6 cycles of chemotherapy with pemetrexed. So far, her progression-free-survival has reached 21 months.

Conclusion

In this case, we firstly report a novel IGR (chr2: 30,316,870)-ALK fusion by using targeted NGS, and highlight the efficacy of crizotinib combined with pemetrexed to reduce unbearable gastrointestinal adverse reactions. It provides valuable clinical guidance for the treatment of similar cases in the future.

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

Objective

To assess the influence of F1174S mutation on kinase activity and drug sensitivity of the echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) fusion (EML4-ALK) variants 1 and 3.

Methods

We constructed mammalian expression plasmids of both wildtype and F1174 mutant EML4-ALK variants 1 and 3, and then characterized them with cell models by performing immunoblotting, neurite outgrowth assay, focus formation assay as well as protein stability assay. Drug sensitivity to ALK tyrosine kinase inhibitors was also compared between wildtype and F1174 mutant EML4-ALK fusions. In addition, we characterized the effect of different F1174 kinase domain mutations in the context of EML4-ALK fusions.

Results

In contrast to the oncogenic ALK-F1174S mutation that has been reported to be activating in the context of full-length ALK in neuroblastoma, EML4-ALK (F1174S) variant 1 exhibits impaired kinase activity leading to loss of oncogenicity. Furthermore, unlike the previously reported F1174C/L/V mutations, mutation of F1174 to S sensitizes EML4-ALK variants 3a and 3b to crizotinib.

Conclusion

These findings highlight the complexity of drug selection when treating patients harboring resistance mutations and suggest that the F1174S mutation in EML4-ALK variant 1 is likely not a potent oncogenic driver. Additional oncogenic driver or other resistance mechanisms should be considered in the case of EML4-ALK variant 1 with F1174S mutation.

Clinical Characteristics of Patients with Advanced ALK-Translocated Non-small Cell Lung Cancers and Long-Term Responses to Crizotinib (CRIZOLONG GFPC 05-19 Study)

BACKGROUND

Although ALK-translocated (ALK+) advanced non-small cell lung cancers (aNSCLCs) are currently treated with second- or third-generation ALK inhibitors (ALK-TKIs), some patients respond durably to the first-generation ALK-TKI crizotinib.

OBJECTIVE

This study aimed to describe the clinical characteristics of these long-term responders.

PATIENTS AND METHODS

This national, multicenter, retrospective, non-interventional study included patients with ALK+ aNSCLCs and long-term responses to first (L1)- or subsequent (≥ L2)-line crizotinib, defined, respectively, as treatments lasting > 18 and > 10 months. Median treatment duration (mDOT) was the primary endpoint.

RESULTS

A total of 85 patients (32 L1 and 53 ≥ L2 responders) from 23 centers were included (receiving crizotinib between 10/24/2011-10/02/2018): median age of 59 years, 83.6% non-smokers or ex-smokers, 85.9% performance status (PS) 0/1, 94.1% with adenocarcinomas, median of one metastatic site, and 22.4% with brain metastases (BMs). After median follow-up of 73.4 [95% confidence interval, 67.5-79.9] months, respective L1 and ≥ L2 mDOTs were 43.3 [26.7-56.8] and 29.6 [22.6-35.8] months, with overall survival (OS) not reached (NR) and 116.2 [83.4-NR] months. BM presence or absence did not affect mDOT (31.4 versus 32.9 months) but significantly impacted median OS (70.6 versus 158.6 months; p = 0.0008). Progression on crizotinib was paucisymptomatic (74.1%) and oligometastatic (34.8%), especially BMs (42.4%). After crizotinib discontinuation, 65 (76.5%) patients received subsequent systemic therapy: 57 (67.1%) with second-generation ALK-TKIs. Respective mDOTs of first- and second-line post-crizotinib ALK-TKIs lasted 19.4 [14.9-25.6] and 11.1 [4.8-17.9] months, respectively.

CONCLUSIONS

Most ALK+ aNSCLC patients with prolonged crizotinib efficacy had paucisymptomatic and oligometastatic disease without BMs. They subsequently benefited from a sequential strategy with other ALK-TKIs.

Comprehensive NGS profiling to enable detection of ALK gene rearrangements and MET amplifications in non-small cell lung cancer

Introduction

Next-generation sequencing (NGS) is currently widely used for biomarker studies and molecular profiling to identify concurrent alterations that can lead to the better characterization of a tumor's molecular landscape. However, further evaluation of technical aspects related to the detection of gene rearrangements and copy number alterations is warranted.

Methods

There were 12 ALK rearrangement-positive tumor specimens from patients with non-small cell lung cancer (NSCLC) previously detected via fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), and an RNA-based NGS assay, and 26 MET high gene copy number (GCN) cases detected by FISH, selected for this retrospective study. All 38 pre-characterized cases were reassessed utilizing the PGDx™ elio™ tissue complete assay, a 505 gene targeted NGS panel, to evaluate concordance with these conventional diagnostic techniques.

Results

The detection of ALK rearrangements using the DNA-based NGS assay demonstrated excellent sensitivity with the added benefit of characterizing gene fusion partners and genomic breakpoints. MET copy number alterations were also detected; however, some discordances were observed likely attributed to differences in algorithm, reporting thresholds and gene copy number state. TMB was also assessed by the assay and correlated to the presence of NSCLC driver alterations and was found to be significantly lower in cases with NGS-confirmed canonical driver mutations compared with those without (p=0.0019).

Discussion

Overall, this study validates NGS as an accurate approach for detecting structural variants while also highlighting the need for further optimization to enable harmonization across methodologies for amplifications.

Brigatinib in Japanese patients with ALK-positive non-small-cell lung cancer: Final results of the phase 2 J-ALTA trial

The phase 2, single-arm, multicenter, open-label J-ALTA study evaluated the efficacy and safety of brigatinib in Japanese patients with advanced ALK+ non-small-cell lung cancer (NSCLC). One expansion cohort of J-ALTA enrolled patients previously treated with ALK tyrosine kinase inhibitors (TKIs); the main cohort included patients with prior alectinib ± crizotinib. The second expansion cohort enrolled patients with TKI-naive ALK+ NSCLC. All patients received brigatinib 180 mg once daily (7-day lead-in at 90 mg daily). Among 47 patients in the main cohort, 5 (11%) remained on brigatinib at the study end (median follow-up: 23 months). In this cohort, the independent review committee (IRC)-assessed objective response rate (ORR) was 34% (95% CI, 21%-49%); median duration of response was 14.8 months (95% CI, 5.5-19.4); median IRC-assessed progression-free survival (PFS) was 7.3 months (95% CI, 3.7-12.9). Among 32 patients in the TKI-naive cohort, 25 (78%) remained on brigatinib (median follow-up: 22 months); 2-year IRC-assessed PFS was 73% (90% CI, 55%-85%); IRC-assessed ORR was 97% (95% CI, 84%-100%); the median duration of response was not reached (95% CI, 19.4-not reached); 2-year duration of response was 70%. Grade ≥3 adverse events occurred in 68% and 91% of TKI-pretreated and TKI-naive patients, respectively. Exploratory analyses of baseline circulating tumor DNA in ALK TKI-pretreated NSCLC showed associations between poor PFS and EML4-ALK fusion variant 3 and TP53. Brigatinib is an important treatment option for Japanese patients with ALK+ NSCLC, including patients previously treated with alectinib.

Novel PPFIA1-ALK, ALK-C2orf91(intergenic) double-fusion responded well to alectinib in an advanced lung adenocarcinoma patient: a case report

Non-small cell lung cancers (NSCLCs) with anaplastic lymphoma kinase (ALK)-rearrangement have favorable responses to ALK inhibitors. However, ALK fusion mutations harbored approximately 90 distinct fusion partners. Patients with different ALK fusions might respond distinctly to different-generation ALK inhibitors. In this case report, we identified a novel non-reciprocal ALK fusion, ALK-C2orf91(intergenic) (A19: intergenic) and PPFIA1-ALK (P2:A20), by next-generation DNA sequencing in an advanced lung adenocarcinoma patient. After 2 months of alectinib, the targeted lung lesion regressed significantly, and evaluation of therapeutic efficiency indicated partial response. To date, the patient had achieved 12 months of progression-free survival from alectinib treatment. Our study extended the spectrum of ALK fusion partners in ALK-positive NSCLC, and we reported a new ALK fusion, PPFIA1-ALK and ALK-C2orf91(intergenic), and its sensitivity to alectinib firstly in lung cancer. We believe that this case report has an important clinical reference.

Efficacy and safety of first-line treatments for patients with advanced anaplastic lymphoma kinase mutated, non-small cell cancer: A systematic review and network meta-analysis

BACKGROUND

This study compares the safety and efficacy of first-line treatments for anaplastic lymphoma kinase (ALK)-mutated non-small cell lung cancer (NSCLC).

METHODS

A comprehensive literature search was conducted in PubMed, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases. Abstracts related to lung cancer presented at important international conferences were also reviewed. Randomized clinical trials that qualified the inclusion criteria were subjected to Bayesian network meta-analysis and systematically reviewed.

RESULTS

The authors included a total of nine studies including 2441 patients and seven first-line treatments (ensartinib, brigatinib, crizotinib, lorlatinib, alectinib, ceritinib, and pemetrexed-based chemotherapy). Overall, lorlatinib appeared to confer the best progression-free survival (PFS) (probability of being the best [Prbest], 90%; surface under the cumulative ranking curve [SUCRA], 98%), and the same conclusion was obtained on paired comparisons (lorlatinib vs. ceritinib [hazard ratio (HR), 0.31; 95% confidence interval (CI), 0.20-0.47); lorlatinib vs. chemotherapy [HR, 0.17; 95% CI, 0.12-0.23]; crizotinib vs. lorlatinib [HR, 3.6; 95% CI, 2.4-5.2]; and brigatinib vs. lorlatinib [HR, 1.7; 95% CI, 1.0-2.8]). Alectinib conferred the best overall survival (OS) and safety profile. In the Asian population, ensartinib conferred the best PFS (Prbest 50%, SUCRA 87%), and for patients with brain metastases at baseline, lorlatinib showed the best PFS (Prbest 70%, SUCRA 93%).

CONCLUSIONS

For first-line treatment of patients with ALK-positive NSCLC, lorlatinib was associated with the best PFS and objective response rate, but poorer safety profile, whereas alectinib demonstrated the best OS and safety profile. In Asians, ensartinib conferred the best PFS benefit, and in the brain baseline metastasis population, lorlatinib conferred the best PFS benefit.

PLAIN LANGUAGE SUMMARY

Among the many molecularly targeted drugs currently used to treat anaplastic lymphoma kinase mutation-positive non-small cell lung cancer, lorlatinib may be one of the most effective targeted drugs. Lung cancer has long been at the top of cancer rankings in terms of incidence and mortality. Today, the treatment of lung cancer has moved into the era of precision therapy. In this article, we use a statistical approach to compare the efficacy and safety of targeted drugs that have been used in the first-line treatment of anaplastic lymphoma kinase mutations to improve the reference for clinicians to make treatment decisions in the real world.

Molecular determinants of clinical outcomes for anaplastic lymphoma kinase-positive non-small cell lung cancer in Chinese patients: A retrospective study

Gene complexity affects the clinical outcomes of anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC). Here, we reviewed the medical records of patients with NSCLC between September 2015 and December 2020 in a single institution. We examined the clinical and genomic predictors of these outcomes using multivariate Cox proportional hazards analysis. Overall, 105 patients with ALK-rearranged NSCLC were included. Echinoderm microtubule-associated protein-like 4 (EML4) was the predominant fusion partner (96.2%). Five patients (4.8%) had non-EML4 fusion partners; three had novel partners. EML4::ALK variant 3 (36.5%) was predominant. One patient had the following three subtypes: E13::A20, E6ins33::A20, and E20::A20. Median progression-free survival (PFS), but not overall survival (OS), was significantly different between patients with variants 3 and 1. TP53 was the most common concomitant mutation (21.4%). The presence of TP53 mutations was associated with shorter PFS among patients who received ALK-TKI. Patients with concomitant oncogene mutations presented significantly shorter OS and PFS than those with only ALK rearrangement. In a multivariate Cox regression model, concomitant oncogene mutations and variant 3 carrier status were prognostic factors for PFS, whereas baseline brain metastasis was a prognostic factor for OS.

Silibinin Overcomes EMT-Driven Lung Cancer Resistance to New-Generation ALK Inhibitors

Epithelial-to-mesenchymal transition (EMT) may drive the escape of ALK-rearranged non-small-cell lung cancer (NSCLC) tumors from ALK-tyrosine kinase inhibitors (TKIs). We investigated whether first-generation ALK-TKI therapy-induced EMT promotes cross-resistance to new-generation ALK-TKIs and whether this could be circumvented by the flavonolignan silibinin, an EMT inhibitor. ALK-rearranged NSCLC cells acquiring a bona fide EMT phenotype upon chronic exposure to the first-generation ALK-TKI crizotinib exhibited increased resistance to second-generation brigatinib and were fully refractory to third-generation lorlatinib. Such cross-resistance to new-generation ALK-TKIs, which was partially recapitulated upon chronic TGFβ stimulation, was less pronounced in ALK-rearranged NSCLC cells solely acquiring a partial/hybrid E/M transition state. Silibinin overcame EMT-induced resistance to brigatinib and lorlatinib and restored their efficacy involving the transforming growth factor-beta (TGFβ)/SMAD signaling pathway. Silibinin deactivated TGFβ-regulated SMAD2/3 phosphorylation and suppressed the transcriptional activation of genes under the control of SMAD binding elements. Computational modeling studies and kinase binding assays predicted a targeted inhibitory binding of silibinin to the ATP-binding pocket of TGFβ type-1 receptor 1 (TGFBR1) and TGFBR2 but solely at the two-digit micromolar range. A secretome profiling confirmed the ability of silibinin to normalize the augmented release of TGFβ into the extracellular fluid of ALK-TKIs-resistant NSCLC cells and reduce constitutive and inducible SMAD2/3 phosphorylation occurring in the presence of ALK-TKIs. In summary, the ab initio plasticity along the EMT spectrum may explain the propensity of ALK-rearranged NSCLC cells to acquire resistance to new-generation ALK-TKIs, a phenomenon that could be abrogated by the silibinin-driven attenuation of the TGFβ/SMAD signaling axis in mesenchymal ALK-rearranged NSCLC cells.

PI3Kβ inhibition enhances ALK-inhibitor sensitivity in ALK-rearranged lung cancer

Treatment with anaplastic lymphoma kinase (ALK) inhibitors significantly improves outcome for non-small-cell lung cancer (NSCLC) patients with ALK-rearranged tumors. However, clinical resistance typically develops over time and, in the majority of cases, resistance mechanisms are ALK-independent. We generated tumor cell cultures from multiple regions of an ALK-rearranged clinical tumor specimen and deployed functional drug screens to identify modulators of ALK-inhibitor response. This identified a role for PI3Kβ and EGFR inhibition in sensitizing the response regulating resistance to ALK inhibition. Inhibition of ALK elicited activation of EGFR, and subsequent MAPK and PI3K-AKT pathway reactivation. Sensitivity to ALK targeting was enhanced by inhibition or knockdown of PI3Kβ. In ALK-rearranged primary cultures, the combined inhibition of ALK and PI3Kβ prevented the EGFR-mediated ALK-inhibitor resistance, and selectively targeted the cancer cells. The combinatorial effect was seen also in the background of TP53 mutations and in epithelial-to-mesenchymal transformed cells. In conclusion, combinatorial ALK- and PI3Kβ-inhibitor treatment carries promise as a treatment for ALK-rearranged NSCLC.

ALK-R3HDM1 and EML4-ALK fusion as a mechanism of acquired resistance to gefitinib: A case report and literature review

We report a case with a novel ALK-R3HDM1 and EML4-ALK dual fusion that might be a delicate mechanism for the acquired resistance of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI). A patient with EGFR L858R lung adenocarcinoma developed disease progression after 72.7 months of gefitinib therapy; rebiopsy was done, and next-generation sequencing showed the disappearance of the previous EGFR mutations. In addition, two new ALK fusions emerged, indicating that the emergence of dual ALK rearrangement may be the underlying mechanism of gefitinib resistance. The patient exhibits an excellent response to second-line alectinib treatment with a significant clinical benefit and a high quality of life. Finally, we summarized previous studies in which ALK fusion is a required resistance mechanism to EGFR-TKI.

Therapeutic Advances of Rare ALK Fusions in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancer cases and is the leading cause of cancer-related death. Despite advances in chemotherapy and immunotherapy, the prognosis for advanced patients remains poor. The discovery of oncogenic driver mutations, such as anaplastic lymphoma kinase (ALK) mutations, means that a subset of patients has opportunities for targeted therapy. With the improvement of genetic testing coverage, more and more ALK fusion subtypes and ALK partners have been discovered, and more than 90 rare ALK fusion subtypes have been found in NSCLC. However, unlike the common fusion, echinoderm microtubule-associated protein-like 4 (EML4)-ALK, some rare ALK fusions such as striatin (STRN)-ALK and huntingtin interacting protein 1 (HIP1)-ALK, etc., the large-scale clinical data related to its efficacy are still immature. The clinical application of ALK-tyrosine kinase inhibitors (ALK-TKIs) mainly depends on the positivity of the ALK gene, regardless of the molecular characteristics of the fusion partner. Recent clinical studies in the ALK-positive NSCLC population have demonstrated differences in progression-free survival (PFS) among patients based on different ALK fusion subtypes. This article will introduce the biological characteristics of ALK fusion kinase and common detection methods of ALK fusion and focus on summarizing the differential responses of several rare ALK fusions to ALK-TKIs, and propose corresponding treatment strategies, so as to better guide the application of ALK-TKIs in rare ALK fusion population.

A non-functional 5' ALK fusion validated at the RNA level as a classical EML4-ALK that responds well to the novel ALK inhibitor ensartinib: A case report

Background

Currently, many targeted drugs are approved for treatment of ALK fusion non-small cell lung cancer. However, it has been previously assumed that patients with 5′ non-oncogenic kinase (5′ NOK) fusion detected by DNA next-generation sequencing (NGS) would not benefit from ALK inhibitors because of lack of an intact kinase domain.

Case description

A novel 5′ NOK fusion form, ALK-CYP27C1 (A19:C5), was detected by DNA NGS in surgical tissue specimens of a patient with recurrent lung adenosquamous carcinoma. The patient achieved 29 months of progression-free survival with ensartinib treatment. The results of RNA NGS from the same operative tissue identified EML4-ALK (E13:A20) fusion variant type I.

Conclusion

This is the first case to provide real-world evidence of effective treatment of a patient with the 5′ NOK fusion form at the DNA level but functional EML4-ALK at the RNA level, illustrating the need for RNA testing in 5′ NOK patients.

Confirmation of lung adenocarcinoma as the primary cancer with detection of EML4-ALK rearrangement using next-generation sequencing: a case study

We report a female patient, who presented as a carcinoma of unknown primary site with multiple tumors in breast, lung, stomach, and ovary, was confirmed to be lung adenocarcinoma as primary cancer through detecting EML4-ALK rearrangement by the next generation sequencing (NGS). The patient was treated with crizotinib and resulted in significant regression of the primary and metastatic tumors, but resistance to crizotinib was developed 5 months after the treatment. Targeted therapy was, therefore, switched to alectinib, one of the second-generation of anaplastic lymphoma kinase (ALK) inhibitors, with excellent therapeutic response till November 16th, 2021. This study suggested that NGS be recommended to detect ALK rearrangement in the patients with carcinoma of unknown primary site, and that resistance to targeted therapy with ALK inhibitors should be considered for personalized precision medicine.

The Landscape of ALK-Rearranged Non-Small Cell Lung Cancer: A Comprehensive Review of Clinicopathologic, Genomic Characteristics, and Therapeutic Perspectives

Simple Summary

In recent years, prognosis of non-small cell lung cancer (NSCLC) patients significantly improved thanks to the introduction of tyrosine kinase inhibitors (TKIs) in clinical practice. ALK-rearranged NSCLC patients benefit from treatment with ALK inhibitors (ALK-i), which have shown a greater efficacy and a better intracranial activity than chemotherapy. Comparative studies between next-generation ALK-i are still lacking and clinicians are looking for reliable tools to determine which drug suits best for each patient. The aim of this review is to deepen the role of clinical and pathological characteristics influencing patients’ prognosis during treatment with ALK-i and to provide an overview of molecular mechanisms of ALK-i resistance. In this setting, liquid biopsy may play an important role in predicting tumor response and monitoring resistance mutations. We will summarize ongoing trials developing new ALK-i or combinations between ALK-i and other agents, which may represent future scenarios in the field of NSCLC research.

Abstract

During the last decade, the identification of oncogenic driver mutations and the introduction of tyrosine kinase inhibitors (TKIs) in daily clinical practice have substantially revamped the therapeutic approach of oncogene-addicted, non-small cell lung cancer (NSCLC). Rearrangements in the anaplastic lymphoma kinase (ALK) gene are detected in around 3–5% of all NSCLC patients. Following the promising results of Crizotinib, a first-generation ALK inhibitor (ALK-i), other second-generation and more recently third-generation TKIs have been developed and are currently a landmark in NSCLC treatment, leading to a significant improvement in patients prognosis. As clinical trials have already demonstrated high efficacy of each ALK-i, both in terms of systemic and intracranial disease control, comparative studies between second and third generation ALK-i are still lacking, and primary or secondary ALK-i resistance inevitably limit their efficacy. Resistance to ALK-i can be due to ALK-dependent or ALK-independent mechanisms, including the activation of bypass signaling pathways and histological transformation: these findings may play an important role in the future to select patients’ subsequent therapy. This review aims to provide an overview of underlying molecular alterations of ALK-i resistance and point out promising role of liquid biopsy in predicting tumor response and monitoring resistance mutations. The purpose of this review is also to summarize current approval for ALK-rearranged NSCLC patients, to help clinicians in making decisions on therapeutic sequence, and to deepen the role of clinicopathological and genomic characteristics influencing patients’ prognosis during treatment with ALK-i.

[A Case of Advanced Lung Squamous Cell Carcinoma with CLIP1-ALK Fusion Gene]

Anaplastic lymphoma kinase (ALK) fusion gene is an important tumor driver gene of non-small cell lung cancer, accounting for about 5% of patients with non-small cell lung cancer, of which 97% are patients with lung adenocarcinoma. Since the first discovery of echinoderm microtubule associated protein-like 4 (EML4)-ALK fusion in patients with lung adenocarcinoma in 2007, a variety of ALK fusion partners have been detected. CLIP1-ALK fusion gene was detected by next generation sequencing (NGS) in this patient with advanced lung squamous cell carcinoma, and Alectinib and Ensartinib were taken orally on May 5, 2021. Aletinib was effective for this patient but the patients died on September 30, 2021. This is a report of lung squamous cell carcinoma patients with CLIP1-ALK fusion gene treated with ALK inhibitors.
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Detection of ALK fusion variants by RNA-based NGS and clinical outcome correlation in NSCLC patients treated with ALK-TKI sequences

INTRODUCTION

Anaplastic lymphoma kinase (ALK) fusions identify a limited subset of non-small cell lung cancer (NSCLC) patients, whose therapeutic approach have been radically changed in recent years. However, diagnostic procedures and clinical-radiological responses to specific targeted therapies remain heterogeneous and intrinsically resistant or poor responder patients exist.

METHODS

A total of 290 patients with advanced NSCLC defined as ALK+ by immunohistochemistry (IHC) and/or fluorescent in situ hybridisation (FISH) test and treated with single or sequential multiple ALK inhibitors (ALKi) from 2011 to 2017 have been retrospectively retrieved from a multicentre Italian cancer network database. In 55 patients with enough leftover tumour tissue, specimens were analysed with both targeted and customised next generation sequencing panels. Identified fusion variants have been correlated with clinical outcomes.

RESULTS

Of the 55 patients, 24 received crizotinib as first-line therapy, 1 received ceritinib, while 30 received chemotherapy. Most of the patients (64%) received ALKi in sequence. An ALK fusion variant was identified in 73% of the cases, being V3 variant (E6A20) the most frequent, followed by V1 (E13A20) and more rare ones (e.g. E6A19). In three specimens, four new EML4-ALK fusion breakpoints have been reported. Neither fusion variants nor brain metastases were significantly associated with overall survival (OS), while it was predictably longer in patients receiving a sequence of ALKi. The presence of V1 variant was associated with progression-free survival (PFS) improvement when crizotinib was used (p = 0.0073), while it did not affect cumulative PFS to multiple ALKi.

CONCLUSION

Outcomes to sequential ALKi administration were not influenced by fusion variants. Nevertheless, in V1+ patients a prolonged clinical benefit was observed. Fusion variant identification by NGS technology may add relevant information about rare chromosomal events that could be potentially correlated to worse outcomes.

Excellent response of lung adenocarcinoma harboring a rare SLC8A1 downstream intergenic region ALK fusion to ceritinib treatment: A case report

RATIONALE

Anaplastic lymphoma kinase (ALK) gene fusion, an important driver gene alteration leading to the development of lung cancer, occurs in 5% of nonsmall cell lung cancer (NSCLC) cases in China. In addition to echinoderm microtubule-associated protein-like 4 (EML4)-ALK, which is the most common type of ALK fusion, various fusion partner genes have been identified in recent years. However, ALK intergenic breakpoint fusions confound fusion detection and targeted treatment.

PATIENT CONCERNS

A 40-year-old woman presented to our hospital with a 2-month history of a cough.

DIAGNOSIS

Based on the right hilar lymph node biopsy and positron emission tomography computed tomography (PET-CT) examination, the patient was diagnosed with "stage IV lung adenocarcinoma" showing metastases in the mediastina, right hilar lymph nodes, and C7 vertebral body. A rare solute carrier family 8 member A1 (SLC8A1) downstream intergenic region ALK fusion was identified in biopsy specimens using next-generation sequencing (NGS).

INTERVENTIONS

The patient received first-line molecular-targeted therapy (ceritinib).

OUTCOMES

After nearly 9 months, the best evaluation of partial remission (PR) was obtained.

LESSONS

This is the first clinical evidence of advanced NSCLC due to a rare SLC8A1 downstream intergenic region ALK fusion that has been effectively treated with ceritinib. Whether this finding represents an inherent property of this fusion protein or its unique clinicopathological characteristics in patients carrying this fusion protein remains to be investigated. Moreover, the patient's durable response to ceritinib and future resistance mechanisms require further follow-up.

Artificial intelligence-based prediction of clinical outcome in immunotherapy and targeted therapy of lung cancer

Lung cancer accounts for the main proportion of malignancy-related deaths and most patients are diagnosed at an advanced stage. Immunotherapy and targeted therapy have great advances in application in clinics to treat lung cancer patients, yet the efficacy is unstable. The response rate of these therapies varies among patients. Some biomarkers have been proposed to predict the outcomes of immunotherapy and targeted therapy, including programmed cell death-ligand 1 (PD-L1) expression and oncogene mutations. Nevertheless, the detection tests are invasive, time-consuming, and have high demands on tumor tissue. The predictive performance of conventional biomarkers is also unsatisfactory. Therefore, novel biomarkers are needed to effectively predict the outcomes of immunotherapy and targeted therapy. The application of artificial intelligence (AI) can be a possible solution, as it has several advantages. AI can help identify features that are unable to be used by humans and perform repetitive tasks. By combining AI methods with radiomics, pathology, genomics, transcriptomics, proteomics, and clinical data, the integrated model has shown predictive value in immunotherapy and targeted therapy, which significantly improves the precision treatment of lung cancer patients. Herein, we reviewed the application of AI in predicting the outcomes of immunotherapy and targeted therapy in lung cancer patients, and discussed the challenges and future directions in this field.

Case report: Two novel intergenic region-ALK fusions in non-small-cell lung cancer resistant to alectinib: A report of two cases

Background

The anaplastic lymphoma kinase (ALK) mutation, also known as the diamond mutation in non–small-cell lung cancer (NSCLC), has been treated with tremendous success since it was first reported in 2007. Alectinib, a second generation ALK-Tyrosine kinase inhibitor (TKI), has been reported to have significantly longer progression- free survival (PFS) than first generation ALK inhibitors in untreated ALK positive NSCLC. However, the clinical efficacy of ALK-TKIs on rare ALK fusions remains unclear. In recent years, with the popularity of next-generation sequencing (NGS) technology, an increasing number of novel ALK fusion partners have been reported, but the responses are heterogeneous among different ALK fusions. Considering the inconsistent reactions, the clinical efficacy of ALK-TKIs in rare ALK gene fusions remains to be evaluated in more cases.

Methods

To seek for individualized therapy, the tumor tissues acquired during biopsy were sent for genomic testing by NGS based on a 139-gene panel and a 425-gene panel in a centralized clinical testing center (GENESEEQ Technology Inc, Nanjing, China). See Supplementary Material for more details about the methods for DNA-based NGS, RNA-based NGS.

Results

We present two cases of patients with lung adenocarcinoma harboring two novel Intergenic Region (IGR)-ALK rearrangements detected by DNA sequencing, which had limited clinical response to ALK-TKIs but showed sensitivity to chemotherapy combined with bevacizumab therapy in patient 2, with a PFS of over 1 year up till the last follow‐up assessment.

Conclusions

In summary, our cases emphasize the need for comprehensive molecular analysis of different ALK fusion partners at the DNA level to formulate accurate treatment strategies and provide a certain therapeutic reference for these two types of novel IGR-ALK fusions.

Genetic correlation of crizotinib efficacy and resistance in ALK- rearranged non-small-cell lung cancer

OBJECTIVES

Crizotinib remains one of the most commonly used targeted therapies for ALK fusion-positive patients. However, the mutational profiles and mechanisms of resistance to first-line crizotinib treatment remain to be thoroughly examined.

MATERIALS AND METHODS

We retrospectively reviewed 125 ALK-positive patients with histological and/or cytological diagnosis of NSCLC. Of these, baseline samples were available from 62 patients and 63 had resistance samples following first-line crizotinib treatment, with 18 patients having paired baseline and resistance samples. All patients were genetically profiled by NGS using a 139 lung cancer gene panel (Pulmocan®, Nanjing Geneseeq Technology Inc.). Survival associations of progression-free survival (PFS) and resistance mechanisms were evaluated in relation to ALK fusion variants and background genetic alterations.

RESULTS

The median age of the cohort was 53 years old (range 26-78; 46.4 % females). Three novel ALK fusion partners were identified, including PSME4, cullin3 (CUL3) and coiled-coil domain containing 85A (CCDC85A). Among the different ALK fusion genes, patients carrying the v3 variant experienced worse PFS outcome compared with other non-v3 fusions (P = 0.01) in response to first-line crizotinib. Profiling of the genetic landscape revealed TP53 as the most frequently co-mutated gene, alterations of which were associated with unfavorable outcome (P = 0.024) and were among the secondary acquired mutations in the resistance samples. Examinations of the resistance mechanisms showed that the v3 variant was more likely to acquire ALK activating mutations (P = 0.04). Off-target resistance mechanisms included mutations in genes in the RAS/MAPK and its parallel pathway genes, such as ERBB2, BRAF, KRAS, FGFR3, NF1 and CREBBP.

CONCLUSION

In this study, through profiling of the mutational landscape of ALK-positive advanced NSCLCs both at baseline and disease progression, we characterized resistance mechanisms and molecular correlations of PFS in response to first-line crizotinib. Our findings may facilitate rational selection of subsequent ALK TKIs in the clinic.

Identification and therapeutic evaluation of ALK rearrangements in non-small-cell lung cancer

This study aimed to present a comprehensive assessment of anaplastic lymphoma kinase (ALK) rearrangements evaluated by DNA/RNA-based next-generation sequencing (NGS) and Ventana immunohistochemistry (IHC) in patients with non-small-cell lung cancer (NSCLC) and to evaluate the therapeutic outcomes of ALK tyrosine kinase inhibitor (TKI) treatment. We investigated ALK gene fusions in 14,894 patients with NSCLC using Ventana IHC and NGS, including 12,533 cases detected via DNA-based NGS and 2,361 cases using RNA-based NGS. The overall percentage agreement (OPA), positive percentage agreement (PPA), and negative percentage agreement (NPA) were calculated when comparing the results between NGS and IHC. The therapeutic responses to ALK-TKIs were also evaluated. In total, 3.50% (439/12,533) of specimens were NGS ALK-positive (NGS-p) in the DNA-based NGS cohort and 3.63% (455/12,533) were IHC ALK-positive (IHC-p). The OPA of NGS was 99.60%, whereas its PPA and NPA were 92.75 and 99.86%, respectively. In the adenocarcinoma (ADC) subcohort, the PPA was 95.69%. In the RNA-based NGS cohort, 2.20% (52/2,361) of specimens were NGS-p and 2.63% (62/2,361) were IHC-p. The OPA of NGS was 99.49%; its PPA and NPA were 82.26 and 99.96%, respectively. Thirteen patients with discordant results received ALK-TKI treatment. In the seven NGS-p/IHC-negative (IHC-n) patients, the overall response rate (ORR) was 85.4% (6/7) and the disease control rate (DCR) was 100%. In the six NGS-negative/IHC-p patients, the ORR was 66.7% (4/6) and the DCR was 100%. In summary, a high concordance of ALK gene fusion detected via NGS and IHC was observed in this study. DNA-based NGS had a higher OPA, PPA, and PPA in the ADC subcohort, whereas RNA-based NGS had a higher NPA. Overall, the results suggest that the combination of NGS and IHC can improve the accuracy of ALK fusion detection; hence, a result determination algorithm for clinical detection of ALK gene fusion was also proposed.

Alternative Treatment Options to ALK Inhibitor Monotherapy for EML4-ALK-Driven Lung Cancer

EML4-ALK is an oncogenic fusion protein that accounts for approximately 5% of NSCLC cases. Targeted inhibitors of ALK are the standard of care treatment, often leading to a good initial response. Sadly, some patients do not respond well, and most will develop resistance over time, emphasizing the need for alternative treatments. This review discusses recent advances in our understanding of the mechanisms behind EML4-ALK-driven NSCLC progression and the opportunities they present for alternative treatment options to ALK inhibitor monotherapy. Targeting ALK-dependent signalling pathways can overcome resistance that has developed due to mutations in the ALK catalytic domain, as well as through activation of bypass mechanisms that utilise the same pathways. We also consider evidence for polytherapy approaches that combine targeted inhibition of these pathways with ALK inhibitors. Lastly, we review combination approaches that use targeted inhibitors of ALK together with chemotherapy, radiotherapy or immunotherapy. Throughout this article, we highlight the importance of alternative breakpoints in the EML4 gene that result in the generation of distinct EML4-ALK variants with different biological and pathological properties and consider monotherapy and polytherapy approaches that may be selective to particular variants.

Lorlatinib as a treatment for ALK-positive lung cancer

Lorlatinib, a third-generation ALK tyrosine kinase inhibitor, has been approved as a treatment for ALK-positive lung cancer. This review provides information regarding the pharmacology and clinical features of lorlatinib, including its efficacy and associated adverse events. Pivotal clinical trials are discussed along with the current status of lorlatinib as a treatment for ALK-positive lung cancer and future therapeutic challenges.

A novel SLC8A1/LINC01913 intergenic region-ALK fusion identified by NGS and validated by IHC and FISH in a stage IIB lung adenocarcinoma patient who remains relapse-free during the treatment of crizotinib: a case report

In resected non-small cell lung cancer (NSCLC), ALK rearrangements are associated with worse recurrence-free survival (RFS) than other driver genes. In addition, the micropapillary pattern of NSCLC is associated with a poor prognosis. In recent years, crizotinib tyrosine kinase inhibitors (TKIs) have been widely used to treat patients with advanced NSCLC with ALK fusion. Patient survival outcomes have become highly promising, reflecting the necessity of exploring the application of ALK-TKIs in resected, early stage NSCLC with ALK rearrangements. A 60-year-old Chinese man was diagnosed with stage IIB lung adenocarcinoma harboring a novel SLC8A1/LINC01913 intergenic region-ALK fusion identified by NGS and validated by immunohistochemical staining (IHC) and fluorescence in situ hybridization (FISH). Crizotinib (250 mg orally once daily) was administered to the patient following surgery. The patient remained relapse-free after four months and seven months. This report provided a valuable treatment plan for early lung adenocarcinoma patients with high risks to prevent a postoperative recurrence.

Role of chemokine-mediated angiogenesis in resistance towards crizotinib and its reversal by anlotinib in EML4-ALK positive NSCLC

BACKGROUND

The identification of early plasma biomarkers for clinical outcomes and drug resistance has key importance for risk stratification in anaplastic lymphoma kinase (ALK)-positive advanced non-small cell lung cancer (NSCLC) patients. Moreover, it remains unclear whether the anti-angiogenic drug anlotinib can reverse the resistance of ALK-tyrosine kinase inhibitor (ALK-TKI) crizotinib, and no research has explored the effect of anlotinib combined with crizotinib on ALK-positive patients.

METHODS

In this study, 76 baseline and longitudinal plasma samples from 61 ALK-positive NSCLC patients receiving crizotinib treatment were analyzed by Luminex liquid suspension chip for 40 chemokines. RNA sequence (RNA-seq) was used to identify differentially expressed genes (DEGs) between H3122 and H3122-crizotinib resistant (H3122CR) cells. Tube formation assay was performed to investigate the effect of chemokines on angiogenesis. And H3122CR-derived xenograft model was constructed to validate the efficacy and safety of anlotinib combined with crizotinib in vivo.

RESULTS

Baseline and progression plasma samples detection suggested that CCL20 played a crucial role in monitoring and predicting the clinical response of crizotinib (hazard ratio for progression-free survival: 2.27 (1.13-4.58); for overall survival: 2.7 (1.23-5.8)). RNA-seq results for H3122 and H3122CR cells showed that high expression of chemokines and angiogenesis pathways were involved in crizotinib resistance. Subsequently, in vitro experiments indicated that CCL20 may induce crizotinib resistance by activation of angiogenesis via JAK2/STAT3-CCL20-VEGFA/IL6 axis. We further found that anti-angiogenic TKI anlotinib could reverse crizotinib resistance by inhibiting chemokines-induced angiogenesis, and anlotinib combined with crizotinib has a better antitumor effect than monotherapy in vitro & in vivo.

CONCLUSIONS

Overall, CCL20-mediated angiogenesis is involved in crizotinib resistance and could be overcome by using anlotinib in EML4-ALK positive NSCLC. The combination of anlotinib and crizotinib is a promising strategy for patients resistant to ALK-TKIs.

Detecting anaplastic lymphoma kinase (ALK) gene rearrangements with next-generation sequencing remains a reliable approach in patients with non-small-cell lung cancer

Next-generation sequencing (NGS) is rapidly becoming routine in clinical oncology practice to identify therapeutic biomarkers, including gene rearrangements in anaplastic lymphoma kinase (ALK). Our study investigated the concordance of ALK positivity evaluated by DNA-based NGS with orthogonal ALK testing methods such as fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), and RNA-based NGS (RNA-NGS). Thirty-eight patients with lung adenocarcinoma who were detected with ALK rearrangements using DNA-NGS and also had adequate tissue samples submitted for FISH, IHC, and RNA-NGS, were included in this study. Of the 38 patients, RNA samples from 3 patients failed quality control for RNA-NGS. The concordance of ALK positivity was calculated relative to DNA-NGS results. The concordance rates were 97.1% (34/35) for RNA-NGS, 94.7% (36/38) for IHC, and 97.4% (37/38) for FISH. DNA-NGS detected single ALK rearrangements in 14 (35.0%) patients and complex ALK rearrangements in 26 (65.0%). RNA-NGS detected only single transcripts of the primary ALK fusions. A novel LANCL1-ALK (L7:A20) detected using DNA-NGS was detected as EML4-ALK (E13:A20) transcripts using RNA-NGS. Interestingly, patients with single ALK rearrangements were more likely to be detected with atypical isolated red signals (p < 0.001), while patients with complex ALK rearrangements were more likely to be detected with atypical split red and green signals less than 2 signal diameters apart (p < 0.001). Our study highlights the reliability of NGS in the accurate detection of specific ALK fusion variants and concomitant mutations that are crucial for individualized treatment decisions in patients with lung cancer.

Special issue "The advance of solid tumor research in China": Real-world clinical outcomes of alectinib for advanced non-small-cell lung cancer patients with ALK fusion in China

Global phase 3 trials have demonstrated the priority of several next-generation anaplastic lymphoma kinase-tyrosine kinase inhibitors (ALK-TKIs). However, clinical studies are conducted with specific populations that differ from the real world. The study aimed to evaluate the clinical outcomes of alectinib in real-world settings. Patients with advanced non-small-cell lung cancer (NSCLC) and EML4-ALK fusion were enrolled from two medical centers between June 2018 and June 2020. The primary endpoints were objective response rate (ORR) and progression-free survival (PFS) to alectinib. The secondary endpoint was response of brain metastases. The risk factors for disease progression were also investigated. In total, 127 patients with advanced NSCLC were enrolled into this study. Of them, 54.3% received first-line alectinib. The 1- and 2-year PFS rates were 77.4% and 68.3%, respectively. ORR and disease control rate (DCR) were 53.5% and 91.3%, respectively. Among patients with brain metastases, intracranial ORR and DCR were 63.6% and 88.6%, respectively. In addition, we found that "crizotinib pretreatment", "liver metastasis", and "TP53 co-mutation" were individually associated with shorter PFS in alectinib treatment. In conclusion, this study confirms the salient clinical outcomes of alectinib for ALK-fusion-driven NSCLC patients with or without brain metastases, adding real-world evidence to the priority of alectinib in clinical practice. This article is protected by copyright. All rights reserved.

A novel alectinib-sensitive CTNND1-ALK fusion in a lung adenocarcinoma patient: a case report

Genomic fusions of anaplastic lymphoma kinase (ALK) are a well-established therapeutic target in non-small-cell lung cancer (NSCLC). Although various ALK fusion variants have been identified in NSCLC, their responses to ALK tyrosine-kinase inhibitors (TKIs) are heterogeneous. We report the case of a 71-year-old female patient diagnosed with lung adenocarcinoma with liver metastases. A novel CTNND1 (exon 14)-ALK (exon 20) fusion was identified from the biopsy sample by next-generation sequencing (NGS) and validated by immunohistochemistry (IHC) staining. Alectinib was administered, and the patient soon achieved partial response (PR). The progression-free survival (PFS) exceeded 15 months as of January 25, 2022. Our findings expand the spectrum of ALK rearrangements and provide a potential treatment option for lung adenocarcinoma patients with CTNND1-ALK fusions.

ALK fusion variant 3a/b, concomitant mutations, and high PD-L1 expression were associated with unfavorable clinical response to second-generation ALK TKIs in patients with advanced ALK-rearranged non-small cell lung cancer (GASTO 1061)

OBJECTIVES

Second-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) have significantly improved clinical outcomes in patients with advanced ALK-positive non-small cell lung cancer (NSCLC), but clinical responses vary widely. In this study, the impacts of ALK fusion variants, concomitant mutations, and PD-L1 expression on the clinical response were evaluated in patients receiving second-generation ALK TKIs.

MATERIALS AND METHODS

We retrospectively enrolled 193 patients with ALK-rearranged advanced NSCLC who received second-generation ALK TKIs at Sun-yat Sen University Cancer Center from January 2015 to December 2020. The ALK fusion variants and concomitant mutations were identified with next-generation sequencing, while PD-L1 expression was assessed by immunohistochemistry.

RESULTS

The median progression-free survival (PFS) was significantly shorter for variant 3a/b than for other variants (9.93 months vs 16.97 months, HR 1.941, P = 0.0014). Baseline concomitant mutations were significantly associated with shorter PFS while on ALK TKIs (median PFS, 10.87 months vs 22.47 months, HR 1.984, P = 0.002). A subset of 68 patients was analyzed for PD-L1 expression: TPS 0% in 32.4% (22/68) of the patients, 1-49% in 30.9% (21/68) of the patients, and ≥ 50% in 36.7% (25/68) of the patients. Expression of PD-L1 was significantly associated with variant 3a/b and concomitant mutations. Median PFS was shorter in patients with high PD-L1 expression (median PFS in patients with PD-L1 TPS of 0% vs 1-49% vs ≥ 50% were 27.43 months vs 30.63 months vs 9.50 months, respectively, P = 0.001). In multivariate analysis, PD-L1 expression (TPS ≥ 50%), concomitant mutations, and variant 3a/b remained negative prognostic factors for the clinical efficacy of second-generation ALK TKIs in ALK-rearranged non-small cell lung cancer.

CONCLUSION

ALK fusion variant 3a/b, concomitant mutations, and high PD-L1 expression were associated with unfavorable clinical response to second-generation TKIs in ALK-rearranged NSCLC.

Assessment of ALK Fusions in Uncommon Inflammatory Myofibroblastic Tumors With ALK IHC Positivity but FISH-Equivocal Findings by Targeted RNA Sequencing

CONTEXT.—

Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) are common methods to detect ALK status in inflammatory myofibroblastic tumors (IMTs). However, equivocal ALK FISH signals and inconsistency between FISH and IHC are occasionally observed.

OBJECTIVE.—

To study the inconsistency between FISH and IHC, and clarify ALK status in IMT by targeted RNA sequencing (RNAseq).

DESIGN.—

In this study, 12 consultation cases preliminarily diagnosed as uncommon IMTs with ALK IHC positivity but FISH negativity, plus 3 ALK-positive and 3 ALK-negative IMTs, were re-analyzed by IHC, FISH, and RNAseq.

RESULTS.—

As a result, 1 case with FUS-TFCP2 fusion was detected by RNAseq, which was previously misdiagnosed as IMT. In the other 11 uncommon IMTs, 90.9% (10 of 11) showed equivocal ALK FISH signals, and all were confirmed to harbor ALK fusion by RNAseq, except for 1 failure, suggesting that a low threshold for ALK FISH might be proposed in IMT. Furthermore, RNAseq also identified IGFBP5-ALK in 1 case with ALK IHC positivity but typical FISH negativity, suggesting the possibility of false negatives for ALK FISH. For the typical IMTs, ALK fusion was identified by RNAseq in all 3 ALK-positive IMTs as expected, and additionally FN1-ROS1 fusions were identified in 2 of 3 ALK-negative IMTs.

CONCLUSIONS.—

These findings indicated that RNAseq can simultaneously detect multiple gene fusions and provide fusion forms and breakpoints, which is of great value for differential diagnosis, especially for those uncommon IMTs with equivocal FISH findings, or inconsistency between IHC and FISH.

Clinical Impact of Switching to Ceritinib After Severe AEs Related to Crizotinib/Alectinib in a Novel PTH2R-ALK Fusion Lung Adenocarcinoma: A Case Report

Lung cancer is still the leading cause of morbidity and mortality by cancer among men, according to the latest epidemiological data in China. Anaplastic lymphoma kinase (ALK) rearrangements act as key oncogenic drivers of non-small cell lung cancer (NSCLC) and have been identified in 5–6% of NSCLC. Although ALK inhibitors (ALK-TKIs) were proven to be more effective than chemotherapy in ALK-positive NSCLC patients and the safety profile of these drugs was favorable, novel ALK fusions NSCLC might discontinue or switch treatment because of adverse events (AEs) have rarely previously been reported. Here, we describe a male patient with stage IV lung adenocarcinoma who carried a novel PTH2R-ALK fusion identified by next-generation sequencing (NGS). The patient first took crizotinib but switched to alectinib due to gastrointestinal AEs. Although alectinib remained effective on tumors, ceritinib (450 mg) was replaced after the AEs of hyperbilirubinemia occurred. After reducing the dose to 300mg, the diarrhea AEs caused by ceritinib were effectively relieved, and the patient obtained sustained clinical benefit with progression-free survival nearly 12 months. Our findings offer valuable information for the safety management of NSCLC patients with a novel PTH2R-ALK fusion treated by ALK-TKIs.

Secondary mutant ALK-I1171s in pituitary metastases from a patient with ALK fusion-positive advanced lung adenocarcinoma: A case report and literature review

BACKGROUND

Pituitary metastasis accounts for a very low percentage of cases of brain metastasis from lung cancer, and there are uncertainties and challenges in diagnosis and treatment. We hope to shed some light on the diagnosis and treatment by reporting a case of ALK fusion mutation-positive lung cancer pituitary metastasis.

CASE PRESENTATION

We report a 48-year-old female patient with an initial diagnosis of stage IVB lung adenocarcinoma with ALK fusion. The patient developed headache, dizziness, hypopituitarism and hyperprolactinemia one year after treatment with crizotinib. Later, the patient underwent neurosurgical resection of the pituitary tumor and then symptomatic relief. Postoperative pathology suggested pituitary metastasis, and the next-generation gene sequencing conducted on the pituitary metastasis indicated that secondary drug resistance mutation ALK-I1171s occurred after the ALK fusion gene.

CONCLUSION

In this article, we present a patient with suspected pituitary metastases with lung cancer. The progression to pituitary mass resection and next-generation gene sequencing of the pituitary metastasis are suggestive for further diagnosis and treatment.

Identification of triple gene fusion ALK-LRRN2, LTBP1-ALK, and HIP1-ALK in advanced lung adenocarcinoma and response to alectinib: A case report

RATIONALE

Anaplastic lymphoma kinase (ALK) rearrangement is the second most common targetable oncogene-dirven gene in nonsmall cell lung cancer. Owing to the advanced sequencing technologies, new partner genes of ALK have been constantly detected.

PATIENT CONCERNS

A 42-year-old Chinese woman went to our hospital with the chief complaint of cough and expectoration for 1 month. The patient had no fever, chest pain, and hemoptysis.

DIAGNOSES

She was diagnosed with advanced lung adenocarcinoma. The patient underwent lung biopsy guided by computed tomography and pathology showed poorly differentiated adenocarcinoma. To explore possibility of targeted therapy, the tumor samples were subjected to next-generation sequencing, and a rare 3 ALK fusion variant ALK-LRRN2, LTBP1-ALK, and HIP1-ALK was identified.

INTERVENTIONS AND OUTCOMES

The patient subsequently received alectinib treatment, and achieved partial response. No significant drug related adverse reactions were found during alectinib treatment. The progression-free survival achieved 25 months.

LESSONS

Together, we identified a rare triple ALK fusion variant, ALK-LRRN2, LTBP1-ALK and HIP1-ALK, in a patient with lung adenocarcinoma. The patient benefited from alectinib treatment, which could provide a certain reference for the patients with such gene alteration.

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

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

Clinical outcome, long-term survival and tolerability of sequential therapy of first-line crizotinib followed by alectinib in advanced ALK+NSCLC: A multicenter retrospective analysis in China

BACKGROUND

There is limited data on the clinical outcome, long-term survival and tolerability of sequential therapy of first-line crizotinib followed by alectinib in a real-world setting for Chinese patients with advanced ALK+ NSCLC.

METHODS

The medical records of patients who received sequential therapy with first-line crizotinib followed by alectinib (no intermittent systemic therapy was allowed between the two ALK-TKIs) were collected from six centers in China. Combined time treatment to failure (C-TTF) was defined as the period from the start of crizotinib to the complete discontinuation of alectinib due to any cause.

RESULTS

A total of 61 patients were included in our study. Fifty-two patients were switched to alectinib due to disease progression, seven as a result of toxicity, and two due to patient preference. At the time of data cutoff, alectinib treatment was discontinued in 31 patients on account of disease progression while severe adverse events resulted in cessation of alectinib in another two patients. Rebiopsy was conducted in 21 patients following disease progression on alectinib in whom ALK secondary mutation was found in 13 patients. Patients with ALK secondary mutation demonstrated better PFS during treatment with subsequent ALK-TKIs compared with those without (10.4 vs. 3.1 m, p = 0.0018, HR = 0.08). With a median follow-up of 34.3 months, C-TTF was 39.2 months and estimated 5-year OS was 68.6% in the overall population.

CONCLUSION

Sequential therapy with first-line crizotinib followed by alectinib demonstrated long-term benefits. Different efficacy in subsequent ALK-TKI between patients with or without ALK secondary mutation further emphasized the importance of rebiopsy to guide targeted therapy more precisely.

Crizotinib Versus Conventional Chemotherapy in First-Line Treatment for ALK-Positive Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

INTRODUCTION

Lung cancer is the most frequently diagnosed type of cancer and the main cause of death from malignant neoplasms worldwide. One of the most recent discoveries in the context of non-small cell lung cancer (NSCLC) was the mutation of the anaplastic lymphoma kinase receptor (ALK). This genetic alteration is found in approximately 2-5% of NSCLC patients, and crizotinib was the first targeted therapy discovered for its first-line treatment.

OBJECTIVE

To conduct a systematic review and meta-analysis to estimate the magnitude of the overall survival (OS) and progression-free survival (PFS) from using crizotinib as treatment compared to traditional chemotherapy to guide future decision making.

METHODS

PRISMA and Cochrane recommendations were followed using the findings based on studies published in the main international electronic databases. Selection criteria included the following: randomized clinical trials (RCT) or cohort studies that had assessed the efficacy and effectiveness of crizotinib as monotherapy in patients with NSCLC with ALK fusions.

RESULTS

From 2504 publications identified in the literature, only eight publications referring to seven studies met the selection criteria, with high heterogeneity identified between the studies. Overall, there was a significant gain in PFS (HR 0.38; 95% CI 0.30-0.49; p < 0.00001); however, there was no significant gain in OS (HR 0.68; 95% CI 0.43-1.08; p = 0.10).

CONCLUSION

The study highlighted and confirmed that treatment with crizotinib led to clinical improvement in PFS among patients with advanced NSCLC with ALK fusion, as previously reported. However, there was no increase in overall survival in patients with NSCLC with genetic alterations of ALK. This must be considered when reviewing and funding treatments for NSCLC patients with this mutation.

Efficacy and Safety of First-Line Treatment Strategies for Anaplastic Lymphoma Kinase-Positive Non-Small Cell Lung Cancer: A Bayesian Network Meta-Analysis

Background

Targeted therapies have led to significant improvement in the management and prognosis of anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC). We performed a network meta-analysis of frontline treatment options of ALK-positive NSCLC to provide clinical guidance.

Methods

PubMed, Embase, ClinicalTrials.gov, and international conference databases were searched to identify relevant trials from inception to June 30, 2021. Phase III randomized controlled trials (RCTs) comparing treatments for patients with ALK-positive advanced NSCLC in the first-line setting were included in a Bayesian network meta-analysis. Eligible studies reported at least one of the following clinical outcomes: progression-free survival (PFS), overall survival (OS), risk of the central nervous system (CNS) progression, adverse events (AEs) of grade (G) 3 or higher (G3 AEs), or serious AEs (SAEs). Hazard ratios (HRs) and CI for primary outcome of PFS and secondary outcome of OS and risk of CNS progression were obtained. A multivariate, consistency model, fixed-effects analysis was used in the network meta-analysis. Data on G3 AEs and SAEs were abstracted and meta-analyzed. Risk of bias (RoB) was assessed using the Cochrane Collaboration’s tool.

Results

Nine RCTs comprising 2,484 patients were included with seven treatments: alectinib, brigatinib, ceritinib, crizotinib, ensartinib, lorlatinib, and chemotherapy. Compared with chemotherapy, ALK-tyrosine kinase inhibitors (TKIs) significantly prolong PFS and reduced risk of CNS progression except for ceritinib. Lorlatinib appears superior at reducing risk of CNS progression. None of the ALK-TKIs have a significantly prolonged OS as compared with chemotherapy. Lorlatinib increases the risk of G3 AEs as compared with alectinib (odds ratio 4.26 [95% CrI 1.22 to 15.53]), while alectinib caused the fewest G3 AEs.

Conclusions

Lorlatinib is associated with the highest PFS benefit and lowest risk of CNS progression benefits for patients with advanced ALK-positive NSCLC, compared with other first-line treatments, but with higher toxicity. The implementation of a newer generation of ALK-TKIs in the first-line treatment of ALK-positive NSCLC into current clinical practice is evolving rapidly.

The impact of the ALK fusion variant on clinical outcomes in EML4-ALK patients with NSCLC: a systematic review and meta-analysis

Background: Recent studies showed that ALK-fusion variants are associated with heterogeneous clinical outcomes. However, contradictory conclusions have been drawn in other studies showing no correlation between ALK variants and prognoses. Methods: A systematic review and meta-analysis was performed to evaluate the prognostic value of EML4-ALK fusion variants for patient outcomes. Results: 28 studies were included in the analysis. According to the pooled results, patients harboring variant 1 showed equivalent progression-free survival (PFS) and overall survival (OS) with non-v1 patients (hazard ratio [HR] for PFS: 0.91 [0.68-1.21]; p = 0.499; OS: 1.12 [0.73-1.72]; p = 0.610). Similarly, patients with v3 showed the same disease progress as non-v3 patients (pooled HR for PFS = 1.07 [0.72-1.58]; p = 0.741). However, pooled results for OS suggested that patients with v3 had worse survival than non-v3 patients (HR = 3.44 [1.42-8.35]; p = 0.006). Conclusion: Results suggest that patients with v1 exhibited no significant difference from non-v1 in terms of OS and PFS, while v3 was associated with shorter OS in ALK-positive patients with non-small cell lung cancer.

A Case of Lung Adenocarcinoma Response to Alectinib Harboring a Rare EML4-ALK Variant, Exon 6 of EML4 Fused to Exon 18 of ALK

More than 20 types of ALK fusion variant subtypes have been identified, including different fusion partner genes or EML4-ALK fusions with different breakpoints. However, different ALK fusions show different sensitivities to ALK-tyrosine kinase inhibitors (ALK-TKIs) and the emergence of rare fusions brings great challenges to the target therapy in clinic. We report a rare EML4-ALK (E6;A18) fusion in a patient with lung adenocarcinoma that responded well to alectinib. This is the second case of this rare variant reported but the first report of response to an ALK-TKI. This evidence is the first to show that alectinib may be effective for this rare fusion type of non-small cell lung cancer, and these findings have important implications for drug selection in patients with this subtype. Further studies are needed to understand the function of this variant.