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

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.

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.

Real-World Treatment Patterns and Effectiveness of Targeted and Immune Checkpoint Inhibitor-Based Systemic Therapy in BRAF Mutation-Positive NSCLC

Introduction

BRAF mutations (present in 2%-3% of NSCLC) are a known oncogenic driver and emerging therapeutic target. There is a scarcity of real-world data describing the clinical characteristics, treatment patterns, and effectiveness of targeted BRAF-inhibiting and immune checkpoint inhibitor (ICI)-based systemic therapies, yet this is required for appropriate treatment decisions that optimize patient outcome.

Methods

Demographic, clinical, treatment, and outcome data of patients with BRAF mutation-positive NSCLC diagnosed between 2018 and 2022 were identified from the Glans-Look Lung Cancer Research database and included in this analysis.

Results

A total of 53 BRAF mutation-positive patients were identified (V600E, n = 35; non-V600E, n = 18). Furthermore, 46 patients (87%) were diagnosed with metastatic disease, of whom 61% were treated with systemic anticancer therapy, which significantly improved overall survival (34.1 versus 2.2 mo, p = 0.01). ICI-based regimens were found to have effectiveness in the first-line setting for both V600E and non-V600E cohorts (objective response rate: 38%-43%; real-world calculations of median progression-free survival: 10.5-10.8 mo, respectively). Dual-targeted BRAF/MEK inhibition was also found to have effectiveness in the first-line setting for V600E patients (objective response rate: 33%, real-world calculations of median progression-free survival: 15.2 mo).

Conclusions

This study of real-world patients with BRAF mutations confirms the importance of effective systemic therapies. Both dual-targeted BRAF/MEK inhibition and ICI-based regimens have evidence of benefit in this population revealing that real-world populations can experience similar clinical response and outcome to clinical trial cohorts on these treatment regimens. Future studies to clarify the role of co-mutations on response to both dual-targeted BRAF/MEK inhibition and ICI-based regimens may be important to treatment selection and optimization of patient outcome.

Minimizing Sample Failure Rates for Challenging Clinical Tumor Samples

Identification of somatic variants in cancer by high-throughput sequencing has become common clinical practice, largely because many of these variants may be predictive biomarkers for targeted therapies. However, there can be high sample quality control (QC) failure rates for some tests that prevent the return of results. Stem-loop inhibition mediated amplification (SLIMamp) is a patented technology that has been incorporated into commercially available cancer next-generation sequencing testing kits. The claimed advantage is that these kits can interrogate challenging formalin-fixed, paraffin-embedded tissue samples with low tumor purity, poor-quality DNA, and/or low-input DNA, resulting in a high sample QC pass rate. The study aimed to substantiate that claim using Pillar Biosciences oncoReveal Solid Tumor Panel. Forty-eight samples that had failed one or more preanalytical QC sample parameters for whole-exome sequencing from the Australian Translational Genomics Center's ISO15189-accredited diagnostic genomics laboratory were acquired. XING Genomic Services performed an exploratory data analysis to characterize the samples and then tested the samples in their ISO15189-accredited laboratory. Clinical reports could be generated for 37 (77%) samples, of which 29 (60%) contained clinically actionable or significant variants that would not otherwise have been identified. Eleven samples were deemed unreportable, and the sequencing data were likely dominated by artifacts. A novel postsequencing QC metric was developed that can discriminate between clinically reportable and unreportable samples.