Notch inhibition overcomes resistance to tyrosine kinase inhibitors in EGFR-driven lung adenocarcinoma.
ABSTRACT: EGFR-mutated lung adenocarcinoma patients treated with gefitinib and osimertinib show a therapeutic benefit limited by the appearance of secondary mutations, such as EGFRT790M and EGFRC797S. It is generally assumed that these secondary mutations render EGFR completely unresponsive to the inhibitors, but contrary to this, we uncovered here that gefitinib and osimertinib increased STAT3 phosphorylation (p-STAT3) in EGFRT790M and EGFRC797S tumoral cells. Interestingly, we also found that concomitant Notch inhibition with gefitinib or osimertinib treatment induced a p-STAT3-dependent strong reduction in the levels of the transcriptional repressor HES1. Importantly, we showed that tyrosine kinase inhibitor-resistant tumors, with EGFRT790M and EGFRC797S mutations, were highly responsive to the combined treatment of Notch inhibitors with gefitinib or osimertinib, respectively. Finally, in patients with EGFR mutations treated with tyrosine kinase inhibitors, HES1 protein levels increased during relapse and correlated with shorter progression-free survival. Therefore, our results offer a proof of concept for an alternative treatment to chemotherapy in lung adenocarcinoma osimertinib-treated patients after disease progression.
Project description:The discovery of mutations in EGFR significantly changed the treatment paradigm of patients with EGFR-mutant non-small cell lung cancer (NSCLC), a particular group of patients with different clinical characteristics and outcome to EGFR-wild-type patients. In these patients, the treatment of choice as first-line therapy is first- or second-generation EGFR-tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib, erlotinib, or afatinib. Inevitably, after the initial response, all patients become refractory to these drugs. The most common mechanism of acquired resistance to EGFR-TKIs is the development of a second mutation in exon 20 of EGFR (T790M). Osimertinib is a third-generation EGFR-TKI designed for overcoming T790M-mediated resistance. Based on the results of efficacy and tolerability of Phase II and Phase III studies, osimertinib has been approved for treatment of advanced EGFRT790M+ mutation NSCLC following progression on a prior EGFR-TKI. Occurrence of acquired resistance to osimertinib represents an urgent need for additional strategies including combination with other agents, such as other targeted therapies or checkpoint inhibitors, or development of new and more potent compounds.
Project description:The emergence of acquired resistance against targeted drugs remains a major clinical challenge in lung adenocarcinoma patients. In a subgroup of these patients we identified an association between selection of EGFRT790M-negative but EGFRG724S-positive subclones and osimertinib resistance. We demonstrate that EGFRG724S limits the activity of third-generation EGFR inhibitors both in vitro and in vivo. Structural analyses and computational modeling indicate that EGFRG724S mutations may induce a conformation of the glycine-rich loop, which is incompatible with the binding of third-generation TKIs. Systematic inhibitor screening and in-depth kinetic profiling validate these findings and show that second-generation EGFR inhibitors retain kinase affinity and overcome EGFRG724S-mediated resistance. In the case of afatinib this profile translates into a robust reduction of colony formation and tumor growth of EGFRG724S-driven cells. Our data provide a mechanistic basis for the osimertinib-induced selection of EGFRG724S-mutant clones and a rationale to treat these patients with clinically approved second-generation EGFR inhibitors.
Project description:Osimertinib is a novel, irreversible, mutant-selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor targeting EGFR mutations and the EGFR T790 mutation. Here, we report a woman with EGFR-mutated lung adenocarcinoma who, after 23-month treatment with gefitinib, developed the EGFR T790M mutation, which converted the T790M status from positive to negative before osimertinib treatment and developed MET amplification, leading to rapid progression on osimertinib in two months. Subsequent treatment with crizotinib and c-Met inhibitor plus gefitinib also failed to improve the clinical outcome, suggesting the potential existence of another resistance mechanism. Our findings revealed the underlying multiple and heterogeneous mechanisms in resistance to osimertinib, suggesting combination strategies should be considered post-osimertinib progression.
Project description:In Taiwan, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs), gefitinib, erlotinib, and afatinib are served as first-line therapy for non-small lung cell cancer (NSCLC) patients with EGFR sensitizing mutations. However, the majority of patients who initially respond to EGFR-TKIs, progress through acquiring EGFR T790M mutations (T790M), which is the most common resistant mechanism. Patients with T790M gain the opportunity of subsequent treatment with third-generation EGFR-TKI, osimertinib. This study aimed to evaluate the association between prior EGFR-TKI therapy and incidence of acquired T790M resistance in lung adenocarcinoma patients who have progressed on first/second-generation EGFR-TKI therapy. This retrospective study included lung adenocarcinoma patients who had a radiographically-confirmed progressive disease under EGFR-TKI treatment and had re-biopsy samples for T790M testing from seven medical centers in Taiwan from June 2013 to December 2018. Patients harboring de novo T790M or using more than one EGFR-TKI were excluded. Of the 407 patients enrolled, the overall T790M acquisition rate was 52.8%. The patients treated with gefitinib, erlotinib or afatinib had a statistically significant difference in the T790M rates (59.9, 45.5, and 52.7%, respectively; p = 0.037) after disease progression. Patients with common baseline EGFR mutations (Del-19 and L858R) (p = 0.005) and longer treatment duration with EGFR-TKIs (p < 0.001) had higher chances of T790M acquisition. Multivariate logistic regression analysis further showed that patients with common baseline EGFR mutations, gefitinib (compared to erlotinib) administration, and longer treatment duration with EGFR-TKIs had higher T790M incidence. There was no significant difference in the incidence of acquired T790M between different re-biopsy tissue samples or complications. In conclusion, this study showed that patients who progressed from gefitinib treatment, bearing common EGFR mutations, and with longer EGFR-TKI treatment duration had increased incidence of T790M acquisition and, therefore, were suitable for subsequent osimertinib treatment.
Project description:Patients with non-small-cell lung cancer (NSCLC) harboring activating mutations in EGFR benefit from treatment with EGFR small-molecule tyrosine-kinase inhibitors. However, the development of acquired resistance to EGFR inhibitors is universal and limits treatment efficacy. Over half of patients receiving first-generation EGFR inhibitors (erlotinib and gefitinib) develop resistance via the gatekeeper EGFR T790M (EGFRT790M) mutation, and therapies able to overcome T790M-mediated resistance have been an unmet need in NSCLC. Rociletinib (CO-1686) is a third-generation small-molecule EGFR inhibitor with potent activity against EGFRT790M currently in advanced clinical development in NSCLC. Early clinical data suggested significant activity in EGFR-mutant NSCLC harboring T790M alterations. However, important questions regarding side-effect profile, comparability to competitor compounds, acquired resistance, EGFR-therapy sequencing, and combination therapies remain. Here, we review the available preclinical and clinical data for rociletinib, highlight the comparison to other third-generation EGFR inhibitors, and discuss resistance implications and future directions in NSCLC.
Project description:Background:EGFR-tyrosine kinase inhibitors (EGFR-TKIs) including afatinib, dacomitinib, erlotinib, gefitinib, and osimertinib have proven efficacy in terms of progression-free survival (PFS) in patients with non-small-cell lung cancer (NSCLC) harboring EGFR mutations. However, an overall view for comparing efficacy and toxicity on a meta-level is lacking. This study compared efficacy and toxicity of first-line treatment with five different EGFR-TKIs by conducting a network meta-analysis (NMA). Methods:A systematic review was performed, aiming to find eligible literature. Data of PFS, overall survival (OS), objective response rate (ORR), and adverse events were extracted. An NMA based on Bayesian statistics was established to synthesize the efficacy and toxicity of all treatments. Results:Thirteen randomized controlled trials, including data from 3,539 patients with EGFR-mutated NSCLC, were analyzed. Rank probabilities showed that osimertinib had a potentially better efficacy in terms of PFS and OS compared to all other TKIs. For ORR, afatinib and osimertinib showed a trend of superiority compared to the other four TKIs. Furthermore, there was a high risk of diarrhea and rash for patients treated with afatinib or dacomitinib as well as a moderate risk for treatment with erlotinib, gefitinib, and osimertinib. Conclusion:Our study showed a favorable efficacy of osimertinib in terms of PFS and OS compared to all other EGFR-TKIs in patients with NSCLC harboring activating EGFR mutations. Furthermore, gefitinib, erlotinib, and osimertinib were associated with fewer toxicities compared to the other TKIs. Therefore, osimertinib is indicated as a preferable first-line TKI in patients with activating EGFR-mutated NSCLC.
Project description:BACKGROUND:Non-small cell lung cancer (NSCLC) patients with sensitive epidermal growth factor receptor (EGFR) mutations are successfully treated with EGFR tyrosine kinase inhibitors (EGFR-TKIs); however, resistance to treatment inevitably occurs. Given lipid metabolic reprogramming is widely known as a hallmark of cancer and intimately linked with EGFR-stimulated cancer growth. Activation of EGFR signal pathway increased monounsaturated fatty acids (MUFA) and lipid metabolism key enzyme Stearoyl-CoA Desaturase 1 (SCD1) expression. However the correlation between EGFR-TKI resistance and lipid metabolism remains to be determined. METHODS:In this study the differences in lipid synthesis between paired TKI-sensitive and TKI-resistant patient tissues and NSCLC cell lines were explored. Oleic acid (OA, a kind of MUFA, the SCD1 enzymatic product) was used to simulate a high lipid metabolic environment and detected the affection on the cytotoxic effect of TKIs (Gefitinib and osimertinib) in cell lines with EGFR-activating mutations. (20S)-Protopanaxatriol (g-PPT), an aglycone of ginsenosides, has been reported to be an effective lipid metabolism inhibitor, was used to inhibit lipid metabolism. Additionally, synergism in cytotoxic effects and signal pathway activation were evaluated using CCK-8 assays, Western blotting, flow cytometry, Edu assays, plate clone formation assays and immunofluorescence. Furthermore, two xenograft mouse models were used to verify the in vitro results. RESULTS:Gefitinib-resistant cells have higher lipid droplet content and SCD1 expression than Gefitinib-sensitive cells in both NSCLC cell lines and patient tissues. Additionally oleic acid (OA, a kind of MUFA, the SCD1 enzymatic product) abrogates the cytotoxic effect of both Gefitinib and osimertinib in cell lines with EGFR-activating mutations. As a reported effective lipid metabolism inhibitor, g-PPT significantly inhibited the expression of SCD1 in lung adenocarcinoma cells, and then down-regulated the content of intracellular lipid droplets. Combined treatment with Gefitinib and g-PPT reverses the resistance to Gefitinib and inhibits the activation of p-EGFR and the downstream signaling pathways. CONCLUSIONS:Our findings uncover a link between lipid metabolic reprogramming and EGFR-TKI resistance, confirmed that combination target both EGFR and abnormal lipid metabolism maybe a promising therapy for EGFR-TKI resistance and highlighting the possibility of monitoring lipid accumulation in tumors for predicting drug resistance.
Project description:A growing number of progression on Osimertinib among <i>EGFR</i>-mutated lung cancers represents a great challenge clinically. Our study aims to gain insights into novel mechanisms of acquired resistance to Osimertinib. We performed genomic studies on 2 large independent cohorts of lung cancer patients with progressed diseases on different tyrosine kinase inhibitors (TKIs). <i>In silico</i> modeling was used to study the structural mechanism of selected EGFR mutations. Compared with the 1<sup>st</sup>-TKIs-resistant group, <i>EGFR</i> mutations C797S/G, L718Q/V, L792F/H were significantly more enriched in the Osimertinib-resistant cohort, whose sensitivities to Osimertinib were successfully predicted. Importantly, a total of 14 low-frequency <i>EGFR</i> mutations were exclusively or significantly observed in the Osimertinib-resistant group, 7 were predicted to dramatically reduce the binding affinity of EGFR to Osimertinib (G796S, V802F, T725M, Q791L/H, P794S/R). Analysis of pre-Osimertinib treatment samples of two patients supported that <i>EGFR</i> V802F and G796S were acquired during the treatment. In addition, <i>EGFR</i> G796S was predicted to be susceptible to gefitinib. This study represented the largest real-world data so far investigating Osimertinib resistance in <i>EGFR</i>-mutated lung cancer. We identified a collection of coexistent EGFR rare mutations and provided possible guidance for those patients who progressed on the first-line treatment of Osimertinib.
Project description:Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are effective in non-small cell lung cancer (NSCLC) patients harboring EGFR mutations. However, due to the acquired resistance to EGFR-TKIs, even third generation Osimertinib, the patients suffer poor prognosis. The resistance mechanisms are still not fully understood. Here, we demonstrate that increased expression of MUSASHI-2 (MSI2), an RNA binding protein, is novel mechanisms for resistance to EGFR-TKIs. We found that after long-exposure of gefitinib, the first generation EGFR-TKI, lung cancer cells harboring the EGFR-TKI-sensitive mutations became resistant to not only gefitinib but also Osimertinib. Although other mutations in EGFR were not found, expression levels of Nanog, a stemness core protein, and activities of aldehyde dehydrogenase (ALDH) were increased, suggesting that cancer stem-like properties were increased. Transcriptome analysis revealed that MSI2 was among the top list of the stemness-related genes upregulated in the EGFR-TKI-resistant cells. Knockdown of MSI2 reduced cancer stem-like properties, including expression levels of Nanog a core stemness factor. We demonstrate that knockdown of MSI2 restored sensitivity to Osimertinib or gefitinib in the EGFR-TKI-resistant cells to the similar levels of the parental cells in vitro. RNA immunoprecipitation (RIP) assay revealed that antibodies against MSI2 bound to Nanog mRNA, suggesting that MSI2 increases Nanog expression by binding to Nanog mRNA. Moreover, overexpression of MSI2 or Nanog conferred resistance to Osimertinib or gefitinib in parental cells. Finally, knockdown of MSI2 greatly increased sensitivity to Osimertinib in vivo. Collectively, our findings provide proof-of-principle that targeting MSI2-Nanog axis in combination with EGFR-TKIs would effectively prevent emergence of acquired resistance. Overall design: Comaprison in ALDH-high cell populations between PC9 cells and PC9M2 cells.There are four biological replicates for each conditions.
Project description:INTRODUCTION:The clinical efficacy of osimertinib for patients with lung adenocarcinoma harboring epidermal growth factor receptor (EGFR) exon 20 insertion mutations is unclear. Few case reports exist on the successful treatment of such tumors with osimertinib. We report a case wherein osimertinib administration had no effect in a patient with EGFR exon 20 insertion-positive lung adenocarcinoma. PATIENT CONCERNS:A 48-year-old never-smoking woman was referred to our hospital for chronic cough. Computed tomography (CT) and positron emission tomography-CT revealed a nodule in the right middle lobe, consolidation in the right upper lobe, multiple lymph node metastases, liver metastasis, and multiple bone metastases. DIAGNOSIS:On the basis of further examination using transbronchial lung biopsy, the patient was diagnosed with cT1N3M1 stage IVB lung adenocarcinoma. An EGFR exon 20 insertion, without any additional mutations, was identified. INTERVENTIONS:Daily oral administration of 80?mg osimertinib was initiated to treat the EGFR exon 20 insertion-positive lung adenocarcinoma. OUTCOMES:Although the disease appeared to be stable 2.5 months after the administration of osimertinib, the tumor started to grow 3 months after administration, and carcinoembryonic antigen levels became higher than those before treatment. Thus, osimertinib was discontinued, and treatment with carboplatin as well as pemetrexed and bevacizumab was started, which the patient responded to. CONCLUSION:EGFR exon 20 insertion mutations must be classified in more detail to assess the efficacy of EGFR tyrosine kinase inhibitors. Osimertinib doses that provide favorable therapeutic windows should be considered. Further clinical research is required to clarify the efficacy of osimertinib and other drugs for exon 20 insertion mutations.