Comparative analyses of overall survival in patients with anaplastic lymphoma kinase-positive and matched wild-type advanced nonsmall cell lung cancer

Efficacy and survival outcomes of alectinib vs. crizotinib in ALK‑positive NSCLC patients with CNS metastases: A retrospective study

Anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKIs) have transformed the treatment paradigm for patients with ALK-positive non-small cell lung cancer (NSCLC). Yet the differential efficacy between alectinib and crizotinib in treating patients with NSCLC and central nervous system (CNS) metastases has been insufficiently studied. A retrospective analysis was conducted of clinical outcomes of patients with ALK-positive NSCLC and CNS metastases treated at the Shandong Cancer Centre. Based on their initial ALK-TKI treatment, patients were categorised into either the crizotinib group or the alectinib group. Efficacy, progression-free survival (PFS), intracranial PFS and overall survival (OS) were evaluated. A total of 46 eligible patients were enrolled in the present study: 33 patients received crizotinib and 13 patients received alectinib. The median OS of the entire group was 66.8 months (95% CI: 48.5-85.1). Compared with the patients in the crizotinib group, the patients in the alectinib group showed a significant improvement in both median (m)PFS (27.5 vs. 9.5 months; P=0.003) and intracranial mPFS (36.0 vs. 10.8 months; P<0.001). However, there was no significant difference in OS between the alectinib and crizotinib groups (not reached vs. 58.7 months; P=0.149). Furthermore, there were no significant differences between patients receiving TKI combined with radiotherapy (RT) vs. TKI alone with respect to mPFS (11.0 vs. 11.7 months, P=0.863) as well as intracranial mPFS (12.5 vs. 16.9 months, P=0.721). In the present study, alectinib exhibited superior efficacy to crizotinib for treating patients with ALK-positive NSCLC and CNS metastases, especially in terms of delaying disease progression and preventing CNS recurrence. Moreover, the results demonstrated that it might be beneficial to delay local RT for patients with ALK-positive NSCL and CNS metastases.

A retrospective study of ensartinib-treated ALK-positive locally advanced or metastatic NSCLC patients in China

Aim

This retrospective study aimed to assess the efficacy and safety of ensartinib in Chinese patients with ALK-positive advanced NSCLC in real-world clinical practice.

Methods

Clinical data from ALK-positive NSCLC patients treated with ensartinib in China were collected and analyzed. Efficacy end points included objective response rate and progression-free survival. Safety profiles were also evaluated.

Results

A total of 682 patients were included in this study. The study demonstrated promising efficacy with an objective response rate of 54.0%, and the median progression-free survival was not estimable. Ensartinib exhibited a manageable safety profile with treatment-related adverse events (TRAEs) consistent with prior clinical trials. The most common TRAE was rash (21.1%) and no TRAE led to death.

Conclusion

Ensartinib is active and well tolerated for ALK-positive NSCLC patients in real-world clinical settings.

Alectinib Together with Intracranial Therapies Improved Survival Outcomes in Untreated ALK-Positive Patients with Non-Small-Cell Lung Cancer and Symptomatic and Synchronic Brain Metastases: A Retrospective Study

Purpose

The performance of alectinib and crizotinib in untreated anaplastic lymphoma kinase (ALK)-positive patients with non-small-cell lung cancer (NSCLC) and symptomatic and synchronic brain metastases is largely unknown. This retrospective study assessed the effectiveness of alectinib and crizotinib, together with intracranial therapies in a cohort of these patients.

Patients and Methods

This study included 34 previously untreated ALK-positive NSCLC patients with three or fewer intracranial metastases. Of these patients, 13 received oral alectinib 600 mg twice daily, and 21 received oral crizotinib 250 mg twice daily, until progressive disease, unacceptable toxicity, or death. All intracranial metastases were treated with craniotomy, CyberKnife, or both.

Results

Median overall progression-free survival (PFS) was 32.8 months (95% CI 24.4–41.2 months) in patients treated with alectinib and 8.0 months (95% CI 7.3–8.7 months) in patients treated with crizotinib. Median PFS of brain lesions was not yet reached with alectinib (95% CI 30.1 months–not estimated) and was 8.5 months (95% CI 7.2–12.3 months) with crizotinib. Median PFS of lung lesions was 38.5 months (95% CI 27.5–49.5 months) with alectinib and 9.2 months (95% CI 7.4–11.0 months) with crizotinib. Median overall survival was not yet reached with alectinib (95% CI 31.0 months–not estimated) and 30.3 months (95% CI 27.3–37.1 months) with crizotinib.

Conclusion

Compared with crizotinib, alectinib showed superior efficacy and lower toxicity in the treatment of ALK-positive patients with NSCLC and symptomatic and synchronic brain metastases. The inclusion of intracranial therapies such as craniotomy or CyberKnife further improved the brain PFS and overall survival of these patients.

Validation of the Novel International Association for the Study of Lung Cancer Grading System for Invasive Pulmonary Adenocarcinoma and Association With Common Driver Mutations

INTRODUCTION

We aimed to validate the use of the novel grading system proposed by the International Association for the Study of Lung Cancer pathology committee for prognosis stratification of invasive pulmonary adenocarcinomas (ADCs) in Chinese patients. Correlations between the grading system, common driver mutations, and adjuvant chemotherapy (ACT) were also investigated.

METHODS

From 2008 to 2016, the histologic patterns of a large cohort of 950 patients with invasive ADCs (stage I-III) were retrospectively analyzed and classified according to the proposed grading system. Subsequently, tumor grading was correlated with genetic data, ACT, and patient outcome.

RESULTS

Compared with conventional predominant pattern-based groups, the novel grading system carried improved survival discrimination (area under the curve = 0.768 for recurrence-free survival and 0.775 for overall survival). The area under the curve was not further improved when incorporated lymphovascular invasion status. EGFR mutations (p < 0.001) were correlated with moderate grade, whereas KRAS mutations (p = 0.041) and ALK fusions (p = 0.021) were significantly more prevalent in poor grade. The reclassification of the grading system based on EGFR mutation status revealed excellent survival discrimination (p < 0.001). In particular, patients on stage Ib to III with novel high-grade ADCs had an improved prognosis with ACT.

CONCLUSIONS

The novel International Association for the Study of Lung Cancer grading system is a practical and efficient discriminator for patient prognosis and should be part of an integrated pathologic-genetic subtyping to improve survival prediction. In addition, it may support patient stratification for aggressive adjuvant chemotherapy.

Screening for anaplastic lymphoma kinase (ALK) gene rearrangements in non-small-cell lung cancer in New Zealand

BACKGROUND

Lung cancer is a major cause of death in New Zealand. In recent years, targeted therapies have improved outcomes.

AIM

To determine the uptake of anaplastic lymphoma kinase (ALK) testing, and the prevalence, demographic profile and outcomes of ALK-positive non-small-cell lung cancer (NSCLC), in New Zealand, where no national ALK-testing guidelines or subsidised ALK tyrosine kinase inhibitor (TKI) therapies are available.

METHODS

A population-based observational study reviewed databases to identify patients presenting with non-squamous NSCLC over 6.5 years in northern New Zealand. We report the proportion tested for ALK gene rearrangements and the results. NSCLC samples tested by fluorescence in situ hybridisation were retested by next generation sequencing and ALK immunohistochemistry. A survival analysis compared ALK-positive patients treated or not treated with ALK TKI therapy.

RESULTS

From a total of 3130 patients diagnosed with non-squamous NSCLC, 407 (13%) were tested for ALK gene rearrangements, and patient selection was variable and inequitable. Among those tested, 34 (8.4%) had ALK-positive NSCLC. ALK-positive disease was more prevalent in younger versus older patients, non-smokers versus smokers and in Māori, Pacific or Asian ethnic groups than in New Zealand Europeans. Fluorescence in situ hybridisation, ALK immunohistochemistry and next generation sequencing showed broad concordance for detecting ALK-positive disease under local testing conditions. Among patients with ALK-positive metastatic NSCLC, those treated with ALK TKI survived markedly longer than those not treated with ALK TKI (median overall survival 5.12 vs 0.55 years).

CONCLUSION

Lung cancer outcomes in New Zealand may be improved by providing national guidelines and funding policy for ALK testing and access to subsidised ALK TKI therapy.

A population-based study of outcomes in patients with surgically resected non-small cell lung cancer with anaplastic lymphoma kinase-rearranged mutations: A matched-pair study

The present study aimed to evaluate clinical outcomes in patients with surgically resected non-small cell lung cancer (NSCLC) with anaplastic lymphoma kinase (ALK)-rearranged mutations. A matched-pair analysis in completely resected ALK-rearranged NSLC patients and those with neither ALK nor epidermal growth factor receptor (EGFR) mutations diagnosed at 11 institutes was performed between April 2008 and March 2019. A total of 51 patients with surgically resected ALK-rearranged NSCLC were included. Women constituted 68.6%, and smokers 29.4%. The median age was 65 years. In matched-pair analysis, disease-free survival and overall survival did not differ between patients with ALK-rearranged mutations and those without mutations. Post-recurrence survival in patients with ALK mutations was longer than that of patients with neither ALK nor epidermal growth factor receptor mutations. ALK genetic testing should be performed, even in elderly patients with NSCLC. Favorable prognosis might be expected after appropriate treatment for patients with recurrent ALK-mutated disease.

Complex Oncological Decision-Making Utilizing Fast-and-Frugal Trees in a Community Setting-Role of Academic and Hybrid Modeling

Non-small cell lung cancer is a devastating disease and with the advent of targeted therapies and molecular testing, the decision-making process has become complex. While established guidelines and pathways offer some guidance, they are difficult to utilize in a busy community practice and are not always implemented in the community. The rationale of the study was to identify a cohort of patients with lung adenocarcinoma at a City of Hope community site (n = 11) and utilize their case studies to develop a decision-making framework utilizing fast-and-frugal tree (FFT) heuristics. Most patients had stage IV (N = 9, 81.8%) disease at the time of the first consultation. The most common symptoms at initial presentation were cough (N = 5, 45.5%), shortness of breath (N = 3, 27.2%), and weight loss (N = 3, 27.2%). The Eastern Cooperative Oncology Group (ECOG) performance status ranged from 0-1 in all patients in this study. Distribution of molecular drivers among the patients were as follows: EGFR (N = 5, 45.5%), KRAS (N = 2, 18.2%), ALK (N = 2, 18.2%), MET (N = 2, 18.2%), and RET (N = 1, 9.1%). Seven initial FFTs were developed for the various case scenarios, but ultimately the decisions were condensed into one FFT, a molecular stage IV FFT, that arrived at accurate decisions without sacrificing initial information. While these FFT decision trees may seem arbitrary to an experienced oncologist at an academic site, the simplicity of their utility is essential for community practice where patients often do not get molecular testing and are not assigned proper therapy.

Response rate of patients with baseline brain metastases from recently diagnosed non-small cell lung cancer receiving radiotherapy according to EGFR, ALK and KRAS mutation status

Background

Previous studies have identified that patients with EGFR mutations tend to have better responses to targeted therapy, as well as chemotherapy; however, the effect of genetic alterations in terms of radiotherapy (RT)‐related outcomes has not been fully assessed. We studied the impact of common non‐small cell lung cancer (NSCLC) genetic alterations (EGFR, ALK and KRAS) in relation to objective response rate (ORR) to RT in patients with brain metastases.

Methods

From 2009–2015, 153 patients with an available genotyping status were treated with whole‐brain irradiation (WBI) before receiving systemic therapy. Primary outcome was ORR; secondary outcomes included intracranial progression‐free survival (IPFS) and overall survival (OS).

Results

Overall, ORR was 47.1%. ORR to RT varied significantly according to molecular status: EGFR (64.5%) ALK (54.5%) KRAS (20%) and WT (35.4%) (P = 0.001). EGFR mutation was the only independently associated factor for response to WBI (RR 3.52 [95% CI 1.6–7.7]; P = 0.002). Median IPFS was 10.8 months [95% CI 8.2–13.5] overall; however, IPFS also varied significantly according to molecular status: EGFR (18.2 months), ALK (18.4 months), KRAS (6.0 months) and WT (8.7 months) (P < 0.0001). OS for EGFR, ALK, KRAS and WT patients was 36.6, 32.2, 15.5 and 22.4 months, respectively (P = 0.014). Intracranial‐ORR (HR 0.4 [95% CI 0.2–0.6], P < 0.001) and mutation status (HR 0.7 [95% CI 0.6–0.9], P < 0.042) were independently associated with a higher OS.

Conclusions

RT response varies as per tumor molecular status. The presence of EGFR mutations favors the organ‐specific response to RT, and is associated with longer OS in patients with NSCLC and BM.

Key points

This study addressed for the first time the difference in radiotherapy‐related outcomes in patients with different genotypes of non‐small cell lung cancer (NSCLC) before they received systemic therapy.

Results show that response to radiotherapy varies as per tumor molecular status, particularly EGFR‐mutated tumors, have a favorable response to radiotherapy, contrary to KRAS‐mutated tumors.

Systematic review of sequencing of ALK inhibitors in ALK-positive non-small-cell lung cancer

The objective of this study was to understand outcomes of patients treated with ALK inhibitors, especially when ALK inhibitors are followed by other ALK inhibitors. A systematic literature review was conducted in PubMed, Embase, and Cochrane through July 17, 2017. Conference abstracts (three meetings in past 2 years) also were searched. Of 504 unique publications, 80 met inclusion criteria (47 clinical trials, 33 observational studies). Observational studies have the potential to provide information for ALK inhibitors used sequentially. Ten observational studies reported median overall survival of crizotinib-led sequences ranging from 30.3 to 63.75 months from initiation of crizotinib; 49.4-89.6 months from metastatic non-small-cell lung cancer diagnosis; and 15.5-22.0 months from initiation of the second-generation ALK inhibitor after initial crizotinib. Sequencing of ALK inhibitors may benefit patients progressing on initial ALK inhibitors.

Worse disease-free, tumor-specific, and overall survival in surgically-resected lung adenocarcinoma patients with ALK rearrangement

Introduction

This study determined the prevalence of anaplastic lymphoma kinase (ALK) rearrangement, and identified the associations of ALK rearrangement with clinicopathologic characteristics and treatment outcomes in patients with surgically-resected stage I-III lung adenocarcinoma.

Methods

A total of 534 surgically-resected lung adenocarcinoma patients were studied. The prevalence of ALK protein over-expression was determined by a fully-automated immunochemistry assay (with mouse monoclonal Ventana D5F3 antibody), and the associations of ALK rearrangement with clinicopathologic characteristics and treatment outcomes were analyzed.

Results

Forty-two (7.9%) of the 534 lung adenocarcinoma patients were ALK IHC-positive. ALK rearrangement was significantly associated with younger age (P = 0.011), high T-stage (P = 0.025), high pathologic stage (P = 0.002), solid predominant adenocarcinoma with mucin production (P = 0.006), invasive mucinous adenocarcinoma (P = 0.009), and receipt of adjuvant therapy after surgery (P = 0.036), but no significant associations were found between the ALK rearrangement and sex or smoking status. ALK IHC-positivity was significantly associated with a shorter disease-free survival, tumor-specific survival, and overall survival (P = 0.001, 0.026, and 0.007, respectively). Multivariate analysis showed that ALK IHC-positivity was an adverse prognostic factor for disease-free survival (HR, 1.80; 95% CI 1.18-2.77; P = 0.007), tumor-specific survival (HR, 2.59; 95% CI 1.35-4.97; P = 0.004), and overall survival (HR, 1.92; 95% CI 1.07-3.44; P = 0.030).

Conclusion

The clinical characteristics of patients with ALK-positive lung adenocarcinoma were similar to those of EGFR-mutated patients. ALK rearrangement was an adverse prognostic factor in surgically-resected lung adenocarcinoma patients.

Anaplastic lymphoma kinase gene rearrangement predicts better prognosis in NSCLC patients: A meta-analysis

OBJECTIVE

For non-small cell lung cancer (NSCLC), anaplastic lymphoma kinase (ALK) rearrangement and epidermal growth factor receptor (EGFR) mutations are predictive markers of the treatment benefit from selective tyrosine kinase inhibitors (TKI). However, their prognostic roles remained uncertain. Thus, we conducted this meta-analysis to evaluate the prognosis of ALK+ NSCLC patients in the treatment of surgery, chemotherapy, and/or EGFR-TKI.

MATERIALS AND METHODS

PubMed, Embase and Cochrane databases were thoroughly searched to identify relevant studies. Primary endpoints of this study included overall survival (OS), recurrence/progression free survival (RFS/PFS) and objective response rate (ORR). All statistical analyses were performed via REVIEW MANAGER (version 5.3).

RESULTS

In total, 15 studies involving 4981 NSCLC patients were included. This study demonstrated that smoking status profoundly influenced prognosis of ALK related NSCLC. In the general population with NSCLC, compared with ALK- arm, ALK+ arm obtained a significantly better prognosis (HR=0.81 for OS, 95% CI=0.72-0.91; 0.80 for RFS/PFS, 95% CI=0.70-0.90), even after further stratification analysis according to disease stage. However, in the non-smoking population with NSCLC, compared with ALK- arm, those in the ALK+ arm had a worse prognosis (HR=1.65 for OS, 95% CI=1.28-2.12; 1.23 for RFS/PFS, 95% CI=1.05-1.44). Furthermore, ALK+ patients experienced a significantly higher ORR in pemetrexed-based chemotherapy but not in EGFR-TKI.

CONCLUSIONS

Smoking status had a profound influence on the ALK-related prognosis of NSCLC. ALK rearrangement predicted a better prognosis in the general population with NSCLC, but a poor survival in the non-smoking population. Therefore, stratification according to smoking status is strongly recommended for future studies exploring ALK-related prognosis.

ALK protein expression in pulmonary adenocarcinoma of Tunisian patients

BACKGROUND

It is now necessary to determine ALK status in order to use targeted therapy.

AIM

herein, we assess immunohistochemical profile of ALK protein in a series of Tunisian patients with pulmonary adenocarcinoma.

MATERIALS AND METHODS

ALK protein expression was studied applying the D5F3 antibody with a fully automated Ventana CDx technique on a series of 19 patients.

RESULTS

Positive ALK expression was found in one case (5.2%) corresponding to a papillary adenocarcinoma which showed a strong granular and homogenous cytoplasmic staining. The patient was a 30-years-old woman.

CONCLUSION

The frequency of positive ALK expression based on immunohistochemistry in our series was similar to that reported in the world literature.

[Clinical Advanced in Early-stage ALK-positive Non-small Cell Lung Cancer Patients]

肺癌是我国癌症死亡最主要的原因。其中非小细胞肺癌（non-small cell lung cancer, NSCLC）占肺癌患者的85%，且大部分患者初诊时即为晚期。针对晚期NSCLC患者，分子靶向治疗成为人们关注的热点。棘皮动物微管相关蛋白-间变淋巴瘤激酶（echinoderm microtubule-associated protein-like 4 gene and the anaplastic lymphoma kinase gene, EML4-ALK）是NSCLC最常见的分子靶点之一，其特异性的小分子酪氨酸激酶抑制剂（tyrosine kinase inhibitors, TKIs）已被批准应用于ALK阳性晚期NSCLC患者的治疗。然而，ALK融合基因对早期NSCLC患者预后的影响，以及ALK阳性的早期NSCLC患者应用TKIs的必要性等问题尚不明确。本文主要围绕ALK阳性NSCLC患者的检测进展，早期ALK阳性NSCLC患者的临床病理特征、预后、ALK-TKIs应用必要性等情况做一简要综述。

Treatment modalities for advanced ALK-rearranged non-small-cell lung cancer

The ALK gene plays a key role in the pathogenesis of non-small-cell lung cancer (NSCLC). Patients with NSCLC harboring an ALK-rearrangement represent the second oncogene addiction to be identified in this disease. Crizotinib was the first ALK inhibitor showing pronounced clinical activity, and is now a reference treatment for ALK-positive NSCLC disease. However, despite initial impressive responses to crizotinib, acquired resistance almost invariably develops within 12 months. The pressing need for effective second-line agents has prompted the rapid development of next-generation ALK inhibitors. These agents, notably ceritinib and alectinib as the most developed, have a higher potency against ALK than crizotinib, along with activity against tumors harboring crizotinib-resistant mutations and potentially improved CNS penetration.

Lung cancer: Biology and treatment options

Lung cancer remains the leading cause of cancer mortality in men and women in the U.S. and worldwide. About 90% of lung cancer cases are caused by smoking and the use of tobacco products. However, other factors such as radon gas, asbestos, air pollution exposures, and chronic infections can contribute to lung carcinogenesis. In addition, multiple inherited and acquired mechanisms of susceptibility to lung cancer have been proposed. Lung cancer is divided into two broad histologic classes, which grow and spread differently: small-cell lung carcinomas (SCLCs) and non-small cell lung carcinomas (NSCLCs). Treatment options for lung cancer include surgery, radiation therapy, chemotherapy, and targeted therapy. Therapeutic-modalities recommendations depend on several factors, including the type and stage of cancer. Despite the improvements in diagnosis and therapy made during the past 25 years, the prognosis for patients with lung cancer is still unsatisfactory. The responses to current standard therapies are poor except for the most localized cancers. However, a better understanding of the biology pertinent to these challenging malignancies, might lead to the development of more efficacious and perhaps more specific drugs. The purpose of this review is to summarize the recent developments in lung cancer biology and its therapeutic strategies, and discuss the latest treatment advances including therapies currently under clinical investigation.

EML4-ALK enhances programmed cell death-ligand 1 expression in pulmonary adenocarcinoma via hypoxia-inducible factor (HIF)-1α and STAT3

Programmed cell death (PD)-1/PD-1 ligand-1 (PD-L1)-targeted therapy has emerged as a promising therapeutic strategy for lung cancer. However, whether EML4-ALK regulates PD-L1 expression in lung cancer remains unknown. A total of 532 pulmonary adenocarcinomas (pADCs), including 58 ALK-translocated tumors, were immunohistochemically evaluated for PD-L1 and PD-1. H23 (EGFR^Wild-typeEML4-ALK^-PD-L1^Low) and H2228 (EGFR^Wild-typeEML4-ALK⁺PD-L1^High) cells were transfected with EML4-ALK or ALK short interfering RNAs and used to investigate the alterations in PD-L1 expression. PD-L1 expression was detected in 81% of ALK-translocated pADCs; this value was significantly higher than those of pADCs with EGFR mutation, KRAS mutation or lacking ALK, EGFR or KRAS mutation (p <0.005 for all). Moreover, ALK-translocated pADC with PD-L1 expression showed significantly higher numbers of tumor-infiltrating PD-1⁺ cells. ALK knockdown or inhibition (crizotinib treatment) in H2228 cells downregulated PD-L1 expression. Transfection of H23 cells with EML4-ALK enhanced PD-L1 expression, which was compromised by crizotinib treatment. This ALK-dependent upregulation of PD-L1 expression was mediated by STAT3 and hypoxia-inducible factor (HIF)-1α under normoxia and hypoxia. Furthermore, EML4-ALK enhanced HIF-1α expression through increasing transcription and decreasing ubiquitination of HIF-1α. In ALK-translocated pADC tissues, significant positive correlations between PD-L1 and nuclear HIF-1α (p < 0.05) or pSTAT3 expression levels (p<0.005) were observed. Among patients with ALK-translocated pADC, strong PD-L1 expression was significantly associated with shorter progression-free (p = 0.001) and overall survival (p = 0.002) after crizotinib treatment. Collectively, our findings demonstrate that ALK-derived pADCs increase PD-L1 expression via HIF-1α and/or STAT3, thus providing a rationale for PD-1/PD-L1 pathway-targeted therapy in ALK-translocated lung cancer.

Biomarkers and targeted systemic therapies in advanced non-small cell lung cancer

The last decade has witnessed significant growth in therapeutic options for patients diagnosed with lung cancer. This is due in major part to our improved technological ability to interrogate the genomics of cancer cells, which has enabled the development of biologically rational anticancer agents. The recognition that lung cancer is not a single disease entity dates back many decades to the histological subclassification of malignant neoplasms of the lung into subcategories of small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). While SCLC continues to be regarded as a single histologic and therapeutic category, the NSCLC subset has undergone additional subcategorizations with distinct management algorithms for specific histologic and molecular subtypes. The defining characteristics of these NSCLC subtypes have evolved into important tools for prognosis and for predicting the likelihood of benefit when patients are treated with anticancer agents.

Therapeutic management of ALK+ nonsmall cell lung cancer patients

With therapeutic approaches based on oncogene addiction offering significant anticancer benefit, the identification of anaplastic lymphoma kinase (ALK) rearrangements is a key aspect of the management of lung cancers. The EML4-ALK gene fusion is detected in 4-8% of all lung cancers, predominantly in light smokers or nonsmokers. Crizotinib, the first agent to be approved in this indication, is associated with a median progression-free survival of 10.9 months when given as first-line treatment and 7.7 months when administered after chemotherapy. Median overall survival with crizotinib in the second-line setting is 20.3 months. Second-generation ALK inhibitors are currently being evaluated, with early studies giving impressive results, notably in patients resistant to crizotinib or with brain metastases. Among available chemotherapies, pemetrexed appears to be particularly active in this population. Despite this progress, several questions remain unanswered. What detection strategies should be favoured? What underlies the mechanisms of resistance and what options are available to overcome them? What are the best approaches for progressing patients? This review provides an overview of current data in the literature and addresses these questions.

Prevalence and natural history of ALK positive non-small-cell lung cancer and the clinical impact of targeted therapy with ALK inhibitors

Improved understanding of molecular drivers of carcinogenesis has led to significant progress in the management of lung cancer. Patients with non-small-cell lung cancer (NSCLC) with anaplastic lymphoma kinase (ALK) gene rearrangements constitute about 4%-5% of all NSCLC patients. ALK+ NSCLC cells respond well to small molecule ALK inhibitors such as crizotinib; however, resistance invariably develops after several months of treatment. There are now several newer ALK inhibitors, with the next generation of agents targeting resistance mutations. In this review, we will discuss the prevalence and clinical characteristics of ALK+ lung cancer, current treatment options, and future directions in the management of this subset of NSCLC patients.

The Impact of Molecularly Targeted Treatment on Direct Medical Costs in Patients with Advanced Non-small Cell Lung Cancer

Purpose

To investigate the impact of targeted treatment on direct medical costs of patients with advanced non-small cell lung cancer (NSCLC).

Materials and Methods

Medical records of 108 stage IIIB/IV NSCLC patients treated in Seoul National University Hospital between 2003 and 2009, were reviewed to collect medical resources utilization data from the diagnosis of stage IIIB/IV NSCLC to the end of active anti-cancer treatment. The direct medical costs were calculated by multiplying the number of medical resources used by the unit price. All costs were expressed in US dollars for each patient.

Results

The mean total direct medical costs were $34,732 (standard deviation, 21,168) in the study cohort. The mean total direct medical costs were higher in epidermal growth factor receptor (EGFR) mutation (EGFR MT)–positive patients than EGFR wild-type (EGFR WT) patients ($41,403 vs. $30,146, p=0.005). However, the mean monthly direct medical costs did not differ significantly between EGFR MT–positive patients and EGFR WT patients ($2,120 vs. $2,702, p=0.119) because of the longer duration of active anti-cancer treatment in EGFR MT–positive patients. This discrepancy was mainly attributable to EGFR MT–positive patients’ lower non-chemotherapy costs ($948 vs. $1,522, p=0.007). The total and monthly direct medical costs of ALK fusion–positive patients who did not receive ALK inhibitors did not differ from WT/WT patients.

Conclusion

This study suggests that the availability of targeted agents for EGFR MT–positive patients lowers the mean monthly medical costs by prolonging survival and diminishing the use of other medical resources, despite the considerable drug costs.

Clinical challenges in targeting anaplastic lymphoma kinase in advanced non-small cell lung cancer

The revolution in individualized therapy for patients with advanced non-small cell lung cancer (NSCLC) has seen the emergence of a number of molecularly targeted therapies for distinct patient molecular subgroups. Activating anaplastic lymphoma kinase (ALK)-gene rearrangement has been detected in 3-7 % of NSCLC cases, and the ALK inhibitor crizotinib is now an approved treatment for patients with tumors harboring this event. However, resistance to ALK-targeted therapies is a ubiquitous problem in the management of advanced ALK-positive NSCLC and can be mediated by secondary kinase mutations or the activation of compensatory alternative oncogenic drivers. New, more potent ALK inhibitors such as ceritinib (LDK378), alectinib (CH5424802), and AP26113 are now emerging, together with an increased knowledge of the molecular basis of resistance. There is a need to evaluate the optimal clinical application of these new agents, either as sequential therapies or in combination with other targeted agents, to combat resistance and prolong survival in patients with ALK-positive NSCLC. The remarkable clinical activity of ALK inhibitors also emphasizes the importance of optimal diagnostic testing algorithms, to ensure that all eligible patients receive these breakthrough therapies.

Prevalence and Clinical Outcomes for Patients With ALK-Positive Resected Stage I to III Adenocarcinoma: Results From the European Thoracic Oncology Platform Lungscape Project

Purpose

The prevalence of anaplastic lymphoma kinase (ALK) gene fusion (ALK positivity) in early-stage non–small-cell lung cancer (NSCLC) varies by population examined and detection method used. The Lungscape ALK project was designed to address the prevalence and prognostic impact of ALK positivity in resected lung adenocarcinoma in a primarily European population.

Methods

Analysis of ALK status was performed by immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) in tissue sections of 1,281 patients with adenocarcinoma in the European Thoracic Oncology Platform Lungscape iBiobank. Positive patients were matched with negative patients in a 1:2 ratio, both for IHC and for FISH testing. Testing was performed in 16 participating centers, using the same protocol after passing external quality assessment.

Results

Positive ALK IHC staining was present in 80 patients (prevalence of 6.2%; 95% CI, 4.9% to 7.6%). Of these, 28 patients were ALK FISH positive, corresponding to a lower bound for the prevalence of FISH positivity of 2.2%. FISH specificity was 100%, and FISH sensitivity was 35.0% (95% CI, 24.7% to 46.5%), with a sensitivity value of 81.3% (95% CI, 63.6% to 92.8%) for IHC 2+/3+ patients. The hazard of death for FISH-positive patients was lower than for IHC-negative patients (P = .022). Multivariable models, adjusted for patient, tumor, and treatment characteristics, and matched cohort analysis confirmed that ALK FISH positivity is a predictor for better overall survival (OS).

Conclusion

In this large cohort of surgically resected lung adenocarcinomas, the prevalence of ALK positivity was 6.2% using IHC and at least 2.2% using FISH. A screening strategy based on IHC or H-score could be envisaged. ALK positivity (by either IHC or FISH) was related to better OS.

Significance of targeted therapy and genetic alterations in EGFR, ALK, or KRAS on survival in patients with non-small cell lung cancer treated with radiotherapy for brain metastases

BACKGROUND

We determined the impact of genetic alterations in EGFR, ALK, or KRAS on survival after radiotherapy for brain metastases in non-small cell lung cancer (NSCLC).

METHODS

Of 172 genotyped NSCLC patients treated with radiotherapy for brain metastases in 2005-2012, 54 had cancers with EGFR mutations, 12 had ALK rearrangements, 38 had KRAS mutations, and 68 were wild-type (WT). Overall survival (OS) was determined.

RESULTS

Median follow-up was 8.6 months. Median OS was 13.6 months for patients with EGFR mutations and 26.3 months for patients with ALK rearrangements, in contrast to 5.7 months for KRAS-mutant patients and 5.5 months for WT patients (P = .001). On multivariate analysis, adjusting for receipt of targeted therapy after cranial radiotherapy, ALK rearrangements were associated with improved OS (HR, 0.31; 95% CI, 0.13-0.74; P = .008). EGFR mutations were not significantly associated with improved OS on multivariate analysis (HR, 0.71; 95% CI, 0.37-1.38; P = .3). KRAS mutations were also not associated with improved OS (HR, 0.93; 95% CI, 0.59-1.47; P = .8). Receipt of targeted therapy after cranial radiotherapy was independently associated with improved OS (HR, 0.30; 95% CI, 0.17-0.54; P < .001). Receipt of chemotherapy after cranial radiotherapy, number of brain metastases, extracranial metastases, age, and performance status were also associated with OS.

CONCLUSIONS

NSCLC patients with genetic alterations in ALK have improved survival outcomes after radiotherapy for brain metastases compared with EGFR, KRAS, or WT. Subsequent receipt of targeted therapy was associated with additional improvement in OS.

EGFR mutations and clinical outcomes of chemotherapy for advanced non-small cell lung cancer: a meta-analysis

BACKGROUND

This meta-analysis was performed to assess whether epidermal growth factor receptor (EGFR) mutation status was associated with objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) in patients with advanced non-small cell lung cancer (NSCLC) treated with chemotherapy.

METHOD

We systematically identified eligible articles investigating the effects of chemotherapy in patients with NSCLC stratified by EGFR mutation status. The summary risk ratio (RR) for ORR and hazard ratios (HRs) for both PFS and OS were calculated using the inverse variance formula of meta-analysis.

RESULTS

Identification for the current meta-analysis: 5 prospective studies (n=875) and 18 retrospective studies (n=1934) for ORR; 2 prospective studies (n=434) and 10 retrospective studies (n=947) for PFS; 2 prospective studies (n=438) and 7 retrospective studies (n=711) for OS. The ORR was significantly higher in patients with EGFR mutations in prospective studies (RR=1.42; 95% confidence interval [CI], 1.16-1.74; P=0.001), but not in retrospective studies (RR=1.12; 95% CI, 0.96-1.32; P=0.146). There was no obvious association between EGFR mutations and PFS both in prospective (HR=0.84; 95% CI: 0.65-1.09; P=0.197) and retrospective (HR=1.02; 95% CI: 0.87-1.18; P=0.838) studies. Association between EGFR mutations and OS was also not seen in prospective studies (HR=0.74; 95% CI: 0.27-2.05; P=0.566), but was seen in retrospective studies (HR=0.48; 95% CI: 0.33-0.72; P<0.001; I(2)=75.9%; P<0.001) with significant heterogeneity.

CONCLUSION

EGFR mutations in advanced NSCLC may be associated with higher ORRs to chemotherapy, but may have nothing to do with PFS and OS. Further prospective studies are required to identify the influence of EGFR mutations on chemotherapy effects in advanced NSCLC.

Ceritinib for treatment of ALK-rearranged advanced non-small-cell lung cancer

The anaplastic lymphoma kinase (ALK) gene plays a key role in the pathogenesis of selected tumors, including non-small-cell lung cancer (NSCLC). Patients with ALK-rearranged NSCLC are initially sensitive to the ALK inhibitor crizotinib but eventually become resistant, limiting its therapeutic potential. Ceritinib is an oral second-generation ALK inhibitor with greater preclinical antitumor potency than crizotinib in ALK-positive NSCLC. A Phase I trial of ceritinib in ALK-positive tumors demonstrated good activity in patients with advanced NSCLC, including those who had progressed on crizotinib. Adverse events are similar to those seen with other ALK tyrosine kinase inhibitors and are generally manageable. Ongoing trials are evaluating ceritinib in patients with ALK-rearranged NSCLC treated with prior chemotherapy and/or crizotinib.

The molecular detection and clinical significance of ALK rearrangement in selected advanced non-small cell lung cancer: ALK expression provides insights into ALK targeted therapy

BACKGROUND

This study aimed to elucidate clinical significance of anaplastic lymphoma kinase (ALK) rearrangement in selected advanced non-small cell lung cancer (NSCLC), to compare the application of different ALK detection methods, and especially evaluate a possible association between ALK expression and clinical outcomes in crizotinib-treated patients.

METHODS

ALK status was assessed by fluorescent in situ hybridization (FISH), immunohistochemistry (IHC) and quantitative RT-PCR (qRT-PCR) in 173 selected advanced NSCLC patients. Clinicopathologic data, genotype status and survival outcomes were analyzed. Moreover, the association of ALK expression with clinical outcomes was evaluated in ALK FISH-positive crizotinib-treated patients including two patients with concurrent epidermal growth factor receptor (EGFR) mutation.

RESULTS

The positivity detection rate of ALK rearrangement by FISH, IHC and qRT-PCR was 35.5% (59/166), 35.7% (61/171), and 27.9% (34/122), respectively. ALK rearrangement was observed predominantly in young patients, never or light smokers, and adenocarcinomas, especially with signet ring cell features and poor differentiation. Median progression-free survival (PFS) of crizotinib-treated patients was 7.6 months. The overall survival (OS) of these patients was longer compared with that of crizotinib-naive or wild-type cohorts, but there was no significant difference in OS compared with patients with EGFR mutation. ALK expression did not associate with PFS; but, when ALK expression was analyzed as a dichotomous variable, moderate and strong ALK expression had a decreased risk of death (P = 0.026). The two patients with concomitant EGFR and ALK alterations showed difference in ALK expression, response to EGFR and ALK inhibitors, and overall survival.

CONCLUSIONS

Selective enrichment according to clinicopathologic features in NSCLC patients could highly improve the positivity detection rate of ALK rearrangement for ALK-targeted therapy. IHC could provide more clues for clinical trial design and therapeutic strategies for ALK-positive NSCLC patients including patients with double genetic aberration of ALK and EGFR.

Current status of targeted therapy for anaplastic lymphoma kinase-rearranged non-small cell lung cancer

The identification of chromosomal rearrangements involving the anaplastic lymphoma kinase (ALK) gene in ~3-5% of non-small cell lung cancer (NSCLC) tissues and the demonstration that the first-in-class ALK tyrosine kinase inhibitor, crizotinib, can effectively target these tumors represent a significant advance in the evolution of personalized medicine for NSCLC. Single-arm studies demonstrating rapid and durable responses in the majority of ALK-positive NSCLC patients treated with crizotinib have been followed by a randomized phase III clinical trial in which superiority of crizotinib over chemotherapy was seen in previously treated ALK-positive NSCLC patients. However, despite the initial responses, most patients develop acquired resistance to crizotinib. Several novel therapeutic approaches targeting ALK-positive NSCLC are currently under evaluation in clinical trials, including second-generation ALK inhibitors, such as LDK378, CH5424802 (RO5424802802), and AP26113, and heat shock protein 90 inhibitors.

Heterogeneity of genetic changes associated with acquired crizotinib resistance in ALK-rearranged lung cancer

BACKGROUND

Anaplastic lymphoma kinase (ALK)-rearranged non-small-cell lung cancer (NSCLC) is markedly sensitive to the ALK inhibitor crizotinib. However, acquired resistance to crizotinib is inevitable through several mechanisms. Therefore, this study was conducted to identify genetic alterations associated with crizotinib resistance.

METHODS

Tumor samples were derived from seven ALK-positive NSCLC patients who showed acquired resistance to crizotinib, and these patients were analyzed for ALK, EGFR, and KRAS mutations and ALK and EGFR gene amplifications. In vitro cytotoxicity of crizotinib and ALK downstream signals were compared between crizotinib-naive and -resistant NSCLC cells.

RESULTS

After a median duration of 6 months (range, 4-12 months), seven ALK-positive NSCLC patients developed acquired resistance to crizotinib. Three patients harbored secondary ALK mutations, including one patient with both mutations: L1196M (n = 2) and G1269A (n = 2). Of note, one patient displayed ALK gene copy number gain (4.1-fold increase compared with the pre-crizotinib specimen) and EGFR L858R mutation with high polysomy. The amphiregulin concentration was high in the supernatant fluid from five patients with malignant pleural effusion (116.4-18934.0 pg/ml). SNU-2535 cells derived from a patient who harbored the G1269 mutation were resistant to crizotinib treatment similar to H3122 CR1 cells. L1196M and G1269A mutant clones were less sensitive to crizotinib and ALK downstream signals were ineffectively suppressed in these clones.

CONCLUSIONS

Genetic changes associated with crizotinib resistance are heterogeneous in ALK-rearranged NSCLC patients who respond to crizotinib and subsequently develop resistance.

Molecular profiling in non-small cell lung cancer: a step toward personalized medicine

CONTEXT

Lung carcinoma is the result of sequential accumulation of genetic and epigenetic changes. Lung adenocarcinoma is a heterogeneous disease with diverse somatic mutations, and several of them include the so-called driver mutations, which may serve as "druggable" therapeutic targets. Thus, development of personalized approaches for the treatment of non-small cell lung carcinoma (NSCLC) mandates that pathologists make a precise histologic classification inclusive of routine molecular analysis of such tumors.

OBJECTIVE

To address the molecular mechanisms underlying NSCLC and how this knowledge reflects the multidisciplinary approach in the diagnosis and management of these patients. We will also summarize the current available and investigational personalized therapies for patients with resectable early-stage, unresectable locally advanced, and metastatic NSCLC.

DATA SOURCES

Peer-reviewed published literature and personal experience.

CONCLUSIONS

There are multiple mechanisms involved in the pathogenesis of lung cancer, which operate in parallel and involve pathways of activation and inhibition of various cellular events. Further research is essential to characterize the histologic and mutational profiles of lung carcinomas, which will ultimately translate into improved and more personalized therapeutic management of patients with lung cancer.

Fluorescence in situ hybridization and immunohistochemistry as diagnostic methods for ALK positive non-small cell lung cancer patients

Background

Anaplastic Lymphoma Kinase (ALK) positivity represents a novel molecular target in a subset of Non-Small Cell Lung Cancers (NSCLC). We explore Fluorescence in situ Hybridization (FISH) and Immunohistochemistry (IHC) as diagnostic methods for ALK positive patients and to describe its prevalence and outcomes in a population of NSCLC patients.

Methods

NSCLC patients previously screened for Epidermal Growth Factor Receptor (EGFR) at our institution were selected. ALK positive patients were identified by FISH and the value of IHC (D5F3) was explored.

Results

ninety-nine patients were identified. Median age was 61.5 years (range 35–83), all were caucasians, eighty percent were adenocarcinomas, fifty-one percent were male and thirty-eight percent were current smokers. Seven (7.1%) patients were ALK positive by FISH, thirteen (13.1%) were EGFR mutant, and 65 (65.6%) were negative/Wild Type (WT) for both ALK and EGFR. ALK positivity and EGFR mutations were mutually exclusive. ALK positive patients tend to be younger than EGFR mutated or wt patients. ALK positive patients were predominantly never smokers (71.4%) and adenocarcinoma (71.4%). ALK positive and EGFR mutant patients have a better outcome than negative/WT. All patients with ALK FISH negative tumours were negative for ALK IHC. Out of 6 patients positive for ALK FISH with more tissue available, 5 were positive for ALK IHC and 1 negative.

Conclusions

ALK positive patients represent 7.1% of a population of selected NSCLC. ALK positive patients have different clinical features and a better outcome than EGFR WT and ALK negative patients. IHC is a promising method for detecting ALK positive NSCLC patients.

Pemetrexed-based chemotherapy in patients with advanced, ALK-positive non-small cell lung cancer

BACKGROUND

Anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer (NSCLC) is highly responsive to crizotinib. To determine whether ALK-positive NSCLC is also sensitive to pemetrexed, we retrospectively evaluated progression-free survival (PFS) of ALK-positive versus ALK-negative patients who had been treated with pemetrexed-based chemotherapy for advanced NSCLC.

PATIENTS AND METHODS

We identified 121 patients with advanced, ALK-positive NSCLC in the USA, Australia, and Italy. For comparison, we evaluated 266 patients with advanced, ALK-negative, epidermal growth factor receptor (EGFR)-wild-type NSCLC, including 79 with KRAS mutations and 187 with wild-type KRAS (WT/WT/WT). We determined PFS on different pemetrexed regimens.

RESULTS

Among 70 ALK-positive patients treated with a platinum/pemetrexed regimen, the median PFS (mPFS) was 7.3 months (95% confidence interval (CI) 5.5-9.5). The mPFS of 51 ALK-positive patients treated with single-agent pemetrexed or nonplatinum/pemetrexed combinations was 5.5 months (2.8-9.0). For ALK-negative patients, PFS on all pemetrexed-based regimens was similar to that of ALK-positive patients, except in the specific setting of first-line platinum/pemetrexed where the mPFS was only 4.2 and 5.4 months in KRAS and WT/WT/WT patients, respectively. However, among patients with a never/light-smoking history (0-10 pack-year smoking history) treated with first-line platinum/pemetrexed, there was no difference in PFS between ALK-positive and ALK-negative patients.

CONCLUSIONS

PFS on pemetrexed or nonplatinum/pemetrexed combinations was similar in ALK-positive and ALK-negative patients. PFS on first-line platinum/pemetrexed may be prolonged in never/light-smoking patients regardless of ALK status.

Metabolic and metastatic characteristics of ALK-rearranged lung adenocarcinoma on FDG PET/CT

INTRODUCTION

ALK rearrangement in lung cancer has been identified as a novel molecular target in lung adenocarcinoma. In this study, we evaluated metabolic and metastatic features of lung adenocarcinoma by using FDG PET/CT, with regard to specific genotypes of ALK and EGFR mutation.

METHODS

Patients with lung adenocarcinoma initially diagnosed and examined with FDG PET/CT and molecular genotyping with biopsy specimen, from September 2009 to September 2011, were selected retrospectively. ALK fluorescence in situ hybridization and EGFR mutations were tested. Maximum standardized uptake value (SUVmax) and metastatic characteristics on FDG PET/CT were analyzed with regard to ALK and EGFR status.

RESULTS

Of the 331 lung adenocarcinoma patients, 18 were ALK positive (ALK(+)), 156 were EGFR mutation positive (EGFR(+)), and 157 were wild type (WT) for both ALK and EGFR mutation. The ALK(+) tumor showed significantly higher SUVmax and more common metastasis to lymph nodes and distant organs than those of other genotypes in overall patients (P<0.01). In a subgroup analysis of advanced stage (stage IIIb and IV), ALK(+) lung cancer showed significantly higher SUVmax (P<0.05) than EGFR(+) tumors. In another subgroup analysis of size matched groups, ALK(+) tumors showed significant difference in SUVmax, lymph node and distant metastasis (P<0.01), particularly in the moderate-sized tumors (1.5-3cm).

CONCLUSION

ALK-rearranged lung adenocarcinoma represents higher glucose metabolism and more rapid metastasis to lymph nodes or distant sites compared with those with EGFR mutation and wild type, which suggests more aggressive features of ALK rearrangement.

Activity and safety of crizotinib in patients with ALK-positive non-small-cell lung cancer: updated results from a phase 1 study

BACKGROUND

ALK fusion genes occur in a subset of non-small-cell lung cancers (NSCLCs). We assessed the tolerability and activity of crizotinib in patients with NSCLC who were prospectively identified to have an ALK fusion within the first-in-man phase 1 crizotinib study.

METHODS

In this phase 1 study, patients with ALK-positive stage III or IV NSCLC received oral crizotinib 250 mg twice daily in 28-day cycles. Endpoints included tumour responses, duration of response, time to tumour response, progression-free survival (PFS), overall survival at 6 and 12 months, and determination of the safety and tolerability and characterisation of the plasma pharmacokinetic profile of crizotinib after oral administration. Responses were analysed in evaluable patients and PFS and safety were analysed in all patients. This study is registered with ClinicalTrials.gov, number NCT00585195.

FINDINGS

Between Aug 27, 2008, and June 1, 2011, 149 ALK-positive patients were enrolled, 143 of whom were included in the response-evaluable population. 87 of 143 patients had an objective response (60·8%, 95% CI 52·3-68·9), including three complete responses and 84 partial responses. Median time to first documented objective response was 7·9 weeks (range 2·1-39·6) and median duration of response was 49·1 weeks (95% CI 39·3-75·4). The response rate seemed to be largely independent of age, sex, performance status, or line of treatment. Median PFS was 9·7 months (95% CI 7·7-12·8). Median overall survival data are not yet mature, but estimated overall survival at 6 and 12 months was 87·9% (95% CI 81·3-92·3) and 74·8% (66·4-81·5), respectively. 39 patients continued to receive crizotinib for more than 2 weeks after progression because of perceived ongoing clinical benefit from the drug (12 for at least 6 months from the time of their initial investigator-defined disease progression). Overall, 144 (97%) of 149 patients experienced treatment-related adverse events, which were mostly grade 1 or 2. The most common adverse events were visual effects, nausea, diarrhoea, constipation, vomiting, and peripheral oedema. The most common treatment-related grade 3 or 4 adverse events were neutropenia (n=9), raised alanine aminotransferase (n=6), hypophosphataemia (n=6), and lymphopenia (n=6).

INTERPRETATION

Crizotinib is well tolerated with rapid, durable responses in patients with ALK-positive NSCLC. There seems to be potential for ongoing benefit after initial disease progression in this population, but a more formal definition of ongoing benefit in this context is needed.

Crizotinib for the treatment of ALK-rearranged non-small cell lung cancer: a success story to usher in the second decade of molecular targeted therapy in oncology

Crizotinib, an ALK/MET/ROS1 inhibitor, was approved by the U.S. Food and Drug Administration for the treatment of anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) in August 2011, merely 4 years after the first publication of ALK-rearranged NSCLC. The crizotinib approval was accompanied by the simultaneous approval of an ALK companion diagnostic fluorescent in situ hybridization assay for the detection of ALK-rearranged NSCLC. Crizotinib continued to be developed as an ALK and MET inhibitor in other tumor types driven by alteration in ALK and MET. Crizotinib has recently been shown to be an effective ROS1 inhibitor in ROS1-rearranged NSCLC, with potential future clinical applications in ROS1-rearranged tumors. Here we summarize the heterogeneity within the ALK- and ROS1-rearranged molecular subtypes of NSCLC. We review the past and future clinical development of crizotinib for ALK-rearranged NSCLC and the diagnostic assays to detect ALK-rearranged NSCLC. We highlight how the success of crizotinib has changed the paradigm of future drug development for targeted therapies by targeting a molecular-defined subtype of NSCLC despite its rarity and affected the practice of personalized medicine in oncology, emphasizing close collaboration between clinical oncologists, pathologists, and translational scientists.

Treating ALK-positive lung cancer--early successes and future challenges

Rearrangements of the anaplastic lymphoma kinase (ALK) gene occur infrequently in non-small-cell lung cancer (NSCLC), but provide an important paradigm for oncogene-directed therapy in this disease. Crizotinib, an orally bioavailable inhibitor of ALK, provides significant benefit for patients with ALK-positive (ALK+) NSCLC in association with characteristic, mostly mild, toxic effects, and this drug has been approved by the FDA for clinical use in this molecularly defined subgroup of lung cancer. Many new ALK inhibitors are being developed and understanding the challenges of determining and addressing the adverse effects that are likely to be ALK specific, while maximizing the time of benefit on targeted agents, and understanding the mechanisms that underlie drug resistance will be critical in the future for informing the optimal therapy of ALK+ NSCLC.