Clonal evolution and osimertinib resistance mechanisms identified by whole exome and transcriptome sequencing in EGFR mutant NSCLC.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 9049-9049
Author(s):  
Nitin Roper ◽  
Anna-Leigh Brown ◽  
Sivasish Sindiri ◽  
Constance M. Cultraro ◽  
Shaojian Gao ◽  
...  

9049 Background: Osimertinib, a 3rd generation EGFR TKI, has been approved for treatment naïve patients (pts) with metastatic EGFR mutant NSCLC. Mechanisms of resistance to osimertinib are emerging from limited studies using targeted sequencing platforms. Methods: We performed whole exome (WES) and RNA-sequencing of osimertinib resistant tumors of EGFR-mutant NSCLC pts treated in a prospective clinical trial (NCT02759835). Treatment naïve EGFR mutant pts or pts with T790M-positive NSCLC after EGFR-TKI treatment receive osimertinib. Upon progression, pts with ≤5 progressing sites undergo local ablative therapy (LAT; surgery, radiation, RFA) and resume osimertinib. We analyzed paired pre-treatment and post-progression tumors in 10 patients and post-progression tumors in 3 additional patients and investigated intra- and inter-metastatic tumor heterogeneity using tumors procured from LAT surgeries and autopsies. Results: Acquired, focal copy number amplifications (CNA) of oncogenes occurred in the majority of patients (54%, n = 7/13) whereas acquired osimertinib resistance mutation EGFR C797S was less common (15%, n = 2/13). Early progression on osimertinib ( < 12 months PFS) in treatment naïve pts was associated with acquired, focal CNA. Despite pre-existing EGFR amplification, further amplification of the mutant allele of EGFR was the most common focal CNA (33%, n = 3/9). Other oncogenes amplified in resistant tumors include MET, KRAS, ERBB2 and YES1. CD274 (PD-L1) amplification occurred as the only putative mechanism of resistance in a pt without prior EGFR-TKI treatment. Using RNA-seq, we identified a pt who retained NSCLC histology, but upregulated genes associated with neuroendocrine differentiation upon osimertinib resistance. Clonal evolutionary analysis using WES of prospectively collected sensitive and resistant tumor tissue, including at autopsy is underway. Conclusions: Unbiased WES and transcriptome sequencing revealed heterogeneity, clonal evolution and novel osimertinib resistance mechanisms. Majority of pts had two or more resistance mechanisms suggesting the requirement of combination therapies to overcome resistance. Clinical trial information: NCT02759835.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 9030-9030
Author(s):  
Zhiyong He ◽  
Jinghui Lin ◽  
Yueming He ◽  
Jing Zhang ◽  
Dongyong Yang ◽  
...  

9030 Background: Currently,EGFR-TKIs are widely accepted as the standard treatment for EGFR- mutant advanced non-small-cell lung cancer (NSCLC); however, acquired resistance is inevitable. Combination therapy is considered as a strategy to overcome the resistance to EGFR-TKIs. Anlotinib, a novel multi-targeting, small-molecule TKI, has shown active to suppress tumor angiogenesis and growth. However, there is still a lack of evidence supporting the use of EGFR-TKIs in combination with anlotinib for the treatment of NSCLC until now. A multi-center, single-arm, phase II clinical trial was therefore designed to examine the efficacy and safety of EGFR-TKIs combined with anlotinib for treatment-naïve, advanced NSCLC patients, and unravel the possible mechanisms. Methods: This study was conducted in 14 research centers in Fujian, China. The main eligibility criteria were stage IV or relapsed nonsquamous NSCLC with EGFR mutations (exon 19 deletion,, and L858R), ECOG score 0-2,and age 20 to 75 years and no previous systemic treatment. Patients with asymptomatic brain metastases were admitted.Eligible patients were given gefitinib (250 mg QD) or icotinib (125 mg TID) in combination with anlotinib (10 mg per day, on days 1‒14; 21 days per cycle) until disease progression. The primary endpoint is progression-free survival (PFS) and safety, and the secondary endpoint is overall survival (OS), objective response rate (ORR) and disease control rate (DCR).Peripheral blood was sampled pre-treatment, once every two months during treatment and after disease progression, and T790M mutation was detected in plasma ctDNA using a droplet digital PCR (ddPCR) assay. Results: Of 60 patients enrolled (August 2, 2018 to May 28, 2020). As of February 1, 2021, 37 patients (61.7%) experienced PFS events and 10 (16.7%) died. The ORR was 78.3%, and the DCR was100%.Median PFS was 13.0 months (95%CI,10.7-15.3).The 5 most common treatment-related adverse events included rash (63.3%), fatigue (55.0%), hypertension (48.3%), diarrhea (33.3%) and hand-foot syndrome (30.0%), and grade 3 adverse events included hypertension (5.0%), rash (1.67%), hypertriglyceridemia (1.67%), vomiting (1.67%) and elevated ALT (1.67%); no grade 4 adverse events or drug-related deaths were observed. Peripheral blood samples were collected from 36 patients pre-treatment, and 30.6% were identified with low-frequency de novo T790M mutations, with the mutation-allele frequency (MAF) ranging from 0.01% to 0.28%. Conclusions: The combination of the first-generation EGFR-TKIs and anlotinib shows impressive ORR and DCR, and acceptable toxicity in treatment-naïve advanced NSCLC patients with activating EGFR mutations, and we observed a high proportion of patients harboring de novo EGFR T790M mutations in this study. Clinical trial information: NCT03720873.


2015 ◽  
Vol 26 ◽  
pp. vii138
Author(s):  
Hayato Koba ◽  
Shingo Nishikawa ◽  
Taro Yoneda ◽  
Takashi Sone ◽  
Hideharu Kimura ◽  
...  

2019 ◽  
Vol 12 (2) ◽  
pp. 625-630 ◽  
Author(s):  
Mike Ralki ◽  
Brigitte Maes ◽  
Karin Pat ◽  
Jokke Wynants ◽  
Kristof Cuppens

Epidermal growth factor receptor (EGFR)-targeted therapy has become standard of care in advanced stages EGFR-mutant non-small cell lung cancer. Acquired resistance to first-line EGFR-tyrosine kinase inhibitor (TKI) and subsequent disease progression is a common problem and mostly due to a secondary mutation (T790M) in EGFR. We report a case of a patient with EGFR-mutated lung adenocarcinoma who developed a complex resistance profile: T790M mutation, HER2 mutation and HER2 amplification after first-line EGFR-TKI. This patient was safely treated with a combination of osimertinib and trastuzumab and achieved a clinically meaningful and clear molecular response.This is the first reported case of acquired resistance to first-line EGFR-TKI based on three resistance mechanisms, treated with molecular targeted combination therapy.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e20545-e20545 ◽  
Author(s):  
Chul Kim ◽  
Nitin Roper ◽  
Chuong D. Hoang ◽  
Eva Szabo ◽  
Maureen Connolly ◽  
...  

e20545 Background: EGFR tyrosine kinase inhibitors (EGFR-TKIs) improve progression-free survival (PFS) in patients with EGFR-mutant NSCLC, but disease progression limits efficacy. Retrospective studies show a survival benefit to LAT in patients with oligoprogressive disease (progression at a limited number of anatomic sites). Methods: This is a prospective study of LAT in patients with oligoprogressive EGFR-mutant NSCLC. Patients with no prior EGFR-TKI therapy (cohort 1) or progression after 1st/2ndgeneration EGFR-TKIs with acquired T790M mutation (cohort 2) receive osimertinib. Upon progression, eligible patients with < = 5 progressing sites undergo LAT and resume osimertinib until disease progression. Patients previously treated with osimertinib qualifying for LAT upon disease progression are also eligible for treatment (cohort 3). Primary endpoint: evaluation of safety and efficacy of reinitiation of osimertinib after LAT (assessed by PFS). Additional goals are assessment of mechanisms of resistance to osimertinib by multi-omics analyses of tumor, blood, and saliva. Results: Between 04/2016 and 01/2017, 15 patients were enrolled (cohort 1: 9, cohort 2: 3, cohort 3: 3). Median age was 57 (range 36-71). Treatment was well tolerated. The most common adverse events (AEs) were rash, diarrhea, thrombocytopenia, and alanine transaminase elevation. Grade 3/4 AEs were observed in 4 (27%) patients. Among evaluable patients, objective response rates prior to LAT in cohorts 1 and 2 were 71% (5/7) and 100% (2/2), respectively, with 6.8 months median PFS (95% CI: 3.4 months-undefined) in cohort 1 and no progressions in cohort 2. To date, 5 patients (33%; cohort 1: 2; cohort 3: 3) had LAT. Two patients with 3 progressing sites underwent a combination of surgery and radiation. Three patients with 1 progressing site underwent surgery alone. Post-LAT PFS and results of molecular analyses will be presented. Conclusions: Patients with EGFR-mutant NSCLC and oligoprogression after EGFR-TKI therapy can be safely treated with LAT. In selected patients, this approach could potentially maximize duration of EGFR-TKI treatment and prevent premature switching to other systemic therapies. Clinical trial information: NCT02759835.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 3138-3138
Author(s):  
Jun Zhao ◽  
Caixia Liu ◽  
Hui Liu ◽  
Yong He ◽  
Liqiang Rao ◽  
...  

3138 Background: Actionable muts in EGFR and ALK define two molecular subtypes sensitive to EGFR-TKIs and ALK-TKIs, respectively. Although generally mutually exclusive, they did co-exist in some cases. However, when and how do they co-exist are not well understood. Methods: Pts with concurrent actionable muts in ALK and EGFR were selected from our database. Their mutation profiles and treatment histories were analyzed. PFS was estimated using Kaplan-Meier method. Results: Among 341 ALK-positive ( ALK-pos) and 3804 EGFR-positive ( EGFR-pos) pts, 9 (2.6% of ALK-pos, 0.2% of EGFR-pos) had concurrent EGFR and ALK actionable muts, including 3 EX19Indel + EML4-ALK, 2 EX19Indel + STRN-ALK, 2 L858R + L1152R, 1 L858R + EML4-ALK, and 1 G719C + S768I + STRN-ALK. All 9 pts had lung cancer. One pt with EX19Indel + EML4-ALK was treatment naïve. The other 8 pts have taken ≥ 1 EGFR-TKIs. The mPFS of these pts on first-generation EGFR-TKIs was 22 mo (95% CI: 11 - NR). Except for 1 pt who progressed on Gefitinib and subsequently on Osimertinib had a T790M+C797G, the other 7 EGFR-TKI resistance pts had no common known resistance muts. 3 pts ordered NGS tests before taking EGFR-TKIs. None of them had ALK muts at that time. Later, 1 pt (19Indel) gained an STRN-ALK after 15 mo on Osimertinib, 1 pt (L858R) gained an EML4-ALK after 5 mo on Gefitinib, and 1 pt (L858R) gained an L1152R after 10 mo on Afatinib. Therefore, ALK muts were likely developed as resistance mechanisms during EGFR-TKIs therapies in these 3 pts. Unfortunately, with no information on ALK status before EGFR-TKI therapies, we can not tell if the ALK muts were also developed during and conferred resistance to EGFR-TKI therapies in the other 5 pts. Both STRN-ALK and ALK L1152R were recorded 4 times in our database, and they concurred with EGFR actionable muts in 3 and 2 of the 4 records, respectively. Conclusions: ALK and EGFR actionable muts concurred at a relatively low frequency in our pts. In some cases, ALK muts were developed during EGFR-TKI therapies. Developed either together or sequentially, some combinations of EGFR and ALK muts, such as L858R with L1152R and EX19Indel with ALK fusion, may form more easily or may be preferable than other combinations for the development or evoluation of tumors.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e20603-e20603
Author(s):  
Ying Jin ◽  
Hua Bao ◽  
Xiuning Le ◽  
Xiaojun Fan ◽  
Ming Tang ◽  
...  

e20603 Background: EGFR-mutant non-small-cell lung cancer (NSCLC) patients inevitably develop drug resistance when treated with EGFR tyrosine kinase inhibitors (TKIs). Clonal and clinical analyses of genetic alterations at baseline and progressive disease (PD), as well as differences between acquired T790M and T790M-negative patients in drug-resistant mechanisms, have not been systematically studied. Methods: We performed targeted sequencing of pre-treatment and PD tumor samples from 54 EGFR-mutant NSCLC patients. Correlation between genomic features and patients’ progression-free survival (PFS) was evaluated. Ten additional patients were sequenced using whole exome sequencing to infer the clonal evolution patterns. Results: We observed new pathways limiting EGFR-inhibitor response, including NOTCH1/ STK11 co-deletion, and TGF-beta alterations. Besides acquired T790M mutation, chromosomal instability (CIN) related genes including AURKA and TP53 alterations were the most frequently acquired events. CIN significantly increased with TKI treatment in T790M-negative patients. Transcriptional regulators including HNF1A, ATRX and NKX2-1 acquired alterations were enriched in T790M-positive patients, and diverse oncogenic pathway alterations were more common in T790M-negative patients. T790M-positive patients had improved PFS compared to T790M-negative patients. We identified subgroups within T790M-positive or T790M-negative patients with distinct PFS. Interestingly, we observed a death-and-birth process of RTK-RAS mutations during TKI treatment, and baseline and acquired RTK-RAS mutations had opposite effects on PFS. Clonal evolution analysis indicated progression of T790M-positive patients depends on competition between T790M and non-T790M resistant subclones. Conclusions: T790M-positive and T790M-negative patients display divergent landscape of acquired somatic events. Subgroups of patients were identified within T790M-positive and T790M-negative patients with distinct survival. Our results point the importance of clonal competition between T790M and non-T790M resistant subclones.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 9056-9056 ◽  
Author(s):  
Hiroe Kayatani ◽  
Keisuke Aoe ◽  
Kadoaki Ohashi ◽  
Hiroshige Yoshioka ◽  
Akihiro Bessho ◽  
...  

9056 Background: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are a key treatment for EGFR-mutated non-small-cell lung carcinoma (NSCLC). To date, a biomarker to predict whether NSCLC will exhibit a short- or long-term response to first- or second-generation EGFR-TKIs has not been established for clinical use. Human epidermal growth factor receptor-2 (HER2) aberrations are mechanisms for acquired resistance to EGFR-TKIs; however, their impact on EGFR-TKI therapy outcomes in EGFR-mutant NSCLC has not yet been systematically evaluated. Methods: Patients with advanced NSCLC were prospectively registered from more than 35 institutes (HER2-CS STUDY UMIN 000017003). EGFR mutations or anaplastic lymphoma kinase gene translocations were assessed at each institution using a commercially approved test. HER2 protein expression levels were determined by immunohistochemistry (IHC) using the Ventana I-VIEW PATHWAY anti-HER-2/neu (4B5). The IHC status scoring system applied to gastric cancer was used. Results: Of 1,126 screened patients with NSCLC, 354 (31.8%) had EGFR-mutated tumors, and the HER2 protein statuses were as follows: IHC0 (n = 71, 26%), IHC1+ (n = 148, 53%), IHC2+ (n = 51, 18%), and IHC3+ (n = 7, 3%). The patients’ demographics were almost identical in those with lung tumors harboring EGFR mutations and HER2-IHC2+/3+ (group P) or EGFR mutations and HER2-IHC0/1 (group N). The EGFR-TKI response rates were not different between these groups (Table). However, group P showed significantly shorter time to EGFR-TKI treatment failure than group N (median 19.1 vs. 13.3 months; log rank p = 0.038). Conclusions: These data from a large prospective cohort show that HER2 protein expression in EGFR-mutant NSCLC may have a negative impact on the effect of EGFR-TKIs. A clinical trial of EGFR/HER2-TKIs (e.g., afatinib) is warranted for this population. [Table: see text]


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 9601-9601
Author(s):  
Ji-Youn Han ◽  
Myung-Ju Ahn ◽  
Sang-We Kim ◽  
Ki Hyeong Lee ◽  
Eun Kyung Cho ◽  
...  

9601 Background: While EGFR mutant ( EGFRm) non-small cell lung cancer (NSCLC) patients usually experience improved clinical benefit with EGFR TKIs, most eventually progress. Understanding mechanisms of resistance (MoR) may allow for more personalized treatment. Lazertinib is an irreversible third generation EGFR TKI for which MoR are unknown. Obtaining sufficient tumor tissue for genotyping at progression is often difficult. Therefore, we utilized plasma ctDNA from patients treated with lazertinib to explore MoR. Methods: Plasma samples from 47 NSCLC patients in the phase 2 trial of lazertinib (NCT03046992) were collected at screening and progressive disease (PD) and underwent ctDNA NGS of 74 genes using Guarant360. All patients were positive for an EGFR Ex19del or L858R ( EGFRm) and T790M by tissue testing at screening. Acquired, nonsynonymous, characterized mutations detected in a PD sample but not in the screening sample from the respective patient were considered putative MoR, excluding aneuploidy. Patients with detectable plasma EGFRm and/or T790M at screening were evaluable. Results: ctDNA was detected in 47 (100%) screening samples and 43/45 (96%) PD samples (two failed sequencing). An EGFRm was detected in 85% of patients at screening (n = 40), 38 of which had PD ctDNA results and were included in analysis. T790M was detected in 30 patients at screening and subsequently not detected at PD in 21 of these patients, 55% of all 38 included patients. Among the ten patients with T790M detected at PD, on-target MoR were detected in 7 (18% of all included patients) including EGFR C797S (n = 3, 8%), EGFR amplification (n = 3, 8%), and EGFR T854A (n = 1, 3%). All C797S were in cis with T790M. No on-target MoR were detected in patients without T790M detected at PD. Off-target MoR were seen in 34% of patients (13/38) including mutations in PIK3CA (13%; 2 E545K, 2 E542K, 1 E81K), ERBB2 (5%; 1 D769H, 1 V777L), KRAS (3%; 1 G12C), and BRAF (3%; 1 G469A). Gene amplifications were detected in CCND1 (n = 1, 3%) , CCNE1 (n = 2, 5%) , ERBB2 (n = 1, 3%) , FGFR1 (n = 1, 3%) , MET (n = 4, 11%) , and PIK3CA (n = 1, 3%), with some patients having multiple MoR. Conclusions: The spectrum of MoR identified in this cohort of patients treated with lazertinib is similar to that reported in other third generation EGFR TKIs, but with some differences in frequencies. The most common resistance mechanisms are T790M loss and PIK3CA alterations which may address the mechanism of action. Our findings suggest putative MoR of lazertinib and show that ctDNA NGS is an effective way to identify MoR in patients progressing on targeted therapy. Clinical trial information: NCT03046992 .


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