Molecular mechanisms of resistance to BRAF and MEK inhibitors in BRAFV600E non-small cell lung cancer

Patients outcomes in lung adenocarcinoma transforming to small-cell lung cancer after tyrosine kinase inhibitor therapy

BACKGROUND

Non-small cell lung cancer (NSCLC) transforming to small cell lung cancer (SCLC) is one of the mechanisms of resistance to tyrosine kinase inhibitors (TKIs). Cases of NSCLC transforming into SCLC have been discovered. However, we lack concentrated data on the characteristics of this population and the transformed SCLC to aid our insight of the biology and clinical value of NSCLC transforming with positive.

METHODS

We systematically reviewed the published literatures and summarized the pathological and clinical characteristics, and the prognosis, of published cases.

RESULTS

140 patients with lung adenocarcinoma (LUAD) were included in this study, with a median age of 56.8 years. The median time from the first diagnosis of LUAD transforming to SCLC (ttSCLC) was 20.0 months. The median overall survival (mOS) after the diagnosis of SCLC was 11.0 months (95% CI, 7.41 to 14.59 months). In the univariate analysis, ever smoking (either former or current) was a promising predictor of a shorter ttSCLC (HR, 1.73; 95% CI, 1.14 to 2.62; P = 0.010). TKIs therapy administered as a second line and beyond treatment was related to a significant delay in SCLC onset compared to first-line therapy (HR, 0.62; 95% CI, 0.40 to 0.96; P = 0.031). The median progression-free survival (mPFS) on first-line platinum plus etoposide after the conversion to SCLC was 3.0 months. Female appeared to be related to worse outcomes after transformation of SCLC.

CONCLUSION

Transformed SCLC exhibited poor response to primary SCLC classic chemotherapy and immunotherapy. It carries a worse prognosis. Exploring novel therapeutic strategies for transformed SCLC is imperative.

Genomic landscape and comparative analysis of tissue and liquid-based NGS in Taiwanese anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma (ATC) is an aggressive cancer that requirements rapid diagnosis and multimodal treatment. Next-generation sequencing (NGS) aids in personalized therapies and improved trial enrollment. The role of liquid-based NGS in ATC remains unclear. This study analyzed ATC samples using tissue-based NGS, liquid-based NGS, or both platforms. Genetic alterations showed highly heterogeneity, including mutations in RAS/RAF/MEK/ERK, PI3K/AKT/mTOR, cell cycle regulation, other receptor tyrosine kinases, DNA damage response, mismatch repair, and chromatin remodeling. TP53 (65.4%) and BRAF (30.8%) were the most frequently mutated genes in tissue NGS. In paired samples, the concordance rates were 69.2% for TP53 and 84.6% for BRAF. One of two patients treated with dabrafenib and trametinib showed a copy number gain in post-treatment tissue NGS, potentially indicating resistance. Liquid biopsy provides valuable supplementary information when tissue samples are insufficient. Further studies are necessary to understand resistance mechanisms and develop strategies to overcome them in BRAF-targeted therapy.

Navigating Therapeutic Challenges in BRAF-Mutated NSCLC: Non-V600 Mutations, Immunotherapy, and Overcoming Resistance

Although rare in non-small cell lung cancer (NSCLC), BRAF mutations present considerable therapeutic challenges. While the use of BRAF and MEK inhibitor combinations has significantly improved survival outcomes in patients with BRAF V600E mutations, no targeted therapies are currently available for class II and III mutations, leaving the optimal treatment strategy and prognosis for these patients uncertain. Additionally, despite immunotherapy typically showing limited benefit in patients with other activating genomic alterations, it appears to deliver comparable efficacy in BRAF-mutated NSCLC, emerging as a potentially viable treatment option, particularly in patients with a history of smoking. However, resistance to BRAF pathway inhibitors is inevitable, leading to disease progression, and a well-defined strategy to overcome these resistance mechanisms is lacking. This review aims to explore the critical challenges in the management of BRAF-mutated NSCLC, providing a comprehensive summary of the current evidence and highlighting ongoing clinical trials that aim to address these critical gaps.

Expanding the spectrum of low-grade sinonasal adenocarcinoma with biphasic seromucinous differentiation and activating HRAS/AKT1 mutations

AIMS

Low-grade non-intestinal-type sinonasal adenocarcinoma (LGSNAC) is a rare heterogeneous and poorly characterised group of tumours, distinct from intestinal- and salivary-type neoplasms. Therefore, further characterisation is needed for clearer biological understanding and classification.

METHODS AND RESULTS

Clinical, histological and molecular characterisation of four cases of biphasic, low-grade adenocarcinomas of the sinonasal tract was performed. All patients were male, aged between 48 and 78 years, who presented with polypoid masses in the nasal cavity. Microscopically, virtually all tumours were dominated by tubulo-glandular biphasic patterns, microcystic, focal (micro)papillary, oncocytic or basaloid features. Immunohistochemical staining confirmed biphasic differentiation with an outer layer of myoepithelial cells. Molecular profiling revealed HRAS (p.G13R, p.Q61R) mutations, and concomitant AKT1 (p.E17K, p.Q79R) mutations in two cases. Two cases showed potential in-situ/precursor lesions adjacent to the tumour. Follow-up periods ranged from 1 to 30 months, with one case relapsing locally after 12 and > 20 years.

CONCLUSION

This study further corroborates a distinct biphasic low-grade neoplasm of the sinonasal tract with seromucinous differentiation. Although morphological and molecular features overlap with salivary gland epithelial-myoepithelial carcinoma, several arguments favour categorising these tumours within the spectrum of LGSNAC.

Navigating the complexity of BRAF mutations in non-small cell lung cancer: current insights and future prospects

There are many challenges that are faced in the treatment of Non-Small Cell Lung Cancer (NSCLC) due to the complexities associated with the tumor. Association of different types of mutations are one of the major complexities. Among these mutations, BRAF mutations are significantly gathering more attention due to their impact on disease progression and therapeutic response. This review provides an analysis of the current understanding of BRAF mutations in NSCLC, focusing on the molecular intricacies, clinical implications, and therapeutic advancements. The article explores the diverse spectrum of BRAF mutations, highlighting the prevalence of specific mutations such as V600E and non-V600E alterations. The review also highlights the intricate signalling pathways influenced by BRAF mutations, shedding light on their role in tumorigenesis and metastasis. Therapeutically, we critically evaluate the existing targeted therapies tailored for BRAF-mutant NSCLC, addressing their efficacy, limitations, and emerging resistance mechanisms. Furthermore, we outline ongoing clinical trials and promising investigational agents that hold potential for reshaping the treatment of NSCLC. This review provides comprehensive current information about the role of BRAF mutations in NSCLC. Understanding the molecular diversity, clinical implications, and therapeutic strategies associated with BRAF-mutant NSCLC is crucial for optimizing patient outcomes and steering the direction of future research in this evolving field.

Expert consensus on the diagnosis and treatment of solid tumors with BRAF mutations

The BRAF gene is an important signaling molecule in human cells that is involved in the regulation of cell growth, differentiation, and survival. When the BRAF gene mutates, it can lead to abnormal activation of the signaling pathway, which promotes cell proliferation, inhibits cell apoptosis, and ultimately contributes to the occurrence and development of cancer. BRAF mutations are widely present in various cancers, including malignant melanoma, thyroid cancer, colorectal cancer, non-small cell lung cancer, and hairy cell leukemia, among others. BRAF is an important target for the treatment of various solid tumors, and targeted combination therapies, represented by BRAF inhibitors, have become one of the main treatment modalities for a variety of BRAF-mutation-positive solid tumors. Dabrafenib plus trametinib, as the first tumor-agnostic therapy, has been approved by the US Food and Drug Administration for the treatment of adult and pediatric patients aged 6 years and older harboring a BRAF V600E mutation with unresectable or metastatic solid tumors that have progressed following prior treatment and who have no satisfactory alternative treatment options. This is also the first time a BRAF/MEK inhibitor combination has been approved for use in pediatric patients. As research into the diagnosis and treatment of BRAF mutations advances, standardizing the detection of BRAF mutations and the clinical application of BRAF inhibitors becomes increasingly important. Therefore, we have established a universal and systematic strategy for diagnosing and treating solid tumors with BRAF mutations. In this expert consensus, we (1) summarize the epidemiology and clinical characteristics of BRAF mutations in different solid tumors, (2) provide recommendations for the selection of genetic testing methods and platforms, and (3) establish a universal strategy for the diagnosis and treatment of patients with solid tumors harboring BRAF mutations.

Deciphering resistance mechanisms in cancer: final report of MATCH-R study with a focus on molecular drivers and PDX development

BACKGROUND

Understanding the resistance mechanisms of tumor is crucial for advancing cancer therapies. The prospective MATCH-R trial (NCT02517892), led by Gustave Roussy, aimed to characterize resistance mechanisms to cancer treatments through molecular analysis of fresh tumor biopsies. This report presents the genomic data analysis of the MATCH-R study conducted from 2015 to 2022 and focuses on targeted therapies.

METHODS

The study included resistant metastatic patients (pts) who accepted an image-guided tumor biopsy. After evaluation of tumor content (TC) in frozen tissue biopsies, targeted NGS (10 < TC < 30%) or Whole Exome Sequencing and RNA sequencing (TC > 30%) were performed before and/or after the anticancer therapy. Patient-derived xenografts (PDX) were established by implanting tumor fragments into NOD scid gamma mice and amplified up to five passages.

RESULTS

A total of 1,120 biopsies were collected from 857 pts with the most frequent tumor types being lung (38.8%), digestive (16.3%) and prostate (14.1%) cancer. Molecular targetable driver were identified in 30.9% (n = 265/857) of the patients, with EGFR (41.5%), FGFR2/3 (15.5%), ALK (11.7%), BRAF (6.8%), and KRAS (5.7%) being the most common altered genes. Furthermore, 66.0% (n = 175/265) had a biopsy at progression on targeted therapy. Among resistant cases, 41.1% (n = 72/175) had no identified molecular mechanism, 32.0% (n = 56/175) showed on-target resistance, and 25.1% (n = 44/175) exhibited a by-pass resistance mechanism. Molecular profiling of the 44 patients with by-pass resistance identified 51 variants, with KRAS (13.7%), PIK3CA (11.8%), PTEN (11.8%), NF2 (7.8%), AKT1 (5.9%), and NF1 (5.9%) being the most altered genes. Treatment was tailored for 45% of the patients with a resistance mechanism identified leading to an 11 months median extension of clinical benefit. A total of 341 biopsies were implanted in mice, successfully establishing 136 PDX models achieving a 39.9% success rate. PDX models are available for EGFR (n = 31), FGFR2/3 (n = 26), KRAS (n = 18), ALK (n = 16), BRAF (n = 6) and NTRK (n = 2) driven cancers. These models closely recapitulate the biology of the original tumors in term of molecular alterations and pharmacological status, and served as valuable models to validate overcoming treatment strategies.

CONCLUSION

The MATCH-R study highlights the feasibility of on purpose image guided tumor biopsies and PDX establishment to characterize resistance mechanisms and guide personalized therapies to improve outcomes in pre-treated metastatic patients.

SIRT7 promotes mitochondrial biogenesis to render the adaptive resistance to MAPK inhibition in melanoma

Melanoma, arising from the malignant transformation of melanocytes, stands as the most lethal type of skin cancer. While significant strides have been made in targeted therapy and immunotherapy, substantially enhancing therapeutic efficacy, the prognosis for melanoma patients remains unoptimistic. SIRT7, a nuclear-localized deacetylase, plays a pivotal role in maintaining cellular homeostasis and adapting to external stressors in melanoma, with its activity closely tied to intracellular nicotinamide adenine dinucleotide (NAD+). However, its involvement in adaptive resistance to targeted therapy remains unclear. Herein, we unveil that up-regulated SIRT7 promotes mitochondrial biogenesis to render the adaptive resistance to MAPK inhibition in melanoma. Initially, we observed a significant increase of SIRT7 expression in publicly available datasets following targeted therapy within a short duration. In consistent, we found elevated SIRT7 expression in melanoma cells subjected to BRAF or MEK inhibitors in vitro. The up-regulation of SIRT7 expression was also confirmed in xenograft tumors in mice after targeted therapy in vivo. Furthermore, we proved that SIRT7 deficiency led to decreased cell viability upon prolonged exposure to BRAF or MEK inhibitors, accompanied by an increase in cell apoptosis. Mechanistically, SIRT7 deficiency restrained the upregulation of genes associated with mitochondrial biogenesis and intracellular ATP levels in response to targeted therapy treatment in melanoma cells. Ultimately, we proved that SIRT7 deficieny could sensitize BRAF-mutant melanoma cells to MAPK inhibition targeted therapy in vivo. In conclusion, our findings underscore the role of SIRT7 in fostering adaptive resistance to targeted therapy through the facilitation of mitochondrial biogenesis. Targeting SIRT7 emerges as a promising strategy to overcome MAPK inhibitor adaptive resistance in melanoma.

The prospect of substrate-based kinase inhibitors to improve target selectivity and overcome drug resistance

Human kinases are recognized as one of the most important drug targets associated with cancer. There are >80 FDA-approved kinase inhibitors to date, most of which work by inhibiting ATP binding to the kinase. However, the frequent development of single-point mutations within the kinase domain has made overcoming drug resistance a major challenge in drug discovery today. Targeting the substrate site of kinases can offer a more selective and resistance-resilient solution compared to ATP inhibition but has traditionally been challenging. However, emerging technologies for the discovery of drug leads using recombinant display and stabilization of lead compounds have increased interest in targeting the substrate site of kinases. This review discusses recent advances in the substrate-based inhibition of protein kinases and the potential of such approaches for overcoming the emergence of resistance.

In vivo vulnerabilities to GPX4 and HDAC inhibitors in drug-persistent versus drug-resistant BRAFV600E lung adenocarcinoma

The current targeted therapy for BRAFV600E-mutant lung cancer consists of a dual blockade of RAF/MEK kinases often combining dabrafenib/trametinib (D/T). This regimen extends survival when compared to single-agent treatments, but disease progression is unavoidable. By using whole-genome CRISPR screening and RNA sequencing, we characterize the vulnerabilities of both persister and D/T-resistant cellular models. Oxidative stress together with concomitant induction of antioxidant responses is boosted by D/T treatment. However, the nature of the oxidative damage, the choice of redox detoxification systems, and the resulting therapeutic vulnerabilities display stage-specific differences. Persister cells suffer from lipid peroxidation and are sensitive to ferroptosis upon GPX4 inhibition in vivo. Biomarkers of lipid peroxidation are detected in clinical samples following D/T treatment. Acquired alterations leading to mitogen-activated protein kinase (MAPK) reactivation enhance cystine transport to boost GPX4-independent antioxidant responses. Similarly to BRAFV600E-mutant melanoma, histone deacetylase (HDAC) inhibitors decrease D/T-resistant cell viability and extend therapeutic response in vivo.

Case report: Metastatic BRAF V600E-mutated adult Wilms' tumor with robust response to BRAF/MEK inhibitor therapy

Nephroblastoma or Wilms' tumor (WT) is the most common pediatric renal malignancy but rare in adults. Treatment protocols for adults are typically extrapolated from pediatric guidelines, but there are no standard guidelines for adults due to the rarity of the disease. However, next-generation sequencing has led to new therapeutic options for adult WT patients. We present the first case to our knowledge of a recurrent adult WT treated with dual BRAF/MEK-targeted therapy, which showed initial robust clinical response and was well tolerated.

Challenges in the treatment of BRAF K601E-mutated lung carcinoma: a case report of rapid response and resistance to dabrafenib and trametinib

We report a case of limited effectiveness of dabrafenib and trametinib in a 59-year-old man with poorly differentiated lung carcinoma and a rare BRAF K601E mutation. The patient, unresponsive to chemotherapy and immunotherapy, received these targeted agents as second-line treatment. Despite a notable initial response, tumor regression lasted only 52 days. A subsequent liquid biopsy revealed additional alterations (BRAF amplification, KIT amplification, TP53 S241F), indicating a complex resistance mechanism. This case underscores the challenges in treating BRAF K601E-mutant lung carcinoma, emphasizing the need for advanced molecular diagnostics, personalized approaches, and further research into more effective therapies for unique genetic profiles.

Pathways and targeting avenues of BRAF in non-small cell lung cancer

INTRODUCTION

BRAF is a serine-threonine kinase implicated in the regulation of MAPK signaling cascade. BRAF mutation-driven activation occurs in approximately 2-4% of treatment-naive non-small cell carcinomas (NSCLCs). BRAF upregulation is also often observed in tumors with acquired resistance to receptor tyrosine kinase inhibitors (TKIs).

AREAS COVERED

This review describes the spectrum of BRAF mutations and their functional roles, discusses treatment options available for BRAF p.V600 and non-V600 mutated NSCLCs, and identifies some gaps in the current knowledge.

EXPERT OPINION

Administration of combined BRAF/MEK inhibitors usually produces significant, although often a short-term, benefit to NSCLC patients with BRAF V600 (class 1) mutations. There are no established treatments for BRAF class 2 (L597, K601, G464, G469A/V/R/S, fusions, etc.) and class 3 (D594, G596, G466, etc.) mutants, which account for up to two-thirds of BRAF-driven NSCLCs. Many important issues related to the use of immune therapy for the management of BRAF-mutated NSCLC deserve further investigation. The rare occurrence of BRAF mutations in NSCLC is compensated by high overall incidence of lung cancer disease; therefore, clinical studies on BRAF-associated NSCLC are feasible.

RAF and MEK Inhibitors in Non-Small Cell Lung Cancer

Lung cancer, despite recent advancements in survival rates, represents a significant global health burden. Non-small cell lung cancer (NSCLC), the most prevalent type, is driven largely by activating mutations in Kirsten rat sarcoma viral oncogene homologue (KRAS) and receptor tyrosine kinases (RTKs), and less in v-RAF murine sarcoma viral oncogene homolog B (BRAF) and mitogen-activated protein-kinase kinase (MEK), all key components of the RTK-RAS-mitogen-activated protein kinase (MAPK) pathway. Learning from melanoma, the identification of BRAFV600E substitution in NSCLC provided the rationale for the investigation of RAF and MEK inhibition as a therapeutic strategy. The regulatory approval of two RAF-MEK inhibitor combinations, dabrafenib-trametinib, in 2017, and encorafenib-binimetinib, in 2023, signifies a breakthrough for the management of BRAFV600E-mutant NSCLC patients. However, the almost universal emergence of acquired resistance limits their clinical benefit. New RAF and MEK inhibitors, with distinct biochemical characteristics, are in preclinical and clinical development. In this review, we aim to provide valuable insights into the current state of RAF and MEK inhibition in the management of NSCLC, fostering a deeper understanding of the potential impact on patient outcomes.

BRAFV600E-mutant metastatic NSCLC: disease overview and treatment landscape

In this review, we cover the current understanding of BRAF mutations and associated clinical characteristics in patients with metastatic NSCLC, approved and emerging treatment options, BRAF sequencing approaches, and unmet needs. The BRAFV600E mutation confers constitutive activity of the MAPK pathway, leading to enhanced growth, proliferation, and survival of tumor cells. Testing for BRAF mutations enables patients to be treated with therapies that directly target BRAFV600E and the MAPK pathway, but BRAF testing lags behind other oncogene testing in metastatic NSCLC. Additional therapies targeting BRAFV600E mutations provide options for patients with metastatic NSCLC. Emerging therapies and combinations under investigation could potentially overcome issues of resistance and target non-V600E mutations. Therefore, because targeted therapies with enhanced efficacy are on the horizon, being able to identify BRAF mutations in metastatic NSCLC may become even more important.

New clinical trial design in precision medicine: discovery, development and direction

In the era of precision medicine, it has been increasingly recognized that individuals with a certain disease are complex and different from each other. Due to the underestimation of the significant heterogeneity across participants in traditional "one-size-fits-all" trials, patient-centered trials that could provide optimal therapy customization to individuals with specific biomarkers were developed including the basket, umbrella, and platform trial designs under the master protocol framework. In recent years, the successive FDA approval of indications based on biomarker-guided master protocol designs has demonstrated that these new clinical trials are ushering in tremendous opportunities. Despite the rapid increase in the number of basket, umbrella, and platform trials, the current clinical and research understanding of these new trial designs, as compared with traditional trial designs, remains limited. The majority of the research focuses on methodologies, and there is a lack of in-depth insight concerning the underlying biological logic of these new clinical trial designs. Therefore, we provide this comprehensive review of the discovery and development of basket, umbrella, and platform trials and their underlying logic from the perspective of precision medicine. Meanwhile, we discuss future directions on the potential development of these new clinical design in view of the "Precision Pro", "Dynamic Precision", and "Intelligent Precision". This review would assist trial-related researchers to enhance the innovation and feasibility of clinical trial designs by expounding the underlying logic, which be essential to accelerate the progression of precision medicine.

Resistance to BRAF inhibition explored through single circulating tumour cell molecular profiling in BRAF-mutant non-small-cell lung cancer

BACKGROUND

Resistance mechanisms to combination therapy with dabrafenib plus trametinib remain poorly understood in patients with BRAFV600E-mutant advanced non-small-cell lung cancer (NSCLC). We examined resistance to BRAF inhibition by single CTC sequencing in BRAFV600E-mutant NSCLC.

METHODS

CTCs and cfDNA were examined in seven BRAFV600E-mutant NSCLC patients at failure to treatment. Matched tumour tissue was available for four patients. Single CTCs were isolated by fluorescence-activated cell sorting following enrichment and immunofluorescence (Hoechst 33342/CD45/pan-cytokeratins) and sequenced for mutation and copy number-alteration (CNA) analyses.

RESULTS

BRAFV600E was found in 4/4 tumour biopsies and 5/7 cfDNA samples. CTC mutations were mostly found in MAPK-independent pathways and only 1/26 CTCs were BRAFV600E mutated. CTC profiles encompassed the majority of matched tumour biopsy CNAs but 72.5% to 84.5% of CTC CNAs were exclusive to CTCs. Extensive diversity, involving MAPK, MAPK-related, cell cycle, DNA repair and immune response pathways, was observed in CTCs and missed by analyses on tumour biopsies and cfDNA. Driver alterations in clinically relevant genes were recurrent in CTCs.

CONCLUSIONS

Resistance was not driven by BRAFV600E-mutant CTCs. Extensive tumour genomic heterogeneity was found in CTCs compared to tumour biopsies and cfDNA at failure to BRAF inhibition, in BRAFV600E-mutant NSCLC, including relevant alterations that may represent potential treatment opportunities.

Ultrasound-propelled liposome circumvention and siRNA silencing reverse BRAF mutation-arised cancer resistance to trametinib

BRAF-V600E mutation is regarded as the source of lung cancer resistance to trametinib (Tr), and no solution available for completely addressing this intractable resistance has emerged yet. Herein, the combination of ultrasonic (US) propelled folic acid (FA)-modified liposomes strategy and BRAF-driven gene silencing program is proposed to effectively reverse Tr's resistance to lung cancer. Meanwhile, the prepared cationic nanoliposomes can assist Tr drug and BRAF siRNA to escape lysosome disposal, thereby avoiding Tr drug pumping out or siRNA degradation. More significantly, loaded BRAF siRNA is designed to silence BRAF-V600E mutation genes via modulating BRAF-ERK-pathway and remarkably reverse the PC9R resistance to Tr. Systematic experiments validate that these cooperatively sensitize PC9R cells to Tr and shrink resistant NSCLC in vivo, especially after combining with FA-mediated targeting and US-enhanced permeability that permits more intratumoral accumulations of Tr. Such a biocompatible targeting drug-resistance liberation agent and its underlying design strategy lay a foundation avenue to completely reverse tumor resistance, which is preferable to treat BRAF mutation-arised resistance of various tumors, holding high clinical translation potentials.

The Treatment of a New Entity in Advanced Non-small Cell Lung Cancer: MET Exon 14 Skipping Mutation

BACKGROUND

MET (MET Proto-Oncogene, Receptor Tyrosine Kinase) exon 14 skipping mutation represents one of the most common MET alterations, accounting for approximately 1-3% of all mutations in advanced lung adenocarcinomas. While until 2020 no specific treatment was available for this subset of patients, as of today, three MET Tyrosine Kinase Inhibitors (TKIs) are currently approved in this setting, namely capmatinib, tepotinib and savolitinib.

OBJECTIVE

This article aims to provide an extensive overview of the current therapeutic standard of care for exon 14 skipped advanced Non-small Cell Lung Cancer (NSCLC) patients, alongside with mentions of the main future challenges and opportunities.

CONCLUSION

FDA-approved MET-TKIs currently represent the best option for treating exon 14 skipped advanced NSCLC patients, thanks to their excellent efficacy profile, alongside their manageable safety and tolerability. However, we currently lack specific agents to treat patients progressing on capmatinib or tepotinib, due to a limited understanding of the mechanisms underlying both on- and off-target resistance. In this respect, on-target mutations presently constitute the most explored ones from a mechanistic point of view, and type II MET-TKIs are currently under investigation as the most promising agents capable of overcoming the acquired resistance.

Therapeutic strategies for BRAF mutation in non-small cell lung cancer: a review

Lung cancer is the leading cause of cancer related deaths. Among the two broad types of lung cancer, non-small cell lung cancer accounts for 85% of the cases. The study of the genetic alteration has facilitated the development of targeted therapeutic interventions. Some of the molecular alterations which are important targets for drug therapy include Kirsten rat sarcoma (KRAS), Epidermal Growth Factor Receptor (EGFR), V-RAF murine sarcoma viral oncogene homolog B (BRAF), anaplastic lymphoma kinase gene (ALK). In the setting of extensive on-going clinical trials, it is imperative to periodically review the advancements and the newer drug therapies being available. Among all mutations, BRAF mutation is common with incidence being 8% overall and 1.5 - 4% in NSCLC. Here, we have summarized the BRAF mutation types and reviewed the various drug therapy available - for both V600 and nonV600 group; the mechanism of resistance to BRAF inhibitors and strategies to overcome it; the significance of comprehensive profiling of concurrent mutations, and the role of immune checkpoint inhibitor in BRAF mutated NSCLC. We have also included the currently ongoing clinical trials and recent advancements including combination therapy that would play a role in improving the overall survival and outcome of NSCLC.

Evolving Acquired Vemurafenib Resistance in a BRAF V600E Mutant Melanoma PDTX Model to Reveal New Potential Targets

Malignant melanoma is challenging to treat, and metastatic cases need chemotherapy strategies. Targeted inhibition of commonly mutant BRAF V600E by inhibitors is efficient but eventually leads to resistance and progression in the vast majority of cases. Numerous studies investigated the mechanisms of resistance in melanoma cell lines, and an increasing number of in vivo or clinical data are accumulating. In most cases, bypassing BRAF and resulting reactivation of the MAPK signaling, as well as alternative PI3K-AKT signaling activation are reported. However, several unique changes were also shown. We developed and used a patient-derived tumor xenograft (PDTX) model to screen resistance evolution in mice in vivo, maintaining tumor heterogeneity. Our results showed no substantial activation of the canonical pathways; however, RNAseq and qPCR data revealed several altered genes, such as GPR39, CD27, SLC15A3, IFI27, PDGFA, and ABCB1. Surprisingly, p53 activity, leading to apoptotic cell death, was unchanged. The found biomarkers can confer resistance in a subset of melanoma patients via immune modulation, microenvironment changes, or drug elimination. Our resistance model can be further used in testing specific inhibitors that could be used in future drug development, and combination therapy testing that can overcome inhibitor resistance in melanoma.

High Wnt2 Expression Confers Poor Prognosis in Colorectal Cancer, and Represents a Novel Therapeutic Target in BRAF-Mutated Colorectal Cancer

Background and Objectives: We aimed to investigate the role of Wnt2 expression in colorectal cancer (CRC) prognosis and evaluate its potential as a therapeutic target in BRAF-mutated CRC. Materials and Methods: Exactly 136 samples of formalin-fixed paraffin-embedded CRC tissue specimens were obtained from patients who underwent surgical resection for CRC. The gene mutation status of the samples was detected using fluorescence PCR. Wnt2 expression was detected using immunohistochemistry. Survival curves with high Wnt2 expression and BRAF mutations were compared using the Kaplan-Meier method. A nomogram was constructed to determine the estimated overall survival probability. We also predicted the 3-year and 5-year survival rates for patients with high Wnt2 expression and BRAF mutations. In total, 50 samples of BRAF-mutated CRC were collected and detected Wnt2 expression by immunohistochemistry. The Chi-squared test was used to analyze the association between Wnt2 expression and BRAF-mutated CRC. Results: High Wnt2 expression and BRAF mutations are associated with poor prognosis of CRC. Multivariate survival analyses indicated that high Wnt2 expression and BRAF mutations are significant independent predictors of CRC prognosis. Furthermore, high Wnt2 expression was significantly associated with BRAF-mutated CRC, and Wnt2 may be a potential therapeutic target for BRAF-mutated CRC. Conclusions: High Wnt2 expression confers poor prognosis in colorectal cancer and represents a novel therapeutic target in BRAF-mutated CRC.

Targeted Therapy for Non–Small Cell Lung Cancer

This article provides an updated review of the management of oncogene-driven non-small cell lung cancer. The use of targeted therapies for lung cancer driven by EGFR, ALK, ROS1, RET, NTRK, HER2, BRAF, MET, and KRAS are discussed, both in the first-line setting and in the setting of acquired resistance.

Target therapy for BRAF mutated anaplastic thyroid cancer: a clinical and molecular study

OBJECTIVES

Anaplastic thyroid carcinoma (ATC) has a poor survival. The combination of Dabrafenib plus Trametinib (DT) had a significant impact in survival of BRAF p.V600E patients. However, durable responses may be compromised by resistance. We aim to present our experience with DT in BRAF positive ATC patients and compare the outcomes with usual therapy, and to study tumor molecular alterations in the DT group.

METHODS

Patients treated between May 2018 and April 2022 in a tertiary referral center, assessed for BRAF status were included. Patients were divided in three groups: BRAF p.V600E treated with DT, BRAF wild type (WT) under multimodal therapy (MT), and BRAF WT under compassionate care (CC). Response was assessed monthly in the first 6 months and every 3 months afterwards, by RECIST 1.1. Overall survival (OS) and progression-free survival (PFS) were estimated with the Kaplan-Meier method and compared with the log-rank test.

RESULTS

Twenty-seven ATC patients were included (DT = 9, MT = 8, and CC = 10). Median OS was 475 days for DT, 156 days for MT, and 39 days for CC (P < .001). At 12 months, only patients in the DT group were alive (71%). Median PFS was 270 days, in the DT group, compared with less than 32 days in BRAF WT (P < .001). No severe adverse events were reported. Molecular profiling showed that in one of the four clinical progressions, a pathogenic NRAS mutation was found.

CONCLUSIONS

Our results show a significant real-world efficacy of Dabrafenib plus Trametinib in both survival and recurrence compared with standard treatment, with a good safety profile.

BRAF/MEK inhibition in NSCLC: mechanisms of resistance and how to overcome it

Targeted therapy for oncogenic genetic alterations has changed the treatment paradigm of advanced non-small cell lung cancer (NSCLC). Mutations in the BRAF gene are detected in approximately 4% of patients and result in hyper-activation of the MAPK pathway, leading to uncontrolled cellular proliferation. Inhibition of BRAF and its downstream effector MEK constitutes a therapeutic strategy for a subset of patients with NSCLC and is associated with clinical benefit. Unfortunately, the majority of patients will develop disease progression within 1 year. Preclinical and clinical evidence suggests that resistance mechanisms involve the restoration of MAPK signaling which becomes inhibition-independent due to upstream or downstream alterations, and the activation of bypass pathways, such as the PI3/AKT/mTOR pathway. Future research should be directed to deciphering the mechanisms of cancer cells' oncogenic dependence, understanding the tissue-specific mechanisms of BRAF-mutant tumors, and optimizing treatment strategies after progression on BRAF and MEK inhibition.

Non-small-cell lung cancer: how to manage BRAF-mutated disease

BRAF mutations are reported in about 3-5% of non-small-cell lung cancer (NSCLC), almost exclusively in adenocarcinoma histology, and are classified into three different classes. The segmentation of BRAF mutations into V600 (class 1) and non-V600 (classes 2 and 3) relies on their biological characteristics and is of interest for predicting the therapeutic benefit of targeted therapies and immunotherapy. Given the relative rarity of this molecular subset of disease, evidence supporting treatment choices is limited. This review aims to offer a comprehensive update about available therapeutic options for patients with NSCLC harbouring BRAF mutations to guide the physician in the choice of treatment strategies. We collected the most relevant available data, from single-arm phase II studies and retrospective analyses conducted in advanced NSCLC, regarding the efficacy of BRAF and MEK inhibitors in both V600 and non-V600 BRAF mutations. We included case reports and smaller experiences that could provide information on specific alterations. With respect to immunotherapy, we reviewed retrospective evidence on immune-checkpoint inhibitors in this molecular subset, whereas data about chemo-immunotherapy in this molecular subgroup are lacking. Moreover, we included the available, though limited, retrospective evidence of immunotherapy as consolidation after chemo-radiation for unresectable stage III BRAF-mutant NSCLC, and an overview of ongoing clinical trials in the peri-operative setting that could open new perspectives in the future.

Tumor immune microenvironment and immunotherapy efficacy in BRAF mutation non-small-cell lung cancer

Previous small-size studies reported BRAF-mutated NSCLC patients have comparable sensitivity to immune checkpoint inhibitors (ICIs). However, how BRAF mutation affects the tumor immune microenvironment (TIME) is unknown. We performed Nanostring-panel RNA sequencing to evaluate TIME in 57 BRAF mutated and wild-type (WT) NSCLC specimens (cohort A). The efficacy of ICI monotherapy or combined therapies was determined in 417 patients with WT and BRAF mutated NSCLC (cohort B). We found that BRAF-mutant tumors had similar ratios of CD8+ T cells to Tregs, the balance of cytotoxicity gene expression signatures and immune suppressive features, and similar ICI-response-related biomarkers to WT NSCLC. A similar TIME pattern was observed between the BRAF V600E and Non-V600E subgroups of NSCLC. The further retrospective study confirmed that treatment with ICI monotherapy or combined therapies resulted in similar overall survival (OS) (HR: 0.85; 95% CI, 0.56 to 1.30; p = 0.47) and progress-free survival (PFS) (HR: 1.02; 95% CI, 0.72 to 1.44; p = 0.91) of patients with WT (n = 358) and BRAF mutant (n = 59) NSCLC. Similarly, both patients with BRAF V600E or Non-V600E NSCLC had similar responses to immunotherapy. Our findings support that BRAF mutation did not modulate TIME in NSCLC and therapeutic responses to ICIs. Patients with NSCLC harboring BRAF mutation should not be denied treatment with ICIs.

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.

Histologic transformation in lung cancer: when one door shuts, another opens

Histologic transformation (HT) is a major cause of drug resistance to therapy in patients with lung cancer. HTs to small-cell lung cancer (SCLC) have been reported frequently in patients with epidermal growth factor receptor (EGFR)-mutated lung cancer. Although HTs have an impact on the clinical outcomes in patients owing to a high refractoriness to treatments, there is limited data on the prevalence, causes, mechanisms, treatment efficacy, and future treatment strategies. In this review, we assess the literature regarding HTs comprehensively, including those describing EGFR-tyrosine kinase inhibitors, other molecular targeted drugs, and immune checkpoint inhibitors. Furthermore, we discuss the mechanisms of HTs and the lineage plasticity to SCLC and squamous cell carcinoma in lung cancer. In addition, we summarize the treatment efficacy and future perspectives of HTs in patients with lung cancer, and propose better management strategies for this group of patients.

Prognostic Value of Circulating Tumor DNA (ctDNA) in Oncogene-Driven NSCLC: Current Knowledge and Future Perspectives

As we enter an unprecedented era of personalized medicine, molecular targeted therapies have the potential to induce improved survival outcome in patients with non-small cell lung cancer (NSCLC). However, a significant percentage of oncogene-driven NSCLC patients will relapse even after definitive treatment, whereas chronic and durable response to targeted therapies is a less common event in advanced-stage lung cancer. This phenomenon could be attributed to minimal residual disease (MRD), defined as a population of disseminated tumor cells that survive during the course or after treatment, eventually leading to recurrence and limiting patient survival. Circulating tumor DNA (ctDNA) is a powerful biomarker for MRD detection and monitoring and is a non-invasive approach of treating cancer, and especially NSCLC, based on a real-time assessment of the tumor genomic landscape. In this review, we present the key findings of studies that have used ctDNA with regard to its prognostic value and in respect to the most common druggable driver mutations of genes in NSCLC, such as epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1), rearranged during transfection (RET), Kirsten rat sarcoma virus (KRAS), B-Raf proto-oncogene (BRAF), and mesenchymal epithelial transition factor receptor (MET).

Targeting mitochondrial metabolism for metastatic cancer therapy

Primary tumors evolve metabolic mechanisms favoring glycolysis for adenosine triphosphate (ATP) generation and antioxidant defenses. In contrast, metastatic cells frequently depend on mitochondrial respiration and oxidative phosphorylation (OxPhos). This reliance of metastatic cells on OxPhos can be exploited using drugs that target mitochondrial metabolism. Therefore, therapeutic agents that act via diverse mechanisms, including the activation of signaling pathways that promote the production of reactive oxygen species (ROS) and/or a reduction in antioxidant defenses may elevate oxidative stress and inhibit tumor cell survival. In this review, we will provide (1) a mechanistic analysis of function-selective extracellular signal-regulated kinase-1/2 (ERK1/2) inhibitors that inhibit cancer cells through enhanced ROS, (2) a review of the role of mitochondrial ATP synthase in redox regulation and drug resistance, (3) a rationale for inhibiting ERK signaling and mitochondrial OxPhos toward the therapeutic goal of reducing tumor metastasis and treatment resistance. Recent reports from our laboratories using metastatic melanoma and breast cancer models have shown the preclinical efficacy of novel and rationally designed therapeutic agents that target ERK1/2 signaling and mitochondrial ATP synthase, which modulate ROS events that may prevent or treat metastatic cancer. These findings and those of others suggest that targeting a tumor's metabolic requirements and vulnerabilities may inhibit metastatic pathways and tumor growth. Approaches that exploit the ability of therapeutic agents to alter oxidative balance in tumor cells may be selective for cancer cells and may ultimately have an impact on clinical efficacy and safety. Elucidating the translational potential of metabolic targeting could lead to the discovery of new approaches for treatment of metastatic cancer.

The Evolution of BRAF Activation in Non-Small-Cell Lung Cancer

Non-small-cell lung cancer (NSCLC) is the most common subtype of lung cancer, of which approximate 4% had BRAF activation, with an option for targeted therapy. BRAF activation comprises of V600 and non-V600 mutations, fusion, rearrangement, in-frame deletions, insertions, and co-mutations. In addition, BRAF primary activation and secondary activation presents with different biological phenotypes, medical senses and subsequent treatments. BRAF primary activation plays a critical role in proliferation and metastasis as a driver gene of NSCLC, while secondary activation mediates acquired resistance to other targeted therapy, especially for epidermal growth factor tyrosine kinase inhibitor (EGFR-TKI). Treatment options for different activation of BRAF are diverse. Targeted therapy, especially two-drug combination therapy, is an important option. Besides, immune checkpoint inhibitors (ICIs) would be another option since BRAF activation would be a positive biomarker of tumor response of ICIs therapy. To date, no high level evidences support targeted therapy or immunotherapy as prioritized recommendation. After targeted therapy, the evolution of BRAF includes the activation of the upstream, downstream and bypass pathways of BRAF. In this review, therapeutic modalities and post-therapeutic evolutionary pathways of BRAF are discussed, and future research directions are also provided.

Targeting molecular alterations in non-small-cell lung cancer: what's next?

In recent years, major advances have been achieved in our understanding of non-small-cell lung cancer (NSCLC) with oncogenic driver alterations and in the specific treatment of these with tyrosine kinase inhibitors. Currently, state-of-the-art management of patients with NSCLC (particularly adenocarcinoma or non-adenocarcinoma but with mild tobacco exposure) consists of the determination of EGFR, ALK, ROS1 and BRAF status, as they have US FDA and EMA approved targeted therapies. The increase in molecular knowledge of NSCLC and the development of drugs against other targets has settled new therapeutic indications. In this review we have incorporated the development around MET, KRAS and NTRK in the diagnosis of NSCLC given the therapeutic potential that they represent, as well as the drugs approved for these indications.

Clinical Characteristics, Co-Mutations, and Treatment Outcomes in Advanced Non-Small-Cell Lung Cancer Patients With the BRAF-V600E Mutation

Background

Limited treatment outcome data is available for advanced non-small cell lung cancer (NSCLC) patients with BRAF V600E mutations. In this multicenter study, we describe therapeutic options and survival outcomes for patients with mutated BRAF V600E.

Method

This was a retrospective study in which BRAF V600E-mutated advanced NSCLC patients were retrospectively recruited between January 2015 and December 2021 and had their clinical characteristics, co-mutations, and treatment efficacy assessed.

Results

Fifty-three patients with BRAF V600E-mutant advanced NSCLC were included in the study, of which 64.2% were non-smokers, and the BRAF V600E mutation was more prevalent in men (52.8%). In addition, 96.2% of the patients had adenocarcinoma, and most (96.2%) received first-line therapy (23.5% anti-BRAF), with a progression-free survival (PFS) and overall survival (OS) of 10.0 [95% confidence interval (CI): 1.5–36.0 months] and 24.0 months [95% CI: 3.0–53.0 months], respectively. Twenty-three patients (43.4%) received second-line treatment (39.1% anti-BRAF), and PFS and OS were 5.0 [95% CI: 1.0–21.0 months] and 13.0 months [95% CI: 1.5–26.0 months], respectively. BRAF and MEK-targeted therapy (dabrafenib plus trametinib) produced longer PFS compared with that of chemotherapy with or without bevacizumab as a first-line (NA vs. 4.0 months, P = 0.025) or second-line therapy (6.0 vs. 4.6 months, P = 0.017). NSCLC patients harboring driver oncogene mutations such as BRAF V600E, EGFR, or ALK should be treated using targeted therapies. Concurrent TP53 mutations were the most common, affecting 11.3% (n = 6) of the patients, followed by EGFR 19 Del (n = 5). Patients with concurrent mutations had shorter PFS (9.0 vs. 10.0 months, P = 0.875) and OS (14.0 vs. 15.0 months, P = 0.555) than those without these mutations.

Conclusion

These results suggest that combined BRAF- and MEK-targeted therapy is effective in BRAF V600E-mutated advanced NSCLC patients. Dabrafenib and trametinib re-challenge is also an option for patients with BRAF V600E-mutated NSCLC.

La résistance aux inhibiteurs de BRAF

La voie de signalisation MAPK/ERK est une voie centrale de la signalisation intracellulaire. Sa dérégulation participe à la transformation et la progression tumorales. Dans plusieurs cancers, la découverte de mutations activatrices de BRAF, à l’origine de l’activation de cette voie, a ouvert de nouvelles perspectives thérapeutiques avec le développement d’inhibiteurs spécifiques de la protéine. Selon les cancers, ces inhibiteurs ont cependant montré soit une efficacité insuffisante, due à la résistance primaire des cellules tumorales, soit une efficacité transitoire, due à l’apparition d’une résistance acquise. Dans cette revue, nous revenons sur les découvertes qui ont conduit au développement de ces inhibiteurs de BRAF. Nous détaillons également les mécanismes moléculaires et cellulaires de la résistance à ces inhibiteurs observée dans différents types de cancers. Comprendre ces mécanismes est en effet primordial pour développer des stratégies thérapeutiques qui soient plus efficaces.

The multi-molecular mechanisms of tumor-targeted drug resistance in precision medicine

Clinically, cancer drug therapy is still dominated by chemotherapy drugs. Although the emergence of targeted drugs has greatly improved the survival rate of patients with advanced cancer, drug resistance has always been a difficult problem in clinical cancer treatment. At the current level of medicine, most drugs cannot escape the fate of drug resistance. With the emergence and development of gene detection, liquid biopsy ctDNA technology, and single-cell sequencing technology, the molecular mechanism of tumor drug resistance has gradually emerged. Drugs can also be updated in response to drug resistance mechanisms and bring higher survival benefits. The use of new drugs often leads to new mechanisms of resistance. In this review, the multi-molecular mechanisms of drug resistance are introduced, and the overcoming of drug resistance is discussed from the perspective of the tumor microenvironment.

Morphologic-Molecular Transformation of Oncogene Addicted Non-Small Cell Lung Cancer

Patients with non-small cell lung cancer, especially adenocarcinomas, harbour at least one oncogenic driver mutation that can potentially be a target for therapy. Treatments of these oncogene-addicted tumours, such as the use of tyrosine kinase inhibitors (TKIs) of mutated epidermal growth factor receptor, have dramatically improved the outcome of patients. However, some patients may acquire resistance to treatment early on after starting a targeted therapy. Transformations to other histotypes-small cell lung carcinoma, large cell neuroendocrine carcinoma, squamous cell carcinoma, and sarcomatoid carcinoma-have been increasingly recognised as important mechanisms of resistance and are increasingly becoming a topic of interest for all specialists involved in the diagnosis, management, and care of these patients. This article, after examining the most used TKI agents and their main biological activities, discusses histological and molecular transformations with an up-to-date review of all previous cases published in the field. Liquid biopsy and future research directions are also briefly discussed to offer the reader a complete and up-to-date overview of the topic.

Beyond epidermal growth factor receptor: MET amplification as a general resistance driver to targeted therapy in oncogene-driven non-small-cell lung cancer

The rapidly changing treatment paradigm for patients with metastatic oncogene-driven lung cancer continues to evolve, and consequently our understanding of the landscape of resistance must also advance. MET amplification is an established and frequent driver of resistance in EGFR-mutant non-small-cell lung cancer (NSCLC). Recently, the combination of MET proto-oncogene (MET) and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has shown promise in overcoming this molecularly defined resistance in clinical trials, and this combination strategy is being pursued in ongoing trials. Emerging data also demonstrate MET amplification as a resistance driver to TKI-treated ALK-, RET-, and ROS-1-fusion NSCLC, consistently at the range of 15%, while the resistance profiling data are maturing for other molecular targets. In this review, we discuss MET amplification as a driver of acquired resistance in well-defined molecular subsets of NSCLC, explore the biology behind this mechanism of resistance, and summarize the recently published clinical data, including the proposed combination strategies in the clinic achieving success in overcoming acquired MET amplification-dependent resistance.

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Understanding mechanisms of resistance in oncogene-driven lung cancer is crucial.

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MET amplification is a recurrent driver of resistance, across molecularly defined subsets of NSCLC.

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Overcoming this resistance in clinical trials, using combination strategies, is currently being pursued.

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We explore the biology behind this mechanism of resistance and summarize recent successes in the clinic.

Cyclin-dependent kinase 4 upregulation mediates acquired resistance of dabrafenib plus trametinib in BRAF V600E-mutated lung cancer

Background

Combination therapy with the B-Raf inhibitor, dabrafenib, and the MEK inhibitor, trametinib (DT) is commonly used to treat patients with B-Raf proto-oncogene, serine/threonine kinase V600E (BRAF V600E)-mutated non-small cell lung cancer (NSCLC). However, the mechanisms through which cancer develops DT resistance are unclear. Here, we investigated new mechanisms underlying acquired DT-resistant NSCLC with the BRAF V600E mutation.

Methods

We compared genomic signatures before and after DT treatment in patients with NSCLC.

Results

Two of four patients treated with DT developed carcinomatous pleuritis within 3 months. Target DNA sequencing and quantitative polymerase chain reaction (PCR) analyses revealed the increased expression level of cyclin-dependent kinase 4 (CDK4). We also found prominent protein expression of CDK4 after DT treatment. Induction of CDK4 expression in a cell line derived from a patient with the BRAF V600E mutation resulted in partial resistance to dabrafenib.

Conclusions

Our findings suggest a possible relationship between CDK4 upregulation and acquired resistance to DT therapy.

[Current Advance in Targeted Treatment and Immunotherapy for BRAF-mutant Advanced Non-small Cell Lung Cancer]

随着精准医学的发展，靶向驱动基因的治疗显著改善了晚期非小细胞肺癌（non-small cell lung cancer, NSCLC）患者的预后和生活质量。其中鼠类肉瘤病毒癌基因同源物B1（v-raf murine sar-coma viral oncogene homolog B1, BRAF）基因突变的NSCLC较为罕见，传统治疗遵循无驱动基因突变NSCLC的治疗方案，远远没有满足临床需求。近年来，针对BRAF V600E突变NSCLC的靶向治疗疗效显著，其他BRAF突变亚型靶向治疗仍在探索阶段。免疫疗法在BRAF V600E和非V600E亚型的NSCLC中也显示出积极的抗肿瘤活性。本文就BRAF阳性NSCLC患者的靶向和免疫治疗研究进展作一综述。

Next Generation Sequencing Technology in Lung Cancer Diagnosis

Simple Summary

Lung cancer is still one of the most commonly diagnosed and deadliest cancers in the world. Its diagnosis at an early stage is highly necessary and will improve the standard of care of this disease. The aim of this article is to review the importance and applications of next generation sequencing in lung cancer diagnosis. As observed in many studies, next generation sequencing has been proven as a very helpful tool in the early detection of different types of cancers, including lung cancer, and has been used in the clinic, mainly due to its many advantages, such as low cost, speed, efficacy, low quantity usage of biological samples, and diversity.

Abstract

Lung cancer is still one of the most commonly diagnosed cancers, and one of the deadliest. The high death rate is mainly due to the late stage of diagnosis and low response rate to therapy. Previous and ongoing research studies have tried to discover new reliable and useful cbiomarkers for the diagnosis and prognosis of lung cancer. Next generation sequencing has become an essential tool in cancer diagnosis, prognosis, and evaluation of the treatment response. This article aims to review the leading research and clinical applications in lung cancer diagnosis using next generation sequencing. In this scope, we identified the most relevant articles that present the successful use of next generation sequencing in identifying biomarkers for early diagnosis correlated to lung cancer diagnosis and treatment. This technique can be used to evaluate a high number of biomarkers in a short period of time and from small biological samples, which makes NGS the preferred technique to develop clinical tests for personalized medicine using liquid biopsy, the new trend in oncology.

Autophagy Inhibition in BRAF-Driven Cancers

Simple Summary

BRAF is a protein kinase that is frequently mutationally activated in cancer. Mutant BRAF can be pharmacologically inhibited, which in combination with blockade of its direct effector, MEK1/2, is an FDA-approved therapeutic strategy for several BRAF-mutated cancer patients, such as melanoma, non-small-cell lung carcinoma, and thyroid cancer. However, therapy resistance is a major clinical challenge, highlighting the need for comprehensive investigations on the biological causes of such resistance, as well as to develop novel therapeutic strategies to improve patient survival. Autophagy is a cellular recycling process, which has been shown to allow cancer cells to escape from BRAF inhibition. Combined blockade of autophagy and BRAF signaling is a novel therapeutic strategy that is currently being tested in clinical trials. This review describes the relationship between BRAF-targeted therapy and autophagy regulation and discusses possible future treatment strategies.

Abstract

Several BRAF-driven cancers, including advanced BRAF^V600E/K-driven melanoma, non-small-cell lung carcinoma, and thyroid cancer, are currently treated using first-line inhibitor combinations of BRAF^V600E plus MEK1/2. However, despite the success of this vertical inhibition strategy, the durability of patient response is often limited by the phenomenon of primary or acquired drug resistance. It has recently been shown that autophagy, a conserved cellular recycling process, is increased in BRAF-driven melanoma upon inhibition of BRAF^V600E signaling. Autophagy is believed to promote tumor progression of established tumors and also to protect cancer cells from the cytotoxic effects of chemotherapy. To this end, BRAF inhibitor (BRAFi)-resistant cells often display increased autophagy compared to responsive lines. Several mechanisms have been proposed for BRAFi-induced autophagy, such as activation of the endoplasmic reticulum (ER) stress gatekeeper GRP78, AMP-activated protein kinase, and transcriptional regulation of the autophagy regulating transcription factors TFEB and TFE3 via ERK1/2 or mTOR inhibition. This review describes the relationship between BRAF-targeted therapy and autophagy regulation, and discusses possible future treatment strategies of combined inhibition of oncogenic signaling plus autophagy for BRAF-driven cancers.

The evolving paradigm of precision medicine in lung cancer

PURPOSE OF REVIEW

In this review, we report a complete and updated summary of the most recent treatment advances in the fields of oncogene-addicted disease and provide expert perspectives on the evolving paradigm of precision medicine in lung cancer patients.

RECENT FINDINGS

The advent of innovative genome sequencing technologies is rapidly increasing the number of targetable molecular alterations in advanced nonsmall cell lung cancer (NSCLC), leading to the introduction of novel selective inhibitors into the clinical arena, showing unprecedent tumor responses against rare and elusive NSCLC targets. The results of the ADAURA trial suggested that targeting EGFR pathway in the adjuvant setting is a feasible and effective strategy. The routine use of next-generation sequencing (NGS) is currently recommended as new standard approach to profile advanced NSCLC samples while recent findings suggest the potential application of a plasma-based first approach for tumor genotyping. Innovative umbrella trials provide the right infrastructure to investigate the role of precision medicine in advanced NSCLC, but failed to show clinical benefit.

SUMMARY

Implementing NGS-based molecular screening, increasing patients' access to biomarker driven-clinical trials, ensuring equal access to molecular testing and innovative treatments, overcoming disparities and preserve health systems' financial sustainability represents the main challenges of precision medicine worldwide.

Precision Medicine in Oncology: A Review of Multi-Tumor Actionable Molecular Targets with an Emphasis on Non-Small Cell Lung Cancer

Precision medicine is essential for the modern care of a patient with cancer. Comprehensive molecular profiling of the tumor itself is necessary to determine the presence or absence of certain targetable abnormalities or biomarkers. In particular, lung cancer is a disease for which targetable genomic alterations will soon guide therapy in the majority of cases. In this comprehensive review of solid tumor-based biomarkers, we describe the genomic alterations for which targeted agents have been approved by the United States Food and Drug Administration (FDA). While focusing on alterations leading to approvals in a tumor-agnostic fashion (MSI-h, TMB-h, NTRK) and on those alterations with approvals in multiple malignancies (BRAF, ERBB2, RET, BRCA, PD-L1), we also describe several biomarkers or indications that are likely to lead to an approved drug in the near future (e.g., KRAS G12C, PD-L1 amplification, HER2 overexpression in colon cancer, HER2 mutations in lung cancer). Finally, we detail the current landscape of additional actionable alterations (EGFR, ALK, ROS1, MET) in lung cancer, a biomarker-rich malignancy that has greatly benefitted from the precision oncology revolution.

Identification of genetic variations associated with drug resistance in non-small cell lung cancer patients undergoing systemic treatment

Non-small cell lung cancer (NSCLC) is characterized by relatively rapid response to systemic treatments yet inevitable resistance and predisposed to distant metastasis. We thus aimed at performing sequencing analysis to determine genomic events and underlying mechanisms concerning drug resistance in NSCLC. We performed targeted sequencing of 40 medication-relevant genes on plasma samples from 98 NSCLC patients and analyzed impact of genetic alterations on clinical presentation as well as response to systemic treatments. Profiling of multi-omics data from 1024 NSCLC tissues in public datasets was carried out for comparison and validation of identified molecular events implicated in resistance. A genetic association of CYP2D6 deletion with drug resistance was identified through circulating tumor DNA (ctDNA) profiling and response assessment. FCGR3A amplification was potentially involved in resistance to EGFR inhibitors. We further verified our findings in tissue samples and focused on potential resistance mechanisms, which uncovered that depleted CYP2D6 affected a set of genes involved in EMT, oncogenic signaling as well as inflammatory pathways. Tumor microenvironment analysis revealed that NSCLC with CYP2D6 loss manifested increased levels of immunomodulatory gene expressions, PD-L1 expression, relatively high mutational burden and lymphocyte infiltration. DNA methylation alterations were also found to be correlated with mRNA expressions and copy numbers of CYP2D6. Finally, MEK inhibitors were identified by CMap as the prospective therapeutic drugs for CYP2D6 deletion. These analyses identified novel resistance mechanisms to systemic NSCLC treatments and had significant implications for the development of new treatment strategies.

Overcoming Resistance to Tumor-Targeted and Immune-Targeted Therapies

Resistance to anticancer therapies includes primary resistance, usually related to lack of target dependency or presence of additional targets, and secondary resistance, mostly driven by adaptation of the cancer cell to the selection pressure of treatment. Resistance to targeted therapy is frequently acquired, driven by on-target, bypass alterations, or cellular plasticity. Resistance to immunotherapy is often primary, orchestrated by sophisticated tumor-host-microenvironment interactions, but could also occur after initial efficacy, mostly when only partial responses are obtained. Here, we provide an overview of resistance to tumor and immune-targeted therapies and discuss challenges of overcoming resistance, and current and future directions of development. SIGNIFICANCE: A better and earlier identification of cancer-resistance mechanisms could avoid the use of ineffective drugs in patients not responding to therapy and provide the rationale for the administration of personalized drug associations. A clear description of the molecular interplayers is a prerequisite to the development of novel and dedicated anticancer drugs. Finally, the implementation of such cancer molecular and immunologic explorations in prospective clinical trials could de-risk the demonstration of more effective anticancer strategies in randomized registration trials, and bring us closer to the promise of cure.