Project description:Most patients with non-small cell lung cancer (NSCLC) harboring common epidermal growth factor receptor (EGFR) mutations, such as deletions in exon 19 or the L858R mutation in exon 21, respond dramatically to EGFR tyrosine kinase inhibitors (EGFR-TKI), and their sensitivities to various EGFR-TKI have been well characterized. Our previous article showed the in vitro sensitivities of EGFR exon 18 mutations to EGFR-TKI, but little information regarding the sensitivities of other uncommon EGFR mutations is available. First, stable transfectant Ba/F3 cell lines harboring EGFR L858R (Ba/F3-L858R), L861Q (Ba/F3-L861Q) or S768I (Ba/F3-S768I) mutations were created and their drug sensitivities to various EGFR-TKI were examined. Both the Ba/F3-L861Q and Ba/F3-S768I cell lines were less sensitive to erlotinib, compared with the Ba/F3-L858R cell line, but their sensitivities to afatinib were similar to that of the Ba/F3-L858R cell line. The Ba/F3-L861Q cell line was similarly sensitive and the Ba/F3-S768I cell line was less sensitive to osimertinib, compared with the Ba/F3-L858R cell line. The results of western blot analyses were consistent with these sensitivities. Next, similar experiments were also performed using the KYSE270 (L861Q) and KYSE 450 (S768I) cell lines, and their results were compatible with those of the transfectant Ba/F3 cell lines. Our findings suggest that NSCLC harboring the EGFR L861Q mutation might be sensitive to afatinib or osimertinib and that NSCLC harboring the EGFR S768I mutation might be sensitive to afatinib. Overall, afatinib might be the optimal EGFR-TKI against these uncommon EGFR mutations.
Project description:EGFR mutations identify patients who are more likely to respond to treatment with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) than cytotoxic chemotherapy. The distinct success of the first-generation EGFR TKIs erlotinib and gefitinib has been accompanied by the observation that acquired resistance to these treatments develops after a median of 1 year of treatment. Newer, second-generation EGFR TKIs have been developed with the intent to delay or overcome acquired resistance by the broader inhibition of kinases (eg, HER2 and vascular endothelial growth factor receptor) and/or altering the interactions with EGFR through irreversibly binding to the kinase domain. This article discusses many of these agents (including afatinib, dacomitinib, XL647, AP26113, and CO-1686) which have the potential for greater efficacy compared with first-generation EGFR TKIs, and may also have clinical activity against other oncogenic mutations within the EGFR family, including HER2.
Project description:First-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), including gefitinib and erlotinib, have proven to be highly effective agents for advanced non-small cell lung cancer (NSCLC) in patients harboring an activating EGFR mutation such as the exon 19 deletion mutation and L858R. Although those reversible small molecular targeted agents provide a significant response and survival benefit, all responders eventually acquire resistance. Second-generation EGFR-targeting agents, such as irreversible EGFR/HER2 tyrosine kinase inhibitors and pan-HER TKIs, may improve survival further and be useful for patients who acquired resistance to first-generation EGFR-TKIs. This review discusses novel therapeutic strategies for EGFR-mutated advanced NSCLC using first- and second-generation EGFR-TKIs.
Project description:Tumours with sensitizing mutations in the EGFR gene constitute a distinct molecular subgroup of non-small-cell lung cancers (nsclcs) that benefit from precision medicine. First- and second-generation epidermal growth factor receptor (egfr) tyrosine kinase inhibitors (tkis) are recommended as upfront therapy for EGFR-mutated advanced nsclc and, compared with chemotherapy, have resulted in superior progression-free survival, improved tumour response rates, and improved quality of life. However, resistance inevitably develops, and the third-generation tki osimertinib has been approved to target the gatekeeper EGFR mutation T790M, which is responsible for resistance in 60% of cases. Multiple drivers of tki resistance have now been identified, and many new drugs are in development. With respect to this rapidly evolving field, our review highlights the current status of treatment options for patients with EGFR-mutated advanced nsclc, focusing especially on identified causes of resistance, challenges, and clinical trials aiming to improve outcomes in this patient population.
Project description:The body of evidence investigating human epidermal growth factor receptor-2 (HER2) directed therapy in patients with breast cancer (BC) has been growing within the last decade. Recently, the use of tyrosine kinase inhibitors (TKIs) has been of particular interest in the treatment of human malignancies. This literature commentary is intended to highlight the most recent findings associated with the widely-studied TKI agents and their clinical significance in improving the outcomes of HER2 positive BC.
Project description:BackgroundEpidermal growth factor receptor (EGFR) mutations in non-small-cell lung cancer predict sensitivity to EGFR tyrosine kinase inhibitors (TKIs). EGFR mutation types are associated with efficacy of EGFR TKIs. We investigated the clinical outcomes of afatinib, erlotinib, and gefitinib according to EGFR mutation type in patients with lung adenocarcinoma.MethodsBetween May 2010 and December 2018, we investigated 363 patients with advanced lung adenocarcinoma harboring EGFR mutations who received EGFR TKIs. Efficacies of EGFR TKIs such as response rate, progression-free survival (PFS), and overall survival (OS) were retrospectively evaluated according to exon 19 deletion (E19del), L858R point mutation (L858R) and uncommon mutations.ResultsThe frequency of E19del was 48.2%, that of L858R was 42.4%, and that of uncommon mutations was 9.4%. E19del and L858R were associated with superior PFS and OS compared with uncommon mutations. Erlotinib showed significantly inferior OS than other TKIs (30.8 ± 3.3 in erlotinib vs. 39.1 ± 4.3 in afatinib vs. 48.4 ± 6.3 in gefitinib; p = 0.031) in patients with L858R. Gefitinib showed significantly inferior PFS (4.6 ± 1.1 in gefitinib vs. 11.6 ± 2.7 in afatinib vs. 10.6 ± 2.7 in erlotinib; p = 0.049) in patients with uncommon mutations.ConclusionAfatinib was significantly associated with a longer PFS, presenting constant effectiveness in all EGFR mutation types. Caution may be needed on the use of erlotinib for L858R and the use of gefitinib for uncommon EGFR mutations.
Project description:Next-generation sequencing (NGS) of tumor samples and circulating tumor DNA has revolutionized diagnostic and therapeutic strategies in lung cancer. The identification of the epidermal growth factor receptor (EGFR) oncogenic driver has translated into successful therapy of advanced lung cancer using EGFR tyrosine kinase inhibitors (TKI). Unfortunately, responses are limited by acquired mechanisms of resistance. We review herein the current landscape of acquired resistance mechanisms to EGFR-TKI therapy and recent advances in therapeutic strategies to overcome acquired resistance.
Project description:PurposeEGFR-mutant lung cancer was first described as a new clinical entity in 2004. Here, we present an update on new controversies and conclusions regarding the disease.MethodsThis article reviews the clinical implications of EGFR mutations in lung cancer with a focus on epidermal growth factor receptor tyrosine kinase inhibitor resistance.ResultsThe discovery of EGFR mutations has altered the ways in which we consider and treat non-small-cell lung cancer (NSCLC). Patients whose metastatic tumors harbor EGFR mutations are expected to live longer than 2 years, more than double the previous survival rates for lung cancer.ConclusionThe information presented in this review can guide practitioners and help them inform their patients about EGFR mutations and their impact on the treatment of NSCLC. Efforts should now concentrate on making EGFR-mutant lung cancer a chronic rather than fatal disease.
Project description:The Lung Adjuvant Cisplatin Evaluation (LACE) meta-analysis and the meta-analysis of individual participant data reported by non-small cell lung cancer (NSCLC) Meta-analysis Collaborative Group in neo-adjuvant setting validated respectively that adjuvant and neoadjuvant chemotherapy would significantly improve overall survival (OS) and recurrence-free survival for resectable NSCLC. However, chemotherapy has reached a therapeutic plateau. It has been confirmed that epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) targeting therapy provides a dramatic response to patients with advanced EGFR-mutation positive NSCLC. Researchers have paid more attention to exploring applications of TKIs to early resectable NSCLCs. Several studies on adjuvant TKI treatment concluded its safety and feasibility. But there existed certain limitations of these studies as inference factors to interpret data accurately: the BR19 study recruited patients among which almost 52% had stage IB and only 15 (3.0%, 15/503) had been confirmed with EGFR-mutant type; retrospective studies performed at Memorial Sloan Kettering Cancer Center (MSKCC) selected EGFR mutant-type NSCLC patients but couldn't avoid inherent defects inside retrospective researches; the RADIANT study revised endpoints from targeting at EGFR immunohistochemistry (IHC)+ and/or fluorescence in situ hybridization (FISH)+ mutation to only EGFR IHC+ mutation, leading to selective bias; despite that the SELECT study validated efficacy of adjuvant TKI and second round of TKI after resistance occurred, a single-arm clinical trial is not that persuasive in the absence of comparison with chemotherapy. Taking all these limitations into account, CTONG1104 in China and IMPACT in Japan have been conducted and recruiting patients to offer higher level of evidences to explore efficacy of preoperative TKI therapy for early resectable EGFR mutation positive NSCLC patients (confirmed by pathological results of tumor tissue or lymph node biopsy). On the other hand, case reports and several phase II clinical trials with small sample size tried to elbow their way on respect of preoperative TKI treatment and advised that TKI tended to improve response rate. However, no data on survival rate was present. The first phase II study of biomarker-guided neoadjuvant therapy for stage IIIA-N2 NSCLC patients stratified by EGFR mutation status, sponsored by CSLC0702, showed erlotinib tended to improve response rate, but failed to show benefits of disease-free survival (DFS) or OS. Subsequently, CTONG1103 was designed to investigate efficacy of erlotinib vs. combination of gemcitabine/cisplatin (GC) as neoadjuvant treatment in stage IIIA-N2 NSCLC with sensitizing EGFR mutation in exon 19 or 21. All these ongoing trials should be worthy of our expect to provide convincing evidences for customized therapy for patients with resectable NSCLC.
Project description:Most advanced non-small-cell lung cancers (NSCLCs) with activating epidermal growth factor receptor (EGFR) mutations (exon 19 deletions or L858R) initially respond to the EGFR tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib. However, over time (median of 6-12 months), most tumors develop acquired resistance to EGFR TKIs. Intense research in these NSCLCs has identified two major mechanisms of resistance to gefitinib/erlotinib: secondary resistance mutations and "oncogene kinase switch" systems. The secondary T790M mutation occurs in 50% of EGFR-mutated patients with TKI resistance, and in vitro, this mutation negates the hypersensitivity of activating EGFR mutations. Sensitive detection methods have identified a proportion of TKI-naive tumors that carry T790M, and these resistant clones may be selected after exposure to gefitinib or erlotinib. Other secondary resistance mutations (D761Y, L747S, T854A) seem to be rare. The amplification of the MET oncogene is present in 20% of TKI-resistant tumors; however, in half of the cases with this "oncogene kinase switch" mechanism the T790M is coexistent. It is possible that other kinases (such as insulin-like growth factor-1 receptor [IGF-1R]) might also be selected to bypass EGFR pathways in resistant tumors. The growing preclinical data in EGFR-mutated NSCLCs with acquired resistance to gefitinib or erlotinib has spawned the initiation or conception of clinical trials testing novel EGFR inhibitors that in vitro inhibit T790M (neratinib, XL647, BIBW 2992, and PF-00299804), MET, or IGF-1R inhibitors in combination with EGFR TKIs, and heat shock protein 90 inhibitors. Ongoing preclinical and clinical research in EGFR-mutated NSCLC has the potential to significantly improve the outcomes of patients with these somatic mutations.