Resensitization to Crizotinib by the Lorlatinib ALK Resistance Mutation L1198F

Clinician Perspectives on Current Issues in Lung Cancer Drug Development

Recent advances in molecularly targeted therapy and immunotherapy offer a glimmer of hope for potentially realizing the dream of personalized therapy for lung cancer. This article highlights current questions in clinical trial design, enrollment strategies and patient focused drug development, with particular emphasis on unique issues in trials of targeted therapy and immunotherapy.

Molecular Mechanisms of Resistance to First- and Second-Generation ALK Inhibitors in ALK-Rearranged Lung Cancer

Advanced, anaplastic lymphoma kinase (ALK)-positive lung cancer is currently treated with the first-generation ALK inhibitor crizotinib followed by more potent, second-generation ALK inhibitors (e.g., ceritinib and alectinib) upon progression. Second-generation inhibitors are generally effective even in the absence of crizotinib-resistant ALK mutations, likely reflecting incomplete inhibition of ALK by crizotinib in many cases. Herein, we analyzed 103 repeat biopsies from ALK-positive patients progressing on various ALK inhibitors. We find that each ALK inhibitor is associated with a distinct spectrum of ALK resistance mutations and that the frequency of one mutation, ALK^G1202R, increases significantly after treatment with second-generation agents. To investigate strategies to overcome resistance to second-generation ALK inhibitors, we examine the activity of the third-generation ALK inhibitor lorlatinib in a series of ceritinib-resistant, patient-derived cell lines, and observe that the presence of ALK resistance mutations is highly predictive for sensitivity to lorlatinib, whereas those cell lines without ALK mutations are resistant.

SIGNIFICANCE

Secondary ALK mutations are a common resistance mechanism to second-generation ALK inhibitors and predict for sensitivity to the third-generation ALK inhibitor lorlatinib. These findings highlight the importance of repeat biopsies and genotyping following disease progression on targeted therapies, particularly second-generation ALK inhibitors. Cancer Discov; 6(10); 1118-33. ©2016 AACRSee related commentary by Qiao and Lovly, p. 1084This article is highlighted in the In This Issue feature, p. 1069.

Tackling ALK in non-small cell lung cancer: the role of novel inhibitors

Crizotinib is an oral inhibitor of anaplastic lymphoma kinase (ALK) with remarkable clinical activity in patients suffering from ALK-rearranged non-small cell lung cancer (NSCLC), accounting to its superiority compared to chemotherapy. Unfortunately, virtually all ALK-rearranged tumors acquire resistance to crizotinib, frequently within one year since the treatment initiation. To date, therapeutic strategies to overcome crizotinib resistance have focused on the use of more potent and structurally different compounds. Second-generation ALK inhibitors such as ceritinib (LDK378), alectinib (CH5424802/RO5424802) and brigatinib (AP26113) have shown relevant clinical activity, consequently fostering their rapid clinical development and their approval by health agencies. The third-generation inhibitor lorlatinib (PF-06463922), selectively active against ALK and ROS1, harbors impressive biological potency; its efficacy in reversing resistance to crizotinib and to other ALK inhibitors is being proven by early clinical trials. The NTRK1-3 and ROS1 inhibitor entrectinib (RXDX-101) has been reported to act against NSCLC harboring ALK fusion proteins too. Despite the quick development of these novel agents, several issues remain to be discussed in the treatment of patients suffering from ALK-rearranged NSCLC. This position paper will discuss the development, the current evidence and approvals, as long as the future perspectives of new ALK inhibitors beyond crizotinib. Clinical behaviors of ALK-rearranged NSCLC vary significantly among patients and differential molecular events responsible of crizotinib resistance account for the most important quote of this heterogeneity. The precious availability of a wide range of active anti-ALK compounds should be approached in a critical and careful perspective, in order to develop treatment strategies tailored on the disease evolution of every single patient.

Targeted therapies and immunotherapy in non-small-cell lung cancer

Non-small-cell lung cancer is still considered a difficult disease to manage because of its aggressiveness and resistance to common therapies. Chemotherapy remains the gold standard in nearly 80% of lung cancers, but clinical outcomes are discouraging, and the impact on median overall survival (OS) barely reaches 12 months. At the end of the last century, the discovery of oncogene-driven tumours completely changed the therapeutic landscape in lung cancers, harbouring specific gene mutations/translocations. Epidermal growth factors receptor (EGFR) common mutations first and anaplastic lymphoma kinase (ALK) translocations later led new insights in lung cancer biology knowledge. The use of specific tyrosine kinases inhibitors overturned the biological behaviour of EGFR mutation positive tumours and became a preclinical model to understand the heterogeneity of lung cancers and the mechanisms of drug resistance. In this review, we summarise the employment of targeted agents against the most representative biomolecular alterations and provide some criticisms of the therapeutic strategies.

[Graphic Evolution Witness the Development of Lung Cancer Translational Research]

肺癌从传统化疗到分子靶向，再到如今免疫治疗的转变，转化性研究发挥着无可替代的作用，其中图表演化更是见证一次次重大变迁，从“森林图”到“生存曲线图”，“瀑布图”，“蜘蛛图”再到最近的“时间线区域面积图”，纵向展示了肺癌治疗从群体逐渐向个体深入细化的理念和演进过程。尽管目前最新的免疫治疗炙手可热，但其研究结果并没有达到预期理想，同时传统的治疗手段仍然存在局限性，需要更深入探索。本文将从图表演化角度论述肺癌转化性研究的发展历程，剖析部分失败的外科临床研究，以期对未来肺癌治疗及图表演化有所启发。

Spotlight on crizotinib in the first-line treatment of ALK-positive advanced non-small-cell lung cancer: patients selection and perspectives

Around 4% of advanced non-small-cell lung cancers (NSCLCs) have an ALK rearrangement at the time of diagnosis. This molecular feature is more frequent in young patients, with no/light smoking habit and with adenocarcinoma pathological subtype. Crizotinib is a tyrosine kinase inhibitor, targeting ALK, ROS1, RON, and MET. The preclinical efficacy results led to a fast-track clinical development. The US Food and Drug Administration (FDA) approval was achieved after the Phase I clinical trial in 2011 in ALK-rearranged advanced NSCLC progressing after a first-line treatment. In 2013, the randomized Phase III trial PROFILE-1007 confirmed the efficacy of crizotinib in ALK-rearranged NSCLC, compared to cytotoxic chemotherapy, in second-line setting or more. In 2014, the PROFILE-1014 trial showed the superiority of crizotinib in the first-line setting compared to the pemetrexed platinum doublet chemotherapy. The response rate was 74%, and the progression-free survival was 10.9 months with crizotinib. Based on these results, crizotinib received approval from the FDA and European Medicines Agency for first-line treatment of ALK-rearranged NSCLC. The various molecular mechanisms at the time of the progression (ALK mutations or amplification, ALK-independent mechanisms) encourage performing re-biopsy at the time of progression under crizotinib. The best treatment strategy at the progression (crizotinib continuation beyond progression, switch to second-generation tyrosine kinase inhibitors, or cytotoxic chemotherapy) depends on the phenotype of the progression, the molecular status, and the physical condition of the patient.

Emerging treatment for ALK-positive lung cancer

INTRODUCTION

Lung cancer is associated with poor prognosis and limited benefit from chemotherapy. The treatment of non-small cell lung cancer (NSCLC) has been revolutionized by the discovery of targetable genetic alterations, including the ALK fusion oncogene.

AREAS COVERED

Three drugs have been approved for clinical use in ALK-positive patients - crizotinib, ceritinib and alectinib. Unfortunately, treatment resistance inevitably develops. Several mechanisms of acquired resistance are reported. In this review, we will discuss emerging treatment options in ALK-positive advanced NSCLC and strategies to overcome resistance mechanisms, including newer generation of ALK inhibitors, Hsp90 inhibitors and immunotherapy.

EXPERT OPINION

Tremendous advances have been made in the treatment of ALK-positive lung cancers, but management hurdles still exist, including universal development of resistance to ALK inhibitors and limited CNS activity. Given that specific treatment strategies target distinct patterns of resistance, re-biopsy at the time of progression appears necessary to optimize management. However, there remain many issues in routine clinical application including the burden placed on the patients by serial biopsies and the risks of repeat invasive procedures. Future studies are needed to validate the usage of non- or minimally invasive tests and to determine the optimal orders of utilizing different ALK inhibitors.

Use of big data in drug development for precision medicine

Drug development has been a costly and lengthy process with an extremely low success rate and lack of consideration of individual diversity in drug response and toxicity. Over the past decade, an alternative "big data" approach has been expanding at an unprecedented pace based on the development of electronic databases of chemical substances, disease gene/protein targets, functional readouts, and clinical information covering inter-individual genetic variations and toxicities. This paradigm shift has enabled systematic, high-throughput, and accelerated identification of novel drugs or repurposed indications of existing drugs for pathogenic molecular aberrations specifically present in each individual patient. The exploding interest from the information technology and direct-to-consumer genetic testing industries has been further facilitating the use of big data to achieve personalized Precision Medicine. Here we overview currently available resources and discuss future prospects.

Profile of Ventana ALK (D5F3) companion diagnostic assay for non-small-cell lung carcinomas

The development of several ALK inhibitors means that the importance of accurately identifying ALK-positive lung cancer has never been greater. Therefore, it is crucial that ALK testing assays become more standardized. The aim of this review is to comment on the recently FDA-approved VENTANA ALK (D5F3) Companion Diagnostic (CDx) Assay. This kit provides high sensitivity and specificity for the detection of ALK rearrangements and seamless integration into the laboratory workflow, with a fully automated analytical phase and fast interpretation. The use of controls increases the sensitivity and specificity and a dichotomous scoring approach enhances reproducibility.

Genomic Aberrations in Crizotinib Resistant Lung Adenocarcinoma Samples Identified by Transcriptome Sequencing

ALK-break positive non-small cell lung cancer (NSCLC) patients initially respond to crizotinib, but resistance occurs inevitably. In this study we aimed to identify fusion genes in crizotinib resistant tumor samples. Re-biopsies of three patients were subjected to paired-end RNA sequencing to identify fusion genes using deFuse and EricScript. The IGV browser was used to determine presence of known resistance-associated mutations. Sanger sequencing was used to validate fusion genes and digital droplet PCR to validate mutations. ALK fusion genes were detected in all three patients with EML4 being the fusion partner. One patient had no additional fusion genes. Another patient had one additional fusion gene, but without a predicted open reading frame (ORF). The third patient had three additional fusion genes, of which two were derived from the same chromosomal region as the EML4-ALK. A predicted ORF was identified only in the CLIP4-VSNL1 fusion product. The fusion genes validated in the post-treatment sample were also present in the biopsy before crizotinib. ALK mutations (p.C1156Y and p.G1269A) detected in the re-biopsies of two patients, were not detected in pre-treatment biopsies. In conclusion, fusion genes identified in our study are unlikely to be involved in crizotinib resistance based on presence in pre-treatment biopsies. The detection of ALK mutations in post-treatment tumor samples of two patients underlines their role in crizotinib resistance.

Anaplastic Lymphoma Kinase (ALK) Kinase Domain Mutation Following ALK Inhibitor(s) Failure in Advanced ALK Positive Non-Small-Cell Lung Cancer: Analysis and Literature Review

BACKGROUND

Secondary anaplastic lymphoma kinase (ALK) mutation may occur in patients with advanced ALK-positive non-small cell lung cancer treated with ALK inhibitors, but its nature is not well-known.

PATIENTS AND METHODS

We analyzed tumor specimens after the failure of treatment with ALK inhibitor(s) (crizotinib, alectinib, and ceritinib) for secondary ALK kinase domain mutation, EGFR, K-ras, and PIK3CA mutations. The literature regarding acquired ALK-inhibitor(s) resistance was also reviewed.

RESULTS

Among 59 patients who received ALK inhibitor(s) during the period of December 2010 to April 2015, 7 had re-biopsied tumor specimens for analyses following ALK inhibitor(s) failure. One had G1202R after crizotinib and alectinib failure, and 6 were wild type. No EGFR, K-ras, or PIK3CA mutations were found. In our review of the literature and taken together with our patients, 25 of the 88 (28%) patients with crizotinib failure had secondary ALK mutation; L1196M mutation was most common (n = 11). Patients with secondary ALK mutation other than L1196M had a longer progression-free survival after crizotinib than patients with L1196M (median, 12.0 vs. 7.0 months; P = .04). Of the 9 patients with alectinib failure, 5 had I1171 mutation and 2 had G1202R. Of the 11 patients with ceritinib failure, 2 had G1202R, 1 had F1174C, and 1 had both G1202R and F1174V. I1171 mutation, G1202R, and F1174 mutations were also found in crizotinib-failed patients.

CONCLUSIONS

Some acquired ALK mutations may cause co-resistance to other ALK inhibitors. Re-biopsy for ALK mutation analysis might be suggested prior to choosing a second-line ALK inhibitor treatment.

Second- and third-generation ALK inhibitors for non-small cell lung cancer

Crizotinib as the first-generation ALK inhibitor has shown significant activity in ALK-mutated non-small cell lung cancer (NSCLC). Second- and third-generation ALK inhibitors are entering clinical applications for ALK+ NSCLC. In addition, a third-generation ALK inhibitor, lorlatinib (PF-06463922), was reported to resensitize NSCLC to crizotinib. This review provided a summary of clinical development of alectinib, ceritinib, brigatinib (AP26113), and lorlatinib.

Tumor Evolutionary Principles: How Intratumor Heterogeneity Influences Cancer Treatment and Outcome

Recent studies have shown that intratumor heterogeneity contributes to drug resistance in advanced disease. Intratumor heterogeneity may foster the selection of a resistant subclone, sometimes detectable prior to treatment. Next-generation sequencing is enabling the phylogenetic reconstruction of a cancer's life history and has revealed different modes of cancer evolution. These studies have shown that cancer evolution is not always stochastic and has certain constraints. Consideration of cancer evolution may enable the better design of clinical trials and cancer therapeutics. In this review, we summarize the different modes of cancer evolution and how this might impact clinical outcomes. Furthermore, we will discuss several therapeutic strategies for managing emergent intratumor heterogeneity.