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

2019 ◽  
Vol 20 (16) ◽  
pp. 3951 ◽  
Author(s):  
Marzia Del Re ◽  
Stefania Crucitta ◽  
Giulia Gianfilippo ◽  
Antonio Passaro ◽  
Iacopo Petrini ◽  
...  

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.

Author(s):  
Jing Sun

Traditional treatments for non-small cell lung adenocarcinomas do produce impressive improvements in patient health. Newly developed biologically based treatments exploit the drug-sensitivity conferred by mutations in the epidermal growth factor receptor (EGFR). In adenocarcinomas, cell proliferation and survival depend on mutant EGFR activity. For patients with certain EGFR mutations, treatment with tyrosine kinase inhibitors (TKIs) rather than chemotherapy improves patient survival. However, almost every patient acquires resistance to TKI treatment. About 50% of acquired resistance is because of a secondary mutation in EGFR. MET gene amplification, which allows cells to use MET to activate downstream signals, is another established mechanism. A third known mechanism is epithelial to mesenchymal transition (EMT). About 30% of all resistance mechanisms still remain unknown. This semester, the HCC2279 EGFR-mutant human adenocarcinoma line was characterized in hopes of discovering new models of resistance. Growth inhibition assays and immunoblotting were used to analyze the effects of treatments and to examine the status of signaling molecules. The HCC2279 resistant line appeared to have an EGFR-independent mechanism and did not seem to use MET as a major mechanism of resistance. The resistant cells continued to grow in the presence of TKI and TKI plus MET inhibitor, and immunoblotting showed that TKIs were capable of completely inhibiting the activation and phosphorylation of EGFR and MET. Signs of EMT were detected via immunoblotting due to a loss of E-cadherin and gain of vimentin, and EMT was corroborated by histological changes such as a loss in resistant cell polarity.


2020 ◽  
Vol 106 (6) ◽  
pp. NP52-NP56
Author(s):  
Shaonan Xie ◽  
Huiyan Deng ◽  
Guangjie Liu ◽  
Qingyi Liu

Background: It remains controversial whether patients with EGFR-mutant lung adenocarcinoma should stop using epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) after progression during treatment. Case report: We report a 35-year-old man with poorly differentiated adenocarcinoma of the left upper lobe and an exon 19 deletion (Ex19Del) mutation found by large-panel next-generation sequencing. The patient underwent video-assisted thoracoscopic surgery 12 months after oral administration of icotinib 125 mg tid, and the left upper lobe and surrounding lymph nodes were removed. Postoperative pathology supported a diagnosis of left upper lobe adenocarcinoma and subcarinal (1/2), main pulmonary artery window (1/2), and left hilar (1/2) lymph node metastases. The EGFR mutations in the residual lesions had disappeared, and Ex19Del mutations were still visible in the mediastinal lymph node metastasis. Conclusion: Spatial heterogeneity of the resistance mechanism may explain why patients who continue to receive EGFR-TKIs in combination with local therapies (e.g., radiotherapy) for progressing lesions may benefit even after progression during EGFR-TKI therapy. The loss of the EGFR mutation allele as a putative resistance mechanism requires additional preclinical and clinical confirmation.


2020 ◽  
Author(s):  
Pedro E. N. S. Vasconcelos ◽  
Ikei S. Kobayashi ◽  
Susumu S. Kobayashi ◽  
Daniel B. Costa

AbstractBackgroundEpidermal growth factor receptor (EGFR) exon 20 insertion mutations account for 10% of all EGFR mutations and are mostly insensitive to approved EGFR-tyrosine kinase inhibitors (EGFR-TKIs). Novel EGFR-TKIs have been developed or repurposed for these mutants. A limited number of preclinical studies have detailed these EGFR-TKIs. We sought to use commercially available mobocertinib (TAK-788) to characterize the preclinical therapeutic window of this EGFR-TKI against EGFR mutations and to probe possible on-target mechanisms of resistance (EGFR-C797S).MethodsWe used models of EGFR mutations to probe representative 1st, 2nd, 3rd generation, and in-development EGFR exon 20-active (poziotinib, mobocertinib) TKIs. We also introduced EGFR-C797S to these models to identify mechanisms of resistance.ResultsCells driven by the most common EGFR exon 20 insertion mutations (A767_V769dupASV, D770_N771insSVD, H773_V774insH and others) were inhibited by in-development EGFR TKIs at doses below those affecting EGFR-wildtype; albeit more common EGFR mutations (exon 19 deletions and L858R) were inhibited more readily by mobocertinib and poziotinib. Mobocertinib was able to inhibit phosphorylation of EGFR in multiple preclinical models. The presence of EGFR-C797S led to >200-fold resistance in proliferation assays probing mobocertinib and osimertinib. Review of clinical studies of mobocertinib disclosed responses that could be lasting.ConclusionsThis is one of the initial reports to characterize the novel EGFR TKI mobocertinib and highlights its broad activity against EGFR mutants plus the therapeutic window to EGFR exon 20 insertion mutations; as well as EGFR-C797S as a possible mechanism of resistance. Further clinical development of mobocertinib merits continuation.


Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3553
Author(s):  
Dylan A. Farnsworth ◽  
Yankuan T. Chen ◽  
Georgia de Rappard Yuswack ◽  
William W. Lockwood

Epidermal growth factor receptor (EGFR) mutations are the molecular driver of a subset of non-small cell lung cancers (NSCLC); tumors that harbor these mutations are often dependent on sustained oncogene signaling for survival, a concept known as “oncogene addiction”. Inhibiting EGFR with tyrosine kinase inhibitors has improved clinical outcomes for patients; however, successive generations of inhibitors have failed to prevent the eventual emergence of resistance to targeted agents. Although these tumors have a well-established dependency on EGFR signaling, there remain questions about the underlying genetic mechanisms necessary for EGFR-driven oncogenesis and the factors that allow tumor cells to escape EGFR dependence. In this review, we highlight the latest findings on mutant EGFR dependencies, co-operative drivers, and molecular mechanisms that underlie sensitivity to EGFR inhibitors. Additionally, we offer perspective on how these discoveries may inform novel combination therapies tailored to EGFR mutant NSCLC.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1500
Author(s):  
Jing Zhu ◽  
Qian Yang ◽  
Weiguo Xu

Molecular targeted therapy has been reported to have fewer adverse effects, and offer a more convenient route of administration, compared with conventional chemotherapy. With the development of sequencing technology, and research on the molecular biology of lung cancer, especially whole-genome information on non-small cell lung cancer (NSCLC), various therapeutic targets have been unveiled. Among the NSCLC-driving gene mutations, epidermal growth factor receptor (EGFR) mutations are the most common, and approximately 10% of Caucasian, and more than 50% of Asian, NSCLC patients have been found to have sensitive EGFR mutations. A variety of targeted therapeutic agents for EGFR mutations have been approved for clinical applications, or are undergoing clinical trials around the world. This review focuses on: the indications of approved small molecular kinase inhibitors for EGFR mutation-positive NSCLC; the mechanisms of drug resistance and the corresponding therapeutic strategies; the principles of reasonable and precision molecular structure; and the drug development discoveries of next-generation inhibitors for EGFR.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 7010-7010 ◽  
Author(s):  
Joel W. Neal ◽  
Nathan A. Pennell ◽  
Ramaswamy Govindan ◽  
Michael Lanuti ◽  
Rachel Pam Greenerger Rosovsky ◽  
...  

7010 Background: Cancers with activating EGFR mutations are exquisitely sensitive to EGFR tyrosine kinase inhibitors (TKIs) and retrospective data suggests adjuvant TKIs may improve outcomes in EGFR mutants. This prospective trial investigates the safety and efficacy of adjuvant erlotinib in EGFR mutation-positive NSCLC. Methods: Patients (pts) with surgically resected stage IA-IIIA NSCLC harboring activating EGFR mutations were treated with 150 mg/day of erlotinib for 2 years (y) after completion of any standard adjuvant chemotherapy and/or radiotherapy. The trial was designed to enroll 36 patients, and powered to demonstrate a primary endpoint of 2 y disease free survival (DFS) exceeding 85%, which would suggest improvement over the historically expected 70% 2 y DFS in early stage EGFR-mutant NSCLC (J Thorac Oncol 6:569). Results: Thirty-six pts were enrolled at five sites between 1/08 and 11/09; 53% stage I; 19% stage II; 28% stage IIIA. Toxicities were typical of erlotinib; no grade 4 or 5 events or pneumonitis occurred. 8 pts (22%) required one dose reduction to 100 mg/day and 5 (14%) two reductions to 50 mg/day for grade 3 or persistent grade 2 toxicities. 11 pts discontinued before 2 full years (<1 month (mo) [4], 1-12 mo [2] and 12-23 mo [5]) for toxicities [6], patient preference [3], prostate cancer [1] and recurrence [1]. After a median follow-up of 2.5 y, the 2 y DFS from enrollment is 94% (95% CI 80%, 99%). 10 patients have recurred, 1 during erlotinib treatment and the others after stopping erlotinib (interval before recurrence 2 mo [1], 6-12 mo [4], >12 mo [4]). Genotyping on repeat biopsies from seven of the recurrent cases is underway, as is assessment of response to subsequent erlotinib therapy. Two pts have died of recurrence: one at 1.5 y who stopped erlotinib after 1 mo for toxicity, and one at 2 y who progressed while on erlotinib. Conclusions: This is the first prospective study to report the efficacy of adjuvant erlotinib in NSCLC pts with EGFR mutations. This approach is feasible and yields excellent 2y DFS compared to historical genotype-matched controls. This trial was subsequently expanded to 100 pts to permit subgroup analysis by stage.


2021 ◽  
pp. 477-482
Author(s):  
Miriam Blasi ◽  
Daniel Kazdal ◽  
Michael Thomas ◽  
Petros Christopoulos ◽  
Mark Kriegsmann ◽  
...  

Tyrosine kinase inhibitors (TKIs) represent the standard treatment for patients with non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations. The duration of the response is, however, limited in time owing to the development of resistance mechanisms to both first- and second-generation agents such as MET oncogene amplification. This report describes the successful results obtained with the combination of the third-generation TKI osimertinib with the multitargeted TKI and MET inhibitor crizotinib in a patient with EGFR-mutant NSCLC with emerging MET amplification with a tolerable toxicity profile.


Cancers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 434 ◽  
Author(s):  
Ming-Ju Tsai ◽  
Jen-Yu Hung ◽  
Mei-Hsuan Lee ◽  
Chia-Yu Kuo ◽  
Yu-Chen Tsai ◽  
...  

Patients with lung adenocarcinoma harboring common epidermal growth factor receptor (EGFR) mutations usually have a good response rate (RR) and longer progression-free survival (PFS) to EGFR tyrosine kinase inhibitors (TKIs). However, the treatment efficacy to uncommon EGFR mutations remains controversial. We, therefore, performed a retrospective study, screening 2958 patients. A total of 67 patients with lung adenocarcinoma harboring uncommon EGFR mutations were enrolled and 57 patients with stage IV diseases receiving a first-line EGFR TKI were included for further analyses. The patients were classified into 27 (47%) “a single sensitizing uncommon mutation”, 7 (12%) “multiple sensitizing mutations”, 5 (9%) “a sensitizing mutation and a resistant uncommon mutation”, and 18 (32%) “other resistant uncommon mutations”. No significant difference was noted in PFS or overall survival (OS) between groups. Patients receiving different first-line EGFR TKIs had similar PFS and OS. The elder patients had a significantly poorer performance status than the younger patients but a significantly longer PFS than the younger patients (median PFS: 10.5 vs. 5.5 months, p = 0.0320). In conclusion, this is the first study to identify that elderly patients with stage IV lung adenocarcinoma harboring uncommon EGFR mutation might have a longer PFS. Large-scale prospective studies are mandatory to prove our findings.


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