Programmed Cell Death Ligand 1 Expression in Untreated EGFR Mutated Advanced NSCLC and Response to Osimertinib Versus Comparator in FLAURA

IntroductionEGFR mutated (EGFRm) NSCLC tumors occasionally express programmed cell death ligand 1 (PD-L1), although frequency and clinical relevance are not fully characterized. We report PD-L1 expression in patients with EGFRm advanced NSCLC and association with clinical outcomes following treatment with osimertinib or comparator EGFR tyrosine kinase inhibitors in the FLAURA trial (phase III, NCT02296125).MethodsOf 231 tissue blocks available from the screened population (including EGFRm-positive and -negative samples), 197 had sufficient tissue for PD-L1 testing using the SP263 (Ventana, Tucson, Arizona) immunohistochemical assay. Tumor cell (TC) staining thresholds of PD-L1 TC greater than or equal to 1%, TC greater than or equal to 25%, and TC greater than or equal to 50% were applied. Progression-free survival (PFS) was investigator-assessed, per Response Evaluation Criteria in Solid Tumor, version 1.1, according to PD-L1 expressors (TC ≥ 1%) or negatives (TC < 1%) in randomized patients.ResultsPD-L1 staining was successful in 193 of 197 patient formalin-fixed paraffin-embedded blocks; of these, 128 of 193 were EGFRm-positive and 106 of 128 patients were randomized to treatment (osimertinib: 54; comparator: 52). At the PD-L1 TC greater than or equal to 25% threshold, 8% (10 of 128) of EGFRm-positive tumors expressed PD-L1 versus 35% (23 of 65) of EGFRm-negative tumors. With the TC greater than or equal to 1% threshold, 51% (65 of 128) versus 68% (44 of 65) were mutation-positive and –negative, respectively, and with the TC greater than or equal to 50% threshold, 5% (7 of 128) versus 28% (18 of 65), were mutation-positive and -negative, respectively. For PD-L1 expressors (TC ≥ 1%), median PFS was 18.4 months with osimertinib and 6.9 months with comparator (hazard ratio = 0.30; 95% confidence interval: 0.15–0.60). For PD-L1–negative patients (TC < 1%), median PFS was 18.9 months with osimertinib and 10.9 months with comparator (hazard ratio = 0.37; 95% confidence interval: 0.17–0.74).ConclusionsClinical benefit with osimertinib was unaffected by PD-L1 expression status.     

可切除非小细胞肺癌患者术后奥西替尼靶向治疗分析

目的分析可切除非小细胞肺癌(NSCLC)患者术后奥希替尼靶向治疗的效果。 方法2018年1月至2018年12月我院收治的53例可切除NSCLC患者为对象,其术后联合奥希替尼治疗。检测经奥希替尼治疗前后的血清生长转化因子-α(TGF-α)、癌胚蛋白(CEA)、细胞角蛋白19片段抗原21-1(CA21-1)水平,评估奥希替尼在治疗可手术切除的NSCLC中的疗效。 结果经奥希替尼治疗2个月后,行手术切除NSCLC患者血清TGF-α[(14.39±1.47)μg/L vs.(9.86±1.76)μg/L]、CEA[(9.63±1.86)ng/ml vs.(6.69±1.15)ng/ml]以及CA21-1[(5.31±1.49)μg/L vs.(2.31±0.53)μg/L]水平均下降(t＝14.382、9.788、13.810,P<0.05);奥希替尼治疗后不良反应为皮疹,其次为腹泻及瘙痒,但以上不良反应为轻度,经治疗后减轻;随访2年,7例死亡,46例患者存活;15例疾病进展,疾病中位无进展生存时间(mPFS)16.5个月。COX多因素分析提示,中高分化是手术切除NSCLC患者奥希替尼治疗后疾病无进展生存时间。绘制生存曲线发现,低分化者生存率低于中高分化者,差异具有统计学意义(Rank＝4.924,P<0.05)。 结论奥希替尼可进一步提高NSCLC患者肺癌根治术效果,在中高分化者中的应用具有临床意义。     

晚期肺癌奥西替尼获得性耐药进展模式及挽救治疗效果分析

目的:探讨伴有表皮生长因子受体（EGFR）敏感突变或经酪氨酸激酶抑制剂（TKI）治疗后T790M突变的肺癌晚期患者接受奥西替尼治疗后的耐药进展模式以及挽救治疗方法和效果。方法:收集2017年4月（奥西替尼在中国获批时）至2019年5月在江苏省肿瘤医院采用奥西替尼治疗的145例晚期肺癌患者资料。截至2019年12月最后一...     

Critical Assessment in Routine Clinical Practice of Liquid Biopsy for EGFR Status Testing in Non–Small-Cell Lung Cancer: A Single-Laboratory Experience (LPCE,Nice, France)

BackgroundThe introduction of liquid biopsy using PCR-based assays into routine practice has had a strong impact on the treatment of EGFR-mutated lung adenocarcinoma and is now commonly used for routine testing of EGFR mutations in certain clinical settings. To assess whether the claimed benefits of PCR-based assays hold true in daily practice at a multicenter clinical institution, we assessed how treatment decisions are affected by PCR-based assays for the analysis of EGFR mutations from plasma samples in a centralized laboratory (LPCE, Nice, France).Patients and MethodsA total of 345 samples were analyzed using the US Food and Drug Administration–approved Cobas EGFR Mutation Test v2 and 103 using the Therascreen EGFR Plasma RGQ PCR Kit over 3 years (395 samples from 324 patients). Eleven plasma samples were validated independently using Cobas at 3 institutions, and 130 samples were analyzed using Stilla digital PCR. Clinical data were collected for 175 (54%) of 324 patients.ResultsCobas was superior to the Therascreen assay and demonstrated 100% reproducibility. Digital PCR showed only 48%, 83%, and 58% concordance with Cobas for exon 19 deletions, L858R mutations, and T790M mutations, respectively. Liquid biopsies helped inform and change treatment when resistance occurred and enabled the detection of EGFR mutations in patients when biopsy tissue results were unavailable.ConclusionPCR-based assays are a fast and convenient test, allowing the detection of primary and secondary EGFR mutations from plasma. Cobas proved to be a reliable test, whereas digital PCR produced too many inconclusive results to be currently recommended as a principal testing device.     

Genotyping of Cerebrospinal Fluid Associated With Osimertinib Response and Resistance for Leptomeningeal Metastases in EGFR-Mutated NSCLC

IntroductionPatients with NSCLC with leptomeningeal metastases (LM) presented dismal prognosis. Cerebrospinal fluid (CSF) is suggested as a medium of liquid biopsy of LM. However, the clinical implications of CSF genotyping on treatment outcomes remained elusive.MethodsPatients with EGFR-mutated advanced NSCLC with LM were included: cohort 1, patients with LM who were treated with osimertinib with CSF and plasma genotyping performed before the first dosing of osimertinib (baseline, n = 45); cohort 2, CSF genotyping on progression on osimertinib and development of LM (the progression event on osimertinib is the diagnosis of LM, n = 35). Circulating tumor DNA in CSF underwent next-generation sequencing.ResultsSensitivity of CSF genotyping for EGFR-sensitizing mutations was 93.3% (42 of 45) and 97.1% (34 of 35) in cohorts 1 and 2, respectively. In cohort 1, patients with EGFR exon 19 deletion had higher median intracranial progression free survival (iPFS) than those with EGFR exon 21 L858R mutation (11.9 versus 2.8 mo; p = 0.02). Median iPFS was significantly longer in patients with T790M-positive CSF genotyping (15.6 mo) than T790M-negative CSF (7.0 mo, p = 0.04). Concurrent CDK4 (2.8 versus 11.6 mo, p = 0.002) and CDKN2A (2.5 versus 9.6 mo, p = 0.04) mutation with EGFR-sensitizing mutations indicated lower median iPFS. Patients with T790M-negative CSF, EGFR exon 21 L858R mutation, concurrent FGF3 alteration, and over first-line osimertinib had shortened iPFS. In cohort 2, possible EGFR-related and EGFR-independent resistance mechanisms were found including C797S mutation, MET dysregulation, and TP53 plus RB1 co-occurrence. Patients with loss of T790M in CSF had a shorter median iPFS (7.4 mo) compared with those with reserved T790M (13.6 mo, p = 0.01).ConclusionsGenotyping of CSF indicated heterogeneous response to osimertinib and revealed the genetic characteristic of LM on osimertinib failure in patients with EGFR-mutated NSCLC diagnosed with LM.     

Osimertinib versus Standard of Care EGFR TKI as First-Line Treatment in Patients with EGFRm Advanced NSCLC: FLAURA Asian Subset

Introduction

Here we report efficacy and safety data of an Asian subset of the phase III FLAURA trial (NCT02296125), which compares osimertinib with standard of care (SoC) EGFR tyrosine kinase inhibitors (TKIs) in patients with previously untreated advanced NSCLC with tumors harboring exon 19 deletion (Ex19del)/L858R EGFR TKI–sensitizing mutations.

Detection of EGFR-Activating and T790M Mutations Using Liquid Biopsy in Patients With EGFR-Mutated Non–Small-Cell Lung Cancer Whose Disease Has Progressed During Treatment With First- and Second-Generation Tyrosine Kinase Inhibitors: A Multicenter Real-Life Retrospective Study

BackgroundIn advanced epidermal growth factor receptor (EGFR)-mutated non–small-cell lung cancer (NSCLC) patients whose disease has progressed during treatment with first- and second-generation tyrosine kinase inhibitors (TKIs), liquid biopsy (LB) is routinely used to evaluate the presence of EGFR T790M as an acquired resistance mechanism. The objective of this study was to assess a real-life picture of EGFR T790M detection in LB.Materials and MethodsLiquid biopsies performed between June 2016 and October 2018 for advanced EGFR-mutated NSCLC at disease progression during treatment with first- and second-generation TKIs were retrospectively evaluated in 5 Italian centers. Circulating tumor DNA was extracted from plasma and tested with different commercial kits. The detection rate in LBs and the patients’ characteristics were correlated.ResultsWe enrolled 120 consecutive patients. The overall T790M detection rate observed using LB was 25.8%. Fifty-four of 89 (60.7%) patients with negative LB results underwent tissue rebiopsy, and 56% were positive for T790M. The overall rate of T790M positivity in the study cohort was 49.2%. LB performed before formal tumor progression according to Response Evaluation Criteria In Solid Tumors criteria was negative for T790M in all patients (n = 21; P = .012). T790M positivity was statistically significantly higher in cases of disease progression at extrathoracic metastatic sites (P = .008) and, specifically, in the case of worsening bone disease (P = .003).ConclusionOur study shows that the detection of T790M-positive patients whose disease progressed during treatment with first- and second-generation TKIs in real life was according to the literature. However, this result was obtained with a specific clinical course (repeat LBs and tissue rebiopsy), thus implying the necessity for multidisciplinary management.