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

Recording and classifying MET receptor mutations in cancers

Tyrosine kinase inhibitors (TKI) directed against MET have been recently approved to treat advanced non-small cell lung cancer (NSCLC) harbouring activating MET mutations. This success is the consequence of a long characterization of MET mutations in cancers, which we propose to outline in this review. MET, a receptor tyrosine kinase (RTK), displays in a broad panel of cancers many deregulations liable to promote tumour progression. The first MET mutation was discovered in 1997, in hereditary papillary renal cancer (HPRC), providing the first direct link between MET mutations and cancer development. As in other RTKs, these mutations are located in the kinase domain, leading in most cases to ligand-independent MET activation. In 2014, novel MET mutations were identified in several advanced cancers, including lung cancers. These mutations alter splice sites of exon 14, causing in-frame exon 14 skipping and deletion of a regulatory domain. Because these mutations are not located in the kinase domain, they are original and their mode of action has yet to be fully elucidated. Less than five years after the discovery of such mutations, the efficacy of a MET TKI was evidenced in NSCLC patients displaying MET exon 14 skipping. Yet its use led to a resistance mechanism involving acquisition of novel and already characterized MET mutations. Furthermore, novel somatic MET mutations are constantly being discovered. The challenge is no longer to identify them but to characterize them in order to predict their transforming activity and their sensitivity or resistance to MET TKIs, in order to adapt treatment.

Crizotinib Has Preclinical Efficacy in Philadelphia-Negative Myeloproliferative Neoplasms

PURPOSE

The Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) polycythemia vera, essential thrombocythemia, and primary myelofibrosis are characterized by JAK/STAT pathway activation. JAK inhibitors are approved for MPN treatment, but persistence has been observed, due to JAK/STAT reactivation.

EXPERIMENTAL DESIGN

Using MPN patient samples, JAK2-mutated cell lines, and MPN mouse models, we examined both the efficacy and mechanism by which crizotinib, the ALK/MET/RON/ROS1 inhibitor approved for the treatment of non-small cell lung cancer, alters MPN cell proliferation and JAK/STAT activation.

RESULTS

We found that crizotinib suppresses proliferation and activation of JAK/STAT signaling, and decreases the disease burden in the JAK2V617F mouse model of MPN. Furthermore, we found that crizotinib could overcome JAK inhibitor persistence to ruxolitinib. Interestingly, phosphorylation of the crizotinib target RON kinase was enhanced in ruxolitinib-persistent cells. We show that phospho-JAK2 and phospho-RON can physically interact to sustain JAK/STAT signaling, and that the combination of crizotinib and ruxolitinib disrupts this interaction. Furthermore, RON knockdown suppresses proliferation and activation of JAK/STAT signaling in JAK2-mutated cells, and RON deletion in a JAK2V617F mouse MPN model decreases the disease burden. We also observed RON hyperactivation in MPN patient cells, suggesting that RON may be an important target of crizotinib in MPN.

CONCLUSIONS

In summary, we demonstrate that crizotinib has preclinical efficacy in MPN patient cells, JAK2-mutated cell lines, and a JAK2-mutated mouse model, and that the combination of crizotinib with JAK inhibitors suppresses JAK inhibitor persistence. Our work suggests that crizotinib should be investigated for the treatment of patients with MPN.

The utility of transbronchial rebiopsy for peripheral pulmonary lesions in patients with advanced non-squamous non-small cell lung cancer

Background

Patients treated for non-squamous (non-Sq) non-small cell lung cancer (NSCLC) often require repeat biopsies to determine the optimal subsequent treatment. However, the differences between rebiopsy and initial biopsy in terms of their diagnostic yields and their ability to test the molecular profiles using bronchoscopy with radial endobronchial ultrasound guidance in patients with advanced NSCLC remain unclear. Hence, we aimed to compare the diagnostic yields and ability for molecular analyses of rebiopsies with those of initial biopsies.

Methods

We investigated 301 patients with advanced non-Sq NSCLC who underwent radial endobronchial ultrasound-guided transbronchial biopsy (TBB) for peripheral pulmonary lesions (PPLs) between August 2014 and July 2017. Patients were divided into the rebiopsy and initial biopsy groups: the latter referred to the biopsy that determined the definitive diagnosis. The diagnostic yields and ability for molecular analyses were compared between the two groups, and the factors affecting the TBB diagnostic yield were identified using univariate and multivariate analyses.

Results

The diagnostic yields of the rebiopsy and initial biopsy groups were comparable (86.8 and 90.8%, respectively; p = 0.287). Furthermore, 93.0 and 94.0% of the patients in the rebiopsy and initial biopsy groups, respectively, had adequate specimens for gene profiling and mutational analysis (p = 0.765). The factors that increased the diagnostic yield were a positive bronchus sign (p < 0.001) and tumour location within the internal two-thirds of the lungs (p = 0.026).

Conclusions

The PPL diagnostic yield of the rebiopsy group was as high as that of the initial biopsy group. Hence, TBB for PPLs is feasible for patients requiring rebiopsy as well as for those with initial diagnoses. Adequate, high-quality biopsy specimens can be obtained by transbronchial rebiopsy for molecular testing.

[Epidemiology and diagnosis of mutations in the ALK gene in patients with non-small cell lung cancer in the Moscow region]

AIM OF STUDY

To determine a diagnostic algorithm for detecting translocation of the ALK gene and its frequency in the Moscow region.

MATERIALS AND METHODS

During the priod between 2014 and 2018 (inclusive), 488 patients without activating mutations in the EGFR gene in the Moscow region were tested. To detect translocation of the ALK gene, fluorescence in situ hybridization (FISH) methods, an immunohistochemical method, and, in some cases, a polymerase chain reaction were used.

RESULTS

Revealed ALK gene rearrangement in a population of patients with lung adenocarcinoma amounted to an average of 7.6% of cases. With this, the main method that we used was immunohistochemical method, applicable in more than 80% of cases. The use of other methods for verification of abnormalities in the ALK gene was found necessary in rare cases (3.3%).

CONCLUSIONS

Using the algorithm presented in the article, it was possible to detect ALK gene rearrangement in a population of patients with lung adenocarcinoma in the Moscow region in an average of 7.6% of cases.

Favorable predictors for survival in advanced ALK-positive non-small cell lung cancer patients beyond crizotinib resistance

Background

Crizotinib has demonstrated favorable efficacy in patients with advanced ALK‐positive non‐small cell lung cancer (NSCLC). Unfortunately, the majority of ALK‐positive patients ultimately develop acquired resistance within one year after the initiation of crizotinib treatment; however, the estimation of overall survival (OS) beyond crizotinib resistance has not yet been fully demonstrated. The purpose of this study was to identify favorable predictors affecting survival outcome.

Methods

In this single‐center retrospective study, the data of 136 patients with advanced ALK‐positive NSCLC beyond crizotinib resistance were analyzed between January 2013 and December 2017. Patients were divided into two groups according to intracranial or extracranial progression on crizotinib, and sequential therapies including crizotinib continuation with local therapy, next‐generation ALK inhibitors, and chemotherapy. The primary endpoint was the median OS duration from the start of crizotinib resistance to death or the last follow‐up. Univariate and multivariate Cox analyses of OS were carried out.

Results

At the time of analysis, 60 (41.1%) of the 136 patients had died. Median progression free survival (PFS) and OS from the metastatic diagnosis were 10.4 and 41.3 months, respectively. Sequential therapies administered beyond crizotinib treatment were: next‐generation ALK inhibitors (54 patients), chemotherapy (20 patients), and crizotinib continuation with local therapy (62 patients). Multivariate Cox analysis revealed that long PFS with crizotinib (≥ 10.4 months), intracranial progression, and next‐generation ALK inhibitors were significantly associated with a decreased risk of death.

Conclusion

Long PFS with crizotinib (≥10.4 months), intracranial progression, and use of next‐generation ALK inhibitors might be favorable predictors for OS in advanced ALK‐positive NSCLC patients.

Which Should Be Used First for ALK-Positive Non-Small-Cell Lung Cancer: Chemotherapy or Targeted Therapy? A Meta-Analysis of Five Randomized Trials

Background and objectives: Targeted therapy is widely used in the era of precision medicine. Whether the sequence in which targeted therapy and chemotherapy are performed matters, is however not known. We examined the impact of the sequential treatment of targeted therapy and chemotherapy among advanced anaplastic lymphoma kinase (ALK), non-small cell lung cancer (NSCLC) patients. Materials and Methods: Randomized controlled trials comparing the use of ALK inhibitors with chemotherapy were included in this meta-analysis. We estimated the hazard ratios (HRs) and 95% confidence intervals (CI), for progression-free survival (PFS) and overall survival (OS) from a random effects model. Two-sided statistical tests were used to determine the significance of these estimates. Results: In five eligible studies (1404 patients), ALK targeted therapy, in comparison with chemotherapy, had a significantly higher PFS (HR = 0.48; 95% CI, 0.42–0.55), but not significantly higher OS (HR = 0.88; 95% CI, 0.72–1.07). Crossover from chemotherapy to ALK inhibitors was allowed after progression in all trials. The sensitivity analysis of the use of ALK inhibitors as either the first- or second-line treatment, showed improvements in PFS but not in OS. Conclusions: Our results indicate that using targeted therapy first improved PFS, but that the sequence in which the treatments were performed did not cause a significant difference in overall survival.

Spotlight on brigatinib and its potential in the treatment of patients with metastatic ALK-positive non-small cell lung cancer who are resistant or intolerant to crizotinib

In the last decade, there have been major therapeutic advances in the management of patients with anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer. Crizotinib was the first approved ALK inhibitor with significant benefits over chemotherapy. However, patients inevitably develop disease progression especially in central nervous system and acquire resistance to crizotinib. Several next-generation ALK inhibitors have been developed to overcome these resistance mechanisms and have demonstrated clinical benefits in crizotinib-refractory non-small cell lung cancer including in central nervous system. Brigatinib is a second-generation ALK inhibitor with high level of activity against ALK and several other targets. It is active in vitro against many ALK kinase domain mutations including L1196M, E1210K, and G1202R which may mediate acquired resistance to other ALK inhibitors. In Phase I/II and ALTA clinical studies, brigatinib has demonstrated substantial and durable responses and intracranial responses after progression on crizotinib. It has acceptable safety profile, but early pulmonary toxicity has been observed prompting to pursue daily dosing of 180 mg (with lead-in). Overall, 180 mg (with lead-in) has showed consistently better efficacy than 90 mg. In this review, we will discuss in detail these two pivotal trials that led to the accelerated approval for brigatinib and its future directions.