Progress of non-small-cell lung cancer with ROS1 rearrangement

ALK-based dual inhibitors: Focus on recent development for non-small cell lung cancer therapy

As a prevalent oncogenic driver gene in non-small cell lung cancer (NSCLC), ALK represents a crucial and efficacious therapeutic target. To date, seven ALK inhibitors have been approved for ALK fusion-positive NSCLC, with several others undergoing clinical trials. These therapies demonstrate significant efficacy in ALK fusion-positive NSCLC patients. However, acquired resistance mechanisms, including ALK kinase domain mutations, ALK gene amplification, and bypass pathway activation, significantly compromise the efficacy of targeted therapy in ALK fusion-positive NSCLC. Therefore, the discovery of novel ALK inhibitors and the development of related treatment strategies remain critical. Compared to the combination therapy strategy based on ALK inhibitors, dual-target inhibitors (targeting two distinct pathways within a single molecule) may reduce systemic toxicity and mitigate resistance mechanisms in cancer treatment. Notably, recent years have witnessed remarkable progress in dual-target ALK inhibitor development for NSCLC. Consequently, this review aims to summarize the advancements achieved through dual ALK-based inhibitors in NSCLC therapy, analyze their rational design and structure-activity relationships, and provide perspectives for overcoming resistance through next-generation inhibitors and innovative therapeutic approaches.

Laminin-γ2-NR6A1 Fusion Protein Promotes Metastatic Potential in Non-Small-Cell Lung Carcinoma Cells without Epidermal Growth Factor Receptor Mutation

Laminin-γ2 fusion gene (Lm-γ2F), formed by translocation between LAMC2 and NR6A1, functions as an epidermal growth factor receptor (EGFR) ligand. However, its expression and impact on cancers beyond the initially studied contexts remain unclear. This study focused on Lm-γ2F protein secretion and its role in non-small-cell lung carcinoma (NSCLC), where EGFR signaling plays a pivotal role in malignancy progression. Lm-γ2F secretion was confirmed in serum-free conditioned medium from six NSCLC cell lines by Western blot analysis and further validated in NCI-H1650 cells. Hypothesizing that Lm-γ2F functions as an EGFR ligand, its effects in NSCLC cells lacking EGFR mutations were explored. In EKVX and RERF-LC-KJ cell lines, Lm-γ2F overexpression significantly enhanced cell growth, survival, motility, and invasiveness through EGFR signaling activation compared with controls. Conversely, no effects were observed in VMRC-LCD cells lacking EGFR expression. Additionally, increased membrane-type 1 matrix metalloproteinase expression was detected in Lm-γ2F-expressing EKVX cells. In vivo, these cells exhibited elevated metastatic activity in a lung metastasis model. These findings suggested that ectopic Lm-γ2F expression contributes to malignant progression in NSCLC cells without EGFR mutations. Furthermore, EGFR tyrosine kinase inhibitors may suppress metastasis in these contexts. This study provides novel insights into the oncogenic role of Lm-γ2F in NSCLC, highlighting its potential as a therapeutic target to mitigate tumor progression and metastasis.

Molecular Underpinnings of Brain Metastases

Brain metastases are the most commonly diagnosed type of central nervous system tumor, yet the mechanisms of their occurrence are still widely unknown. Lung cancer, breast cancer, and melanoma are the most common etiologies, but renal and colorectal cancers have also been described as metastasizing to the brain. Regardless of their origin, there are common mechanisms for progression to all types of brain metastases, such as the creation of a suitable tumor microenvironment in the brain, priming of tumor cells, adaptations to survive spreading in lymphatic and blood vessels, and development of mechanisms to penetrate the blood-brain barrier. However, there are complex genetic and molecular interactions that are specific to every type of primary tumor, making the understanding of the metastatic progression of tumors to the brain a challenging field of study. In this review, we aim to summarize current knowledge on the pathophysiology of brain metastases, from specific genetic characteristics of commonly metastatic tumors to the molecular and cellular mechanisms involved in progression to the central nervous system. We also briefly discuss current challenges in targeted therapies for brain metastases and how there is still a gap in knowledge that needs to be overcome to improve patient outcomes.

Inhibition of the anti-apoptotic protein BCL2 in EML4-ALK cell models as a second proposed therapeutic target for non-small cell lung cancer

The anaplastic lymphoma kinase (ALK) oncoprotein plays a crucial role in non-small cell lung cancer (NSCLC) by activating signaling pathways involved in cell proliferation and survival through constitutive phosphorylation. While first-line crizotinib can regulate phosphorylation, mutations in the ALK gene can lead to resistance against ALK inhibitors (ALKi) such as ceritinib and alectinib. On the other hand, overexpression of BCL2, a protein involved in cell death regulation, has been observed in NSCLC and is considered a potential therapeutic target. In this study, we propose to inhibit BCL2 as a secondary therapeutic target in EML4-ALK cell models to overcome resistance caused by ALK mutations. Four Ba/F3 EML4-ALK cell models (WT, C1156Y, L1196M, and G1202R) generated by site-directed mutagenesis exhibited varying levels of BCL2 expression. Both the WT and G1202R models showed overexpression of BCL2, while C1156Y and L1196M models approached baseline levels. We treated these cells with ABT-199, a selective BCL2 inhibitor, and found that models with high BCL2 expression exhibited resistance, while those with lower expression showed sensitivity to BCL2 inhibition. In addition, our analysis using bioinformatics indicated that ABT-199 not only targets BCL2 but also binds to the active site of all ALK mutants, it was contrasted by in vitro ALK kinase activity inhibition by ABT-199 (5.5 μM). This interaction was further supported by a significant decrease of ALK phosphorylation in single and combination treatment with 300nM ABT-199. Finally, when ABT-199 was combined with ALKi, we observed a wide range of synergistic effects in the WT and G1202R cell models, while the C1156Y and L1196M models showed limited synergy. In conclusion, our findings indicate that BCL2 targeting with ABT-199, in combination with ALKi, can significantly reduce tumor cell survival in Ba/F3 EML4-ALK cell models.

The continually evolving landscape of novel therapies in oncogene-driven advanced non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is a highly heterogeneous disease that is frequently associated with a host of known oncogenic alterations. Advances in molecular diagnostics and drug development have facilitated the targeting of novel alterations such that the majority of NSCLC patients have driver mutations that are now clinically actionable. The goal of this review is to gain insights into clinical research and development principles by summary, analysis, and discussion of data on agents targeting known alterations in oncogene-driven, advanced NSCLC beyond those in the epidermal growth factor receptor (EGFR) and the anaplastic lymphoma kinase (ALK). A search of published and presented literature was conducted to identify prospective trials and integrated analyses reporting outcomes for agents targeting driver gene alterations (except those in EGFR and ALK) in molecularly selected, advanced NSCLC. Clinical efficacy data were extracted from eligible reports and summarized in text and tables. Findings show that research into alteration-directed therapies in oncogene-driven, advanced NSCLC is an extremely active research field. Ongoing research focuses on the expansion of new agents targeting both previously identified targets (particularly hepatocyte growth factor receptor (MET), human epidermal growth factor receptor 2 (HER2), and Kirsten rat sarcoma viral oncogene homolog (KRAS)) as well as novel, potentially actionable targets (such as neuregulin-1 (NRG1) and phosphatidylinositol 3-kinase (PI3K)). The refinement of biomarker selection criteria and the development of more selective and potent agents are allowing for increasingly specific and effective therapies and the expansion of clinically actionable alterations. Clinical advances in this field have resulted in a large number of regulatory approvals over the last 3 years. Future developments should focus on the continued application of alteration therapy matching principles and the exploration of novel ways to target oncogene-driven NSCLC.

Discovery of Oral Degraders of the ROS1 Fusion Protein with Potent Activity against Secondary Resistance Mutations

The development of therapeutic resistance in the majority of patients limits the long-term benefit of ROS1 inhibitor treatment. On-target mutations of the ROS1 kinase domain confer resistance to crizotinib and lorlatinib in more than one-third of acquired resistance cases with no current effective treatment option. As an alternative to stoichiometric inhibition, proteolytic degradation of ROS1 could provide an effective tool to combat resistance generated by these mutations. Our study has identified a potent, orally active ROS1 degrader with an excellent pharmacokinetics profile. The degrader can effectively inhibit ROS1-dependent cell proliferation and tumor growth by degrading the ROS1 kinase, thereby eliminating the active phospho-ROS1. More importantly, the degradation-based therapeutic modality can overcome on-target mutation resistance to tyrosine kinase inhibitors by efficient degradation of the mutated kinase to achieve greater potency than inhibition.

Non-Small-Cell Lung Cancer Patients Harboring ROS1 Rearrangement: Real World Testing Practices, Characteristics and Treatment Patterns (ROS1REAL Study)

ROS1 rearrangements are considered rare in non-small-cell lung cancer (NSCLC). This retrospective real-world study aimed to evaluate first-line treatment with crizotinib, a tyrosine kinase inhibitor (TKI) standard of care vs. new generation ROS1 anti-cancer agents. Forty-nine ROS1-expressing NSCLC patients, diagnosed with advanced metastatic disease, were included. Molecular profiling using either FISH/CISH or NGS was performed on tissue samples. Twenty-eight patients were treated with crizotinib, while fourteen patients were administered newer drugs (entrectinib, repotrectinib) and seven patients received platinum-doublet chemotherapy in a first-line setting. Overall response rate and disease control rate for the crizotinib and entrectinb/repotrectinib cohort were 68% and 82% vs. 86% and 93%, respectively. Median progression free survival was 1.6 years (95% CI 1.15-2.215) for the crizotinib treatment vs. 2.35 years for the entrectinib/repotrectinib cohort (95% CI 1.19-3.52). Central nervous system progression was noted in 20% and 25% of the crizotinib and entrectinib/repotrectinib cohorts, respectively. This multi-center study presents real-world treatment patterns of ROS1 NSCLC population, indicating that crizotinib exhibited comparable results to entrectinib/repotrectinib in a first-line setting, although both response rate and survival was numerically longer with treatment with newer agents.

Advances in Non-Small Cell Lung Cancer: Current Insights and Future Directions

The leading cause of cancer deaths worldwide is attributed to non-small cell lung cancer (NSCLC), necessitating a continual focus on improving the diagnosis and treatment of this disease. In this review, the latest breakthroughs and emerging trends in managing NSCLC are highlighted. Major advancements in diagnostic methods, including better imaging technologies and the utilization of molecular biomarkers, are discussed. These advancements have greatly enhanced early detection and personalized treatment plans. Significant improvements in patient outcomes have been achieved by new targeted therapies and immunotherapies, providing new hope for individuals with advanced NSCLC. This review discusses the persistent challenges in accessing advanced treatments and their associated costs despite recent progress. Promising research into new therapies, such as CAR-T cell therapy and oncolytic viruses, which could further revolutionize NSCLC treatment, is also highlighted. This review aims to inform and inspire continued efforts to improve outcomes for NSCLC patients globally, by offering a comprehensive overview of the current state of NSCLC treatment and future possibilities.

Current treatment and novel insights regarding ROS1-targeted therapy in malignant tumors

BACKGROUND

The proto-oncogene ROS1 encodes an intrinsic type I membrane protein of the tyrosine kinase/insulin receptor family. ROS1 facilitates the progression of various malignancies via self-mutations or rearrangements. Studies on ROS1-directed tyrosine kinase inhibitors have been conducted, and some have been approved by the FDA for clinical use. However, the adverse effects and mechanisms of resistance associated with ROS1 inhibitors remain unknown. In addition, next-generation ROS1 inhibitors, which have the advantage of treating central nervous system metastases and alleviating endogenous drug resistance, are still in the clinical trial stage.

METHOD

In this study, we searched relevant articles reporting the mechanism and clinical application of ROS1 in recent years; systematically reviewed the biological mechanisms, diagnostic methods, and research progress on ROS1 inhibitors; and provided perspectives for the future of ROS1-targeted therapy.

RESULTS

ROS1 is most expressed in malignant tumours. Only a few ROS1 kinase inhibitors are currently approved for use in NSCLC, the efficacy of other TKIs for NSCLC and other malignancies has not been ascertained. There is no effective standard treatment for adverse events or resistance to ROS1-targeted therapy. Next-generation TKIs appear capable of overcoming resistance and delaying central nervous system metastasis, but with a greater incidence of adverse effects.

CONCLUSIONS

Further research on next-generation TKIs regarding the localization of ROS1 and its fusion partners, binding sites for targeted drugs, and coadministration with other drugs is required. The correlation between TKIs and chemotherapy or immunotherapy in clinical practice requires further study.