EGFR-mutated Advanced NSCLC Research Articles

1158P Study of patients’ characteristics associated with osimertinib outcomes upfront or in following lines in EGFR-positive NSCLC

In first line (L1) for EGFR-mutated (mEGFR) advanced NSCLC (aNSCLC), osimertinib (osi) has been the preferred option since 2018. First generation anti-EGFR TKI (1G) alone followed by osi, or 1G + anti-angiogenic or 1G + chemotherapy are other options. We aimed to assess the subgroups of patients (pts) that do not benefit from 1G alone compared with osimertinib L1 in mEGFR aNSCLC. Retrospective international study including pts with mEGFR aNSCLC treated with either osi or the sequence of 1G followed by osi (seq group). Primary endpoint was the PFS of the global strategy (PFSglob) defined as the time between L1 start and progression after L2 treatment or death. Subgroups analyses included pts with high tumour burden (high-TM; > 3 metastatic sites and/or central nervous system (CNS) involvement), poor performance status (PS), and T790M negative (seq subgroup only). A total of 235 pts were included: 104 in the seq group, 118 in the osi L1 group. 15 had T790M negative at PD after 1G, they received osi as a therapeutic test. From these pts, 222 had an exon19 or 21 EGFR mut, 13 had uncommon mEGFR. Mean age was 65 years, 64% were female, and 60% never smokers. Pts from the osi L1 group had poorer PS (23% vs 10%), higher rate of co-mutations (23% vs 19%) and more CNS involvement (47% vs 19%). After a median (m) follow up of 30.6 months in the exon 19 and 21 population, mPFSglob was 27.4 mo (23.0-31.0) and mPFS L1 was 15.5mo (13.7-18.4) Table. The sequence was associated with shorter PFS L1 compared with osi L1 particularly in high-TM (10.5 mo vs 17.1 mo, p<0.0001); PFS was numerically shorter in poor PS (≥2) population (11.0 mo vs 15.6 mo, p=0.1).Table: 1158POsimertinib L1 groupORR L1PFS L1, 18mo rate (95%CI)PFSglob, 36mo rate (95%CI)Exon 19 and 21 mut (n=118)84.3%46.4% (37.0-58.1)36.8% (19.9-68.2)CNS involvement (n=55)92.6%42.2% (28.3-62.7)20.6% (4.7-89.0)Poor PS (n=23)90.5%46.4% (27.7-77.8)55.1% (35.5-85.5)Sequence groupExon 19 and 21 mut (n=104)87.4%41.8% (33.2-52.5)37.8% (29.1-49.1)CNS involvement (n=20)90.0%25% (11.7-53.4)16.6% (5.2-53.0)Poor PS (n=9)88.9%13.9% (2.3-83.6)0%ORR L2PFS L1, 18mo rate (95%CI)PFS L2, mo (95%CI)T790M analysis from the sequence groupT790M positive at L1 PD (n=82)63.2%39.0% (29.8-51.1)10.3 (8.8-14.1)T790M negative at L1 PD (n=9)83.3%44.4% (21.4-92.3)12.8 (6.7-Not Reached) Open table in a new tab 1G TKI followed by osi seemed to be detrimental compared with os L1 for pts with high-TM or poor PS mEGFR aNSCLC. In this population, the intensification of L1 treatment with osimertinib or a combination of 1G with anti-angiogenic or chemotherapy could be the better option in the first-line setting. Updated results will be presented at the congress.

EP08.02-081 Cabozantinib Plus Atezolizumab in First or Second-Line Advanced NSCLC and Previously-Treated EGFR Mutant Advanced NSCLC

Cabozantinib, a multitargeted receptor tyrosine kinase inhibitor (TKI), promotes an immune-permissive environment that may enhance immune checkpoint inhibitor (ICI) activity. COSMIC-021 (NCT03170960) is a multicenter phase 1b study evaluating cabozantinib plus atezolizumab in advanced solid tumors. In COSMIC-021, cabozantinib plus atezolizumab demonstrated encouraging clinical activity in a cohort of patients with advanced NSCLC (aNSCLC) previously treated with ICIs (Neal. ASCO 2020. Abstr 9610).

MO11-4 A retrospective analysis of locally advanced EGFR-mutated NSCLC patients with durvalumab after chemoradiotherapy

MO11-4 A retrospective analysis of locally advanced EGFR-mutated NSCLC patients with durvalumab after chemoradiotherapy

Retrospective Analysis of Real-World Management of EGFR-Mutated Advanced NSCLC, After First-Line EGFR-TKI Treatment: US Treatment Patterns, Attrition, and Survival Data.

Background and ObjectivesEpidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are standard-of-care first-line (1L) treatment for EGFR mutation-positive advanced/metastatic non-small cell lung cancer. In 2015, osimertinib, a third-generation EGFR-TKI, received US accelerated approval for second-line (2L) EGFR T790M-positive non-small cell lung cancer treatment. The objective of this US study was to characterize treatment patterns, attrition, and survival in EGFR mutation-positive non-small cell lung cancer, after 1L first-/second-generation EGFR-TKI treatment.MethodsWe retrospectively analyzed 1029 patients diagnosed with stage IIIB/IV non-small cell lung cancer from 1 January, 2011 to 31 December, 2018 using the US electronic medical record CancerLinQ Discovery® database. Demographic/disease characteristics, EGFR mutations, treatments, and death dates were collected.ResultsFrom 1 January, 2011 to 31 December, 2014 (< 2015 cohort), 519 patients received 1L EGFR-TKIs and 510 between 1 January, 2015 and 31 December, 2018 (≥ 2015 cohort). Median follow-up from advanced diagnosis was 19.8 months (interquartile range: 9.9–33.4 months). Twenty-eight percent of patients (288/1029) died without receiving 2L, and 52% (539/1029) initiated 2L with 35% (186/539) receiving osimertinib; in the < 2015 and ≥ 2015 cohorts, the same proportion initiated 2L (52%; 272/519 vs 267/510, respectively). Median overall survival from advanced diagnosis for patients initially diagnosed with stage I–IIIA disease was 43.3 months (95% confidence interval 30.9–73.7), vs 26.4 months (95% confidence interval 24.4–28.1) for stage IIIB–IV; all-cause mortality hazard ratio: 1.56 (95% confidence interval 1.2–2.0; p = 0.001).ConclusionsWe identified disease stage, performance status, and central nervous system metastasis as survival predictors, highlighting the importance of optimal 1L treatment selection. Over a quarter of patients died before initiating 2L; half progressed after 1L and received 2L, of whom a third received 2L osimertinib.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40801-022-00302-w.

Addition of Bevacizumab to Erlotinib as First-Line Treatment of Patients With EGFR-Mutated Advanced Nonsquamous NSCLC: The BEVERLY Multicenter Randomized Phase 3 Trial

IntroductionAdding bevacizumab to erlotinib prolonged progression-free survival (PFS) of patients with EGFR-mutated advanced NSCLC in the Japanese JO25567 trial, but limited data were available in non-Asian patients. BEVERLY is an Italian, multicenter, randomized, phase 3 investigating the addition of bevacizumab to erlotinib as first-line treatment of advanced EGFR-mutated NSCLC. MethodsEligible patients were randomized 1:1 to erlotinib plus bevacizumab or erlotinib alone. Investigator-assessed PFS and blinded independent centrally reviewed PFS were coprimary end points. With 80% power in detecting a 0.60 hazard ratio and two-sided α error of 0.05, 126 events of 160 patients were needed. The trial was registered as NCT02633189 and EudraCT 2015-002235-17. ResultsFrom April 11, 2016, to February 27, 2019, a total of 160 patients were randomized to erlotinib plus bevacizumab (80) or erlotinib alone (80). At a median follow-up of 36.3 months, median investigator-assessed PFS was 15.4 months (95% confidence interval [CI]: 12.2–18.6) with erlotinib plus bevacizumab and 9.6 months (95% CI: 8.2–10.6) with erlotinib alone (hazard ratio = 0.66, 95% CI: 0.47–0.92). Blinded independent centrally reviewed PFS analysis confirmed this result. A statistically significant interaction with treatment effect was found for smoking habit (p = 0.0323), with PFS prolongation being clinically significant only among current or previous smokers. Hypertension (grade ≥3: 24% versus 5%), skin rash (grade ≥ 3: 31% versus 14%), thromboembolic events (any grade: 11% versus 4%), and proteinuria (any grade: 23% versus 6%) were more frequent with the combination. ConclusionsThe addition of bevacizumab to first-line erlotinib prolonged PFS in Italian patients with EGFR-mutated NSCLC; toxicity was increased with the combination but without unexpected safety issues.

Aumolertinib activity in patients with CNS metastases and EGFR-mutated NSCLC treated in the randomized double-blind phase III trial (AENEAS).

9096 Background: We previously reported (Lu, ASCO 2021, abstract # 9013) that treatment with aumolertinib (Au), a 3rd generation EGFR TKI, led to robust improvement in progression free survival (PFS) (median PFS 19.3 to 9.9 months, HR = 0.46, p &lt; 0.0001) when compared to gefitinib (G) with a predictable and encouraging safety profile. This benefit was maintained across all prespecified stratification factors including the subset of ̃ 27% of patients (pts) with CNS metastases (HR = 0.38). Here we undertook this analysis to more fully characterize the activity and benefit of Au as compared to G in this clinically important subset of EGFR mutant NSCLC pts. Methods: Pts with previously untreated metastatic or locally advanced NSCLC with EGFR sensitizing mutations were enrolled and randomly assigned in a 1:1 ratio to receive either Au (110 mg QD) or G (250 mg QD). Predefined stratification factors were EGFR-mutated status (Ex19del vs L858R) and CNS metastases (yes vs no). Patients with stable, asymptomatic CNS metastases were eligible for enrollment. All pts had baseline brain imaging by magnetic resonance imaging or computed tomography. The primary endpoint was PFS assessed by investigator per RECIST v1.1 in full analysis set (systemic analysis). Independent CNS efficacy was performed both in pts with baseline CNS metastases (CNS full analysis set, cFAS) and in pts with baseline CNS target lesions (CNS evaluable-for-response set, cEFS) by blinded independent central neuroradiology review (BICR) per RECIST v1.1. Results: Of 429 pts, 106 pts (Au, n = 51; G, n = 55) were found to have CNS metastases (cFAS) and 61 pts (Au, n = 29; G, n = 32) had CNS target lesions as defined by RECIST 1.1 (cEFS) at baseline by BICR. At the cutoff date (Aug 6, 2021), based on cEFS, CNS PFS events were observed in 11 pts (38%) treated with Au versus 20 pts (63%) who were randomized to receive G. Treatment with Au significantly prolonged CNS median PFS compared with G (29.0 vs 8.3 months; HR = 0.300; 95% CI, 0.137-0.657; P = 0.0015). Estimated CNS PFS rate at 12 and 18 months were 71% and 62% in Au arm compared with 23% and 0% in G arm. The confirmed CNS ORR were 82.8% and 75.0% in pts treated with Au and G, respectively (odds ratio = 1.600; 95% CI, 0.457-5.597; P = 0.4621). Au also achieved longer CNS median PFS over G in cFAS (29.0 vs 8.3 months; HR = 0.323; 95% CI, 0.181-0.576; P &lt; 0.0001). No new safety findings were observed. Conclusions: Au demonstrated superior clinical efficacy against CNS metastases over G as first-line therapy in EGFR-mutated advanced NSCLC, and the safety profile was consistent with that reported previously. Additional randomized studies of Au in pts with CNS metastases are ongoing (NCT04870190). Clinical trial information: NCT03849768.

Afatinib (Afa) + bevacizumab (Bev) versus afatinib alone as first-line treatment of patients with EGFR-mutated advanced non-squamous NSCLC: Primary analysis of the multicenter, randomized, phase II study—AfaBev-CS study.

9112 Background: Adding Bev to erlotinib prolonged PFS in NEJ026 and CTONG1509 trials, but limited data are available adding Bev to a second-generation EGFR-tyrosine kinase inhibitor. AfaBev-CS is a Japanese no-profit, randomized, open-label, multicenter phase II trial of Afa plus Bev vs Afa alone as first-line treatment for EGFR-mutated advanced NSCLC. Methods: This study enrolled untreated pts of advanced non-squamous NSCLC harboring EGFR sensitizing mutation (Del19 or L858R) and without symptomatic brain metastases. 100 eligible pts were randomized in a 1:1 ratio to receive either Afa (30 mg, daily) plus Bev (15 mg/kg, every 3 weeks) (AfaBev arm) or Afa (40 mg, daily) monotherapy (Afa arm), and stratified according to stage, EGFR mutation status and institution. The primary endpoint was PFS and the secondary endpoints were OS, tumor response and time to treatment failure. The sample size was set in terms of feasibility. The power is greater than 50% under the assumptions of a median PFS of 12 months for the Afa arm and HR of 0.6 for the AfaBev arm, with an accrual of 2.5 years and a minimum planned follow-up period of 2 years with the type 1 error of 0.05 (two-sided). Results: Between August 2017 and September 2019, 100 pts were enrolled (each arm, 50 pts). At a median follow-up of 31.3 months for all randomized pts, total 69 events occurred. Median PFS was 16.3 months for AfaBev arm and 16.1 months for Afa arm, with a hazard ratio (HR) of 0.865 (95%CI, 0.539 – 1.388; loglank p = 0.5476). In subgroup analysis, pts &lt; 70 years old (HR 0.347) and pts with brain metastasis (HR 0.353) showed better trend of PFS in AfaBev arm. On the other hand, pts ≥ 70 years old (HR 1.738) and pts without brain metastasis (HR 1.196) did not show better trend in AfaBev arm. In terms of OS, result was immature because number of events was still small. Objective response rate was 77.6% in AfaBev arm and 72.0% in Afa arm. Severe adverse events were observed in 11 pts for each arm. Grade 3 or more diarrhea, hypertension, rash acneiform, paronychia and stomatitis were frequently observed in AfaBev arm. Pneumonitis was not observed for AfaBev arm and observed in 3 (6.0%) for Afa arm, and grade 3 in one patient. Conclusions: This study failed to show the efficacy of AfaBev arm for improving PFS in untreated pts with EGFR mutated non-squamous NSCLC. In pts &lt; 70 years old, Afa plus Bev might be promising. Clinical trial information: jRCTs061180006.

Outcomes of Patients with EGFR-Mutant Advanced NSCLC in a Developing Country in Southeast Asia.

BackgroundAlthough first- and second-generation EGFR TKIs are considered first-line treatment in EGFRm+ NSCLC, most patients develop resistance and progress, commonly, EGFR T790M mutation. The third-generation EGFR-TKI has demonstrated efficacy in patients with progressive disease harboring the T790M mutation and in the first-line setting, bypassing this mode of resistance. The primary objectives of this study are to describe the proportion of EGFRm+ NSCLC patients treated with first-, second- and third-generation EGFR TKIs, and cytotoxic chemotherapy in the first-line setting, and the time on treatment for each category. Secondary objectives are to determine the dropout rate, the rates for T790M mutation testing at disease progression and the type of subsequent treatment.MethodsThis multicenter retrospective study utilized data from the Malaysian Lung Cancer Registry that actively registers all lung cancer patients ≥18 years, with primary lung cancer confirmed histologically or cytologically. All patients diagnosed with advanced stages (ie stages IIIB, IIIC and IV) EGFRm+ NSCLC from 1st of January 2015 to 31st December 2019 were included.ResultsOf 406 patients with EGFRm+ NCSLC, 351 were treated. Types of first-line treatment were as follows: EGFR-TKIs (first generation – 54.1%, second generation – 25.6% and third-generation – 12.5%) and chemotherapy (7.7%). The median time of treatment for each generation of EGFR-TKI was 12 months, 12 months and 24 months, and 2 months for chemotherapy. The dropout rate was 28.7% (n = 101). Nearly half (49.4%) of patients who were on first- or second-generation EGFR-TKI had further genetic testing via liquid or tissue biopsies upon disease progression. About 24.9% of those who developed disease progression after first- or second-generation EGFR TKI were started on a third-generation EGFR TKI.ConclusionIn the real-world, the management of EGFRm+ advanced NSCLC patients in an Asian cost-restrictive setting may adversely affect the choice of first-line therapy, time on each line of treatment and subsequently the overall survival of patients.

Afatinib (AFA) plus bevacizumab (BEV) combination after osimertinib (OSI) resistance in advanced EGFR-mutant NSCLC: A phase II study (ABCD-study).

9117 Background: After OSI failure, various resistant mechanisms such as C797S and uncommon EGFR mutations, or MET amplification have been reported. AFA is an irreversible EGFR-TKI with a potency as pan-HER inhibitor, including high sensitivity to uncommon EGFR mutations. Many clinical studies have also shown a synergy of EGFR-TKIs and VEGF inhibitors. Methods: ECOG PS 0-1 patients (pt) with EGFR-mutant NSCLC were enrolled after OSI resistance. AFA was prescribed at 30-40 mg QD, and BEV was administered at 15 mg/kg tri-weekly until progression. Plasma/histologic rebiopsied samples taken after OSI failure but before enrollment were analyzed to examine resistant mechanisms including gene alterations/copy-number gain using cancer personalized profiling by deep sequencing. Results: Between January 2018 and October 2020, 28 pts were enrolled. Mutation subtypes were: 9 (32%) Del-19; 5 (18%) Del-19+T790M; 5 (18%) L858R; 7 (25%) L858R+T790M; 1 (4%) Del-19+L858R+T790M; and 1 (4%) G719S. Median line of prior OSI was 2 (range, 1-9). CR/PR was obtained by prior OSI in 24 (86%) pts. Regarding AFA+BEV efficacy, one (4%) CR, 4 (14%) PR, and 17 (61%) SD were confirmed, resulting in response rate of 17.9% and disease control rate of 78.6%. Median DoR was 9.0 (range, 4.2-22.3) months. Median PFS and OS were 2.7 (95% CI, 2.0-4.6) months and not reached, respectively. Twenty-eight (100%) plasma and/or 21 (75%) histologic rebiopsies identified: 17 (61%) TP53; 15 (54%) T790M; 9 (32%) uncommon EGFR; 9 (32%) MET; 6 (21%) C797S; 3 (11%) BRAF; 2 (7%) HER2; 2 (7%) KRAS; and 2 (7%) PI3K mutations; or 14 (50%) EGFR; 6 (21%) MET; and 2 (7%) HER2 amplifications. One (4%) small cell transformation was found. Among 6 C797S pts, 1 CR, 4 SD, and 1 PD were confirmed. Three (33%) of 9 uncommon EGFR and 1 (50%) of 2 HER2 mutation positive pts achieved radiographic response. All 15 T790M-positive pts showed no response, but 5 (38%) of 13 T790M-negative pts responded to AFA+BEV. None (0%) of six pts with EGFR downstream signaling mutations such as BRAF, KRAS, or PI3K responded. Five (50%) of 10 pts without T790M/BRAF/KRAS/PIK3 mutations exhibited confirmed response. FAT1 mutation was found in two (40%) of 5 responded pts. Dose reduction/interruption of AFA was performed in 15 (54%) pts. Median number of BEV administrations was 4 (range, 1-32). There were neither TRD nor ILD. Adverse events ≥grade 3: hypertension (29%); proteinuria (7%); diarrhea (7%); and rash (4%) were observed. One (4%) grade 4 duodenal perforation was reported. Conclusions: AFA+BEV after OSI resistance demonstrated moderate efficacy and favorable safety. A small portion of C797S pts exhibited the sensitivity. Higher potency was suggested in T790M/BRAF/KRAS/PIK3 mutation-negative and uncommon EGFR/HER2 mutation-positive pts. Selected population could obtain clinical benefit from AFA+BEV, based on rebiopsy results after OSI resistance. Clinical trial information: UMIN000030545.

Clinical Utility of Liquid Biopsy (Cell-free DNA) Based EGFR Mutation Detection Post treatment Initiation as a Disease Monitoring Tool in Patients With Advanced EGFR-mutant NSCLC

IntroductionPlasma cfDNA-based mutation analysis has shown disease-monitoring potential in various cancers. We assessed the potential of cfDNA-based EGFR mutation testing as a monitoring tool in patients with NSCLC. Patients and MethodsPatients with NSCLC harboring EGFR mutations receiving first-line treatment as per institutional protocol were enrolled. EGFR mutation status was determined using plasma samples at baseline and post treatment initiation. Patients in whom EGFR mutation was detected or persisted after treatment initiation were considered circulating tumor DNA (ctDNA)-positive. Progression-free survival (PFS) and overall survival (OS) for ctDNA-positive and negative patients post treatment initiation were the primary endpoints; concordance for baseline EGFR status between tissue and plasma and proportion of patients who were ctDNA-positive post treatment initiation were the secondary endpoints. ResultsWe enrolled 158 patients; 76 received gefitinib, and 82 received gefitinib plus chemotherapy. Median follow-up duration was 42 months. About 25% of patients were ctDNA-positive post treatment initiation. Median PFS for ctDNA-negative patients post treatment initiation was 14 (95% confidence interval [CI], 12.0-17.0) months, while that for ctDNA-positive patients was 8 (95% CI, 6.0-10.0) months. Median OS for ctDNA-negative patients post treatment initiation was 27 (95% CI, 24.0-32.0) months, while that for ctDNA-positive patients was 15 (95% CI, 11.0-19.0) months. Concordance at baseline between tissue and plasma samples was 75.4%. ConclusionPlasma-based EGFR mutation detection post treatment initiation can be used as a predictive marker for outcome in patients with EGFR-mutant NSCLC receiving first-line treatment.

High-Dose Osimertinib for CNS Progression in EGFR+ NSCLC: A Multi-Institutional Experience

IntroductionThis multicenter review evaluated the efficacy and safety of osimertinib dose escalation for central nervous system (CNS) progression developing on osimertinib 80 mg in EGFR-mutant NSCLC. MethodsRetrospective review identified 105 patients from eight institutions with advanced EGFR-mutant NSCLC treated with osimertinib 160 mg daily between October 2013 and January 2020. Radiographic responses were clinically assessed, and Kaplan-Meier analyses were used. We defined CNS disease control as the interval from osimertinib 160 mg initiation to CNS progression or discontinuation of osimertinib 160 mg. ResultsAmong 105 patients treated with osimertinib 160 mg, 69 were escalated for CNS progression, including 24 treated with dose escalation alone (cohort A), 34 who received dose-escalated osimertinib plus concurrent chemotherapy and/or radiation (cohort B), and 11 who received osimertinib 160 mg without any prior 80 mg exposure. The median duration of CNS control was 3.8 months (95% confidence interval [CI], 1.7–5.8) in cohort A, 5.1 months (95% CI, 3.1–6.5) in cohort B, and 4.2 months (95% CI 1.6–not reached) in cohort C. Across all cohorts, the median duration of CNS control was 6.0 months (95% CI, 5.1–9.0) in isolated leptomeningeal progression (n = 27) and 3.3 months (95% CI, 1.0–3.1) among those with parenchymal-only metastases (n = 23). Patients on osimertinib 160 mg experienced no severe or unexpected side effects. ConclusionAmong patients with EGFR-mutant NSCLC experiencing CNS progression on osimertinib 80 mg daily, dose escalation to 160 mg provided modest benefit with CNS control lasting approximately 3 to 6 months and seemed more effective in patients with isolated leptomeningeal CNS progression.

Overall Survival Benefits of First-Line Treatments for Asian Patients With Advanced EGFR-Mutated NSCLC Harboring L858R Mutation: A Systematic Review and Network Meta-Analysis

IntroductionRandomized controlled trials have investigated different first-line treatments for patients with advanced EGFR-mutated NSCLC. Nevertheless, their efficacy, in particular, the long-term overall survival (OS) benefit in Asian patients with L858R mutation, remains unclear. MethodsWe performed a systematic review and frequentist network meta-analysis by retrieving relevant literature from PubMed/MEDLINE, Ovid, EMBASE, Cochrane Library, trial registries, and other sources. We included randomized controlled trials comparing two or more treatments in the first-line setting for Asian patients with L858R mutation. This study was registered in the Prospective Register of Systematic Reviews (CRD 42022295897). ResultsThere were a total of 18 trials that involved 1852 Asian patients and 12 treatments, including the following: EGFR tyrosine kinase inhibitors (TKIs) (osimertinib, dacomitinib, afatinib, erlotinib, gefitinib, and icotinib), pemetrexed-based chemotherapy, pemetrexed-free chemotherapy, and combination treatments (gefitinib plus apatinib, erlotinib plus ramucirumab, erlotinib plus bevacizumab and gefitinib plus pemetrexed-based chemotherapy). Asian patients with L858R mutation had no significant OS benefits from all these treatments. Gefitinib plus pemetrexed-based chemotherapy, dacomitinib, osimertinib, and erlotinib plus bevacizumab were found to be consistent in yielding the best progression-free survival benefit (p scores = 93%, 79%, 77%, and 70%). Combination treatments caused more toxicity, especially erlotinib plus bevacizumab and gefitinib plus pemetrexed-based chemotherapy, resulting in the greatest incidence of grade greater than or equal to 3 adverse events. ConclusionsIn Asian patients harboring L858R mutation, EGFR TKIs and combination treatments had no OS benefit when compared with conventional chemotherapies. Further studies are warranted to investigate the resistance mechanism with TKIs and potential combination strategies in patients with this common but less favorable mutation.

Research Advances of EGFR-TP53 Co-mutation in Advanced Non-small Cell Lung Cancer

随着二代基因检测（next generation sequencing, NGS）技术的快速发展及广泛应用，多种共突变基因被我们发现。许多研究表明，共突变在表皮生长因子受体（epidermal growth factor receptor, EGFR）突变型非小细胞肺癌（non-small cell lung cancer, NSCLC）中对EGFR酪氨酸激酶抑制剂（EGFR tyrosine kinase inhibitor, EGFR-TKI）的反应和耐药起着重要作用。其中，TP53作为EGFR突变型NSCLC最常见的共突变基因，已被证明是一代、二代及三代EGFR-TKIs治疗预后差的重要因素，如何为EGFR-TP53共突变的晚期NSCLC患者选择最佳的治疗策略，目前仍在探索中。本文就近年来关于晚期NSCLC患者EGFR-TP53共突变的研究进展作一综述。

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.

Induction EGFR tyrosine kinase inhibitors prior to definitive chemoradiotherapy in unresectable stage III EGFR-mutated non-small cell lung cancer

IntroductionIncreasing evidence suggests that consolidation durvalumab confers limited benefits for patients with stage III EGFR-mutated NSCLC. Induction or maintenance EGFR tyrosine kinase inhibitors (TKIs) added to concurrent chemoradiotherapy (CRT) may optimize definitive treatment, but there are limited data supporting an induction TKI strategy. MethodsWe evaluated the efficacy and safety of induction EGFR TKIs administered before concurrent CRT in a retrospective series of patients with unresectable locally advanced EGFR-mutated NSCLC. Circulating tumor DNA (ctDNA) analysis was performed on a patient subset using CAPP-seq and correlated with outcomes. ResultsOf six patients, three received erlotinib and three osimertinib as induction therapy before CRT. Induction TKIs were administered for a median of 2.5 months. The objective response rate after induction TKI was 83%. One patient had a complete response to induction erlotinib and continued erlotinib for 4 years until local progression, which was treated with CRT. Two patients completed maintenance erlotinib after CRT, and another received consolidation durvalumab. After a median follow-up of 20.5 months, only one patient developed disease recurrence, with rising ctDNA coinciding with recurrence. ctDNA remained undetectable in patients without recurrence, or low-level in a patient receiving maintenance erlotinib. Adverse events were mild and expected, and none developed pneumonitis. ConclusionInduction EGFR TKI before CRT may achieve high disease control rates with promising signs of durability in patients with locally advanced EGFR-mutated NSCLC. ctDNA analysis after CRT can correlate well with clinical outcomes. Prospective studies are needed to define the role of induction EGFR TKIs in this setting.

Afatinib After Progression on Osimertinib in EGFR-Mutated Non-Small Cell Lung Cancer

After the development of acquired resistance to osimertinib, the standard-of-care treatment for advanced EGFR-mutated NSCLC is chemotherapy. Whether afatinib, a pan-ErbB family tyrosine kinase inhibitor, is active after progression on osimertinib is unknown. We conducted a single-institution retrospective analysis of patients with advanced EGFR-mutated NSCLC who received afatinib-containing therapy after progression on osimertinib. Kaplan-Meier analyses evaluated progression-free survival (PFS) and overall survival (OS) from initiation of afatinib. After progression on first (N=3) or second-line plus (N=12) osimertinib, 15 patients received afatinib monotherapy (N=3), afatinib and cetuximab (N=10), or afatinib and bevacizumab (N=2). The objective response rate was 6.7% and disease control rate was 53.3%. Median PFS was 2.5 months and median OS was 7.7 months. Median PFS of ≥ 6 months versus < 6 months on osimertinib was associated with a significantly greater median PFS on afatinib (4.0 versus 1.4 months; P=0.003), although there was no significant difference in median OS (9.3 versus 6.6 months; P=0.123). Best response of stable disease/partial response versus progressive disease on osimertinib was associated with a significantly greater median PFS on afatinib (3.4 versus 1.6 months; P=0.036) and a significantly greater median OS (8.7 versus 4.6 months; P=0.017). Afatinib-containing therapy had limited activity in patients with EGFR-mutated NSCLC after progression on osimertinib in this cohort of mostly second-line plus osimertinib. Response and longer PFS to prior osimertinib may be predictive of response to afatinib. Strategies based on osimertinib resistance mechanisms may further define the role of subsequent afatinib.

Gefitinib plus tremelimumab combination in refractory non-small cell lung cancer patients harbouring EGFR mutations: The GEFTREM phase I trial

IntroductionA phase I open-label multicentre study was initiated to evaluate the association of tremelimumab with gefitinib in EGFR-mutant NSCLC patients who progressed after first-generation EGFR-TKI. Here we provide the efficacy data from the entire cohort. Material and methodsPatients with advanced EGFR-mutant NSCLC with progression after response to EGFR-TKI were enrolled. Study treatment was gefitinib 250 mg daily and tremelimumab at 3 dose levels: 3, 6 and 10 mg/kg IV Q4W for 6 cycles followed by Q12W until progression or unacceptable toxicity. The primary objective was safety and tolerability, and to establish a RP2D. ResultsBetween January 2014 and July 2015, 27 patients (21 in the escalating dose cohort and 6 in expansion cohort) received at least one dose of tremelimumab. DLTs occurred in 4 patients: 1 at 3 mg/kg (one grade 3 diarrhoea), 1 at 6 mg/kg (one grade 3 diarrhoea) and 2 at 10 mg/kg (one grade 3 diarrhoea and one grade 3 AST/ALT increase) of tremelimumab. Grade 3 TRAE occurred in 22 patients (81%), most frequently diarrhoea (30%) and ALT/AST increase (15%). Stable disease was the best overall response in 72% patients, with median PFS of 2.2 months (95% CI, 1.8–4.2). All patients discontinued treatment, most frequently due to disease progression (63% of patients). ConclusionThe recommended dose of tremelimumab in combination with gefitinib in EGFR-mutant NSCLC patients was 3 mg/kg. The gastrointestinal toxicity and the limited efficacy data prevented further evaluation of this combination. (GEFTREM; clinical trial number NCT02040064)

Incorporating circulating tumor DNA detection to radiographic assessment for treatment response in advanced EGFR-mutant lung cancer

PurposeResponse Evaluation Criteria in Solid Tumors (RECIST) has limitations but remains the conventional approach for tumor assessments. We explored whether circulating tumor DNA (ctDNA) can be incorporated into RECIST to provide a more robust measure of tumor response in advanced EGFR-mutant NSCLC. Patients and methodsIn FASTACT-2, patients with advanced NSCLC received platinum/gemcitabine intercalated with erlotinib or placebo. EGFR mutation (tumor and plasma ctDNA) was detected using cobas v2. Patients selected for this hypothesis-generating analysis had EGFR mutations (on either tumor or plasma) at baseline and evaluable week 8 plasma EGFR. Week 8 ctDNA and radiologic response status were correlated with survival using landmark cox regression analyses. ResultsOf the original 451 patients, 86 (19.1%) were eligible for this analysis. 73% (n = 63) had detectable ctDNA at baseline. At week 8, 40% (n = 34) had radiologic partial response (PR), 60% (n = 52) had stable disease (SD); 80% (n = 69) had a ctDNA response (undetectable ctDNA). In patients who had initial PR and undetectable ctDNA, 93% (28/30) had ongoing PR subsequently at week 16. The median duration of response was 14.9 months. In patients with SD and undetectable ctDNA at week 8, 28% had radiological PR at week 16. Amongst those with PR at week 8, survival outcomes for those with undetectable vs detectable ctDNA were not statistically significant (PFS HR 0.49, 95%CI 0.16–1.48, p = 0.21; OS HR 0.39, 95%CI 0.13–1.19, p = 0.10). Amongst those with SD at week 8, there was significantly longer survival for those with undetectable vs detectable ctDNA (PFS HR 0.27, 95% CI 0.13–0.57, p < 0.0001; OS HR 0.40, 95% CI 0.20–0.80, p = 0.009). ConclusionIn patients with SD, undetectable ctDNA at week 8 correlated with survival improvement. Both radiologic and ctDNA responses are prognostic of PFS. Incorporation of ctDNA with RECIST may improve tumor response assessment in EGFR-mutant NSCLC.

Plasma ctDNA Response Is an Early Marker of Treatment Effect in Advanced NSCLC.

Patients with advanced EGFR-mutant NSCLC across three phase I NCI osimertinib combination trials were analyzed in this study, and an institutional cohort of patients with KRAS-, EGFR-, and BRAF-mutant advanced NSCLC receiving systemic treatment was used for validation. Plasma was collected before treatment initiation and serially before each cycle of therapy, and key driver mutations in ctDNA were characterized by droplet digital polymerase chain reaction. Timing of plasma versus imaging response was compared in a separate cohort of patients with EGFR-mutant NSCLC treated with osimertinib. Across cohorts, we also studied ctDNA variability before treatment start. In the NCI cohort, 14/16 (87.5%) patients exhibited ≥ 90% decrease in mutation abundance by the first on-treatment timepoint (20-28 days from treatment start) with minimal subsequent change. Similarly, 47/56 (83.9%) patients with any decrease in the institutional cohort demonstrated ≥ 90% decrease in mutation abundance by the first follow-up draw (7-30 days from treatment start). All 16 patients in the imaging cohort with radiographic partial response showed best plasma response within one cycle, preceding best radiographic response by a median of 24 weeks (range: 3-147 weeks). Variability in ctDNA levels before treatment start was observed. Plasma ctDNA response is an early phenomenon, with the majority of change detectable within the first cycle of therapy. These kinetics may offer an opportunity for early insight into treatment effect before standard imaging timepoints.

Monitoring cfDNA in Plasma and in Other Liquid Biopsies of Advanced EGFR Mutated NSCLC Patients: A Pilot Study and a Review of the Literature.

Simple SummaryIn advanced non-small cell lung cancer (NSCLC) patients, tumor tissue biopsy represents the gold standard for molecular analysis procedures. However, to achieve the necessary information, both at the time of diagnosis and progressive disease, is sometimes challenging, considering the small cancer material available. Liquid biopsy consists of a non-invasive alternative approach that owns the potential to provide useful information for molecular diagnostic. We aimed to prove the worth of liquid biopsy as plasma but also as urine and exhaled breath condensate (EBC) as the best surrogate to tumor tissue as well as to explore the molecular mechanisms that underlying the resistance to second-line osimertinib in advanced EGFR mutated NSCLC. We believe that our findings, with the PLUREX study and the review of literature, may add another brick in the wall on the use of liquid biopsy in the clinical practice in the setting of EGFR-mutated NSCLC disease.In order to study alternatives at the tissue biopsy to study EGFR status in NSCLC patients, we evaluated three different liquid biopsy platforms (plasma, urine and exhaled breath condensate, EBC). We also reviewed the literature of the cfDNA biological sources other than plasma and compared our results with it about the sensitivity to EGFR mutation determination. Twenty-two EGFR T790M-mutated NSCLC patients in progression to first-line treatment were enrolled and candidate to osimertinib. Plasma, urine and EBC samples were collected at baseline and every two months until progression. Molecular analysis of cfDNA was performed by ddPCR and compared to tissue results. At progression NGS analysis was performed. The EGFR activating mutation detection reached a sensitivity of 58 and 11% and for the T790M mutation of 45 and 10%, in plasma and urine samples, respectively. Any DNA content was recovered from EBC samples. Considering the plasma monitoring study, the worst survival was associated with positive shedding status; both plasma and urine molecular progression anticipated the radiological worsening. Our results confirmed the role of plasma liquid biopsy in testing EGFR mutational status, but unfortunately, did not evidence any improvement from the combination with alternative sources, as urine and EBC.