Emerging drugs for EGFR-mutated non-small cell lung cancer

Overcoming AZD9291 Resistance and Metastasis of NSCLC via Ferroptosis and Multitarget Interference by Nanocatalytic Sensitizer Plus AHP-DRI-12

The acquired resistance to Osimertinib (AZD9291) greatly limits the clinical benefit of patients with non-small cell lung cancer (NSCLC), whereas AZD9291-resistant NSCLCs are prone to metastasis. It's challenging to overcome AZD9291 resistance and suppress metastasis of NSCLC simultaneously. Here, a nanocatalytic sensitizer (VF/S/A@CaP) is proposed to deliver Vitamin c (Vc)-Fe(II), si-OTUB2, ASO-MALAT1, resulting in efficient inhibition of tumor growth and metastasis of NSCLC by synergizing with AHP-DRI-12, an anti-hematogenous metastasis inhibitor by blocking the amyloid precursor protein (APP)/death receptor 6 (DR6) interaction designed by our lab. Fe²⁺ released from Vc-Fe(II) generates cytotoxic hydroxyl radicals (•OH) through Fenton reaction. Subsequently, glutathione peroxidase 4 (GPX4) is consumed to sensitize AZD9291-resistant NSCLCs with high mesenchymal state to ferroptosis due to the glutathione (GSH) depletion caused by Vc/dehydroascorbic acid (DHA) conversion. By screening NSCLC patients' samples, metastasis-related targets (OTUB2, LncRNA MALAT1) are confirmed. Accordingly, the dual-target knockdown plus AHP-DRI-12 significantly suppresses the metastasis of AZD9291-resistant NSCLC. Such modality leads to 91.39% tumor inhibition rate in patient-derived xenograft (PDX) models. Collectively, this study highlights the vulnerability to ferroptosis of AZD9291-resistant tumors and confirms the potential of this nanocatalytic-medicine-based modality to overcome critical AZD9291 resistance and inhibit metastasis of NSCLC simultaneously.

Effects of Different Types of Pathogenic Variants on Phenotypes of Familial Hypercholesterolemia

Objective: It has been shown that pathogenic variants are associated with poor clinical outcomes in patients with familial hypercholesterolemia (FH). However, data on the effect of different types of pathogenic variants on FH phenotype is limited.

Methods: We retrospectively investigated the associations between genotypes and phenotypes, including low-density lipoprotein (LDL) cholesterol level and the occurrence of major adverse cardiac events (MACEs), defined as cardiovascular death, myocardial infarction, unstable angina, or coronary artery revascularization, in patients with FH (N = 1,050, male/female = 490/560). Based on genotype, the patients were divided into the following three groups: patients without pathogenic variants, patients with missense variants, and patients with protein-truncating variants (PTVs). Cox proportional hazard model was used to identify the factors associated with MACEs.

Results: The median follow-up duration was 12.6 years (interquartile range = 9.5–17.9 years). There were 665 patients with FH-mutation (277 patients with missense variants and 388 patients with PTVs) and 385 patients without FH-mutation. Over the follow-up duration, 175 MACEs were observed. We identified 89 different pathogenic variants in the 665 patients with FH. LDL cholesterol level was found to be significantly higher in patients with PTVs (256 mg/dl) than in patients with missense variants (236 mg/dl) and patients without pathogenic variants (216 mg/dl). It was also found that PTVs and missense variants are significantly associated with MACEs (hazard ratio [HR] = 1.58, 95% confidence interval [CI] = 1.08–2.08, p = 0.0033 and HR = 3.24, 95% CI = 2.12–4.40, p = 3.9 × 10⁻⁶, respectively), independent of classical risk factors.

Conclusion: Pathogenic variants, especially PTVs, are significantly associated with poor outcomes in patients with FH. Genetic testing is useful for the diagnosis and risk stratification of patients with FH.

Inhibition of Bcl-2 and Bcl-xL overcomes the resistance to the third-generation EGFR tyrosine kinase inhibitor osimertinib in non-small cell lung cancer

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have demonstrated significant benefits to patients with non‑small cell lung cancer (NSCLC) harboring EGFR‑activating mutations; however, acquired resistance limits their long‑term efficacy. Therefore, it remains an urgent requirement to discover the underlying mechanisms and investigate novel therapeutic strategies for overcoming the resistance to EGFR TKIs. The present study aimed to determine the mechanism underlying the resistance of NSCLC cells to osimertinib, a third‑generation EGFR tyrosine kinase inhibitor, the osimertinib‑resistant NSCLC cell sub‑line HCC827/OR was established in the present study. It was found that the expression levels of Bcl‑2 and Bcl‑xL were significantly upregulated in resistant cells compared with sensitive cells. Furthermore, the suppression of Bcl‑2 and Bcl‑xL through small interfering RNA‑mediated gene knockdown or using a small molecule specific inhibitor ABT‑263 re‑sensitized HCC827/OR cells to osimertinib treatment. Moreover, the combined treatment of HCC827/OR cells with ABT‑263 and osimertinib enhanced the rate of cell apoptosis through the mitochondrial apoptotic pathway. Finally, ABT‑263 was able to overcome the resistance of osimertinib in xenograft tumor models. In conclusion, these findings may provide an improved concept for the development of a novel combined therapeutic strategy for the treatment of NSCLC resistance to EGFR TKIs.

Anti-Angiogenic Therapy in the Treatment of Non-Small Cell Lung Cancer

Angiogenesis plays an essential role in the development of most solid tumors by delivering nutrients and oxygen to the tumor. Therefore, anti-angiogenic therapy, particularly anti-VEGF and anti-VEGF receptor (VEGFR) therapy, has been a popular strategy to treat cancer. However, anti-angiogenic therapy does not significantly improve patients' outcomes when used alone because the cutdown of the vessels transforms tumor cells to a hypoxia-tolerant phenotype. While combining anti-angiogenic therapy with other therapies, including chemotherapy, radiotherapy, immunotherapy, and anti-epidermal growth factor receptor (EGFR) therapy, has a promising efficacy due to the vessel normalization effect induced by anti-angiogenic agents. Here, we review the characteristics of tumor angiogenesis, the mechanisms, clinical applications, and prospects of combining anti-angiogenic therapy with other therapies in the treatment of non-small cell lung cancer.

Use of liquid biopsy in monitoring therapeutic resistance in EGFR oncogene addicted NSCLC

Liquid biopsy has emerged as a minimally invasive alternative to tumor tissue analysis for the management of lung cancer patients, especially for epidermal growth factor receptor (EGFR) oncogene addicted tumor. In these patients, despite the clear benefits of tyrosine kinase inhibitors therapy, the development of acquired resistance and progressive disease is inevitable in most cases and liquid biopsy is important for molecular characterization at resistance and, being non-invasive, may be useful for disease monitoring. In this review, the authors will focus on the applications of liquid biopsy in EGFR-mutated non small cells lung cancer at diagnosis, during treatment and at progression, describing available data and possible future scenarios.

Non-small cell lung cancer-small cell lung cancer transformation as mechanism of resistance to tyrosine kinase inhibitors in lung cancer

Mutated or rearranged driver kinases in non-small cell lung cancer (NSCLC) cells are clinically amenable to treatment with tyrosine kinase inhibitors (TKIs) resulting in prolonged survival and significant benefit compared to cytotoxic chemotherapy. The most frequent genomic alterations are observed for epidermal growth factor receptor and anaplastic lymphoma kinase, which can be blocked by a range of specific TKIs in sequence. In clinics, resistance to TKIs emerges after approximately one year and comprises secondary mutations of the kinases (on-target) or alternative pathways circumventing the original kinase (off-target) alterations. A special feature of NSCLC is the occurrence of histological transformation to small cell lung cancer (SCLC) in up to 14% of cases, which, in general, is accompanied by resistance to the original TKIs. SCLC transformed tumors may be treated with the classical platinum/etoposide regimen but thus far there are no definitive guidelines. Four transformed pleural SCLC lines in our lab indicate the presence of a gradual NSCLC-SCLC shift with overlapping drug sensitivities. In conclusion, the treatment of NSCLC-SCLC transformed cancer cells would need a better chemosensitivity assessment using functional genomics to guide further therapy.

Recent advances in targeted small-molecule inhibitor therapy for non-small-cell lung cancer-An update

WHAT IS KNOWN AND OBJECTIVE

Targeted small molecule EGFR Tyrosine Kinase Inhibitors (TKI's) and the Anaplastic Lymphoma Kinase (ALK) inhibitors have been promising tools for advanced non-small-cell lung cancers (NSCLCs). However, tumours tend to develop subsequent mutations, rendering them drug-resistant. Hence, alternative pathways of therapy need to be explored.

COMMENT

Gefitinib, erlotinib and afatinib, once considered as alternatives to platinum-based cytotoxic chemotherapy, have been rendered ineffective in patients with NSCLCs harbouring T790M mutation. Osimertinib is effective in T790M-mutant cancers, but not against those exhibiting the subsequent C797S mutation. ALK gene alterations have rendered tumours insensitive to crizotinib. However, lorlatinib and brigatinib are effective in tumours showing ALK+ mutations. Drugs acting through alternative pathways like the PD-1 pathway, BRAF, VEGFR, EGFR antibodies and NTRK inhibition have been showing promising results.

WHAT IS NEW AND CONCLUSIONS

Osimertinib, brigatinib and allosteric C797S EGFR inhibitors like AI1045, BRAF inhibitors like LXH254 under trials and entrictinib, a recently approved NTRK inhibitor, have all shown improved progression-free survival compared with earlier generations of small molecule inhibitors for NSCLCs.

Dual Targeting of the Epidermal Growth Factor Receptor Using Combination of Nimotuzumab and Erlotinib in Advanced Non-Small-Cell Lung Cancer with Leptomeningeal Metastases: A Report of Three Cases

Leptomeningeal metastases (LM) occur in 3-5% of patients with advanced non-small-cell lung cancer (NSCLC) and are associated with a dismal prognosis. We report three cases of NSCLC with LM who were treated with the combination of nimotuzumab and erlotinib. Magnetic Resonance Imaging (MRI) evaluation during follow-up showed significant improvement in cancer symptoms and decreased tumor size in all three patients. Grade 3 and 4 toxicities were rarely seen. Based on apparent efficacy of the regimen and fewer side effects, we suggest that nimotuzumab in combination with erlotinib may be a promising option for the treatment of NSCLC with LM.

Current Approaches in NSCLC Targeting K-RAS and EGFR

The research and treatment of non-small cell lung cancer (NSCLC) have achieved some important advances in recent years. Nonetheless, the overall survival rates for NSCLC remain low, indicating the importance to effectively develop new therapies and improve current approaches. The understanding of the function of different biomarkers involved in NSCLC progression, survival and response to therapy are important for the development of early detection tools and treatment options. Epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene homolog (K-RAS) are two of the main significant biomarkers for the management of NSCLC. Mutations in these genes were associated with development and response to therapies. For example, the use of small molecule tyrosine kinase (TK) inhibitors and immunotherapy has led to benefits in some, but not all patients with altered EGFR. In contrast, there is still no effective approved drug to act upon patients harbouring K-RAS mutations. In addition, K-RAS mutations have been associated with lack of activity of TK inhibitors. However, promising approaches aimed to inhibit mutant K-RAS are currently under study. Therefore, this review will discuss these approaches and also EGFR therapies, and hopefully, it will draw attention to the need of continued research in the field in order to improve the outcomes in NSCLC patients.