Project description:Osimertinib, an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), potently and selectively inhibits EGFR-TKI-sensitizing and EGFR T790M resistance mutations. In the Phase III FLAURA study (NCT02296125), first-line osimertinib improved outcomes vs comparator EGFR-TKIs in EGFRm advanced non-small cell lung cancer. This analysis identifies acquired resistance mechanisms to first-line osimertinib. Next-generation sequencing assesses circulating-tumor DNA from paired plasma samples (baseline and disease progression/treatment discontinuation) in patients with baseline EGFRm. No EGFR T790M-mediated acquired resistance are observed; most frequent resistance mechanisms are MET amplification (n = 17; 16%) and EGFR C797S mutations (n = 7; 6%). Future research investigating non-genetic acquired resistance mechanisms is warranted.
Project description:ImportanceThe survival of patients with advanced non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) gene mutations has improved substantially in the last decade with the development of targeted tyrosine kinase inhibitors (TKIs). Osimertinib, a third-generation TKI that is approved by the US Food and Drug Administration for the treatment of patients who develop EGFR T790M mutations, has recently shown improved clinical outcomes compared with gefitinib and erlotinib for treatment-naive patients.ObjectiveThe aim of this study was to assess the cost-effectiveness of osimertinib for the first-line treatment of patients with EGFR-mutated NSCLC.Design, setting, and participantsFor this cost-effectiveness analysis, we extracted individual patient data from the FLAURA randomized clinical trial and used findings of our earlier meta-analysis to develop a decision-analytic model and determine the cost-effectiveness of osimertinib (AZD9291) compared with first- and second-generation EGFR-TKIs over a 10-year time horizon. All direct costs were based on US and Brazilian payer perspectives.Main outcomes and measuresThe main outcome of this study was the incremental cost-effectiveness ratio (ICER) expressed as cost per quality-adjusted life-year (QALY) gained by using osimertinib compared with first- or second-generation EGFR-TKIs in previously untreated EGFR-mutated NSCLC.ResultsIn the base case using the data as reported in the FLAURA trial, the incremental QALY for osimertinib was 0.594 compared with the first- and second-generation EGFR-TKIs. In the United States, the osimertinib ICERs were $226 527 vs erlotinib, $231 123 vs gefitinib, and $219 874 vs afatinib. In Brazil, the ICERs were $162 329, $180 804, and $175 432, respectively. The overall survival (95% CI) reported in the FLAURA trial (hazard ratio, 0.63; 95% CI, 0.45-0.88) had the strongest association with the ICER (ranging from $84 342 to $859 771). Osimertinib price adjustments to the FLAURA trial data improved cost-effectiveness. For example, a discount of 10% on osimertinib acquisition cost was associated with a 20% decreased ICER compared with the base case ICER, and a discount of 20% on osimertinib acquisition cost was associated with a 40% decreased ICER compared with the base case ICER.Conclusions and relevanceAt current costs, by World Health Organization cost-effectiveness threshold criteria, osimertinib is not cost-effective for first-line therapy of EGFR-mutated NSCLC in either the United States or Brazil.
Project description:BackgroundThe FLAURA trial demonstrated improved overall survival (OS) with first-line osimertinib for patients with epidermal growth factor receptor (EGFR)-mutated advanced non-small cell lung cancer (NSCLC). We studied the efficacy and safety of osimertinib in a cohort treated during the coronavirus disease 2019 (COVID-19) pandemic.MethodsPatients diagnosed with EGFR-mutated advanced NSCLC between 11 March 2020 to 31 December 2021 who received first-line osimertinib in British Columbia, Canada were identified retrospectively. Kaplan-Meier curves of OS and progression-free survival (PFS) from the start of osimertinib were plotted. The associations of baseline characteristics with PFS, and development of pneumonitis or dose reductions due to toxicity with OS were evaluated with hazard ratios estimated using univariable and multivariable Cox models.ResultsThe cohort comprised 231 individuals. 58.7% of patients with de novo advanced NSCLC were initially diagnosed after presentation to the Emergency Room. At osimertinib initiation, 31.6% were aged ≥75 years and 45.5% had an Eastern Cooperative Oncology Group performance status (ECOG PS) ≥2. Median PFS and OS were 18.0 months [95% confidence interval (CI): 16.1-26.2] and 25.4 months (95% CI: 20.3-not reached), respectively. On multivariable analysis, age ≥75 years (vs. <75), ECOG PS 2/3 (vs. 0/1), ECOG PS 4 (vs. 0/1), current smokers (vs. never smokers), programmed death ligand 1 (PD-L1) expression ≥50% (vs. <1%), and L858R mutation (vs. exon 19 deletion) were associated with shorter PFS. Among 110 patients who progressed, 33.6% received subsequent therapy. A proportion of 16.5% of the cohort developed grade ≥3 adverse events. Pneumonitis from osimertinib (3.9% incidence) was weakly associated with shorter OS (hazard ratio: 2.59, 95% CI: 0.94-7.12, P=0.066); dose reductions were not associated with worse OS. 10.8% of patients developed COVID-19.ConclusionsIn a cohort receiving first-line osimertinib during the COVID-19 pandemic, ECOG PS ≥2 was observed in nearly half of patients at treatment initiation contributing to a median OS shorter than in FLAURA. The incidence of severe adverse events was low and dose reduction for drug toxicity did not impact OS. Identifying and reducing barriers to the diagnosis of NSCLC during the COVID-19 pandemic are required.
Project description:Osimertinib, a third-generation EGFR TKI, is the standard therapy for previously untreated EGFR-mutated non-small cell lung cancer patients following the landmark FLAURA study. However, resistance inevitably hinders patient prognosis, increasing the need for new therapeutic strategies beyond osimertinib. Frontline osimertinib-based combination strategies (platinum-based chemotherapy and angiogenesis inhibitors) are currently being tested primarily to prevent initial resistance. In the later-line setting after osimertinib, many next-line therapeutic candidates have been actively examined in clinical trials. Notably, several drugs with novel mechanisms of action, such as antibody-drug conjugates and EGFR -MET bispecific antibodies, have shown promising efficacy despite the resistance mechanisms and are close to clinical application. In addition, genotype-based target strategies have been investigated for a better understanding of osimertinib resistance mechanisms based on molecular profiling tests at relapse. The C797S mutation and MET gene alterations are commonly identified following osimertinib resistance, for which targeting strategies are actively tested. This review describes current pharmacotherapeutic strategies for EGFR-mutated non-small cell lung cancer based on the results of clinical trials and the latest published data, broadly grouped into two sections: 1) EGFR TKIs-based combination therapy in the front-line setting and 2) novel therapeutic strategies after osimertinib resistance.
Project description:BACKGROUND:It remains unknown which is the optimal first-line treatment regimen for patients with advanced epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC). We performed a network meta-analysis to address this important issue. METHODS:PubMed, Embase, Cochrane Library, Web of Science and major international scientific meetings were searched for relevant randomized controlled trials (RCTs). Progression-free survival (PFS) data was the primary outcome of interest, and overall survival (OS) and serious adverse events (SAEs) were the secondary outcomes of interests, reported as hazard ratio (HR) or odds ratio (OR) and 95% confidence intervals (CIs). RESULTS:25 RCTs with a total of 5005 patients randomized to receive seven treatments were included in the meta-analysis. Third-generation tyrosine kinase inhibitor (TKI) (osimertinib) and first-generation TKIs (F-TKIs) in combination with chemotherapy (F-TKIs+CT) were more effective than F-TKIs alone in terms of PFS (HR = 0.46, 95% CI: 0.22-0.93; P = 0.031 and HR = 0.62, 95% CI: 0.39-0.98; P = 0.041) and OS (HR = 0.63, 95% CI: 0.43-0.91; P = 0.014 and HR = 0.73, 95% CI: 0.57-0.92; P = 0.008). Second-generation TKIs (S-TKIs) showed significant OS advantage over F-TKIs (HR = 0.83, 95% CI: 0.70-0.99; P = 0.04). Based on treatment ranking in terms of PFS and OS, osimertinib had the highest probability of being the most effective treatment (89% and 86%) and with the best tolerability. F-TKIs+CT was ranked the second-most effective regimen, but with relatively high risk of SAEs. CONCLUSIONS:Osimertinib seemed to be the most preferable first-line treatment in advanced EGFR-mutated NSCLC. However, limitations of the study including a single RCT investigating osimertinib and immature OS data need to be considered.
Project description:Osimertinib is an irreversible, third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that is highly selective for EGFR-activating mutations as well as the EGFR T790M mutation in patients with advanced non-small cell lung cancer (NSCLC) with EGFR oncogene addiction. Despite the documented efficacy of osimertinib in first- and second-line settings, patients inevitably develop resistance, with no further clear-cut therapeutic options to date other than chemotherapy and locally ablative therapy for selected individuals. On account of the high degree of tumour heterogeneity and adaptive cellular signalling pathways in NSCLC, the acquired osimertinib resistance is highly heterogeneous, encompassing EGFR-dependent as well as EGFR-independent mechanisms. Furthermore, data from repeat plasma genotyping analyses have highlighted differences in the frequency and preponderance of resistance mechanisms when osimertinib is administered in a front-line versus second-line setting, underlying the discrepancies in selection pressure and clonal evolution. This review summarises the molecular mechanisms of resistance to osimertinib in patients with advanced EGFR-mutated NSCLC, including MET/HER2 amplification, activation of the RAS-mitogen-activated protein kinase (MAPK) or RAS-phosphatidylinositol 3-kinase (PI3K) pathways, novel fusion events and histological/phenotypic transformation, as well as discussing the current evidence regarding potential new approaches to counteract osimertinib resistance.
Project description:BackgroundAlthough the clinical application of osimertinib, a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), has been a new step forward in the first-line treatment of non-small cell lung cancer (NSCLC), an increasing number of patients with progression on osimertinib represents a great challenge clinically. The patterns of resistance mechanisms and subsequent treatment strategies after first-line osimertinib resistance are not well established.MethodsBetween January 1, 2016 and October 31, 2020, a consecutive of 56 EGFR-mutant lung cancer patients treated with osimertinib as first-line therapy at Daping Hospital (Chongqing, China) were retrospective screened. The samples of pre-osimertinib and osimertinib-resistance were all detected by next-generation sequencing (NGS) panels. Statistical analyses were carried out using SPSS 23.0 software. Survival analyses were performed using the Kaplan-Meier method and compared using a log-rank test between groups.ResultsAmong 47 patients with osimertinib effectiveness analysis, the median progression free survival (mPFS) was 15.4 months (95% confidence interval [CI]: 12.2-24.9 months), and median overall survival (mOS) was 35.5 months (95% CI: 23.9 months -NA). A total of 21 patients underwent repeated NGS tests upon osimertinib resistance. MET amplification was the most common resistance mechanism (6/21, 28.6%), followed by C797S mutation (5/21, 23.8%). A total of 15 patients received subsequent treatments, with mPFS of 7.3 months (95% CI 5.0 months -NA). Among them, 7 patients with EGFR C797 S or/and MET amplification received subsequent second-line targeted therapy, achieving mPFS of 7.3 months (95% CI 4.5 months -NA). Of note, 3 patients received immunotherapy as second- or third-line treatment after osimertinib resistance, achieving median clinical benefit of 37.3 months.ConclusionsMET amplification and C797S mutation are main resistance mechanisms, which could be targeted by crizotinib and gefitinib, respectively. More than 50% patients could receive subsequent anticancer targetable therapies after first-line osimertinib resistance. Immunotherapy may also be an acceptable choice after osimertinib resistance.
Project description:PurposeTo assess the utility of the cobas EGFR Mutation Test, with tissue and plasma, for first-line osimertinib therapy for patients with EGFR-mutated (EGFRm; Ex19del and/or L858R) advanced or metastatic non-small cell lung cancer (NSCLC) from the FLAURA study (NCT02296125).Experimental designTumor tissue EGFRm status was determined at screening using the central cobas tissue test or a local tissue test. Baseline circulating tumor (ct)DNA EGFRm status was retrospectively determined with the central cobas plasma test.ResultsOf 994 patients screened, 556 were randomized (289 and 267 with central and local EGFR test results, respectively) and 438 failed screening. Of those randomized from local EGFR test results, 217 patients had available central test results; 211/217 (97%) were retrospectively confirmed EGFRm positive by central cobas tissue test. Using reference central cobas tissue test results, positive percent agreements with cobas plasma test results for Ex19del and L858R detection were 79% [95% confidence interval (CI), 74-84] and 68% (95% CI, 61-75), respectively. Progression-free survival (PFS) superiority with osimertinib over comparator EGFR-TKI remained consistent irrespective of randomization route (central/local EGFRm-positive tissue test). In both treatment arms, PFS was prolonged in plasma ctDNA EGFRm-negative (23.5 and 15.0 months) versus -positive patients (15.2 and 9.7 months).ConclusionsOur results support utility of cobas tissue and plasma testing to aid selection of patients with EGFRm advanced NSCLC for first-line osimertinib treatment. Lack of EGFRm detection in plasma was associated with prolonged PFS versus patients plasma EGFRm positive, potentially due to patients having lower tumor burden.