EGFR T790M mutation after chemotherapy for small cell lung cancer transformation of EGFR-positive non-small cell lung cancer

Outcomes in Patients With Lung Adenocarcinoma With Transformation to Small Cell Lung Cancer After EGFR Tyrosine Kinase Inhibitors Resistance: A Systematic Review and Pooled Analysis

Background

Lung adenocarcinoma can transform into small-cell lung cancer (SCLC) when resistance to tyrosine kinase inhibitors (TKIs) develops. Approximately 3% to 10% of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) could transform to SCLC. This phenomenon has been described in several case reports and small patient series. However, the characteristics and treatment outcomes of this population have not been comprehensively reported, and their clinical course is poorly characterized.

Methods

We performed a systematic review of the published literature to summarize the clinical and pathological features and prognosis of the reported cases and analyzed the demographics, disease features, and outcomes.

Results

A total of 72 patients (50 females and 22 males) initially diagnosed with lung adenocarcinoma were included. EGFR mutations included 19-deletion (75%), L858R (22%), and G719X (3%). All patients received EGFR-TKIs before SCLC transformation. The median time from diagnosis to transformation was 20.5 months (95% CI, 15.45 to 26.55 months). Of the 67 patients with post-translational gene test results, 58 maintained their EGFR mutation, and only 1 of 18 with prior T790M positivity retained T790M mutation. After the pathological transformation, both conventional chemotherapy regimen and chemotherapy combined targeted therapy yielded high response rates. The disease control rate of first-line therapy after transformation was 76%, while the objective response rate was 48%. The median overall survival (OS) since diagnosis was 27 months (95% CI, 22.90 to 31.10 months), whereas median OS since SCLC transformation was 8.5 months (95% CI, 5.50 to 11.60 months).

Conclusion

The prognosis of transformed SCLC is worse than primary SCLC. The response rate to conventional chemotherapy was high. However, the progression-free survival and OS after transformation were short and the prognosis was poor with first-line therapies. New therapies are needed in the management of transformed SCLC.

Integration of liquid biopsy and pharmacogenomics for precision therapy of EGFR mutant and resistant lung cancers

The advent of molecular profiling has revolutionized the treatment of lung cancer by comprehensively delineating the genomic landscape of the epidermal growth factor receptor (EGFR) gene. Drug resistance caused by EGFR mutations and genetic polymorphisms of drug metabolizing enzymes and transporters impedes effective treatment of EGFR mutant and resistant lung cancer. This review appraises current literature, opportunities, and challenges associated with liquid biopsy and pharmacogenomic (PGx) testing as precision therapy tools in the management of EGFR mutant and resistant lung cancers. Liquid biopsy could play a potential role in selection of precise tyrosine kinase inhibitor (TKI) therapies during different phases of lung cancer treatment. This selection will be based on the driver EGFR mutational status, as well as monitoring the development of potential EGFR mutations arising during or after TKIs treatment, since some of these new mutations may be druggable targets for alternative TKIs. Several studies have identified the utility of liquid biopsy in the identification of EGFR driver and acquired resistance with good sensitivities for various blood-based biomarkers. With a plethora of sequencing technologies and platforms available currently, further evaluations using randomized controlled trials (RCTs) in multicentric, multiethnic and larger patient cohorts could enable optimization of liquid-based assays for the detection of EGFR mutations, and support testing of CYP450 enzymes and drug transporter polymorphisms to guide precise dosing of EGFR TKIs.

Small cell lung cancer transformation during antitumor therapies: A systematic review

Lung cancer is the most common cause of cancer-related death. Non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) are the two major histological categories of lung cancers. Drug resistance is a great challenge for cancer treatment, and histological transformation from NSCLC to SCLC is one of the mechanisms underlying drug resistance in NSCLC patients. SCLC-transformed patients show combined characteristics of NSCLC and SCLC; however, they lack timely diagnoses and effective treatment strategies. Thus, we reviewed the clinical characteristics of SCLC transformation patients with a literature search to enhance clinical consciousness, diagnosis, and personalized treatment for patients with it.

Fruquintinib with gefitinib as first-line therapy in patients carrying EGFR mutations with advanced non-small cell lung cancer: a single-arm, phase II study

Background

Fruquintinib is an oral vascular endothelial growth factor receptor inhibitor. Previous gefitinib studies with anti-angiogenics show promising efficacy. This phase II trial assessed efficacy and safety of fruquintinib in combination with gefitinib, in patients with advanced non-small cell lung cancer (NSCLC).

Methods

Fifty patients with stage IIIB/IV NSCLC and an epidermal growth factor receptor (EGFR) exon-19 deletion or exon-21 L858R mutation were enrolled between January 2017 and June 2019. Per protocol (version 1.0), patients received 4 mg fruquintinib once daily (qd) Days 1–21 of Cycle 1, using a 3-week-on/1-week-off schedule, plus continuous gefitinib 250 mg qd. If tolerated, patients proceeded to fruquintinib 5 mg qd (fruquintinib 5 mg group, n=26). Following protocol updates, dose escalation of fruquintinib from 4 mg qd to 5 mg qd was not allowed. The primary efficacy endpoint was objective response rate (ORR); secondary endpoints included progression-free survival (PFS), disease control rate (DCR), time to response, duration of response and adverse events (AEs).

Results

ORR was 73.5% (95% CI, 58.9–85.1) and DCR was 98.0% (95% CI, 89.2–100.0). Median PFS was 14.7 months for both groups; PFS was highest for patients with exon-19 deletion (16.5 months; 95% CI, 12.9–21.2). Grade ≥3 treatment-emergent AEs occurred in 17 (65.3%; fruquintinib 5 mg,) and 11 patients (45.8%; 4 mg). Serious AEs were recorded for nine patients (fruquintinib 5 mg, six patients; 4 mg, three).

Conclusions

Fruquintinib and gefitinib treatment showed an acceptable safety profile and promising efficacy in patients with NSCLC.

A review on RNAi therapy for NSCLC: Opportunities and challenges

Non-small cell lung cancer (NSCLC) is the primary cause of cancer death worldwide. Despite developments in chemotherapy and targeted therapies, the 5-year survival rate has remained at approximately 16% for the last four decades. NSCLC is a heterogeneous group of tumors that, through mutations and drivers, also demonstrate intra-tumor heterogeneity. Thus, current treatment approaches revolve around targeting these oncogenes, often using small molecule inhibitors and chemotherapeutics. However, the efficacy of these therapies has been crippled by acquired and inherent drug-resistance in the tumor, accompanied by increased therapeutic dosages and subsequent devastating off-target effects for patients. Evidently, there is a critical need for developing treatment methodologies more effective than the current standard of care. Fortunately, RNA interference, particularly small interfering RNA (siRNA), presents an alternative of silencing specific oncogenes to control tumor growth. Although siRNA therapy is subject to rapid degradation and poor internalization in vivo, nanoparticles can serve as nontoxic and efficient delivery vehicles, even introducing combinational delivery of multiple therapeutic agents. Indeed, siRNA-nanoconstructs possess extraordinary potential as an innovative modality to address clinical needs. This state-of-the-art review summarizes the recent advancements in the development of novel nanosystems for delivering siRNA to NSCLC tumors and analyzes the efficacy of representative examples. By illuminating the most promising biomarkers for silencing, we hope to streamline current therapeutic efforts and highlight powerful translational opportunities to combat NSCLC. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Lipid-Based Structures Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Understanding the Mechanisms of Resistance in EGFR-Positive NSCLC: From Tissue to Liquid Biopsy to Guide Treatment Strategy

Liquid biopsy has emerged as an alternative source of nucleic acids for the management of Epidermal Growth Factor Receptor (EGFR)-mutant non-Small Cell Lung Cancer (NSCLC). The use of circulating cell-free DNA (cfDNA) has been recently introduced in clinical practice, resulting in the improvement of the identification of druggable EGFR mutations for the diagnosis and monitoring of response to targeted therapy. EGFR-dependent (T790M and C797S mutations) and independent (Mesenchymal Epithelial Transition [MET] gene amplification, Kirsten Rat Sarcoma [KRAS], Phosphatidyl-Inositol 4,5-bisphosphate 3-Kinase Catalytic subunit Alpha isoform [PI3KCA], and RAF murine sarcoma viral oncogene homolog B1 [BRAF] gene mutations) mechanisms of resistance to EGFR tyrosine kinase inhibitors (TKIs) have been evaluated in plasma samples from NSCLC patients using highly sensitive methods (i.e., digital droplet PCR, Next Generation Sequencing), allowing for the switch to other therapies. Therefore, liquid biopsy is a non-invasive method able to detect the molecular dynamic changes that occur under the pressure of treatment, and to capture tumor heterogeneity more efficiently than is allowed by tissue biopsy. This review addresses how liquid biopsy may be used to guide the choice of treatment strategy in EGFR-mutant NSCLC.

Transformation of ALK expression and PD-L1 0% to PD-L1 90% only after surgery: the need for rebiopsy in lung cancer patients

Lung cancer is still diagnosed at a late stage although novel diagnostic techniques are in use. However, as pharmacogenomics have evolved novel targeted therapies either with tyrosine kinase inhibitors or immunotherapy can be currently used as daily treatment. We present the case of a woman with anaplastic lymphoma-positive expression and programmed death-ligand 1 (PD-L1) 0% score upon diagnosis who underwent therapeutic surgery and represented PD-L1 90% expression, however, without anaplastic lymphoma kinase expression. Transformation of the tumor or new tumor is a question to be answered for this patient and possibly we should try and direct rebiopsies for this group of targeted therapy patients.