EGFR-mutant NSCLC Patients Research Articles

12P A phase II study of atezolizumab in combination with bevacizumab, carboplatin or cisplatin, and pemetrexed for EGFR-mutant metastatic NSCLC patients after failure of EGFR TKIs

Acquired resistance to EGFR TKI remains a significant barrier for patients with EGFR-mutated lung cancer, especially for those without acquired EGFRT790M. The current study explored the safety and efficacy of combinational treatment with atezolizumab, bevacizumab, and pemetrexed-platinum in patients with EGFR-mutated NSCLC after failure of EGFR TKIs.

Effect of Osimertinib on CTCs and ctDNA in EGFR Mutant Non-Small Cell Lung Cancer Patients: The Prognostic Relevance of Liquid Biopsy.

Simple SummaryOsimertinib has become the standard of care for the first-line treatment of EGFR-mutant NSCLC patients. The aim of this current translational research study was to assess the clinical relevance of liquid biopsy in 47 patients receiving osimertinib. Effects on circulating tumor cells (CTCs) and plasma-DNA (ctDNA) were investigated before, after one treatment cycle, and at the end of treatment. ctDNA and CTCs decreased after one treatment cycle, but increased at the end of treatment. The detection of ctDNA before and after one treatment cycle was associated with shorter progression-free and overall survivals (PFS and OS), whereas ctDNA clearance after one treatment cycle resulted in a significantly longer PFS and OS. ctDNA at baseline emerged as an independent predictor of shorter PFS. Thus, changes in liquid biopsy status (CTCs, ctDNA) during osimertinib treatment can be used as a tool for treatment efficacy.Introduction: Liquid biopsy is a useful tool for monitoring treatment outcome in solid tumors, including lung cancer. The relevance of monitoring CTCs and plasma ctDNA as predictors of clinical outcome was assessed in EGFR-mutant NSCLC patients treated with osimertinib. Methods: Forty-seven EGFR-mutant NSCLC patients who had progressed on prior first- or second-generation EGFR inhibitors were enrolled in the study and treated with osimertinib, irrespective of the presence of the T790M mutation in the primary tumor or the plasma. Peripheral blood was collected at baseline (n = 47), post-Cycle 1 (n = 47), and at the end of treatment (EOT; n = 39). CTCs were evaluated in 32 patients at the same time points (n = 32, n = 27, and n = 21, respectively) and phenotypic characterization was performed using triple immunofluorescence staining (CK/VIM/CD45). Results: Osimertinib resulted in an ORR of 34% (2 CR) and a DCR of 76.6%. The median PFS and OS values were 7.5 (range, 0.8–52.8) and 15.1 (range, 2.1–52.8) months, respectively. ctDNA was detected in 61.7%, 27.7%, and 61.5% of patients at baseline, post-Cycle 1, and EOT, respectively. CTCs (CK+/CD45-) were detected in 68.8%, 48.1%, and 61.9% of patients at the three time points, respectively. CTCs expressing both epithelial and mesenchymal markers (CK+/VIM+/CD45-) were detected in 56.3% and 29.6% of patients at baseline and post-Cycle 1, respectively. The detection of ctDNA at baseline and post-Cycle 1 was associated with shorter PFS and OS, whereas the ctDNA clearance post-Cycle 1 resulted in a significantly longer PFS and OS. Multivariate analysis revealed that male sex and the detection of ctDNA at baseline were independent predictors of shorter PFS (HR: 2.6, 95% C.I.: 1.2–5.5, p = 0.015 and HR: 3.0, 95% C.I.: 1.3–6.9; p = 0.009, respectively). Conclusions: The decrease in both CTCs and ctDNA occurring early during osimertinib treatment is predictive of better outcome, implying that liquid biopsy monitoring may be a valuable tool for the assessment of treatment efficacy.

The EPICAL trial, a phase Ib study combining first line afatinib with anti-EGF vaccination in EGFR-mutant metastatic NSCLC

IntroductionCombination of anti-EGFR monoclonal antibodies or immune checkpoint inhibitors with TKIs has shown minimal benefit in EGFR mutant (EGFR-mut) NSCLC patients. Consequently, new combination approaches are needed. Patients and methodsThe EPICAL was a single arm, phase 1b study to evaluate safety, tolerability and anti-tumor activity of first line afatinib combined with anti-EGF vaccination in advanced EGFR-mut patients. EGFR status and mutations in liquid biopsies were determined by reverse transcriptase-polymerase chain reaction; serum biomarkers by ELISA and Western blotting analysis. ResultsThe assay enrolled 23 patients, 21 completed the anti-EGF immunization phase. Treatment was well tolerated and no serious adverse events (SAEs) related to the anti-EGF vaccine were reported. Objective response and disease control rates were 78.3% (95%CI = 53.6–92.5) and 95.7% (95%CI = 78.1–99.9), respectively. After a median follow-up of 24.2 months, median progression-free survival (PFS) was 14.8 months (95% CI = 9.5–20.1) and median overall survival (OS) 26.9 months (95% CI = 23.0–30.8). Among the 21 patients completing the immunization phase, PFS was 17.5 months (95% CI = 12.0–23.0) and OS 26.9 months (95% CI = 24.6-NR). At the end of the immunization phase, all 21 patients showed high serum titers of anti-EGF antibodies, while EGF levels had decreased significantly. Finally, treatment with fully immunized patient’s sera inhibited the EGFR pathway in tumor cells growing in vitro. ConclusionsCombination treatment with an anti–EGF vaccine is well tolerated; induces a sustained immunogenic effect and might enhance the clinical efficacy of EGFR TKIs.

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)

Comparison of first-generation EGFR-TKIs (gefitinib, erlotinib, and icotinib) as adjuvant therapy in resected NSCLC patients with sensitive EGFR mutations.

BackgroundSeveral randomized controlled trials have suggested that adjuvant epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) were associated with prolonged disease-free survival (DFS) in EGFR-mutated NSCLC patients after radical resection, comparing with chemotherapy or placebo. We aimed to compare the effectiveness of different first-generation EGFR-TKIs as adjuvant treatment in real-world setting.MethodsEarly-stage EGFR mutated NSCLC patients who underwent radical resection and treated with first-generation EGFR-TKIs (gefitinib, erlotinib, icotinib) as adjuvant therapy between Feb 2010 and Jan 2019 were retrieved from a prospectively-maintained database in our center. The primary endpoint was DFS in stage II/III (TNM 8th) patients with exploratory endpoint regarding DFS in stage I patients. Sensitivity analyses were based on propensity score matched (PSM) cohorts. Treatment failure patterns among different TKIs were also compared.ResultsOf 588 eligible patients, 198 patients (33.7%) received gefitinib, 106 patients (17.9%) received erlotinib, and 284 patients (48.2%) received icotinib. The median DFS of stage II/III patients in the gefitinib, erlotinib and icotinib group were 36.1 months (95% CI, 23.9–49.4), 42.8 months (95% CI, 29.6–97.8), and 32.5 months (95% CI, 23.9–49.4), respectively, with no significant difference (log-rank test P=0.22). There was also no significant difference in DFS among stage I patients receiving different TKIs (P=0.12). PSM adjustments and multivariate analyses adjusting for other confounders revealed similar results. In addition, there were no significant differences in treatment failure pattens in different EGFR-TKI arms, especially in terms of brain metastases (6.1% in gefitinb, 7.5% in erlotinib, 3.9% in icotinib) and bone metastases (8.6% in gefitinb, 9.4% in erlotinib, 7.0% in icotinib).ConclusionsThis first and largest real-world study showed that gefitinib, erlotinib, and icotinib demonstrated comparable clinical effectiveness as adjuvant therapy for patients with early-stage EGFR mutated NSCLC.

DNA Methylation Analysis in Plasma Cell-Free DNA and Paired CTCs of NSCLC Patients before and after Osimertinib Treatment.

Simple SummaryLiquid biopsy is a highly useful tool for the management of NSCLC patients and could provide valuable information on early detection of resistance to osimertinib. Epigenetic biomarkers are very promising for the early diagnosis, prognosis, and prediction of drug response in many types of cancer. We performed a DNA methylation analysis in plasma cell-free DNA and paired CTCs of NSCLC patients before osimertinib treatment and at progression of disease (PD). Our results revealed a significant increase in DNA methylation at PD. Epigenetic alterations should be further evaluated as a possible resistance mechanism to osimertinib and their detection in liquid biopsy samples can be valuable for the follow-up of patients in real time.Osimertinib has been an effective second-line treatment in EGFR mutant NSCLC patients; however, resistance inevitably occurs. DNA methylation has been previously implicated in NSCLC progression and often in therapy resistance, however its distinct role in osimertinib resistance is not elucidated as yet. In the present study, we directly compared DNA methylation of nine selected genes (RASSF1A, RASSF10, APC, WIF-1, BRMS1, SLFN11, RARβ, SHISA3, and FOXA1) in plasma-cfDNA and paired CTCs of NSCLC patients who were longitudinally monitored during osimertinib treatment. Peripheral blood (PB) from 42 NSCLC patients was obtained at two time points: (a) baseline: before treatment with osimertinib and (b) at progression of disease (PD). DNA methylation of the selected genes was detected in plasma-cfDNA (n = 80) and in paired CTCs (n = 74). Direct comparison of DNA methylation of six genes between plasma-cfDNA and paired CTC samples (n = 70) revealed a low concordance, indicating that CTCs and cfDNA give complementary information. DNA methylation analysis of plasma-cfDNA and CTCs indicated that when at least one of these genes was methylated there was a statistically significant increase at PD compared to baseline (p = 0.031). For the first time, DNA methylation analysis in plasma-cfDNA and paired CTCs of NSCLC patients during osimertinib therapy indicated that DNA methylation of these genes could be a possible resistance mechanism.

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.

Stereotactic body radiotherapy to the primary lung lesion improves the survival of the selected patients with non-oligometastatic NSCLC harboring EGFR activating mutation with first-line EGFR-TKIs: a real-world study.

This study aimed to explore the clinical value of SBRT for primary lung lesions of EGFR-mutant NSCLC patients with non-oligometastatic disease during first-line EGFR-TKI treatment. We identified patients with stage IV EGFR-mutant non-oligometastatic NSCLC who were suitable to receive SBRT for the primary tumors after EGFR-TKI treatment. All selected patients were treated with first-line EGFR-TKIs and SBRT for their primary lesions. The primary endpoints were the progression-free survival 1 (PFS1, time of first TKI dose relative to disease progression based on RECIST) and PFS2 (time of first TKI dose relative to disease progression after SBRT). The secondary endpoints were overall survival (OS) and safety. Seventy-nine patients were enrolled, including 45 patients who received SBRT for their primary tumor at the maximal response of EGFR-TKI (the preemptive RT group) and 34 patients who received SBRT for their primary tumor after the occurrence of oligoprogression (the delayed RT group). The preemptive RT group had a significantly better median PFS1 than the delayed RT group (22.3months vs. 12.9months, P = 0.0031). The median PFS2 in the preemptive RT and delayed RT groups were 22.3 and 28.9months, respectively (P = 0.17). The median OS did not differ significantly between the preemptive RT group and the delayed RT group (46.6 versus 51.3months, P = 0.54). No severe toxicities (≥ grade 3) were recorded. This real-world study showed that preemptive RT to primary lung tumors is a feasible option for selected patients with EGFR-mutant non-oligometastatic NSCLC who had stable disease during first-line EGFR-TKI treatment, and that it significantly improved PFS.

OA16.03 Matched Targeted Therapy by cfDNA of CSF Beyond Leptomeningeal Metastases Progression Upon Osimertinib in EGFR-Mutated NSCLC Patients

Despite better efficacy of osimertinib for central nervous system (CNS) metastases, CNS progression is still frequently seen in EGFR-mutated NSCLC patients. Currently, clinical utility of cerebrospinal fluid (CSF) as well as subsequent treatments were unexplored after standard-dose osimertinib failure with leptomeningeal metastases (LM) progression.

P48.03 Spectrum of Resistance Mechanisms to First, Second and Third Generation Tyrosine Kinase Inhibitors in EGFR Mutant NSCLC Patients

Resistance to first(1st), second(2nd) and third (3rd) generation of tyrosine kinase inhibitors(TKIs) in EGFR mutant NSCLC targeted therapies can be classified as either primary (i.e., intrinsic) or secondary (i.e., acquired). Primary resistance implies a de novo lack of response whereas secondary resistance refers to disease progression after a period of initial clinical benefit.Next generation sequencing(NGS) offers a comprehensive method of detecting these mechanisms to decide the next line of treatment.

P59.31 A High Number of Co-Current Genetic Alterations Is Associated With Poor Survival in EGFR Mutated Metastatic NSCLC Patients

Patients with NSCLC harboring EGFR mutations have good tumor responses with EGFR TKI, however approximately 10% of patients show no disease control. Survival in patients receiving EGFR-TKI is associated with the number of genomic alterations and TMB also been associated with worse clinical outcomes. The importance of co-current genomic alterations detected by foundation one remains to be determined. We decide to explore the importance of co-current alterations in our NSCLC patients with EGFR mutations. In a single center from March 2018 to February 2020 we analyzed prospectively 23 tumor tissue of NSCLC patients with EGFR mutations. Patients were diagnosed with RT PCR, and underwent genotyping using Next generation sequencing platform, Foundation One assay. Kaplan Meier curves were used to evaluate median progression-free survival (PFS) and Overall survival (OS). Twenty three patients were evaluated in this cohort. Mean age was 57. 56.5% patients were never smoker. 13 (56.5%) patients had >3 co-current genomic alterations in the foundation one assay. Adenocarcinoma was the only histological type (100%) and solid pattern the most common subtype (34.8%). Exon 19 del and L858R were the most common mutations. 11 patients received EGFR- TKI as first-line treatment. The most common co- current alteration was TP53 mutation in 12 patients (48%). A ROC curve was done and 3 mutations was related with a difference in survival ( AUC 0.67 sensitivity: 90.3 %, specificity: 71.2%). Median PFS was 36.1 vs 5.1 months in patients with <3 vs >3 mutations (p= 0.013). OS was higher in the <3 mutations group, with median OS of 47 months vs 22 months but this was not significant. (p=0.53) (Figure 1) In NSCLC patients with EGFR mutations treated with EGFR-TKI the presence of three or more genomic alterations evaluated by the Foundation one assay was associated with worse survival.

P07.02 Real World data of Advanced Non-Small Cell Lung Cancer Patients EGFR Mutated from a Peruvian Cohort

Tyrosine kinase inhibitors anti-EGFR are the standard of care for NSCLC patients with sensitive EGFR mutations, however, the knowledge on the real benefit of these therapies in the real-world setting remains unclear. The aim of this study is to evaluate the characteristics and outcomes of EGFR mutated NSCLC patients treated in a real-world Latin American setting. Retrospective analysis of advanced NSCLC patients EGFR mutated diagnosed at Instituto Nacional de Enfermedades Neoplasicas (INEN), Lima-Peru from 2013 to 2020. Main clinical analysis, including ORR, PFS and OS, was performed only in patients who received anti-EGFR TKI (Erlotinib) at the institution. Data were collected from medical records. During the study period, we analyzed the EGFR mutational status of 448 cases using tissue PCR or liquid biopsy in cases of insufficient material. Pathological EGFR mutations was found in 47% patients (n=211). Among these, the distribution of mutations was as follows: 61% exon 19 deletion, 25% L858R mutation, 12.6% EGFR uncommon mutations/associations, and 1.4% de-novo T790M mutation. Median age at diagnosis was 60 years (range 22-89y) and most patient were females (65.9%). Out of EGFR mutated patients, 129 (61.1%) received anti-EGFR TKI as a part of treatment at INEN, of them, 20.2% had smoking history and 24.8% biomass exposition as a main risk factor. About clinical presentation, 96 patients (74.4%) had status performance 1 (ECOG) and 37 (28.7%) presented brain metastases at diagnosis. Concerning treatment, 64.3% of patients (n=83) received TKI as first line and 35.7% as second or later line of treatment. The ORR was 86.8%. Median PFS was 14.13 months and median OS was 29.73 months. No differences in PFS and OS were found according to line of treatment (first vs second or later, p=0.69 and p=0.29 respectively) or type of mutation (exon 19 deletion vs L858R mutation vs uncommon mutations/associations, p=0.84 and p=0.50). Out of the 76 patients who progressed, half of them had T790M mutation assessment, finding 27.6% positive cases (21 patients). The proportion of EGFR mutated NSCLC in this cohort is higher than the reported in other countries outside Latin America or Asia. Our patients achieve high response rates and prolonged survival with no differences between the line of treatment or type of mutation. Results of this analysis confirm the benefit of use target therapies in the real-world setting.

Concomitant Pulmonary Tuberculosis Impair Survival in Advanced Epidermal Growth Factor Receptor (EGFR) Mutant Lung Adenocarcinoma Patients Receiving EGFR-Tyrosine Kinase Inhibitor.

ObjectiveLimited studies have clearly demonstrated the effect of EGFR-TKI in the treatment of EGFR mutant NSCLC patients with underlying pulmonary disease, like pulmonary tuberculosis (PTB). Here, we conducted the study to evaluate the impact of PTB on survival of Chinese EGFR mutant lung adenocarcinoma (LUAD) patients that underwent EGFR-TKI treatment.MethodsClinicopathologic data of 1448 LUAD patients harboring EGFR mutations from the Guangzhou Chest Hospital between 2017 and 2019 were reviewed retrospectively. Patients receiving EGFR-TKI treatment were divided into PTB and non-PTB groups. The differences in response to EGFR-TKIs and survival between the two groups were assessed.ResultsAfter EGFR-TKIs treatment, the objective response rate (58.14% vs 47.62%) as well as disease control rate (97.67% vs 85.71%) were higher in the non-PTB group than in the PTB group, but there was no statistical difference. In the survival analysis, both the median progression-free survival (7.47 months vs 11.77 months, p = 0.038) and the overall survival (13.00 months vs 20.00 months, p = 0.001) were significantly shorter in the PTB group than in the non-PTB group. Furthermore, for patients with 19Del mutation, or metastases sites less than 3, or using first-line EGFR-TKI, EGFR-TKIs treatment significantly prolonged the median PFS and OS in patients without PTB.ConclusionLUAD patients with concomitant PTB have a poor response to EGFR-TKI treatment, especially in terms of survival outcome.

Liquid Biopsy for EGFR Mutation Analysis in Advanced Non-Small-Cell Lung Cancer Patients: Thoughts Drawn from a Real-Life Experience.

Background: Liquid biopsy analysis for EGFR detection in cell-free DNA (cfDNA) from NSCLC patients has become routine. The aim of this study was to explore its applicability in clinical practice. Methods: We collected data of EGFR-mutated NSCLC patients with liquid biopsy analysis. Data included test timing, concomitant tissue re-biopsy, therapy change, histology, stage, smoking habits, gender and age. All analyses were performed via a real-time PCR method to analyze EGFR mutations at exons 18, 19, 20 and 21. Variant allele frequency was performed for patients with available sequential EGFR mutation analysis in cfDNA. Overall survival was analyzed through the Kaplan–Meier method. We designed flow charts to show the real-life application of liquid biopsy. Results: We found that liquid biopsy is used in treatment-naïve patients as an alternative to EGFR detection in tumor tissue, and in patients with positive or negative EGFR from tumor biopsy. The majority of liquid biopsy analyses were performed in NSCLC patients who were disease progressive during TKI therapy. The presence of EGFR mutation in cfDNA was associated with a worse prognosis. In two patients, VAF of EGFR mutations in cfDNA was concordant with tumor volume changes. Conclusion: These findings suggest that liquid biopsy for EGFR detection can continue to be useful.

1207O Bevacizumab + erlotinib vs erlotinib alone as first-line treatment of pts with EGFR mutated advanced non squamous NSCLC: Final analysis of the multicenter, randomized, phase III BEVERLY trial

Adding bevacizumab to erlotinib prolonged PFS in NEJ026 and CTONG 1509 trials, but limited data are available in non-Asian patients (pts). BEVERLY is an Italian no-profit, randomized, open-label, multicenter phase III trial of bevacizumab (BEV) plus erlotinib (E) vs E alone as first-line treatment for EGFR-mutated advanced NSCLC. Eligible pts were randomized 1:1 to E (150mg daily) alone or combined with BEV (15mg/kg iv q3w) until disease progression or unacceptable toxicity. Center, ECOG PS and type of mutation (ex19 deletion vs ex21 L858R vs others) were stratification variables. Co-primary endpoints were investigator-assessed PFS (IA-PFS) and blinded-independent centrally-reviewed PFS (BICR-PFS). Secondary endpoints were OS, QoL, IA- and BICR- objective response rate (ORR) and safety; biomarker analyses are also planned. 126 events out of 160 randomized pts were required to detect a PFS prolongation with BEV from 10 to 16.7 mos (HR 0.60), with 2-sided α=0.05, 80% power. From Apr 11, 2016 to Feb 27, 2019, 160 pts were randomized to BEV+E (80) or E alone (80). Pts were mainly female (63.8%), never smokers (51.9%), ECOG PS 0-1 (98.1%), median age 66 (IQR 59-73); 55% of pts had ex19Del and 41% L858R mutation. At a median follow-up of 31 mos, 130/160 (81.3%) pts had a PFS event (progression or death) and 84/160 (52.5%) died. BEV+E significantly prolonged IA-PFS over E alone with a median of 15.4 vs 9.7 mos (HR 0.60; 95%CI 0.42-0.85, log-rank P=0.0039). Median OS was 28.4 vs 23.0 mos in BEV+E and E arms, respectively (HR 0.70; 95%CI 0.46-1.10, log-rank P=0.12). One toxic death was reported, due to intracranial hemorrhage with BEV+E. Hypertension (any grade: 49% vs 18%; grade≥3: 24% vs 5%), skin rash (grade≥3: 31% vs 14%), thromboembolic events (any grade: 11% vs 4%), and proteinuria (any grade: 23% vs 6%) were more frequent with the experimental combination treatment. The addition of BEV to E significantly prolonged IA-PFS compared with E alone as first-line treatment in Italian EGFR-mutated NSCLC patients, with no unexpected safety issues. Blinded radiologic revision of PFS and ORR is ongoing and will be presented at the meeting.

The safety and efficacy of erlotinib and ramucirumab combination in EGFR-mutant non-small-cell lung cancer

ABSTRACT Introduction EGFR-tyrosine kinase inhibitors (TKIs) changed the natural history of EGFR-mutant advanced NSCLC patients, but acquired resistance is inevitable. New strategies are being tested to overcome or prevent the emergence of resistance mechanisms to first-line TKIs, among which combinations of TKIs with antiangiogenic agents. Areas covered We performed a literature search for preclinical and clinical data on the interplay and dual inhibition of EGFR/VEGF pathways, particularly in EGFR-mutant NSCLC. We then focused on RELAY, a placebo-controlled phase 3 trial evaluating ramucirumab combined to erlotinib in treatment-naïve advanced EGFR-mutant NSCLC patients. This article aims to summarize efficacy and safety of the ramucirumab-erlotinib combination in this setting. Expert opinion RELAY confirmed the clinical relevance of combining EGFR and VEGF(R)-targeting therapies, previously investigated in smaller phase 2–3 trials of erlotinib and bevacizumab. However, the meaningful PFS benefit observed in the ramucirumab + erlotinib arm is counterbalanced by the toxicity profile of ramucirumab and the need for bimonthly infusions. Pending OS results are, therefore, critical to assess the real benefit from this combination, especially as first-line osimertinib has improved survival in EGFR-mutant NSCLC patients and will probably remain the pivotal EGFR-TKI in this setting. However, its heterogeneous efficacy across subgroups paves the way for osimertinib-based combinations, which are being investigated in ongoing trials.

Abstract 1431: Role of emt biomarkers in mediating osimertinib resistance in non-small cell lung cancer

Abstract Osimeritinib (OR), a Tyrosine Kinase Inhibitor is a first-line therapy in EGFR-mutant NSCLC patients. Resistance to OR treatment may occur due to acquired C797S mutations, MET amplifications and ALK rearrangements and other mechanisms not clearly defined. EMT may be one of the reasons for TKI resistance. EMT is a process by which epithelial cells acquire mesenchymal characteristics that increase invasiveness. We hypothesize that loss of E-cadherin during EMT, results in abnormal localization of p120 catenin, an E-cadherin regulating protein, and Kaiso factor, a repressor of Wnt signaling, promoting oncogenesis. Protein arginine methyl transferase 1 (PRMT1) an EMT regulator catalyzes methylation of Twist1, which represses E-cadherin. However, their role in OR resistance is still unknown. We have made parental (P) NSCLC cells, H2170, H358, H1975 and H3255 resistant to OR. MTT assays were performed on the parental cells and OR resistant cells which showed that the H2170OR, H3255OR, H358OR, H1975OR cells had IC50 for OR, 2.8-14 fold higher in comparison to parental cells, respectively. We further performed qPCR to study the modulation of EMT biomarkers in OR cells as compared to parental cells and found upregulation of PRMT1, p120 catenin and Kaiso factor by 1.5-3.67 fold respectively in H1975 cells and 1.5-5.73 fold in H3255 cells. Immunofluorescence studies in H1975OR cells for expression of PRMT1 showed that there was 3.18 fold increase as compared to 2.21 fold increase in Erlotinib resistant H1975 (H1975ER) and 4.77 fold increase in H3255OR as compared to 2.27 fold increase in H3255ER. After transfection with p120 siRNA we found that OR efficacy was increased by 33% in comparison to mock siRNA and OR treated cells. The percentage wound closure after 24 hours was found to be 26.2% in the p120-catenin siRNA transfected cells as compared to 7.4%.in mock siRNA transfected cells (p&amp;lt;0.05) indicating its role in EMT and cell migration. Furthermore, our results showed increased expression of p120 catenin in smokers with 50% of smokers showing high expression compared to 0% and 5.8% of quit smokers and nonsmokers indicating that high p-120 expression was associated with smoking (P=0.002). In conclusion, biomarkers like PRMT1 may mediate the process of EMT by methylation of Twist1 and upregulation of p120 that prevents transcriptional repression of Kaiso factor target genes, promoting EMT in OR and ER resistant cells. p-120 expression was found to be higher in smokers compared to quit/nonsmokers indicating that it may have a potential role in lung cancer. Citation Format: Kavya Sri Racherla, Katrina Dovalovsky, Neelu Puri. Role of emt biomarkers in mediating osimertinib resistance in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1431.

MO29-6 Safety and tolerability of lazertinib and in combination with amivantamab in advanced EGFR-mutated Japanese NSCLC

Lazertinib (Laz) is an oral, potent, brain-penetrant 3rd generation EGFR-TKI targeting T790M and activating EGFR mutations while sparing WT EGFR. Amivantamab (Ami) is an EGFR-MET bispecific antibody with immune-cell directing properties. This study (NCT04077463) evaluates the safety, tolerability, PK of Laz (Ph1) or in combinations with Ami (Ph1b combo) in Japan, and to further characterize this combination globally (Ph1b expansion) in advanced EGFR-mutant NSCLC patients (pts). Here, we present the Japanese (JPN) Ph1/1b combo data.

Dynamic Evaluation of Circulating miRNA Profile in EGFR-Mutated NSCLC Patients Treated with EGFR-TKIs.

Background: Resistance to EGFR-TKIs constitutes a major challenge for the management of EGFR-mutated NSCLC, and recent evidence suggests that deregulation of specific microRNAs (miRNAs) may influence resistance to targeted agents. In this retrospective study, we explored the role of specific plasmatic miRNAs (miR-21, miR-27a and miR-181a) as a surrogate for predicting EGFR-TKI performance in EGFR-mutated NSCLC patients. Methods: Plasma samples of 39 advanced EGFR-mutated NSCLC patients treated with EGFR-TKIs were collected at different points in time and miRNA levels were assessed by RT-PCR. Results: Higher basal values of miR-21 were reported in patients who achieved a partial/complete response (PR/CR) compared to those with stability/progression of disease (SD/PD) (p = 0.011). Along the same line, patients who experienced a clinical benefit lasting at least six months displayed higher basal levels of circulating miR-21 (p = 0.039). However, dynamic evaluation of miRNA values after two months from the start of EGFR-TKI treatment showed that patients who experienced SD had an increase in miR-21 levels (Fold Change [FC] = 2.6) compared to patients achieving PR/CR (p = 0.029). The same tendency was observed for miR-27a (FC = 3.1) and miR-181a (FC = 2.0), although without reaching statistical significance. Remarkably, preclinical studies showed an increase in miR-21 levels in NSCLC cells that became resistant after exposure to EGFR-TKIs. Conclusions: Our study provides interesting insights on the role of circulating miRNAs, in particular miR-21, and their dynamic change over time in predicting EGFR-TKI response in EGFR-mutated NSCLC.

Detection of EGFR Mutations in Plasma cfDNA and Paired CTCs of NSCLC Patients before and after Osimertinib Therapy Using Crystal Digital PCR.

Simple SummaryLiquid biopsy is a useful tool during longitudinal monitoring of NSCLC patients and requires highly sensitive and reliable technologies for accurate detection of genomic alterations. We evaluated and used crystal digital PCR to detect and quantify EGFR mutations in plasma cfDNA and paired CTCs of NSCLC patients before treatment with osimertinib and at progression of disease.Circulating tumor DNA (ctDNA) analysis has clinical utility in EGFR mutant NSCLC. Circulating tumor cells (CTCs) consist a unique source of information at the cellular level. Digital PCR (dPCR) is a valuable tool for accurate and valid analysis of gene mutations in liquid biopsy analysis. In the present study we detected EGFR mutations in ctDNA and paired CTCs under osimertinib therapy at two time points using crystal dPCR and the naica® system (Stilla Technologies). We quantified mutation allele frequencies (MAF) of EGFR mutations in 91 plasma cfDNA samples of 48 EGFR mutant NSCLC patients and in 64 matched CTC-derived genomic DNA samples, and the FDA-cleared cobas® EGFR mutation test in 80 identical plasma samples. Direct comparison between crystal dPCR and the cobas EGFR assay revealed a high concordance for all EGFR mutations. Our comparison of crystal dPCR results in ctDNA with the corresponding primary tissue has shown a strong correlation. EGFR mutations analysis in paired CTC-derived gDNA revealed a high heterogeneity. Crystal dPCR offers the unique advantages of high analytical sensitivity, precision, and accuracy for detecting and quantifying multiple EGFR mutations in plasma cfDNA and CTCs of NSCLC patients.