Osimertinib Plus Durvalumab in Patients With EGFR-Mutated,Advanced NSCLC: A Phase 1b,Open-Label,Multicenter Trial

IntroductionEGFR tyrosine kinase inhibitors (TKIs) are recommended for EGFR-mutated NSCLC treatment. EGFR activation up-regulates programmed death-ligand 1 expression and other immunosuppressive factors in NSCLC, causing immune microenvironment remodeling. Osimertinib (an EGFR TKI) plus durvalumab (programmed death-ligand 1 blockade) was evaluated in the TATTON study (NCT02143466).MethodsThis open-label, phase 1b study enrolled patients with advanced EGFR-mutated NSCLC. In part A, patients who had progressed on a previous EGFR TKI received osimertinib (80 mg once daily) plus durvalumab 3 or 10 mg/kg every 2 weeks. In part B, patients received first-line osimertinib plus durvalumab 10 mg/kg every 2 weeks. However, part B enrollment was terminated early owing to an increased incidence of interstitial lung disease (ILD)-related adverse events (AEs). Safety (primary objective) and preliminary anti-tumor activity determined by objective response rate (ORR), best overall response, duration of response (DOR), and progression-free survival were evaluated.ResultsBefore enrollment termination, 23 and 11 patients received treatment across parts A and B, respectively. The most common AEs across parts A and B were as follows: diarrhea (50%), nausea (41%), and decreased appetite (35%). A total of 12 patients (35%) reported ILD-related AEs (lung disorder, ILD or pneumonitis). In part A, ORR was 43% (95% confidence interval [CI]: 23–66); median DOR was 20.4 months. In part B, ORR was 82% (95% CI: 48–98), median DOR was 7.1 months, and median progression-free survival was 9.0 months (95% CI: 3.5–12.3).ConclusionsThis study highlighted a potential risk of ILD-related AEs when combining osimertinib with durvalumab. Further research looking to combine EGFR TKIs with immune checkpoint inhibitors should be approached with caution.     

Osimertinib Improves Overall Survival in Patients With EGFR-Mutated NSCLC With Leptomeningeal Metastases Regardless of T790M Mutational Status

IntroductionOsimertinib, a third-generation EGFR tyrosine kinase inhibitor, efficiently penetrates the blood-brain barrier. This study explored whether treatment with osimertinib leads to improved overall survival (OS) for patients with EGFR-mutated NSCLC with leptomeningeal metastases (LM) compared with those not treated with osimertinib.MethodsFrom October 2008 to October 2019, patients with EGFR-mutated NSCLC and cytologically confirmed LM were retrospectively analyzed for OS according to osimertinib treatment and T790M mutational status. The OS was defined as the time from the diagnosis of LM to death.ResultsFor the 351 patients with LM included in the analysis, the median OS (mOS) was 8.1 months (95% confidence interval [CI]: 7.2–9.0). T790M mutation was detected in 88 of 197 patients tested, and a total of 110 patients were treated with osimertinib after LM. No difference in mOS according to T790M mutational status (10.1 mo [95% CI: 4.31–15.82] versus 9.0 [95% CI: 6.81–11.21], p = 0.936) was found. Nevertheless, patients treated with osimertinib had a superior OS of 17.0 months (95% CI: 15.13–18.94) compared with those not treated with osimertinib who had a mOS of 5.5 months (95% CI: 4.34–6.63), regardless of T790M mutational status (hazard ratio: 0.36 [95% CI: 0.28–0.47], p < 0.001). This was also considerably longer even than the mOS of 8.7 months (95% CI: 7.01–10.39) of those who were never treated with osimertinib but had first- or second-generation EGFR tyrosine kinase inhibitors.ConclusionsOsimertinib is a promising treatment option for EGFR-mutated NSCLC with LM regardless of T790M mutational status.     

Prospective Observational Study of Treatment Resistance-related Gene Screening Using Plasma Circulating Tumor DNA in Third-generation EGFR-TKI Osimertinib Therapy (Elucidator)

BackgroundOsimertinib is a third-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) that potently and selectively inhibits EGFR activating and EGFR T790M resistance mutations. Osimertinib was found to be more effective than first-generation EGFR-TKIs in patients with previously untreated advanced non–small-cell lung cancer (NSCLC) harboring EGFR-positive mutations in a prior phase III trial. Osimertinib is, therefore, one of the most important standard therapies for EGFR mutation-positive patients. However, there are few reports about osimertinib resistance mechanisms in first-line EGFR-TKI therapy. Understanding first-line osimertinib resistance mechanisms is essential for future therapeutic strategies in patients with NSCLC with EGFR-positive mutations. To clarify the resistance mechanisms of first-line osimertinib, we proposed to analyze circulating tumor (ct) deoxyribonucleic acid (DNA) by the ultra-sensitive next-generation sequencing method.Patients and MethodsWe aim to collect ctDNA samples from patients with the following key inclusion criteria: histologically or cytologically proven NSCLC, activating EGFR mutation-positive, planned treatment with first-line osimertinib, and written informed consent. Patients with comorbidities, who are deemed unsuitable for participation by an attending physician, would be excluded. We plan to enroll 180 cases and estimate a final analysis of 120 cases following registration and 2-year observation. ctDNA samples are collected at osimertinib treatment initiation, 3 and 12 months later, and disease progression. The key primary endpoint is to clarify the incidence and ratio of osimertinib resistance. The key secondary endpoint is to examine how the quantity of osimertinib resistance-associated mutations detected in ctDNA at treatment initiation influences disease progression.     

A Phase II Study of Osimertinib Combined With Platinum Plus Pemetrexed in Patients With EGFR-Mutated Advanced Non–Small-cell Lung Cancer: The OPAL Study (NEJ032C/LOGIK1801)

BackgroundOsimertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is now a standard treatment of previously untreated EGFR-mutated advanced non–small-cell lung cancer (NSCLC). However, disease progression occurs within 19 months of treatment. In the NEJ009 study, gefitinib plus carboplatin plus pemetrexed demonstrated significantly better progression-free and overall survival compared with gefitinib monotherapy. Furthermore, the Lung Oncology Group in Kyushu and North East Japan Study Group, major clinical trial groups in Japan, conducted a randomized phase II study to evaluate the efficacy and safety of second-line osimertinib plus carboplatin plus pemetrexed versus osimertinib monotherapy for patients with disease progression during first-line EGFR tyrosine kinase inhibitor therapy and the EGFR T790M resistance mutation (TAKUMI trial; trial registration no., jRCTs071180062). In the first treatment course for the initial 24 patients, no safety issues were reported in the combination arm. Thus, we have planned this phase II study to evaluate the safety and preliminary efficacy of osimertinib plus cisplatin/carboplatin plus pemetrexed therapy for patients with previously untreated EGFR-mutated NSCLC.Patients and MethodsA total of 66 patients will be enrolled, because this sample size will be adequate for assessing treatment safety and efficacy. The co-primary endpoints include safety and the objective response rate, and the secondary endpoints include the complete response rate, disease control rate, and progression-free survival.ConclusionsThis is the first study to explore the efficacy and safety of osimertinib combined with platinum-based chemotherapy in previously untreated NSCLC patients with EGFR-sensitizing mutations. Our findings could provide valuable information for phase III studies such as FLAURA2 and for developing treatment strategies for EGFR-mutated NSCLC.     

Osimertinib in Japanese patients with EGFR T790M mutation‐positive advanced non‐small‐cell lung cancer: AURA3 trial

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are the first‐line treatment for patients with EGFR mutant non‐small‐cell lung cancer (NSCLC). However, most patients become resistant to these drugs, so their disease progresses. Osimertinib, a third‐generation EGFR‐TKI that can inhibit the kinase even when the common resistance‐conferring Thr790Met (T790M) mutation is present, is a promising therapeutic option for patients whose disease has progressed after first‐line EGFR‐TKI treatment. AURA3 was a randomized (2:1), open‐label, phase III study comparing the efficacy of osimertinib (80 mg/d) with platinum‐based therapy plus pemetrexed (500 mg/m²) in 419 patients with advanced NSCLC with the EGFR T790M mutation in whom disease had progressed after first‐line EGFR‐TKI treatment. This subanalysis evaluated the safety and efficacy of osimertinib specifically in 63 Japanese patients enrolled in AURA3. The primary end‐point was progression‐free survival (PFS) based on investigator assessment. Improvement in PFS was clinically meaningful in the osimertinib group (n = 41) vs the platinum‐pemetrexed group (n = 22; hazard ratio 0.27; 95% confidence interval, 0.13‐0.56). The median PFS was 12.5 and 4.3 months in the osimertinib and platinum‐pemetrexed groups, respectively. Grade ≥3 adverse events determined to be related to treatment occurred in 5 patients (12.2%) treated with osimertinib and 12 patients (54.5%) treated with platinum‐pemetrexed. The safety and efficacy results in this subanalysis are consistent with the results of the overall AURA3 study, and support the use of osimertinib in Japanese patients with EGFR T790M mutation‐positive NSCLC whose disease has progressed following first‐line EGFR‐TKI treatment. (ClinicalTrials.gov trial registration no. NCT02151981.)     

Efficacy of immunotherapy targeting the neoantigen derived from epidermal growth factor receptor T790M/C797S mutation in non–small cell lung cancer

Lung cancer is the leading cause of cancer‐related deaths worldwide. Epidermal growth factor receptor‐tyrosine kinase inhibitors (EGFR‐TKI) often have good clinical activity against non–small cell lung cancer (NSCLC) with activating EGFR mutations. Osimertinib, which is a third‐generation EGFR‐TKI, has a clinical effect even on NSCLC harboring the threonine to methionine change at codon 790 of EGFR (EGFR T790M) mutation that causes TKI resistance. However, most NSCLC patients develop acquired resistance to osimertinib within approximately 1 year, and 40% of these patients have the EGFR T790M and cysteine to serine change at codon 797 (C797S) mutations. Therefore, there is an urgent need for the development of novel treatment strategies for NSCLC patients with the EGFR T790M/C797S mutation. In this study, we identified the EGFR T790M/C797S mutation‐derived peptide (790‐799) (MQLMPFGSLL) that binds the human leukocyte antigen (HLA)‐A*02:01, and successfully established EGFR T790M/C797S‐peptide‐specific CTL clones from human PBMC of HLA‐A2 healthy donors. One established CTL clone demonstrated adequate cytotoxicity against T2 cells pulsed with the EGFR T790M/C797S peptide. This CTL clone also had high reactivity against cancer cells that expressed an endogenous EGFR T790M/C797S peptide using an interferon‐γ (IFN‐γ) enzyme‐linked immunospot (ELISPOT) assay. In addition, we demonstrated using a mouse model that EGFR T790M/C797S peptide‐specific CTL were induced by EGFR T790M/C797S peptide vaccine in vivo. These findings suggest that an immunotherapy targeting a neoantigen derived from EGFR T790M/C797S mutation could be a useful novel therapeutic strategy for NSCLC patients with EGFR‐TKI resistance, especially those resistant to osimertinib.     

EGFR Mutation Analysis for Prospective Patient Selection in Two Phase II Registration Studies of Osimertinib

IntroductionOsimertinib is an oral, central nervous system–active, EGFR tyrosine kinase inhibitor (TKI) for the treatment of EGFR T790M–positive advanced NSCLC. Here we have evaluated EGFR mutation frequencies in two phase II studies of osimertinib (AURA extension and AURA2).MethodsAfter progression while receiving their latest line of therapy, patients with EGFR mutation–positive advanced NSCLC provided tumor samples for mandatory central T790M testing for the study selection criteria. Tumor tissue mutation analysis for patient selection was performed with the Roche cobas EGFR Mutation Test (European Conformity–in vitro diagnostic, labeled investigational use only) (Roche Molecular Systems, Pleasanton, CA). Patients should not have been prescreened for T790M mutation status. The cobas test results were compared with those of the MiSeq next-generation sequencing system (Illumina, San Diego, CA), which was used as a reference method.ResultsSamples from 324 and 373 patients screened for AURA extension and AURA2, respectively, produced valid cobas test results. The T790M detection rates were similar between AURA extension and AURA2 (64% and 63%, respectively). The pooled T790M rate was 63%, with no difference by ethnicity (63% for Asian and non-Asian patients alike) or immediately prior treatment with an EGFR TKI (afatinib, 69%; erlotinib, 69%; and gefitinib, 63%). A higher proportion of patients had T790M detected against a background of exon 19 deletions versus L858R mutation (73% versus 58% [p = 0.0002]). In both trials the cobas test demonstrated high sensitivity (positive percent agreement) and specificity (negative percent agreement) for T790M detection when compared with the next-generation sequencing reference method: positive percent agreement of 91% versus 89% and negative percent agreement of 97% versus 98%.ConclusionsIn both trials, the rate of detection of T790M mutation in patients with advanced NSCLC was approximately 63% and was unaffected by immediately prior treatment with an EGFR TKI or ethnicity.     

Osimertinib for Japanese patients with T790M‐positive advanced non‐small‐cell lung cancer: A pooled subgroup analysis

Epidermal growth factor receptor (EGFR)‐tyrosine kinase inhibitors (TKIs) are the standard of care for non‐small‐cell lung cancer (NSCLC) patients harboring EGFR mutations. However, almost all patients develop resistance after approximately 1 y of treatment, with >50% of cases due to the T790M secondary mutation of the EGFR gene. A large global Phase III study (AURA3) demonstrated that osimertinib significantly prolonged progression‐free survival (PFS) over platinum‐doublet chemotherapy in patients with T790M‐positive NSCLC who had progressed on previous EGFR‐TKI therapy. However, it is not clear whether efficacy or safety of osimertinib in Japanese patients is similar to the overall population. We report a pre‐planned subgroup analysis of pooled Phase II data from the AURA Extension and AURA2 trials to investigate the efficacy and safety of osimertinib in Japanese patients. This study included 81 Japanese patients. Patients were administered 80 mg osimertinib orally once daily until disease progression. The main endpoints were objective response rate (ORR), PFS, and safety. The ORR was 63.6% and median PFS was 13.8 mo. Overall survival rate at 36 mo was 54.0%. The most common all‐cause adverse events (AEs) were rash (grouped term; 65.4%), diarrhea (51.9%), paronychia (grouped term; 49.4%), and dry skin (grouped term; 39.5%). Most AEs were grade 1‐2. Five patients (6.2%) developed interstitial lung disease, resulting in two deaths (2.5%). Osimertinib demonstrated favorable ORR and PFS in Japanese patients, similar to the overall population. Additionally, osimertinib has good efficacy and a manageable safety profile in Japanese patients with NSCLC who had acquired resistance due to the T790M mutation.     

Emergence of RET rearrangement co-existing with activated EGFR mutation in EGFR-mutated NSCLC patients who had progressed on first- or second-generation EGFR TKI

ObjectivesThe gatekeeper mutation T790M mutation is the responsible for the majority of the resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in patients with EGFR-mutated non-small cell lung cancer (NSCLC). Other previously described resistance mechanisms include HER2 amplification, MET amplification, PIK3CA mutation, epithelial–mesenchymal transition (EMT), small cell transformation have also been identified. However other resistance mechanisms remains to be discovered.Materials and methodsHybrid-capture based comprehensive genomic profiling (CGP) was performed on pre- and post-EGFR TKI progression EGFR-mutated NSCLC tumor samples during routine clinical care. We identify two paired pre- and post-EGFR TKI progression EGFR-mutated NSCLC patient tumor samples where both post EGFR TKI samples harbored in-frame CCDC6-RET rearrangements but not in the pre-EGFR TKI tumor samples. Furthermore analysis of the clinical database revealed one additional NCOA4-RET rearrangement co-existing with activated EGFR mutation in an EGFR-mutated NSCLC patient who had progressed on afatinib. None of the known resistance mechanisms to EGFR TKI including EGFR T790M, EGFR amplification, HER2 amplification, MET amplification, PIK3CA mutation, BRAF mutation, EMT or small cell transformation was identified in the three post progression samples that now harbored RET rearrangements.Results and conclusionsThis is the first report of RET rearrangement co-existing with activated EGFR mutations in EGFR-mutated patients who had progressed on either first- or second generation EGFR TKI. As such, RET rearrangement may serve as a potential resistance mechanism to EGFR TKI in EGFR-mutated NSCLC.     

Molecular Characteristics of the Uncommon EGFR Exon 21 T854A Mutation and Response to Osimertinib in Patients With Non-Small Cell Lung Cancer

BackgroundEpidermal growth factor receptor (EGFR) T854A is an uncommon exon 21 mutation in patients with non-small cell lung cancer (NSCLC). It was first reported in samples collected after first generation EGFR tyrosine kinase inhibitor (TKI) treatment as an acquired resistant mutation to first generation EGFR-TKI. The efficacy of osimertinib, a third generation EGFR-TKI, in these patients was not clear.MethodsIn this study, a total of 8932 NSCLC patients with NGS data were retrospectively analyzed to investigate the molecular characteristics and clinical outcomes of patients with EGFR T854A mutation.ResultsEight of 8932 patients (0.09%) had EGFR T854A mutation, and 5 of them (62.5%) were treatment-naïve. Interestingly, all EGFR T854A mutations were co-occurred with EGFR L858R mutation in cis. TP53 was the most common concomitant mutation and no other driver mutation was found. Five of the 8 patients received treatment of osimertinib. Four patients achieved partial response, and one had stable disease, resulting in an overall objective response rate of 80% and disease control rate of 100%. The median progression-free survival of patients who received osimertinib was 10 months. Moreover, EGFR C797S mutation was detected in 1 patient after resistant to osimertinib treatment.ConclusionPresence of EGFR T854A mutation was rare in NSCLC patients and our retrospective study provides clinical evidence that osimertinib may be an effective treatment to improve survival outcomes in patients with EGFR T854A.     

Different characteristics and survival in non-small cell lung cancer patients with primary and acquired EGFR T790M mutation

Primary epidermal growth factor receptor (EGFR) T790M mutation can be occasionally identified in previous untreated nonsmall cell lung cancer (NSCLC) patients. To compare clinical characteristics and outcomes in patients with primary and acquired EGFR T790M mutation, we collected the data of patients diagnosed with EGFR mutation from 2012 to 2017 in Shanghai Chest Hospital. Primary EGFR T790M mutation was identified in 61 patients (1.1%; 95% confidence interval (CI): 0.8%–1.3%) of 5685 TKI-naive EGFR mutant patients. Acquired T790M mutation was detected in 98 patients (50.3%; 95%CI: 43.2%–57.3%) of 195 TKI-treated patients. T790M mutation always coexisted with sensitizing EGFR mutations. Primary EGFR T790M always coexisted with 21L858R (46/61) whereas acquired T790M coexisted with 19del (68/98), (p < 0.001). Among them, 18 patients with primary T790M mutation received osimertinib and 72 patients with acquired T790M mutation received osimertinib. The median progression-free survival (PFS) of osimertinib was significantly longer in primary T790M group (17.0 months, 95%CI:14.0–20.0 months) compared to acquired T790M group (10.0 months, 95%CI:8.6–11.4 months, p = 0.022). However, the median overall survival (OS) of acquired T790M mutation patients was significantly longer compared to that of primary T790M mutation patients who received osimertinib (50.4 months vs. 29.9 months, p = 0.016). Our findings suggest that primary T790M mutation likely coexists with 21L858R while acquired mutation likely coexists with 19del. Both mutations showed good response to osimertinib. Patients with primary T790M mutation experienced greater benefits from osimertinib. However, patients with acquired T790M mutation had a better overall survival during the entire clinical treatment.     

A Phase 1/2 Study of Lazertinib 240 mg in Patients With Advanced EGFR T790M-Positive NSCLC After Previous EGFR Tyrosine Kinase Inhibitors

IntroductionThis integrated analysis of a phase 1/2 study (NCT03046992) evaluated the efficacy and safety of lazertinib, a third-generation EGFR tyrosine kinase inhibitor (TKI), in patients with advanced EGFR T790M-positive NSCLC after previous EGFR TKI therapy.MethodsAdults with EGFR mutation-positive NSCLC that progressed after prior EGFR-directed TKIs received once daily oral lazertinib 240 mg continuously until disease progression. Prior TKIs to treat T790M-positive NSCLC were prohibited. Primary endpoints were safety and objective response rate (ORR). Secondary endpoints included progression-free survival, overall survival, and intracranial ORR.ResultsA total of 78 patients received lazertinib 240 mg at 17 centers in South Korea. Among patients with T790M-positive tumors at baseline (N = 76), one (1.3%) had a complete response and 41 (53.9%) had partial responses, giving an ORR of 55.3% (95% confidence interval [CI]: 44.1–66.4). Median progression-free survival was 11.1 months (95% CI: 5.5–16.4). Median overall survival was not reached (median follow-up = 22.0 mo). In patients with measurable intracranial lesions (n = 7), one (14.3%) had a complete intracranial response and five (71.4%) had partial responses, giving an intracranial ORR of 85.7% (95% CI: 59.8%–100.0%). The most common treatment-emergent adverse events were rash (37.2%), pruritus (34.6%), and paresthesia (33.3%); most were mild to moderate in severity. Serious drug-related adverse events occurred in three patients (gastritis, pneumonia, pneumonitis). The major mechanism of resistance was EGFR T790M loss.ConclusionsLazertinib 240 mg/d has a manageable safety profile with durable antitumor efficacy, including brain metastases, in patients with advanced T790M-positive NSCLC after previous EGFR TKI therapy.     

奥希替尼治疗非小细胞肺癌的研究进展

表皮生长因子受体(EGFR)突变的发现以及EGFR酪氨酸激酶抑制剂(TKI)疗效的证明，标志着非小细胞肺癌(NSCLC)精准药物使用时代的到来。奥希替尼是针对EGFR TKI敏感突变和野生型EGFR T790M突变，同时保留野生型EGFR的第三代TKI。因其在临床试验中表现出的显著临床有效性和良好安全性，2015年及2016年初，美国及欧洲首次批准了奥希替尼用于接受EGFR TKI治疗后进展的EGFR T790M突变阳性的NSCLC患者的治疗，2017年3月奥西替尼正式在我国获批上市。本文主要就奥希替尼在NSCLC治疗中的研究进展进行综述。     

BEAMing ddPCR与Super ARMS检测EGFR酪氨酸激酶抑制剂治疗后非小细胞肺癌患者循环肿瘤DNA EGFR基因突变的比较研究

背景与目的:BEAMing微滴数字PCR(droplet digital PCR,ddPCR)被认为是灵敏度极高的基因突变检测方法,探讨该方法和扩增阻碍突变系统(Super amplification refractory mutation system,Super ARMS)检测表皮生长因子受体(epidermal growth factor receptor,EGFR)酪氨酸激酶抑制剂(tyrosine kinase inhibitor,TKI)治疗非小细胞肺癌(non-small cell lung cancer,NSCLC)患者后循环肿瘤DNA(circulating tumor DNA,ctDNA)EGFR基因突变的灵敏度差异,进而为指导临床ctDNA检测方法的选择提供更多参考。方法:收集复旦大学附属肿瘤医院2017-2018年接受过EGFR TKI治疗的NSCLC患者血浆33例及国家病理质控评价中心(PathologyQualityControlCenter,PQCC)模拟血浆10例,采用凯杰血浆游离核酸纯化试剂盒进行循环游离DNA(circulating free DNA,cfDNA)提取,分别用ddPCR和Super ARMS方法进行EGFR基因19 del、T790M和L858R突变检测,两种结果进行对比和统计学分析。结果:33例临床样本应用两种方法检测19 del、T790M和L858R突变,阳性率分别为27.3%vs 27.3%(P=1.00)、42.4%vs 27.3%(P=0.23)和27.3%vs 27.3%(P=1.00)。10例PQCC样本结果与标准结果相比,ddPCR检测T790M符合率显著高于Super ARMS(P=0.01)。ddPCR和Super ARMS检测T790M的样本突变丰度范围分别为0.04%~7.66%和0.05%~7.66%。11例T790MddPCR(+)/Super ARMS(-)的平均突变丰度为0.19%(0.04%~0.76%),与10例Super ARMS(+)平均突变丰度[1.73%(0.05%~7.66%)]差异有统计学意义(P=0.03)。EGFR TKI耐药突变T790M突变丰度在0.01%~0.20%、0.20%~1.00%和>1.00%区间的分布分别为42.9%、14.2%和42.9%。结论:BEAMing ddPCR法较Super ARMS法具有更高的灵敏度,可检出更多T790M耐药患者,可能为更多患者选择最有效的靶向治疗方案提供参考。     

Real-World Pattern of Treatment and Clinical Outcomes of EGFR-Mutant Non-Small Cell Lung Cancer in a Single Academic Centre in Quebec

The discovery of EGFR tyrosine kinase inhibitors (TKI) for the treatment of EGFR mutant (EGFRm) metastatic NSCLC is regarded as a landmark in lung cancer. EGFR-TKIs have now become a standard first-line treatment for EGFRm NSCLC. The aim of this retrospective cohort study is to describe real-world patterns of treatment and treatment outcomes in patients with EGFRm metastatic NSCLC who received EGFR-TKI therapy outside of clinical trials. One hundred and seventy EGFRm metastatic NSCLC patients were diagnosed and initiated on first-line TKI therapy between 2004 and 2018 at the Peter Brojde Lung Cancer Centre in Montreal. Following progression of the disease, 137 (80%) patients discontinued first-line treatment. Moreover, 80/137 (58%) patients received second-line treatment, which included: EGFR-TKIs, platinum-based, or single-agent chemotherapy. At the time of progression on first-line treatment, 73 patients were tested for the T790M mutation. Moreover, 30/73 (41%) patients were found to be positive for the T790M mutation; 62/80 patients progressed to second-line treatment and 20/62 were started on third-line treatment. The median duration of treatment was 11.5 (95% CI; 9.62–13.44) months for first-line treatment, and 4.4 (95% CI: 1.47–7.39) months for second-line treatment. Median OS from the time of diagnosis of metastatic disease was 23.5 months (95% CI: 16.9–30.1) and median OS from the initiation of EGFR-TKI was 20.6 months (95% CI: 13.5–27.6). We identified that ECOG PS ≤ 2, presence of exon 19 deletion mutation, and absence of brain metastases were associated with better OS. A significant OS benefit was observed in patients treated with osimertinib in second-line treatment compared to those who never received osimertinib. Overall, our retrospective observational study suggests that treatment outcomes in EGFRm NSCLC in real-world practice, such as OS and PFS, reflect the result of RCTs. However, given the few observational studies on real-world treatment patterns of EGFR-mutant NSCLC, this study is important for understanding the potential impact of EGFR-TKIs on survival outside of clinical trials. Further real-world studies are needed to characterize patient outcomes for emerging therapies, including first-line osimertinib use and combination of osimertinib with chemotherapy and potential future combination of osimertinib and novel anticancer drug, outside of a clinical trial setting.     

第三代EGFR-TKIs治疗晚期非小细胞肺癌的耐药机制及应对策略研究进展

表皮生长因子受体（EGFR）酪氨酸激酶抑制剂（TKIs）是具有EGFR基因敏感突变的晚期非小细胞肺癌（NSCLC）患者的一线治疗药物。第一、二代EGFR-TKIs可有效治疗EGFR敏感突变的NSCLC,EGFR第20号外显子的T790M突变是第一、二代EGFR-TKIs的主要耐药机制。以奥西替尼为代表的第三代EGFR-TKIs治疗耐药后出现T790M突变的患者疗效显著,给晚期肺癌患者带来更多的生存获益。然而第三代EGFR-TKIs仍不可避免地出现耐药。本文对第三代EGFR-TKIs治疗晚期NSCLC耐药机制及应对策略的研究进展进行综述。     

Real-world Outcomes,Treatment Patterns and T790M Testing Rates in Non-small Cell Lung Cancer Patients Treated with First-line First- or Second-generation Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors from the Slovenian Cohort of the REFLECT Study

BackgroundEpidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are effective treatments for EGFR mutation-positive (EGFRm) non-small cell lung cancer (NSCLC). However, routine clinical practice is different between countries/institutions.Patients and methodsThe REFLECT study ({"type":"clinical-trial","attrs":{"text":"NCT04031898","term_id":"NCT04031898"}}NCT04031898) is a retrospective medical chart review that explored real-life treatment and outcomes of EGFRm NSCLC patients receiving first-line (1L) first-/second-generation (1G/2G) EGFR TKIs in 8 countries. This study included adult patients with documented advanced/metastatic EGFRm NSCLC with 1L 1G/2G EGFR TKIs initiated between Jan 2015 – Jun 2018. We reviewed data on clinical characteristics, treatments, EGFR/T790M testing patterns, and survival outcomes. Here, we report data from 120 medical charts in 3 study sites from Slovenia.ResultsThe Slovenian cohort (median age 70 years, 74% females) received 37% erlotinib, 32% afatinib, 31% gefitinib. At the time of data collection, 94 (78%) discontinuations of 1L TKI, and 89 (74%) progression events on 1L treatment were reported. Among patients progressing on 1L, 73 (82%) were tested for T790M mutation yielding 50 (68%) positive results, and 62 (85%) received 2L treatment. 82% of patients received osimertinib. Attrition rate between 1L and 2L was 10%. The median (95% CI) real-world progression free survival on 1L EGFR TKIs was 15.6 (12.6, 19.2) months; median overall survival (95% CI) was 28.9 (25.0, 34.3) months.ConclusionsThis real-world study provides valuable information about 1G/2G EGFR TKIs treatment outcomes and attrition rates in Slovenian EGFRm NSCLC patients. The reduced attrition rate and improved survival outcomes emphasize the importance of 1L treatment decision.Key words: real-world study, non-small cell lung cancer, epidermal growth factor receptor, T790M testing, attrition     

Poor response to erlotinib in patients with tumors containing baseline EGFR T790M mutations found by routine clinical molecular testing

BackgroundEGFR T790M is the most common mutation associated with acquired resistance to EGFR tyrosine kinase inhibitors (TKIs). Baseline EGFR T790M mutations in EGFR TKI-naïve patients have been reported, but the frequency and their association with response to EGFR TKIs remain unclear.Patients and methodsThe frequency of baseline EGFR T790M as detected by routine molecular genotyping was determined by reviewing clinical results obtained at our institution from 2009 to 2013. We also collected outcome data for treatment with EGFR TKIs.ResultsTo define the incidence of EGFR T790M, we reviewed 2774 sequentially tested patients with lung cancer who underwent molecular testing using a mass spectrometry-based assay, and 11 (0.5%) had baseline EGFR T790M. Compiling results from several molecular techniques, we observed EGFR T790M in tumors from 20 patients who had not previously been treated with an EGFR TKI. In all cases, EGFR T790M occurred concurrently with another EGFR mutation, L858R (80%, 16/20), or exon 19 deletion (20%, 4/20). Two percent of all pre-treatment EGFR-mutant lung cancers harbored an EGFR T790M mutation. Thirteen patients received erlotinib monotherapy as treatment for metastatic disease. The response rate was 8% (1/13, 95% confidence interval 0%–35%). For the patients who received erlotinib, the median progression-free survival was 2 months and the median overall survival was 16 months.ConclusionsDe novo EGFR T790M mutations are rare (<1%) when identified by standard sensitivity methods. TKI therapy for patients with baseline EGFR T790M detected by standard molecular analysis has limited benefit.     

Audit of Molecular Mechanisms of Primary and Secondary Resistance to Various Generations of Tyrosine Kinase Inhibitors in Known Epidermal Growth Factor Receptor-Mutant Non-small Cell Lung Cancer Patients in a Tertiary Centre

AimsPresently, three generations of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are approved against oncogene addicted EGFR-mutant non-small cell lung cancer (NSCLC). Patients with actionable EGFR mutations invariably develop resistance. This resistance can be intrinsic (primary) or acquired (secondary).Materials and methodsThis was a retrospective study carried out between January 2016 and April 2021 analysing 486 samples of NSCLC for primary and secondary resistance to first- (erlotinib, gefitinb), second- (afatinib) and/or third-generation (osimertinib) TKIs in EGFR-mutant NSCLCs by next generation sequencing (NGS). Tissue NGS was carried out using the Thermofischer Ion Torrent? Oncomine? Focus 52 gene assay; liquid biopsy NGS was carried out using the Oncomine Lung Cell-Free Total Nucleic Acid assay. All cases were previously tested for a single EGFR gene with the Therascreen® EGFR RGQ PCR kit.ResultsThe results were divided into four groups: (i) group 1: primary resistance to first- and/or second-generation TKIs. This group, with 21 cases, showed EGFR exon 20 insertions, dual, complex mutations and variant of unknown significance, de novo MET gene amplification besides other mutations. (ii) Group 2: primary resistance to third-generation TKIs. This group showed two cases, with one showing dual EGFR mutation (L858R and E709A) and EGFR gene amplification. (iii) Group 3: secondary resistance to first- and second-generation TKIs. This group had 27 cases, which were previously reported negative for EGFR T790M by single gene testing. Significant findings were MET gene amplification in four cases, with one also showing MET exon 14 skipping mutation. Three cases showed small cell change and one showed loss of primary mutation. (iv) Group 4: secondary resistance to third-generation TKIs. The latter group was further subgrouped into group 4A: secondary resistance to osimertinib (third-generation TKI) when offered as second-line therapy after first- and second-generation TKIs on detection of T790M mutation. This group had 15 cases. EGFR T790M mutation was lost in 10 (10/15; 67%) cases and was retained in five cases. Patients with T790M loss experienced early resistance (6.9 months versus 12.6 months mean, P = 0.0024) compared with cases that retained T790M. Two cases gained MET amplification as the resistance mechanisms. Other mutations that were found when EGFR T790M was lost were in FGFR3, KRAS, PIK3CA, CTNNB1, BRAF genes. One case had EML4-ALK translocation. Two cases showed driver EGFR deletion 19, retained T790M and C797S mutation in Cis form. Group 4B: secondary resistance to osimertinib (when given as first-line therapy) in EGFR-mutant NSCLC. This group had three cases. The duration of osimertinib treatment ranged from 11 to 17 months. Two patients showed additional C797S mutation along with primary EGFR mutation.ConclusionThis study shows the wide spectrum of primary and secondary EGFR resistance mechanisms to first, second and third generation of TKIs and helps us to identify newer therapeutic targets that could carry forward the initial advantage offered by EGFR TKIs.