Optimizing diagnosis and treatment of EGFR exon 20 insertions mutant NSCLC

Mutation-Selected Amplification droplet digital PCR: A new single nucleotide variant detection assay for TP53R249S mutant in tumor and plasma samples

The early detection of gene mutations in physiological and pathological processes is a powerful approach to guide decisions in precision medicine. However, detecting low-copy mutant DNA from clinical samples poses a challenge due to the enrichment of wild-type DNA backgrounds. In this study, we devised a novel strategy, named Mutation-Selected Amplification droplet digital PCR (MSA-ddPCR), to quantitatively analyze single nucleotide variants (SNVs) at low variant allele frequencies (VAFs). Using TP53R249S (a hotspot mutation associated with hepatocellular carcinoma) as a model, we optimized the concentration ratio of primers, the annealing temperature and nucleic acid amplification modifiers. Subsequently, we evaluated the linear range and precision of MSA-ddPCR by detecting TP53R249S and TP53wild-type (TP53WT) plasmid DNA, respectively. MSA-ddPCR demonstrated superior ability to discriminate between mutant DNA and wild-type DNA compared to traditional TaqMan-MGB PCR. We further applied MSA-ddPCR to analyze the TP53R249S mutation in 20 plasma samples and 15 formalin-fixed paraffin-embedded (FFPE) tissue samples, and assessed the agreement rates between MSA-ddPCR and amplicon high-throughput sequencing. The results showed that the limit of blanks of MSA-ddPCR are 0.449 copies μL-1 in the FAM channel and 0.452 copies μL-1 in the VIC channel. MSA-ddPCR could accurately quantify VAFs as low as 0.01 %, surpassing existing PCR and next-generation sequencing (NGS) methods. In the detection of clinical samples, a high correlation was found between MSA-ddPCR and amplicon high-throughput sequencing. Additionally, MSA-ddPCR outperformed sequencing methods in terms of detection time and simplicity of data analysis. MSA-ddPCR can be easily implemented into clinical practice and serve as a robust tool for detecting mutant genes due to its high sensitivity and accuracy.

The current landscape, advancements, and prospects in the treatment of patients with EGFR exon 20 insertion mutations warrant scientific elucidation

Epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations are the third most prevalent mutation in non-small cell lung cancer (NSCLC), following the 19del and L858R mutations. The unique nature of the EGFR ex20ins mutation poses challenges for the effectiveness of first- and second-generation EGFR tyrosine kinase inhibitors (TKIs). As a result, chemotherapy remains the primary and more effective treatment approach. However, with advancements in time and technology, numerous experimental studies have revealed the potential of novel drugs and therapies to have stronger inhibitory effects on EGFR ex20ins mutations. In this comprehensive review, we provide an overview of the current treatment landscape, recent advancements, and the prospects for patients with advanced NSCLC characterized by EGFR ex20ins mutations.

Current status and breakthroughs in treating advanced non-small cell lung cancer with EGFR exon 20 insertion mutations

Recently, targeted therapy and immunotherapy have emerged as effective treatment options for non-small cell lung cancer (NSCLC). This progress has been facilitated by the rapid development of diagnostic and therapeutic technologies and the continuous research and development of new drugs, leading to a new era in precision medicine for NSCLC. This is a breakthrough for patients with common mutations in the human epidermal growth factor receptor (EGFR) gene in NSCLC. Consequently, the use of targeted drugs has significantly improved survival. Nevertheless, certain rare genetic mutations are referred to as EGFR exon 20 insertion (ex20ins) mutations, which differ in structure from conventional EGFR gene mutations, namely, exon 19 deletion mutations (19-Del) and exon 21 point mutations. Owing to their distinct structural characteristics, patients harboring these EGFR ex20ins mutations are unresponsive to traditional tyrosine kinase inhibitor (TKI) therapy. This particular group of patients did not fall within the scope of their applicability. However, the activating A763_Y764insFQEA mutation elicits a more pronounced response than mutations in the near and far regions of the C-helix immediately following it and should, therefore, be treated differently. Currently, there is a lack of effective treatments for EGFR ex20ins mutations NSCLC. The efficacy of chemotherapy has been relatively favorable, whereas the effectiveness of immunotherapy remains ambiguous owing to inadequate clinical data. In addition, the efficacy of the first- and second-generation targeted drugs remains limited. However, third-generation and novel targeted drugs have proven to be effective. Although novel EGFR-TKIs are expected to treat EGFR ex20ins mutations in patients with NSCLC, they face many challenges. The main focus of this review is on emerging therapies that target NSCLC with EGFR ex20ins and highlight major ongoing clinical trials while also providing an overview of the associated challenges and research advancements in this area.

Revolutionizing cancer immunotherapy: unleashing the potential of bispecific antibodies for targeted treatment

Recent progressions in immunotherapy have transformed cancer treatment, providing a promising strategy that activates the immune system of the patient to find and eliminate cancerous cells. Bispecific antibodies, which engage two separate antigens or one antigen with two distinct epitopes, are of tremendous concern in immunotherapy. The bi-targeting idea enabled by bispecific antibodies (BsAbs) is especially attractive from a medical standpoint since most diseases are complex, involving several receptors, ligands, and signaling pathways. Several research look into the processes in which BsAbs identify different cancer targets such angiogenesis, reproduction, metastasis, and immune regulation. By rerouting cells or altering other pathways, the bispecific proteins perform effector activities in addition to those of natural antibodies. This opens up a wide range of clinical applications and helps patients with resistant tumors respond better to medication. Yet, further study is necessary to identify the best conditions where to use these medications for treating tumor, their appropriate combination partners, and methods to reduce toxicity. In this review, we provide insights into the BsAb format classification based on their composition and symmetry, as well as the delivery mode, focus on the action mechanism of the molecule, and discuss the challenges and future perspectives in BsAb development.

EGFR exon20 insertion mutations in non-small cell lung cancer: Clinical implications and recent advances in targeted therapies

The advent of targeted therapies for oncogenic mutations has led to a major paradigm shift in the management of non-small cell lung cancer (NSCLC). Molecular targets, such as epidermal growth factor receptor (EGFR)-activating mutations in the region of exons 18 through 21 are the most common oncogenic driver in NSCLC. Classical activating mutations, such as in-frame deletions in exon 19 and point mutations in exon 21 (L858R), are strong predictors for good clinical response to the approved EGFR-tyrosine kinase inhibitors (EGFR-TKIs). However, low frequency mutations occurring within exon 20 (ex20ins) have poorer responses to first/second generation EGFR-TKIs. Moreover, patients with NSCLC harboring EGFR ex20ins are known to have poorer prognosis than those with other EGFR-TKI sensitive mutations, leading to unmet clinical need of novel specific therapeutic options. Rapid changes in molecular diagnostics identifying specific causes have hastened the translation of diagnostic recommendations into clinical practice. Emergence of treatment strategies targeting EGFR ex20ins, such as newer EGFR-TKIs with increased specificity and novel approaches using bispecific monoclonal antibodies, may hold promising therapeutic options in the near future. In this review, we describe the structural, molecular characteristics, and detection strategies of EGFR ex20ins mutations and summarize the latest clinical data on approved treatments and emerging therapies for patients with NSCLC harboring EGFR ex20ins mutations. Further, we will discuss the response heterogeneity of ex20ins mutations to new drugs and acquired drug resistance mechanisms.

Sintilimab plus anlotinib as second- or third-line therapy in metastatic non-small cell lung cancer with uncommon epidermal growth factor receptor mutations: A prospective, single-arm, phase II trial

BACKGROUND

Patients with non-small-cell lung cancer (NSCLC) and uncommon EGFR alterations typically have worse treatment outcomes than patients with classically EGFR-mutated NSCLC. This study aimed to investigate the efficacy and safety of PD-1 blockade with sintilimab plus anti-angiogenic treatment with anlotinib in patients with NSCLC harboring uncommon EGFR mutations.

METHODS

Patients with metastatic NSCLC harboring uncommon EGFR mutations after two previous treatments, including a platinum-based chemotherapy regimen and a targeted treatment (or chemotherapy only for patients harboring EGFR ex20ins), received sintilimab combined with anlotinib. The primary endpoint was objective response rate (ORR).

RESULTS

At data cutoff (September 27, 2022), median follow-up was 22.3 months (range, 1.2-37.6). Among 21 enrolled patients, 12 had EGFR ex20ins and nine had other uncommon EGFR mutations such as L861Q, G719A, and G709X. Overall, eight patients (38.1%) achieved an objective response, and 18 (85.7%) achieved disease control. Median (95% CI) progression-free survival (PFS) was 7.0 (5.4-8.6) months, and median overall survival (OS) was 20.0 (15.6-24.4) months. The 12-month PFS rate (95% CI) was 22.2% (7.4-42.0), and the 12-month OS rate was 66.7% (42.5-82.5). Patients harboring EGFR ex20ins had similar ORR and PFS to those with other mutations. Six patients (28.6%) experienced grade 3 treatment-related adverse events (TRAEs); hand-foot syndrome was the most common grade 3 TRAE (2 patients; 9.5%). No grade ≥4 TRAEs were observed.

CONCLUSIONS

The combination of sintilimab and anlotinib demonstrated durable efficacy and was generally well tolerated in patients with NSCLC and uncommon EGFR mutations who had received prior standard-of-care treatments. (ClinicalTrials.gov identifier: NCT04790409).

Immune checkpoint inhibitors in EGFR-mutant non-small cell lung cancer: A systematic review

BACKGROUND

Since their first introduction in clinical practice, immune checkpoint inhibitors showed limited benefit in patients with NSCLC harboring EGFR mutations. With the rationale of increasing immune activation, combinatorial ICI strategies have been evaluated also in this subgroup of patients.

METHODS

We performed a systematic review on efficacy of ICI-based strategies in EGFR-mutant NSCLC according to most updated evidence.

RESULTS

Overall, ICI monotherapy and ICI plus chemotherapy confirm to be ineffective in EGFR-mutant NSCLC, whereas the combination of ICI with antiangiogenic and chemotherapy showed promising results. Limited data are available with alternative ICI combination strategies, driven by strong biological rationale of modulating the tumor immune microenvironment.

CONCLUSIONS

To date, the available evidence do not support the use of ICI in patients with NSCLC harboring EGFR mutations. Clinical trials are ongoing to define which is the best timing and exploring novel combinations with ICI in this specific disease.

Improving the turnaround time of molecular profiling for advanced non-small cell lung cancer: Outcome of a new algorithm integrating multiple approaches

BACKGROUND

Molecular tumor profiling to identify oncogenic drivers and actionable mutations has a profound impact on how lung cancer is treated. Especially in the subgroup of non-small cell lung cancer (NSCLC), molecular testing for certain mutations is crucial in daily clinical practice and is recommended by international guidelines. To date, a standardized approach to identify druggable genetic alterations are lacking. We have developed and implemented a new diagnostic algorithm to harmonize the molecular testing of NSCLC.

PATIENTS AND METHODS

In this retrospective analysis, we reviewed 119 patients diagnosed with NSCLC at the University Hospital Zurich. Tumor samples were analyzed using our standardized diagnostic algorithm: After the histological diagnosis was made, tissue samples were further analyzed by immunohistochemical stainings as well as the real-time PCR test Idylla™. Extracted DNA was further utilized for comprehensive genomic profiling (FoundationOne®CDx, F1CDx).

RESULTS

Out of the 119 patients were included in this study, 100 patients were diagnosed with non-squamous NSCLC (nsqNSCLC) and 19 with squamous NSCLC (sqNSCLC). The samples from the nsqNSCLC patients underwent testing by Idylla™ and were evaluated by immunohistochemistry (IHC). F1CDx analysis was run on 67 samples and 46 potentially actionable genomic alterations were detected. Ten patients received the indicated targeted treatment. The median time to test results was 4 days for the Idylla test, 5 days for IHC and 13 days for the F1CDx.

CONCLUSION

In patients with NSCLC, the implementation of a standardized molecular testing algorithm provided information on predictive markers for NSCLC within a few working days. The implementation of broader genomic profiling led to the identification of actionable targets, which would otherwise not have been discovered.

Rare molecular subtypes of lung cancer

Oncogenes that occur in ≤5% of non-small-cell lung cancers have been defined as 'rare'; nonetheless, this frequency can correspond to a substantial number of patients diagnosed annually. Within rare oncogenes, less commonly identified alterations (such as HRAS, NRAS, RIT1, ARAF, RAF1 and MAP2K1 mutations, or ERBB family, LTK and RASGRF1 fusions) can share certain structural or oncogenic features with more commonly recognized alterations (such as KRAS, BRAF, MET and ERBB family mutations, or ALK, RET and ROS1 fusions). Over the past 5 years, a surge in the identification of rare-oncogene-driven lung cancers has challenged the boundaries of traditional clinical grade diagnostic assays and profiling algorithms. In tandem, the number of approved targeted therapies for patients with rare molecular subtypes of lung cancer has risen dramatically. Rational drug design has iteratively improved the quality of small-molecule therapeutic agents and introduced a wave of antibody-based therapeutics, expanding the list of actionable de novo and resistance alterations in lung cancer. Getting additional molecularly tailored therapeutics approved for rare-oncogene-driven lung cancers in a larger range of countries will require ongoing stakeholder cooperation. Patient advocates, health-care agencies, investigators and companies with an interest in diagnostics, therapeutics and real-world evidence have already taken steps to surmount the challenges associated with research into low-frequency drivers.

HMMR associates with immune infiltrates and acts as a prognostic biomaker in lung adenocarcinoma

BACKGROUND

To explore the expression of hyaluronan mediated motility receptor (HMMR) in lung adenocarcinoma (LUAD) and its relationship with clinicopathological features and tumor-infiltrating is not clear.

METHODS

The expression of HMMR in Cancer Cell Line Encyclopedia (CCLE) and The Cancer Genome Atlas (TCGA)-LUAD. TCGA was employed to examine the relationship between the clinicopathological characteristics and HMMR expression and the LUAD patients' prognosis. Tumor Immune Estimation Resource (TIMER)database was employed to analyze the relationship between immune infiltration and HMMR. Gene Set Enrichment Analysis was explored through gene enrichment. Gene Expression Omnibus (GEO) data and our hospital data were utilized to confirm the findings.

RESULTS

The expression level of HMMR in lung adenocarcinoma tissue and cells was greater than that in the normal group, which was linked to clinical stage, smoking history, and recurrence, and could increase the progression or recurrence of LUAD. Patients in the pathological grade had a significant expression of HMMR in moderately differentiated LUAD tissues. In addition, HMMR has an impact on LUAD patients' overall survival rate [P = 9.5e-06; hazard ratio (HR) = 2]. The level of HMMR expression in LUAD was significantly linked to neutrophils, CD8+T, and CD4+T cells. TMB analysis showed that HMMR could also affect the tumor microenvironment in LUAD. HMMR might be employed as an independent predictive biomarker of LUAD, according to a multivariate COX regression analysis. The findings of GSEA analysis showed that the samples with high HMMR expression levels were rich in cell cycle, cell metabolism, and DNA replication. The analysis results of GSE31210 data are basically consistent with those of TCGA-LUAD.

CONCLUSIONS

It is suggested that HMMR has an effect on the occurrence and development of lung adenocarcinoma. Besides, HMMR is also linked to the level of immune infiltration of neutrophils, CD8+T cells, and CD4+T cells and LUAD patients' prognosis. HMMR was suggested to be utilized as a biomarker or therapeutic target to judge the prognosis and immune infiltration of LUAD.