Treating patients with ALK-rearranged non-small-cell lung cancer: mechanisms of resistance and strategies to overcome it

Ensartinib in the treatment of anaplastic lymphoma kinase-positive locally advanced or metastatic patients with lung squamous or adenosquamous carcinoma: A real-world, retrospective study

AIM

To report the efficacy and safety of ensartinib, an anaplastic lymphoma kinase (ALK) inhibitor, in treating patients with ALK-positive advanced lung squamous cell carcinoma (LUSC) or lung adenosquamous carcinoma (LASC) in China.

METHODS

This retrospective study analyzed data for 36 advanced-stage patients with ALK-positive LUSC (cohort A) and 13 patients with ALK-positive LASC (cohort B) between December 16, 2020 and December 16, 2021. All patients received once-daily ensartinib 225 mg. Outcome analysis included the demographic characteristics, tumor response, progression-free survival (PFS), and treatment-related adverse events (TRAE).

RESULTS

Among the 49 patients, the majority were under 65 years old (73.5%), non-smokers (85.7%), had an Eastern Cooperative Oncology Group Performance Status of 0-1 (77.6%), and were at stage IV (71.4%). All patients were included in the efficacy and safety analysis. Seven PFS events were reported in cohort A while no patients experienced PFS events in cohort B. The median PFS was not estimable for both cohorts. In cohort A, the objective response rate (ORR) was 63.9%, and the disease control rate (DCR) was 83.3%. In the cohort B, the ORR was 76.9% and the DCR was 100.0%. Rash was the only TRAE reported in the cohort A (8.3%) and cohort B (23.1%). No patients had grade 3 or higher TRAE.

CONCLUSION

Ensartinib has been tentatively proven favorable efficacy and tolerability in the treatment of patients with ALK-positive advanced LUSC or LASC in the real-world. However, confirmatory studies are still needed in larger sample sizes.

Mechanisms of resistance to targeted therapy and immunotherapy in non-small cell lung cancer: promising strategies to overcoming challenges

Resistance to targeted therapy and immunotherapy in non-small cell lung cancer (NSCLC) is a significant challenge in the treatment of this disease. The mechanisms of resistance are multifactorial and include molecular target alterations and activation of alternative pathways, tumor heterogeneity and tumor microenvironment change, immune evasion, and immunosuppression. Promising strategies for overcoming resistance include the development of combination therapies, understanding the resistance mechanisms to better use novel drug targets, the identification of biomarkers, the modulation of the tumor microenvironment and so on. Ongoing research into the mechanisms of resistance and the development of new therapeutic approaches hold great promise for improving outcomes for patients with NSCLC. Here, we summarize diverse mechanisms driving resistance to targeted therapy and immunotherapy in NSCLC and the latest potential and promising strategies to overcome the resistance to help patients who suffer from NSCLC.

From Development to Place in Therapy of Lorlatinib for the Treatment of ALK and ROS1 Rearranged Non-Small Cell Lung Cancer (NSCLC)

Following the results of the CROWN phase III trial, the third-generation macrocyclic ALK inhibitor lorlatinib has been introduced as a salvage option after the failure of a first-line TKI in ALK-rearranged NSCLC, while its precise role in the therapeutic algorithm of ROS1 positive disease is still to be completely defined. The ability to overcome acquired resistance to prior generation TKIs (alectinib, brigatinib, ceritinib, and crizotinib) and the high intracranial activity in brain metastatic disease thanks to increased blood-brain barrier penetration are the reasons for the growing popularity and interest in this molecule. Nevertheless, the major vulnerability of this drug resides in a peculiar profile of related collateral events, with neurological impairment being the most conflicting and debated clinical issue. The cognitive safety concern, the susceptibility to heterogeneous resistance pathways, and the absence of a valid alternative in the second line are strongly jeopardizing a potential paradigm shift in this oncogene-addicted disease. So, when prescribing lorlatinib, clinicians must face two diametrically opposed characteristics: a great therapeutic potential without the intrinsic limitations of its precursor TKIs, a cytotoxic activity threatened by suboptimal tolerability, and the unavoidable onset of resistance mechanisms we cannot properly manage yet. In this paper, we give a critical point of view on the stepwise introduction of this promising drug into clinical practice, starting from its innovative molecular and biochemical properties to intriguing future developments, without forgetting its weaknesses.

Molecular pathways, resistance mechanisms and targeted interventions in non-small-cell lung cancer

Lung cancer is the leading cause of cancer-related mortality worldwide. The discovery of tyrosine kinase inhibitors effectively targeting EGFR mutations in lung cancer patients in 2004 represented the beginning of the precision medicine era for this refractory disease. This great progress benefits from the identification of driver gene mutations, and after that, conventional and new technologies such as NGS further illustrated part of the complex molecular pathways of NSCLC. More targetable driver gene mutation identification in NSCLC patients greatly promoted the development of targeted therapy and provided great help for patient outcomes including significantly improved survival time and quality of life. Herein, we review the literature and ongoing clinical trials of NSCLC targeted therapy to address the molecular pathways and targeted intervention progress in NSCLC. In addition, the mutations in EGFR gene, ALK rearrangements, and KRAS mutations in the main sections, and the less common molecular alterations in MET, HER2, BRAF, ROS1, RET, and NTRK are discussed. The main resistance mechanisms of each targeted oncogene are highlighted to demonstrate the current dilemma of targeted therapy in NSCLC. Moreover, we discuss potential therapies to overcome the challenges of drug resistance. In this review, we manage to display the current landscape of targetable therapeutic patterns in NSCLC in this era of precision medicine.

Emerging genetic biomarkers in lung adenocarcinoma

Comprehensive genomic profiling is a next-generation sequencing approach used to detect several known and emerging genomic alterations. Many genomic variants detected by comprehensive genomic profiling have become recognized as significant cancer biomarkers, leading to the development of major clinical trials. Lung adenocarcinoma has become one of the most targeted cancers for genomic profiling with a series of actionable mutations such as EGFR, KRAS, HER2, BRAF, FGFR, MET, ALK, and many others. The importance of these mutations lies in establishing targeted therapies that significantly change the outcome in lung adenocarcinoma besides the prognostic value of some mutations. This review sheds light on the development of the comprehensive genomic profiling field, mainly lung adenocarcinoma, and discusses the role of a group of mutations in this disease.

Synchronous bone metastasis in lung cancer: retrospective study of a single center of 15,716 patients from Tianjin, China

Background

This study aimed to describe the incidence, clinical characteristics, and prognosis of lung cancer patients with synchronous bone metastasis (SBM) and to analyze the prognostic factors of the lung cancer patients with SBM.

Methods

A total of 15,716 lung cancer patients who were diagnosed between 2009 to 2018 in the Tianjin Medical University Cancer Institute and Hospital were retrospectively reviewed. Among them, patients with SBM were checked. Both the demographic and clinical characteristics were included as follows: age, gender, marital status, history of smoking, alcohol consumption, family history of tumor, Karnofsky score, lymph node metastasis, histological type. Besides, laboratory data such as alkaline phosphatase, lactate dehydrogenase, carcinoembryonic antigen, squamous cell carcinoma antigen, cytokeratin-19 fragment, and neuron specific enolase were also included. The log-rank test and multivariate Cox regression analysis were employed to reveal the potential prognostic predictors. A further analysis using the Kaplan–Meier was employed to demonstrate the difference on the prognosis of LC patients between adenocarcinoma and non-adenocarcinoma.

Results

Among the included patients, 2738 patients (17.42%) were diagnosed with SBM. A total of 938 patients (34.3%) with SBM were successfully followed and the median survival was 11.53 months (95%CI: 10.57–12.49 months), and the 1-, 2-, and 5-year overall survival rate was 51, 17, and 8%, respectively. Multivariable Cox regression results showed history of smoking and high level of NSE were associated with the poor prognosis, while adenocarcinoma histological type was associated with better survival.

Conclusion

The prevalence of SBM in lung cancer is relatively high with poor survival. The lung cancer patients with SBM showed diverse prognosis. Among all the pathological types, the division of adenocarcinoma suggested different prognosis of the lung cancer patients with SBM. The present study emphasized the importance of pathological diagnosis on prognostic determinants in lung cancer patients with SBM.

Central nervous system metastases and oligoprogression during treatment with tyrosine kinase inhibitors in oncogene-addicted non-small cell lung cancer: how to treat and when?

Up to 70% of non-small cell lung cancer (NSCLC) patients develop central nervous system (CNS) metastases during the course of their disease, especially those with oncogenic drivers treated with a first-generation tyrosine kinase inhibitor (TKI), because of the relatively poor CNS penetration. CNS metastases are associated with a negative impact on quality of life and survival. As, with the introduction of newer generation TKIs, the survival rates are increasing in this particular population, treatment and/or prevention of CNS metastases becomes even more relevant and the TKI with the best CNS efficacy should be selected. Unfortunately, CNS efficacy data in clinical trials are not fully comparable. Furthermore, oligoprogression to the brain without extracranial progression regularly occurs in the oncogenic driver population and both local therapy and switch of systemic therapy are possible treatment options. However, the best order of systemic and local therapy is still not precisely known. In this narrative review, we will summarize incidence and treatment of CNS metastases in oncogene driven NSCLC, including the optimal treatment of CNS oligometastatic disease (synchronous as well as oligoprogressive).

[Histology, cytology and molecular diagnostics of lung cancer]

Traditionally, tissue-based histopathological approaches play an outstanding role in the diagnostics of lung cancer. The importance of these methods has become even more important with the introduction of individualized treatment options. Lung cancer is basically classified following the World Health Organization (WHO) guidelines using conventional histology and immunohistochemistry. For individual entities in certain clinical stages, the evaluation of the tumor biological profile serves as the basis for the so-called individualized treatment or precision medicine where changes in the intracellular signal transduction mechanisms are the target of therapeutic efforts or the therapy tries to re-initiate immunogenic reactions of the autologous immune system against the tumor cells. The histopathologic overexpression of receptors as well as various genetic and epigenetic changes (e.g. inversion, translocation and methylation) are the key players for predictive approaches to uncover the individual tumor biology and to make treatment decisions.

Nationwide comparative study of synchronous and metachronous spine metastasis in the adult Korean population

This nationwide study of the adult Korean population aimed to compare the survival period between synchronous and metachronous group and to determine recent treatment trends in newly diagnosed spine metastasis patients. Data were extracted from the Korean Health Insurance Review and Assessment Service database. Patients in this study were newly diagnosed with metastatic spine tumors between July 1, 2011 and June 31, 2014. The metachronous group was defined when the primary tumor was diagnosed prior to the diagnosis of spine metastasis, otherwise patients were considered to be the part of the synchronous group. The survival period was calculated from the date of first diagnosis of spine metastasis. In a multivariate analysis, patients in the synchronous group survived significantly longer than those in the metachronous group (P < 0.0001). Median overall survival periods were 273.6 days for the metachronous group and 541.4 days for the synchronous group. Conventional radiation therapy (RT) was the most common treatment modality for metastatic spine tumors, whereas surgery combined with RT was a steadily increasing treatment modality during the study period. Synchronous spine metastasis patients survive significantly longer than metachronous patients. Surgery combined with RT is a recently increasing trend among spine metastasis treatments.

Identification of NMU as a potential gene conferring alectinib resistance in non-small cell lung cancer based on bioinformatics analyses

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, and adjuvant targeted therapy has shown great benefits for the NSCLC patients with specific genomic mutations. Alectinib, a selective anaplastic lymphoma kinase (ALK) inhibitor, has been clinically used for the NSCLC patients with ALK-rearrangement, however, irreversible therapeutic resistance for the patients receiving alectinib treatment frequently occurs. Here we show that neuromedin U (NMU) may confer the alectinib resistance in NSCLC via multiple mechanisms based on the integrative bioinformatics analyses. Through employing the bioinformatics analyses of three microarray datasets, NMU, overexpressed in both NSCLC tissues and alectinib-resistant NSCLC cells, was initially identified as potential candidate for causing alectinib resistance in NSCLC. The resistance function of NMU in NSCLC was validated by performing protein/gene interactions and biological process annotation analyses, and further validated by analyzing the transcription factors targeting NMU mRNA. Collectively, these results indicated that NMU may confer alectinib resistance in NSCLC.

The rationale for druggability of CCDC6-tyrosine kinase fusions in lung cancer

Gene fusions occur in up to 17% of solid tumours. Oncogenic kinases are often involved in such fusions. In lung cancer, almost 30% of patients carrying an activated oncogene show the fusion of a tyrosine kinase to an heterologous gene. Several genes are partner in the fusion with the three kinases ALK, ROS1 and RET in lung. The impaired function of the partner gene, in combination with the activation of the kinase, may alter the cell signaling and promote the cancer cell addiction to the oncogene. Moreover, the gene that is partner in the fusion to the kinase may affect the response to therapeutics and/or promote resistance in the cancer cells. Few genes are recurrent partners in tyrosine kinase fusions in lung cancer, including CCDC6, a recurrent partner in ROS1 and RET fusions, that can be selected as possible target for new strategies of combined therapy including TKi.

Targeted drugs for systemic therapy of lung cancer with brain metastases

Brain metastases are very common in lung cancer patients. The condition of these patients is complicated and difficult to treat, and adverse reactions following treatment can affect the nervous system, which severely reduces quality of life. Lung cancers are categorized as small cell lung cancers and non-small cell lung cancers. Patients with brain metastasis of small cell lung cancers are generally treated with brain radiotherapy and systemic chemotherapy, but stage III/IV patients with brain metastasis of non-small cell lung cancers are generally not responsive to radiotherapy or chemotherapy. With the recent development of targeted drugs, tumor molecular profile detection allows the selection of appropriate targeted drugs for adjuvant pharmacological treatment of brain metastasis in lung cancer patients. In recent years, immune checkpoint inhibitors have emerged and have been approved by the Food and Drug Administration (FDA) for the treatment of certain cancers, but their efficacy in lung cancer patients with brain metastases still needs to be confirmed. This paper focuses on highlighting drugs for targeted therapy of brain metastasis in lung cancer patients and their molecular targets and mechanisms of drug resistance.