Non-V600 BRAF mutations recurrently found in lung cancer predict sensitivity to the combination of Trametinib and Dabrafenib

A patient with BRAF N581S mutation-positive lung adenocarcinoma demonstrates durable response to combined anlotinib and tislelizumab: A case report and literature review

BACKGROUND

Targeted therapy with combined dabrafenib and trametinib has been proven to provide clinical benefits in patients with BRAF V600E mutation-positive NSCLC. Nevertheless, the treatment strategy for NSCLC patients with BRAF non-V600E mutations remains limited.

CASE PRESENTATION

Here, we present a NSCLC patient with a BRAF N581S mutation, which is a class III BRAF mutation, and this patient had a durable response to targeted therapy with combined anlotinib and tislelizumab.

CONCLUSION

We hope to bring more attention to rare non-V600 BRAF mutations by presenting this case of NSCLC.

Clinical Response of Advanced Lung Adenocarcinoma with Class III BRAF G466V Missense Mutation to Dabrafenib and Trametinib: A Case Report

Aim

BRAF is a pivotal driver gene in cancer development. Based on this, the combination of dabrafenib and trametinib was approved for treating NSCLC patients with BRAFV600E mutations. However, the majority of BRAF mutations in lung cancer are non-V600E variants, particularly class III mutants, which currently lack targeted therapeutic options and result in unfavorable clinical outcomes.

Case Presentation

We present a case of advanced lung adenocarcinoma with a class III BRAFG466V mutation. The patient experienced significant pleural and pericardial effusion, leading to chest tightness and an inability to lie flat. Severe pain and limited mobility from lumbar destruction seriously affected the patient's quality of life. Due to the patient's intolerance to chemotherapy, dabrafenib and trametinib combination therapy was chosen. After three months of targeted therapy, the patient's overall condition significantly improved, enabling self-care, and achieving partial response (PR) as an indicator of treatment efficacy.

Conclusion

The combination therapy of dabrafenib and trametinib demonstrates remarkable clinical benefits for lung adenocarcinoma patients with the BRAFG466V mutation. Targeted therapy should be considered for patients with BRAF class III mutations, especially those in poor general condition and may not tolerate chemotherapy.

Clinicopathological Features of Non-Small Cell Lung Carcinoma with BRAF Mutation

(1) Background: BRAF mutations affect 4-5% of lung adenocarcinomas. This study aimed to analyze the clinicopathological features of lung carcinomas with BRAF mutations, focusing on V600E vs. non-V600E and the presence of co-mutations. (2) Methods: All BRAF-mutated lung carcinomas were retrieved from a molecular diagnostic unit (the reference unit for four different hospitals). The samples were analyzed using next-generation sequencing. Statistical analyses included log-rank tests for overall survival (OS) and progression-free survival (PFS). (3) Results: In total, 60 BRAF-mutated lung carcinomas were retrieved: 24 (40.0%) with V600E and 36 (60.0%) with non-V600E mutations, and 21 (35.0%) with other co-mutations and 39 (65.0%) with only BRAF mutations. Survival data were available for 54/60 (90.0%) cases. Targeted therapy was documented in 11 cases. Patients with V600E mutations exhibited a better prognosis than patients with non-V600E mutations (p = 0.008 for OS, p = 0.018 for PFS); this was confirmed in PFS (p = 0.036) when considering only patients who received no targeted therapy. Patients with co-mutations displayed no prognostic difference compared to patients carrying only BRAF mutations (p = 0.590 for OS, p = 0.938 for PFS). (4) Conclusions: BRAF-mutated lung carcinomas with V600E (40.0%) had a better prognosis than those without V600E. Concomitant co-mutations (35.0%) did not affect the prognosis.

Design, synthesis, and bioactivity evaluation of novel amide/sulfonamide derivatives as potential anti-inflammatory agents against acute lung injury and ulcerative colitis

The uneven regulation of inflammation is related to various diseases, making anti-inflammation a potential option for the development of novel therapies. In this study, we designed and synthesized a total of fifty-eight novel amide/sulfonamide derivatives based on our previously reported anti-inflammatory compounds. The anti-inflammatory activities of these compounds were evaluated upon LPS-stimulated J774A.1 cells. Compounds 11a, 11b, 11c, and 11d potently reduced the release of IL-6 and TNF-α, and decreased the mRNA level of cytokines in J774A.1 cells. The most active compound 11d with IC50 value of 0.61 μM for IL-6 inhibition, and 4.34 μM for TNF-α inhibition restored IκB α and inhibited the translocation of phosphorylated p65 into the nucleus. In vivo evaluation indicated that 11d improved LPS-induced ALI and alleviated DSS-induced ulcerative colitis in mice. In conclusion, these results suggested compound 11d can be a new lead structure for the development of anti-inflammatory drugs against ALI and ulcerative colitis.

Unique Spectrum of Activating BRAF Alterations in Prostate Cancer

PURPOSE

Alterations in BRAF have been reported in 3% to 5% of prostate cancer, although further characterization is lacking. Here, we describe the nature of BRAF alterations in prostate cancer using a large cohort from commercially available tissue and liquid biopsies subjected to comprehensive genomic profiling (CGP).

EXPERIMENTAL DESIGN

Tissue and liquid biopsies from patients with prostate cancer were profiled using FoundationOne CDx and FoundationOne Liquid CDx CGP assays, respectively. Tissue biopsies from non-prostate cancer types were used for comparison (n = 275,151). Genetic ancestry was predicted using a single-nucleotide polymorphism (SNP) based approach.

RESULTS

Among 15,864 tissue biopsies, BRAF-activating alterations were detected in 520 cases (3.3%). The majority (463 samples, 2.9%) harbored class II alterations, including BRAF rearrangements (243 samples, 1.5%), K601E (101 samples, 0.6%), and G469A (58 samples, 0.4%). BRAF-altered prostate cancers were enriched for CDK12 mutations (OR, 1.87; 9.2% vs. 5.2%; P = 0.018), but depleted in TMPRSS2 fusions (OR, 0.25; 11% vs. 32%; P < 0.0001), PTEN alterations (OR, 0.47; 17% vs. 31%; P < 0.0001), and APC alterations (OR, 0.48; 4.4% vs. 8.9%; P = 0.018) relative to BRAF wild-type (WT) disease. Compared with patients of European ancestry, BRAF alterations were more common in tumors from patients of African ancestry (5.1% vs. 2.9%, P < 0.0001) and Asian ancestry (6.0% vs. 2.9%, P < 0.001).

CONCLUSIONS

Activating BRAF alterations were detected in approximately 3% of prostate cancers, and most were class II mutations and rearrangements; BRAF V600 mutations were exceedingly rare. These findings suggest that BRAF activation in prostate cancer is unique from other cancers and supports further clinical investigation of therapeutics targeting the mitogen-activated protein kinase (MAPK) pathway.

An updated literature on BRAF inhibitors (2018-2023)

BRAF is the most common serine-threonine protein kinase and regulates signal transduction from RAS to MEK inside the cell. The BRAF is a highly active isoform of RAF kinase. BRAF has two domains such as regulatory and kinase domains. The BRAF inhibitors bind in the c-terminus of the kinase domain and inhibit the downstream pathways. The mutation occurs mainly in the A-loop of the kinase domain. The mutation occurs due to a conversion of valine to glutamate/lysine/arginine/aspartic acid at 600th position. Among the diverse mutations, BRAF^V600E is the most common and responsible for numerous cancer such as melanoma, colorectal, ovarian, and thyroid cancer. Due to mutations in RAC1, loss of PTEN, NF1, CCND1, USP28-FBW7 complex, COT overexpression, and CCND1 amplification, the BRAF kinase enzyme developed resistance over the commercially available BRAF inhibitors. There is still unmute urgence for the development of BRAF inhibitors to overcome the persistent limitation such as resistance, mutation, and adverse effects of drugs. In the current study, we described the structure, activation, downstream signaling pathway, and mutation of BRAF. Our group also provided a detailed review of BRAF inhibitors from the last five years (2018-2023) highlighting the structure-activity relationship, mechanistic study, and molecular docking studies. We hope that the current analysis will be a useful resource for researchers and provide chemists a glimpse into the future as design and development of more effective and secure BRAF kinase inhibitors. The development of BRAF inhibitors to overcome the persistent limitation such as resistance, mutation, and adverse effects of drugs. In depth description about different heterocyclic scaffolds (quinoline, imidazole, pyridine, triazole, pyrrole etc.) as BRAF inhibitors from the last five years (2018-2023) highlighting the structure-activity relationship, mechanistic study, and molecular docking studies.

Repurposing Sulfasalazine as a Radiosensitizer in Hypoxic Human Colorectal Cancer

xCT overexpression in cancer cells has been linked to tumor growth, metastasis and treatment resistance. Sulfasalazine (SSZ), an FDA-approved drug for the treatment of rheumatoid sarthritis, and inflammatory bowel diseases, has anticancer properties via inhibition of xCT, leading to the disruption of redox homeostasis. Since reactive oxygen species (ROS) are pivotal for the efficacy of radiotherapy (RT), elevated levels of ROS are associated with improved RT outcomes. In this study, the influence of SSZ treatment on the radiosensitivity of human colorectal cancer (CRC) cells was investigated. Our principal finding in human HCT116 and DLD-1 cells was that SSZ enhances the radiosensitivity of hypoxic CRC cells but does not alter the intrinsic radiosensitivity. The radiosensitizing effect was attributed to the depletion of glutathione and thioredoxin reductase levels. In turn, the reduction leads to excessive levels of ROS, increased DNA damage, and ferroptosis induction. Confirmation of these findings was performed in 3D models and in DLD-1 xenografts. Taken together, this study is a stepping stone for applying SSZ as a radiosensitizer in the clinic and confirms that xCT in cancer cells is a valid radiobiological target.

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.

Molecular Pathways and Mechanisms of BRAF in Cancer Therapy

With the identification of activating mutations in BRAF across a wide variety of malignancies, substantial effort was placed in designing safe and effective therapeutic strategies to target BRAF. These efforts have led to the development and regulatory approval of three BRAF inhibitors as well as five combinations of a BRAF inhibitor plus an additional agent(s) to manage cancer such as melanoma, non-small cell lung cancer, anaplastic thyroid cancer, and colorectal cancer. To date, each regimen is effective only in patients with tumors harboring BRAFV600 mutations and the duration of benefit is often short-lived. Further limitations preventing optimal management of BRAF-mutant malignancies are that treatments of non-V600 BRAF mutations have been less profound and combination therapy is likely necessary to overcome resistance mechanisms, but multi-drug regimens are often too toxic. With the emergence of a deeper understanding of how BRAF mutations signal through the RAS/MAPK pathway, newer RAF inhibitors are being developed that may be more effective and potentially safer and more rational combination therapies are being tested in the clinic. In this review, we identify the mechanics of RAF signaling through the RAS/MAPK pathway, present existing data on single-agent and combination RAF targeting efforts, describe emerging combinations, summarize the toxicity of the various agents in clinical testing, and speculate as to where the field may be headed.

Clinical Activity of Mitogen-Activated Protein Kinase-Targeted Therapies in Patients With Non-V600 BRAF-Mutant Tumors

PURPOSE

Non-V600 mutations comprise approximately 35% of all BRAF mutations in cancer. Many of these mutations have been identified as oncogenic drivers and can be classified into three classes according to molecular characteristics. Consensus treatment strategies for class 2 and 3 BRAF mutations have not yet been established.

METHODS

We performed a systematic review and meta-analysis with published reports of individual patients with cancer harboring class 2 or 3 BRAF mutations from 2010 to 2021, to assess treatment outcomes with US Food and Drug Administration-approved mitogen-activated protein kinase (MAPK) pathway targeted therapy (MAPK TT) according to BRAF class, cancer type, and MAPK TT type. Coprimary outcomes were response rate and progression-free survival.

RESULTS

A total of 18,167 studies were screened, identifying 80 studies with 238 patients who met inclusion criteria. This included 167 patients with class 2 and 71 patients with class 3 BRAF mutations. Overall, 77 patients achieved a treatment response. In both univariate and multivariable analyses, response rate and progression-free survival were higher among patients with class 2 compared with class 3 mutations, findings that remain when analyses are restricted to patients with melanoma or lung primary cancers. MEK ± BRAF inhibitors demonstrated greater clinical activity in class 2 compared with class 3 BRAF-mutant tumors than BRAF or EGFR inhibitors.

CONCLUSION

This meta-analysis suggests that MAPK TTs have clinical activity in some class 2 and 3 BRAF-mutant cancers. BRAF class may dictate responsiveness to current and emerging treatment strategies, particularly in melanoma and lung cancers. Together, this analysis provides clinical validation of predictions made on the basis of a mutation classification system established in the preclinical literature. Further evaluation with prospective clinical trials is needed for this population.

Molecular matched targeted therapies for primary brain tumors-a single center retrospective analysis

PURPOSE

Molecular diagnostics including next generation gene sequencing are increasingly used to determine options for individualized therapies in brain tumor patients. We aimed to evaluate the decision-making process of molecular targeted therapies and analyze data on tolerability as well as signals for efficacy.

METHODS

Via retrospective analysis, we identified primary brain tumor patients who were treated off-label with a targeted therapy at the University Hospital Frankfurt, Goethe University. We analyzed which types of molecular alterations were utilized to guide molecular off-label therapies and the diagnostic procedures for their assessment during the period from 2008 to 2021. Data on tolerability and outcomes were collected.

RESULTS

413 off-label therapies were identified with an increasing annual number for the interval after 2016. 37 interventions (9%) were targeted therapies based on molecular markers. Glioma and meningioma were the most frequent entities treated with molecular matched targeted therapies. Rare entities comprised e.g. medulloblastoma and papillary craniopharyngeoma. Molecular targeted approaches included checkpoint inhibitors, inhibitors of mTOR, FGFR, ALK, MET, ROS1, PIK3CA, CDK4/6, BRAF/MEK and PARP. Responses in the first follow-up MRI were partial response (13.5%), stable disease (29.7%) and progressive disease (46.0%). There were no new safety signals. Adverse events with fatal outcome (CTCAE grade 5) were not observed. Only, two patients discontinued treatment due to side effects. Median progression-free and overall survival were 9.1/18 months in patients with at least stable disease, and 1.8/3.6 months in those with progressive disease at the first follow-up MRI.

CONCLUSION

A broad range of actionable alterations was targeted with available molecular therapeutics. However, efficacy was largely observed in entities with paradigmatic oncogenic drivers, in particular with BRAF mutations. Further research on biomarker-informed molecular matched therapies is urgently necessary.

Recognition of BRAF by CDC37 and Re-Evaluation of the Activation Mechanism for the Class 2 BRAF-L597R Mutant

The kinome specific co-chaperone, CDC37 (cell division cycle 37), is responsible for delivering BRAF (B-Rapidly Accelerated Fibrosarcoma) to the Hsp90 (heat shock protein 90) complex, where it is then translocated to the RAS (protooncogene product p21) complex at the plasma membrane for RAS mediated dimerization and subsequent activation. We identify a bipartite interaction between CDC37 and BRAF and delimitate the essential structural elements of CDC37 involved in BRAF recognition. We find an extended and conserved CDC37 motif, 20HPNID---SL--W31, responsible for recognizing the C-lobe of BRAF kinase domain, while the c-terminal domain of CDC37 is responsible for the second of the bipartite interaction with BRAF. We show that dimerization of BRAF, independent of nucleotide binding, can act as a potent signal that prevents CDC37 recognition and discuss the implications of mutations in BRAF and the consequences on signaling in a clinical setting, particularly for class 2 BRAF mutations.

DIPG Harbors Alterations Targetable by MEK Inhibitors, with Acquired Resistance Mechanisms Overcome by Combinatorial Inhibition

The survival of children with diffuse intrinsic pontine glioma (DIPG) remains dismal, with new treatments desperately needed. In a prospective biopsy-stratified clinical trial, we combined detailed molecular profiling and drug screening in newly established patient-derived models in vitro and in vivo. We identified in vitro sensitivity to MEK inhibitors in DIPGs harboring MAPK pathway alterations, but treatment of patient-derived xenograft models and a patient at relapse failed to elicit a significant response. We generated trametinib-resistant clones in a BRAFG469V model through continuous drug exposure and identified acquired mutations in MEK1/2 with sustained pathway upregulation. These cells showed hallmarks of mesenchymal transition and expression signatures overlapping with inherently trametinib-insensitive patient-derived cells, predicting sensitivity to dasatinib. Combined trametinib and dasatinib showed highly synergistic effects in vitro and on ex vivo brain slices. We highlight the MAPK pathway as a therapeutic target in DIPG and show the importance of parallel resistance modeling and combinatorial treatments for meaningful clinical translation.

SIGNIFICANCE

We report alterations in the MAPK pathway in DIPGs to confer initial sensitivity to targeted MEK inhibition. We further identify for the first time the mechanism of resistance to single-agent targeted therapy in these tumors and suggest a novel combinatorial treatment strategy to overcome it in the clinic. This article is highlighted in the In This Issue feature, p. 587.

Clinicopathological aspects of V-Raf murine sarcoma viral oncogene homolog B1 (BRAF) mutated non-small cell lung carcinoma in an Indian cohort: is there a difference?

INTRODUCTION

Activating mutations in the BRAF gene have been reported in 0.8%-8% cases of NSCLC. Traditionally, diagnostics have mainly focused on detection of V600E and modalities like mutation specific IHC, allele specific real-time PCR have been utilized. This may underestimate true prevalence of the non-V600E variants. Broader panel NGS testing offers a one stop solution and may identify newer potentially targetable variants. This is a retrospective single center experience of patients with BRAF mutated NSCLC characterizing the molecular spectrum and clinicopathologic characteristics.

METHODS

260 patients underwent panel based NGS testing at our center, between 2017-2020. 13 BRAF mutant cases, were detected and were clinically reviewed.

RESULTS

Thirteen cases of BRAF alterations were seen in out of 260 (5%) patients. Median age of the cohort was 62 years (range: 39-86 years) with a female predilection). Canonical BRAF V600E mutation was seen in 6 (46.2%) patients and 7 (53.8%) harbored a non-V600E alteration. Spectrum of non V600E alterations included G466E, G469A, N581I, V600_K601delins, D594G, L597Q, G649V and were commonly female (P>0.01) with a higher trend for liver metastases (P=0.09). Median PFS was 4.8 months on chemotherapy (P=0.8). All patients (13/13, 100%) were never smokers with an adenocarcinoma histology.

CONCLUSION

This is a single center experience from an Indian NSCLC cohort and shows higher prevalence of non-V600E than V600E mutation reported in literature. This may be attributed to increased use of NGS testing revealing otherwise missed alterations on sequential single gene testing.

[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。

Comprehensive Molecular and Clinicopathologic Analysis of 200 Pulmonary Invasive Mucinous Adenocarcinomas Identifies Distinct Characteristics of Molecular Subtypes

PURPOSE

Invasive mucinous adenocarcinoma (IMA) is a unique subtype of lung adenocarcinoma, characterized genomically by frequent KRAS mutations or specific gene fusions, most commonly involving NRG1. Comprehensive analysis of a large series of IMAs using broad DNA- and RNA-sequencing methods is still lacking, and it remains unclear whether molecular subtypes of IMA differ clinicopathologically.

EXPERIMENTAL DESIGN

A total of 200 IMAs were analyzed by 410-gene DNA next-generation sequencing (MSK-IMPACT; n = 136) or hotspot 8-oncogene genotyping (n = 64). Driver-negative cases were further analyzed by 62-gene RNA sequencing (MSK-Fusion) and those lacking fusions were further tested by whole-exome sequencing and whole-transcriptome sequencing (WTS).

RESULTS

Combined MSK-IMPACT and MSK-Fusion testing identified mutually exclusive driver alterations in 96% of IMAs, including KRAS mutations (76%), NRG1 fusions (7%), ERBB2 alterations (6%), and other less common events. In addition, WTS identified a novel NRG2 fusion (F11R-NRG2). Overall, targetable gene fusions were identified in 51% of KRAS wild-type IMAs, leading to durable responses to targeted therapy in some patients. Compared with KRAS-mutant IMAs, NRG1-rearranged tumors exhibited several more aggressive characteristics, including worse recurrence-free survival (P < 0.0001).

CONCLUSIONS

This is the largest molecular study of IMAs to date, where we demonstrate the presence of a major oncogenic driver in nearly all cases. This study is the first to document more aggressive characteristics of NRG1-rearranged IMAs, ERBB2 as the third most common alteration, and a novel NRG2 fusion in these tumors. Comprehensive molecular testing of KRAS wild-type IMAs that includes fusion testing is essential, given the high prevalence of alterations with established and investigational targeted therapies in this subset.

MAP-kinase and JAK-STAT pathways dysregulation in plasmablastic lymphoma

Plasmablastic lymphoma (PBL) is an aggressive B-cell lymphoma with an immunoblastic/large cell morphology and plasmacytic differentiation. The differential diagnosis with Burkitt lymphoma (BL), plasma cell myeloma (PCM) and some variants of diffuse large B-cell lymphoma (DLBCL) may be challenging due to the overlapping morphological, genetic and immunophenotypic features. Furthermore, the genomic landscape in PBL is not well known. To characterize the genetic and molecular heterogeneity of these tumors, we investigated thirty-four PBL using an integrated approach, including fluorescence in situ hybridization, targeted sequencing of 94 B-cell lymphoma related genes, and copy-number arrays. PBL were characterized by high genetic complexity including MYC translocations (87%), gains of 1q21.1-q44, trisomy 7, 8q23.2-q24.21, 11p13-p11.2, 11q14.2-q25, 12p and 19p13.3-p13.13, losses of 1p33, 1p31.1-p22.3, 13q and 17p13.3-p11.2, and recurrent mutations of STAT3 (37%), NRAS and TP53 (33%), MYC and EP300 (19%) and CARD11, SOCS1 and TET2 (11%). Pathway enrichment analysis suggested a cooperative action between MYC alterations and MAPK (49%) and JAK-STAT (40%) signaling pathways. Of note, EBVnegative PBL cases had higher mutational and copy-number load and more frequent TP53, CARD11 and MYC mutations, whereas EBV-positive PBL tended to have more mutations affecting the JAK-STAT pathway. In conclusion, these findings further unravel the distinctive molecular heterogeneity of PBL identifying novel molecular targets and the different genetic profile of these tumors related to EBV infection.

Prolonged response to treatment based on cell-free DNA analysis and molecular profiling in three patients with metastatic cancer: a case series

Background:

Patients with advanced and/or metastatic solid tumors have limited treatment options. Mutations that serve as biomarkers of carcinogenesis can be found in cell-free DNA of patients’ plasma. Analysis of circulating tumor DNA (ctDNA) was developed as a non-invasive, cost-effective alternative to tumor biopsy when such biopsy is not technically feasible or it is associated with high risk for complications. The role of ctDNA in precision oncology is promising but its clinical significance across tumor types remains to be validated. We report a case series of three heavily pretreated patients with advanced solid tumors who received matched targeted therapy based on ctDNA analysis and/or tumor molecular profiling.

Case presentation:

Three patients with advanced, metastatic cancer and the following characteristics are presented: a 71-year-old woman with ovarian cancer and BRCA2 mutation identified in ctDNA and tumor tissue was treated with a PARP inhibitor and achieved partial response by RECIST (Response Evaluation Criteria in Solid Tumors) for 22.6+ months; a 40-year-old woman with adenoid cystic carcinoma of the parotid gland was treated with a MEK/RAF pathway inhibitor on the basis of RAF1 amplification on ctDNA analysis and had stable disease for 20.2 months; and a 56-year-old woman with breast cancer and a BRCA1 mutation identified by ctDNA analysis was treated with a PARP inhibitor and achieved stable disease for 9.1 months. All three patients are alive at the time of this report.

Conclusions:

These results suggest that ctDNA analysis can contribute to selection of targeted therapy in patients with advanced, metastatic cancer. Prospective clinical trials to evaluate and optimize ctDNA biomarkers, as well as the integration of novel and/or alternative targeted therapies, are warranted to fully assess the role of ctDNA analysis in cancer therapy.

Trial registration:

www.clinicaltrials.gov (NCT02152254). Registered May 28, 2014. https://www.clinicaltrials.gov/ct2/show/NCT02152254. MD Anderson protocol # PA12-1161 (approval ID IRB1 FWA00000121) and # PA11-0377 (approval ID IRB4 FWA00005015).

Uncommon targets in non-small cell lung cancer: Everyone wants a slice of cake

Target therapies completely changed the clinical approach in EGFR mutated and ALK rearranged non-small cell lung cancer, ensuring these patients exceptional outcomes with a better toxicity profile compared to conventional chemotherapy. In recent years, beyond EGFR and ALK alterations, new data are emerging about less common alterations, new drugs have been already approved and others agents have been recently investigated or are currently under investigation. In this review we will discuss some uncommon alterations in non-small cell lung cancer such as ROS1, BRAF, RET, HER2, NTRK, MET and other targets that are in an early evaluation phase. We will summarize the characteristics of patients harboring these alterations, the already approved or under investigation therapies and the related resistance mechanisms.

BRAF V600E/V600K Mutations versus Nonstandard Alterations: Prognostic Implications and Therapeutic Outcomes

BRAF and MEK inhibitors are standard of care for BRAF V600E/K-mutated melanoma, but the benefit of BRAF and/or MEK inhibitors for nonstandard BRAF alterations for melanoma and other cancers is unclear. Patients with diverse malignancies whose cancers had undergone next-generation sequencing were screened for BRAF alterations. Demographics, treatment with BRAF and/or MEK inhibitors, clinical response, progression-free survival (PFS), and overall survival (OS) were determined from review of the electronic medical records for patients with standard BRAF V600E/K versus nonstandard BRAF alterations. A total of 213 patients with BRAF alterations (87 with nonstandard alterations) were identified; OS from diagnosis was significantly worse with nonstandard BRAF versus standard alterations, regardless of therapy [HR (95% confidence interval), 0.58 (0.38-0.88); P = 0.01]. Overall, 45 patients received BRAF/MEK-directed therapy (eight with nonstandard alterations); there were no significant differences in clinical benefit rate [stable disease ≥6 months/partial/complete response (74% vs. 63%; P = 0.39) or PFS (P = 0.24; BRAF V600E/K vs. others)]. In conclusion, patients with nonstandard versus standard BRAF alterations (BRAF V600E/K) have a worse prognosis with shorter survival from diagnosis. Even so, 63% of patients with nonstandard BRAF alterations achieved clinical benefit with BRAF/MEK inhibitors. Larger prospective studies are warranted to better understand the prognostic versus predictive implication of standard versus nonstandard BRAF alterations.

Cutaneous Metastasis as the First Presentation of Non-Small-Cell Lung Cancer with a BRAF Mutation: A Case Report

Cutaneous metastasis from a primary visceral malignancy is a relatively uncommon clinical manifestation that occurs as an initial presentation in 1% to 12% of patients with internal malignancies. Additionally, cutaneous metastases are often late signs of an internal malignancy, and in very rare cases they may occur at the same time or before the primary cancer has been detected. Metastasis to the skin has a poor prognosis and is often a sign of widespread malignant tumors. In the present study, we report a 72-year-old male who presented with multiple rapidly growing subcutaneous nodules. Positron emission tomography-computed tomography (PET-CT) revealed a hypermetabolic concentration of radiotracer in the left lower lung and multiple organ metastases associated with multiple skin masses. Biopsy of one of the skin nodules and gene detection indicated metastatic adenocarcinoma consistent with a primary lung origin with a BRAF mutation. BRAF mutations are emerging therapeutic targets in non-small-cell lung cancer (NSCLC), as they are present in 2–4% of NSCLC cases. To the best of our knowledge, this is the first case report to show that BRAF-mutant lung adenocarcinoma can be associated with cutaneous metastasis. Early diagnosis and individualized treatment strategies may prolong patient survival.

Targeting Infrequent Driver Alterations in Non-Small Cell Lung Cancer

The discovery of oncogenic driver mutations led to the development of targeted therapies with non-small cell lung cancer (NSCLC) being a paradigm for precision medicine in this setting. Nowadays, the number of clinical trials focusing on targeted therapies for uncommon drivers is growing exponentially, emphasizing the medical need for these patients. Unfortunately, similar to what is observed with most targeted therapies directed against a driver oncogene, the clinical response is almost always temporary and acquired resistance to these drugs invariably emerges. Here, we review the biology of infrequent genomic actionable alterations in NSCLC as well as the current and emerging therapeutic options for these patients. Mechanisms leading to acquired drug resistance and future challenges in the field are also discussed.

Dichloroacetate Radiosensitizes Hypoxic Breast Cancer Cells

Mitochondrial metabolism is an attractive target for cancer therapy. Reprogramming metabolic pathways can potentially sensitize tumors with limited treatment options, such as triple-negative breast cancer (TNBC), to chemo- and/or radiotherapy. Dichloroacetate (DCA) is a specific inhibitor of the pyruvate dehydrogenase kinase (PDK), which leads to enhanced reactive oxygen species (ROS) production. ROS are the primary effector molecules of radiation and an increase hereof will enhance the radioresponse. In this study, we evaluated the effects of DCA and radiotherapy on two TNBC cell lines, namely EMT6 and 4T1, under aerobic and hypoxic conditions. As expected, DCA treatment decreased phosphorylated pyruvate dehydrogenase (PDH) and lowered both extracellular acidification rate (ECAR) and lactate production. Remarkably, DCA treatment led to a significant increase in ROS production (up to 15-fold) in hypoxic cancer cells but not in aerobic cells. Consistently, DCA radiosensitized hypoxic tumor cells and 3D spheroids while leaving the intrinsic radiosensitivity of the tumor cells unchanged. Our results suggest that although described as an oxidative phosphorylation (OXPHOS)-promoting drug, DCA can also increase hypoxic radioresponses. This study therefore paves the way for the targeting of mitochondrial metabolism of hypoxic cancer cells, in particular to combat radioresistance.

BRAF: A Two-Faced Janus

Gain-of-function of V-Raf Murine Sarcoma Viral Oncogene Homolog B (BRAF) is one of the most frequent oncogenic mutations in numerous cancers, including thyroid papillary carcinoma, melanoma, colon, and lung carcinomas, and to a lesser extent, ovarian and glioblastoma multiforme. This mutation aberrantly activates the mitogen-activated protein (MAP) kinase extracellular signal-regulated kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway, thereby eliciting metastatic processes. The relevance of BRAF mutations stems from its prognostic value and, equally important, from its relevant therapeutic utility as an actionable target for personalized treatment. Here, we discuss the double facets of BRAF. In particular, we argue the need to implement diagnostic molecular algorithms that are able to detect this biomarker in order to streamline and refine diagnostic and therapeutic decisions.

Mutation-oriented profiling of autoinhibitory kinase conformations predicts RAF inhibitor efficacies

Kinase-targeted therapies have the potential to improve the survival of patients with cancer. However, the cancer-specific spectrum of kinase alterations exhibits distinct functional properties and requires mutation-oriented drug treatments. Besides post-translational modifications and diverse intermolecular interactions of kinases, it is the distinct disease mutation which reshapes full-length kinase conformations, affecting their activity. Oncokinase mutation profiles differ between cancer types, as it was shown for BRAF in melanoma and non-small-cell lung cancers. Here, we present the target-oriented application of a kinase conformation (KinCon) reporter platform for live-cell measurements of autoinhibitory kinase activity states. The bioluminescence-based KinCon biosensor allows the tracking of conformation dynamics of full-length kinases in intact cells and real time. We show that the most frequent BRAF cancer mutations affect kinase conformations and thus the engagement and efficacy of V600E-specific BRAF inhibitors (BRAFi). We illustrate that the patient mutation harboring KinCon reporters display differences in the effectiveness of the three clinically approved BRAFi vemurafenib, encorafenib, and dabrafenib and the preclinical paradox breaker PLX8394. We confirmed KinCon-based drug efficacy predictions for BRAF mutations other than V600E in proliferation assays using patient-derived lung cancer cell lines and by analyzing downstream kinase signaling. The systematic implementation of such conformation reporters will allow to accelerate the decision process for the mutation-oriented RAF-kinase cancer therapy. Moreover, we illustrate that the presented kinase reporter concept can be extended to other kinases which harbor patient mutations. Overall, KinCon profiling provides additional mechanistic insights into full-length kinase functions by reporting protein-protein interaction (PPI)-dependent, mutation-specific, and drug-driven changes of kinase activity conformations.

Concomitant Rare KRAS and BRAF Mutations in Lung Adenocarcinoma: A Case Report

In July 2020, an active smoker, 63-year old man was admitted to the oncology unit of A.O.R.N. Sant’Anna e San Sebastiano (Caserta, Italy). Chest radiology highlighted right pleural effusion. Total-body CT scanning revealed a solid lesion with lobulated contours in the apical segment of the upper right lobe. The patient’s oncologist requested a molecular assessment of EGFR, ALK, ROS1, BRAF, and KRAS, as well as an evaluation of PD-L1 expression level. To this end, we carried out NGS analysis, on DNA extracted from cytospins, by adopting a custom-designed NGS panel (SiRe®). Overall, no actionable mutations in the tested genes were identified. Conversely, concomitant BRAF exon 11 p.G469A and a KRAS exon 4 p.A146T mutations were detected. Owing to the limited data on the presence of KRAS exon 4 p.A146T point mutation in lung adenocarcinoma patients, a further molecular confirmatory analysis was carried out with a dedicated KRAS cartridge on a fully automated real time polymerase chain reaction. When DNA was extracted from the TTF-1 positive tumor cell slide, the same KRAS alteration was observed. Unfortunately, the patient died in August 2020 before having the chance to start any type of treatment.

A highly sensitive and specific real-time quantitative PCR for BRAF V600E/K mutation screening

Mutations that lead to constitutive activation of key regulators in cellular processes are one of the most important drivers behind vigorous growth of cancer cells, and are thus prime targets in cancer treatment. BRAF V600E mutation transduces strong growth and survival signals for cancer cells, and is widely present in various types of cancers including lung cancer. A combination of BRAF inhibitor (dabrafenib) and MEK inhibitor (trametinib) has recently been approved and significantly improved the survival of patients with advanced NSCLC harboring BRAF V600E/K mutation. To improve the detection of BRAF V600E/K mutation and investigate the incidence and clinicopathological features of the mutation in lung cancer patients of southern Taiwan, a highly sensitive and specific real-time quantitative PCR (RT-qPCR) method, able to detect single-digit copies of mutant DNA, was established and compared with BRAF V600E-specific immunohistochemistry. Results showed that the BRAF V600E mutation was present at low frequency (0.65%, 2/306) in the studied patient group, and the detection sensitivity and specificity of the new RT-qPCR and V600E-specific immunohistochemistry both reached 100% and 97.6%, respectively. Screening the BRAF V600E/K mutation with the RT-qPCR and V600E-specific immunohistochemistry simultaneously could help improve detection accuracy.

BRAF as a positive predictive biomarker: Focus on lung cancer and melanoma patients

In the era of personalized medicine, BRAF mutational assessment is mandatory in advanced-stage melanoma and non-small cell lung cancer (NSCLC) patients. The identification of actionable mutations is crucial for the adequate management of these patients. To date various drugs have been implemented in clinical practice. Similarly, various methods may be adopted for the identification of BRAF mutations. Here, we briefly review the current literature on BRAF in melanoma and NSCLC, focusing attention in particular on the different methods and drugs adopted in these patients. In addition, an overview of the real-world practice in different Italian laboratories with high expertise in molecular predictive pathology testing is provided.

Patient-derived cell line, xenograft and organoid models in lung cancer therapy

Lung cancer accounts for most cancer-related deaths worldwide and has an overall 5-year survival rate of ~15%. Cell lines have played important roles in the study of cancer biology and potential therapeutic targets, as well as pre-clinical testing of novel drugs. However, most experimental therapies that have cleared preclinical testing using established cell lines have failed phase III clinical trials. This suggests that such models may not adequately recapitulate patient tumor biology and clinical outcome predictions. Here, we discuss and compare different pre-clinical lung cancer models, including established cell lines, patient-derived cell lines, xenografts and organoids, summarize the methodology for generating these models, and review their relative advantages and limitations in different oncologic research applications. We further discuss additional gaps in patient-derived pre-clinical models to better recapitulate tumor biology and improve their clinical predictive power.

Targeting Aberrant RAS/RAF/MEK/ERK Signaling for Cancer Therapy

The RAS/RAF/MEK/ERK (MAPK) signaling cascade is essential for cell inter- and intra-cellular communication, which regulates fundamental cell functions such as growth, survival, and differentiation. The MAPK pathway also integrates signals from complex intracellular networks in performing cellular functions. Despite the initial discovery of the core elements of the MAPK pathways nearly four decades ago, additional findings continue to make a thorough understanding of the molecular mechanisms involved in the regulation of this pathway challenging. Considerable effort has been focused on the regulation of RAF, especially after the discovery of drug resistance and paradoxical activation upon inhibitor binding to the kinase. RAF activity is regulated by phosphorylation and conformation-dependent regulation, including auto-inhibition and dimerization. In this review, we summarize the recent major findings in the study of the RAS/RAF/MEK/ERK signaling cascade, particularly with respect to the impact on clinical cancer therapy.

The optional approach of oncogene-addicted non-small cell lung cancer with brain metastases in the new generation targeted therapies era

In recent years, the study of the molecular characteristics of non-small cell lung cancer (NSCLC) has highlighted a specific role of some genes that represent important therapeutic targets, including epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS-1) and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF). Patients with oncogene-addicted cancer benefit more from therapy with tyrosine kinase inhibitors (TKIs) than from chemotherapy. The brain is a preferred site for tumor spread in these patients. In addition, given greater control of extracranial disease and prolonged survival, the brain is often the first site of progression. Therefore, there is great interest in therapeutic approaches that optimize the control of intracranial disease associated with systemic drugs that, by penetrating the blood-brain barrier (BBB), may improve local control. On the latter, radiotherapy provides excellent efficacy but following the results of clinical trials with new brain penetrant drugs, the question of how and especially when to perform brain radiotherapy in patients with oncogene-addicted NSCLC remains open. Prospective studies may indicate which patients are most likely to benefit from combined use or in what sequence they will undergo systemic and radiotherapy treatment. Due to the heterogeneity of patients and the introduction of new generation TKIs, a multidisciplinary assessment for the best management of therapies in NSCLC patients with molecular driver alterations and brain metastases (BM) is required.

Clonal selection confers distinct evolutionary trajectories in BRAF-driven cancers

Molecular determinants governing the evolution of tumor subclones toward phylogenetic branches or fixation remain unknown. Using sequencing data, we model the propagation and selection of clones expressing distinct categories of BRAF mutations to estimate their evolutionary trajectories. We show that strongly activating BRAF mutations demonstrate hard sweep dynamics, whereas mutations with less pronounced activation of the BRAF signaling pathway confer soft sweeps or are subclonal. We use clonal reconstructions to estimate the strength of "driver" selection in individual tumors. Using tumors cells and human-derived murine xenografts, we show that tumor sweep dynamics can significantly affect responses to targeted inhibitors of BRAF/MEK or DNA damaging agents. Our study uncovers patterns of distinct BRAF clonal evolutionary dynamics and nominates therapeutic strategies based on the identity of the BRAF mutation and its clonal composition.

The extended spectrum of RAS-MAPK pathway mutations in colorectal cancer

Current clinical guidelines recommend mutation analysis for select codons in KRAS and NRAS exons 2, 3, and 4 and BRAF V600E to guide therapy selection and prognostic stratification in advanced colorectal cancer. This study evaluates the impact of extended molecular testing on the detection of RAS-MAPK pathway mutations. Panel next-generation sequencing results of colorectal cancer specimens from 5795 individuals from the American Association for Cancer Research Project Genomics Evidence Neoplasia Information Exchange (AACR Project GENIE) were included. Mutations in RAS-MAPK pathway genes were analyzed and functionally annotated. Colorectal cancers had recurrent pathogenic pathway activating mutations in KRAS (44%), NRAS (4%), HRAS (<1%), BRAF (10%), MAP2K1 (1%), RAF1 (<1%), and PTPN11 (<1%). The proportion of colorectal cancers with pathogenic RAS pathway mutations was 37% when only KRAS codon 12 and 13 mutations were considered, 46% when also including select KRAS and NRAS exons 2, 3, and 4 mutations, 53% when including BRAF V600E mutations, and 56% when including all pathogenic mutations. Panel next-generation sequencing testing identifies additional RAS-MAPK pathway driver mutations beyond current guideline recommendations. These mutations have potential implications in treatment selection for patients with advanced colorectal cancer.

BRAF Mutations Classes I, II, and III in NSCLC Patients Included in the SLLIP Trial: The Need for a New Pre-Clinical Treatment Rationale

BRAF V600 mutations have been found in 1-2% of non-small-cell lung cancer (NSCLC) patients, with Food and Drug Administration (FDA) approved treatment of dabrafenib plus trametinib and progression free survival (PFS) of 10.9 months. However, 50-80% of BRAF mutations in lung cancer are non-V600, and can be class II, with intermediate to high kinase activity and RAS independence, or class III, with impaired kinase activity, upstream signaling dependence, and consequently, sensitivity to receptor tyrosine kinase (RTK) inhibitors. Plasma cell-free DNA (cfDNA) of 185 newly diagnosed advanced lung adenocarcinoma patients (Spanish Lung Liquid versus Invasive Biopsy Program, SLLIP, NCT03248089) was examined for BRAF and other alterations with a targeted cfDNA next-generation sequencing (NGS) assay (Guardant360®, Guardant Health Inc., CA, USA), and results were correlated with patient outcome. Cell viability with single or combined RAF, MEK, and SHP2 inhibitors was assessed in cell lines with BRAF class I, II, and III mutations. Out of 185 patients, 22 had BRAF alterations (12%) of which seven patients harbored amplifications (32%) and 17 had BRAF mutations (77%). Of the BRAF mutations, four out of 22 (18%) were V600E and 18/22 (82%) were non-V600. In vitro results confirmed sensitivity of class III and resistance of class I and II BRAF mutations, and BRAF wild type cells to SHP2 inhibition. Concomitant MEK or RAF and SHP2 inhibition showed synergistic effects, especially in the class III BRAF-mutant cell line. Our study indicates that the class of the BRAF mutation may have clinical implications and therefore should be defined in the clinical practice and used to guide therapeutic decisions.

CRAF mutations in lung cancer can be oncogenic and predict sensitivity to combined type II RAF and MEK inhibition

Two out of 41 non-small cell lung cancer patients enrolled in a clinical study were found with a somatic CRAF mutation in their tumor, namely CRAF^P261A and CRAF^P207S. To our knowledge, both mutations are novel in lung cancer and CRAF^P261A has not been previously reported in cancer. Expression of CRAF^P261A in HEK293T cells and BEAS-2B lung epithelial cells led to increased ERK pathway activation in a dimer-dependent manner, accompanied with loss of CRAF phosphorylation at the negative regulatory S259 residue. Moreover, stable expression of CRAF^P261A in mouse embryonic fibroblasts and BEAS-2B cells led to anchorage-independent growth. Consistent with a previous report, we could not observe a gain-of-function with CRAF^P207S. Type II but not type I RAF inhibitors suppressed the CRAF^P261A-induced ERK pathway activity in BEAS-2B cells, and combinatorial treatment with type II RAF inhibitors and a MEK inhibitor led to a stronger ERK pathway inhibition and growth arrest. Our findings suggest that the acquisition of a CRAF^P261A mutation can provide oncogenic properties to cells, and that such cells are sensitive to combined MEK and type II RAF inhibitors. CRAF mutations should be diagnostically and therapeutically explored in lung and perhaps other cancers.

Clinical mutational profiling and categorization of BRAF mutations in melanomas using next generation sequencing

Background

Analysis of melanomas for actionable mutations has become the standard of care. Recently, a classification scheme has been proposed that categorizes BRAF mutations based on their mechanisms for activation of the MAPK pathway.

Methods

In this analysis BRAF, KIT, NRAS, and PIK3CA mutations were examined by next generation sequencing (NGS) in 446 melanomas in a clinical diagnostic setting. KRAS and HRAS were also analyzed to elucidate coexisting BRAF and RAS mutations. BRAF mutations were categorized into class-1 (kinase-activated, codon 600), class-2 (kinase-activated, non-codon 600) and class-3 (kinase-impaired), based on the newly proposed classification scheme.

Results

NGS demonstrated high analytic sensitivity. Among 355 mutations detected, variant allele frequencies were 2–5% in 21 (5.9%) mutations and 2–10% in 47 (13%) mutations. Mutations were detected in BRAF (42%), NRAS (25%), KIT (4.9%) and PIK3CA (2.7%). The incidence of class-1, class-2 and class-3 mutations were 33% (26% p.V600E and 6.1% p.V600K), 3.1 and 4.9% respectively. With a broader reportable range of NGS, class-1, class-2 and class-3 mutations accounted for 77, 7.4 and 12% of all BRAF mutations. Class-3 mutations, commonly affecting codons 594, 466 and 467, showed a higher incidence of coexisting RAS mutations, consistent with their RAS-dependent signaling. Significant association with old age and primary tumors of head/neck/upper back suggest chronic solar damage as a contributing factor for melanomas harboring BRAF p.V600K or class-3 mutations.

Conclusion

This study categorizes the range, frequency, coexisting driver mutations and clinical characteristics of the three classes of BRAF mutations in a large cohort of melanomas in a clinical diagnostic setting. Further prospective studies are warranted to elucidate the clinical outcomes and benefits of newly developed targeted therapy in melanoma patients carrying each class of BRAF mutation.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5864-1) contains supplementary material, which is available to authorized users.

Therapeutic outcomes in non-small cell lung cancer with BRAF mutations: a single institution, retrospective cohort study

Background

Data describing therapeutic outcomes in patients with non-small cell lung cancers (NSCLC) with BRAF mutations remains limited.

Methods

We conducted a retrospective cohort study of 31 patients with metastatic NSCLC treated at Duke University Hospital who had been identified by next-generation sequencing methods to bear a BRAF mutation in their tumor in order to evaluate clinical response to immunotherapy and chemotherapy.

Results

Sixty-five percent of patients identified in this cohort were current or former smokers. Fourteen (45.2%) of patients had a BRAF V600E mutation and 17 (54.8%) had a non-V600E mutation. Median progression-free survival (PFS) in the 23 patients who received first-line chemotherapy was 6.4 months [95% confidence interval (CI), 2.3 to 13.0]. Overall survival (OS) in patients who received first-line chemotherapy showed a median survival of 18 months (95% CI, 7.4 to 28.6). OS comparing patients who had never received immunotherapy at any point was 18.4 months (95% CI, 4.1 to NE) compared to 19.0 months (95% CI, 9.9 to 28.6) in those who had received immunotherapy. We did not find a statistically significant difference in OS in patients with BRAF V600E, BRAF amplification, or non-V600E mutations. There was also no difference in OS in patients treated with targeted BRAF inhibitors compared to those who were not treated with targeted BRAF inhibitors.

Conclusions

We describe therapeutic outcomes for patients with metastatic NSCLC with BRAF mutations treated with either cytotoxic chemotherapy or immunotherapy. Although the sample size is small, the survival curves do not suggest improved clinical activity in this population when treated with immunotherapy.

Efficacy and Safety of BRAF Inhibitors With or Without MEK Inhibitors in BRAF-Mutant Advanced Non-Small-Cell Lung Cancer: Findings From a Real-Life Cohort

BACKGROUND

Real-life comparative data on BRAF inhibitors (BRAFi) and BRAFi + MEK inhibitors (MEKi) combination in BRAF-mutant (BRAFm) non-small-cell lung cancer (NSCLC) is lacking.

PATIENTS AND METHODS

Consecutive BRAFm advanced NSCLC patients (n = 58) treated in 9 Israeli centers in 2009-2018 were identified. These were divided according to mutation subtype and treatment into groups A1 (V600E, BRAFi; n = 5), A2 (V600E, BRAFi + MEKi; n = 15), A3 (V600E, no BRAFi; n = 7), B1 (non-V600E, BRAFi ± MEKi; n = 7), and B2 (non-V600E, no BRAFi; n = 23); one patient received both BRAFi and BRAFi + MEKi. Safety, objective response rate, progression-free survival with BRAFi ± MEKi, and overall survival were assessed.

RESULTS

Objective response rate was 40%, 67%, and 33% in groups A1, A2, and B1, respectively (P = .5 for comparison between groups A1 and A2). In group B1, G469A and L597R mutations were associated with response to BRAFi + MEKi. Median progression-free survival was 1.2 months (95% confidence interval [CI], 0.5-5.3), 5.5 months (95% CI, 0.7-9.3), and 3.6 months (95% CI, 1.5-6.7) for groups A1, A2, and B1, respectively (log-rank for comparison between groups A1 and A2, P = .04). Median overall survival with BRAFi ± MEKi was 1.7 months (95% CI, 0.5-NR), 9.5 months (95% CI, 0.2-14.9), and 7.1 months (95% CI, 1.8-NR) in groups A1, A2, and B1, respectively (log-rank for comparison between groups A1 and A2, P = .6). Safety profiles differed slightly, and similar treatment discontinuation rates were observed with BRAFi and BRAFi + MEKi.

CONCLUSION

In the real-life setting, activity and safety of BRAFi + MEKi in V600E BRAFm NSCLC are comparable to those observed in prospective clinical trials; the combination of BRAFi + MEKi is superior to monotherapy with a BRAFi. Further research should be done to explore the impact of BRAFi + MEKi treatment on the natural history of BRAFm NSCLC.

Imaging characteristics of BRAF-mutant non-small cell lung cancer by functional class

OBJECTIVES

Mutations in the BRAF gene have emerged as a validated molecular target in the treatment of non-small cell lung cancer (NSCLC). These mutations can be classified into three functional classes based on their mechanisms of oncogenesis. The relationship between these functional classes and their imaging features has not been systematically investigated. The goal of this work is to determine if imaging features of the primary tumor and the pattern of metastasis correlate with the functional class of BRAF mutation.

METHODS

We reviewed pre-treatment computed tomography (CT) images of patients with BRAF-mutated NSCLC with known functional class. We assessed and recorded the features of the primary tumor and the patterns of lymphadenopathy and distant metastasis. Wilcoxon rank-sum test and Kruskal-Wallis test were performed to compare continuous characteristics, and Fisher's exact test was used to compare categorical features between groups.

RESULTS AND CONCLUSIONS

105 patients with BRAF-mutant NSCLC had pre-treatment imaging available for review (n = 43 class I, n = 40 class II, and n = 22 class III). Approximately half of the primary tumors were considered masses (n = 54/105, 51%) and most were solid (n = 81/105, 77%). There were no statistically significant differences in imaging features of the primary tumor among the three functional classes. Intrathoracic metastases occurred more frequently in class I tumors compared to tumors with class II and III mutations (p = 0.03). The odds of class I mutation were higher among tumors involving the pleural space (OR: 4.39, 95% CI: 1.11-17.4) and lower among tumors disseminating to the abdomen (OR: 0.25, 95% CI: 0.07-0.92). Our findings suggest that class I (V600) mutated NSCLC may be more likely to have intrathoracic metastases, while classes II and III (non-V600) mutated NSCLC may be more likely to have intra-abdominal metastases at the time of presentation.

Targeted therapies for advanced non-small cell lung cancer

Lung cancer is a serious health problem and the leading cause of cancer death worldwide, due to its high incidence and mortality. 85% of lung cancers are represented by the non-small cell lung cancer (NSCLC). Traditional chemotherapy has been the main treatment option in NSCLC. However, it is often associated with limited efficacy and overall poor patient survival. In recent years, molecular targeting has achieved great progress in therapeutic treatment of cancer and plays a crucial role in the current clinical treatment of NSCLC, due to enhanced efficacy on cancer tissues and reduced toxicity for normal tissues. In this review, we summarize the current targeting treatment of NSCLC, including inhibition of the epidermal growth factor receptor (EGFR), phosphatidylinositol 3-kinase (PI3Ks), mechanistic target of rapamycin (mTOR), epidermal growth factor receptor 2 (ErbB2), vascular epidermal growth factor receptor (VEGFR), kirsten human rat sarcoma protein (KRAS), mesenchymal-epithelial transition factor or hepatocyte growth factor receptor (c-MET), anaplastic lymphoma kinase (ALK), v-Raf murine sarcoma viral oncogene homolog B (BRAF). This article may serve as a guide to clinicians and researchers alike by assisting in making therapeutic decisions. Challenges of acquired drug resistance targeted therapy and imminent newer treatment modalities against NSCLC are also discussed.

Therapeutic potential of trametinib to inhibit the mutagenesis by inactivating the protein kinase pathway in non-small cell lung cancer

Introduction:Mitogen-activated protein kinase (MAPK) pathway is known to be involved in the tumorigenesis of cancer cells including non-small cell lung cancer (NSCLC) and kinases involved in this pathway are frequently mutated. The development of new targeted therapies in cancer has led to the evaluation of MEK-inhibitors. Areas covered: This article reviews different studies using trametinib alone, in combination with other targeted therapies or associated with other non-targeted therapies in NSCLC, with a focus on KRAS mutant and BRAF mutant NSCLC. Expert commentary: Trametinib demonstrated activity in association with a BRAF inhibitor when BRAF was mutated. The combination of trametinib and dabrafenib has been approved for this population of BRAF mutant NSCLC patients. For KRAS mutant NSCLC, the combination of trametinib with chemotherapy has showed promising results and should be further assessed. Several clinical trials are ongoing, assessing trametinib in combination with other targeted therapies. In addition, preclinical studies suggest a synergistic effect of trametinib in combination with immune checkpoint inhibitors and such combinations should be studied in clinical trials.