Concomitant EGFR Mutations Research Articles

A randomized phase II trial of 8 months of afatinib switching to osimertinib (A) versus osimertinib alone (B) as first-line treatment in advanced NSCLC patients with common EGFR mutation: YAMATO study (TORG1939/WJOG12919L).

8574 Background: NSCLC with common EGFR mutation (L858R or exon 19 deletion (Del19)) is known to originally comprise small portion of uncommon and compound EGFR variant cells including T790M-mutant ones albeit treatment-naïve. To overcome concomitant heterogeneous EGFR mutations, we planned a randomized phase II trial to assess the strategy of switching to osimertinib following 8 months of afatinib compared with osimertinib alone. Methods: YAMATO study is an open-label, multi-center, randomized phase II study. Patients with newly diagnosed stage III/IV/recurrent NSCLC harboring EGFR activating mutations (L858R or Del19) were randomized in a 1:1 ratio to receive up-front 8 months of afatinib (30 mg or 40 mg QD) followed by osimertinib (80 mg QD) (arm A) or osimertinib (80mg QD) alone (arm B) until disease progression or intolerable toxicity. The primary endpoint is 2-year progression free survival (PFS) rate with threshold rate of 22% and expected rate of 40% (one-tailed alpha of 0.1, beta of 0.2). Secondary endpoints are objective response rate (ORR), PFS, time to treatment failure, overall survival and adverse events. Results: Between May 2020 and Apr 2021, 113 patients were enrolled from 27 institutions (A/B 56/57). Patient characteristics were as follows: median ages, 73.5/71 years (range 41-85/41-92 years); proportion of males, 42.9/35.1%; EGFR mutation types, L858R/Del19 59/41% in A, 58/42% in B. The difference of two-year PFS rate was not observed statistically significant between groups (37.3% [80% CI, 29.0 to 45.5] in arm A vs 47.4% [80% CI, 38.5 to 55.7] in arm B; p=0.44; HR:1.28 [80% CI, 0.95-1.73]). The ORR was 82% in arm A and 87% in arm B. With the median follow-up of 27.5 months, median PFS was 16.8 months in arm A, and 22.2 months in arm B (HR: 1.280, p = 0.29). Severe pneumonitis occurred in 7% in arm A, most of which developed after switching to osimertinib, and 1.8% in arm B. Conclusions: YAMATO study failed to demonstrate the superiority of EGFR-TKI switching therapy of 8 months afatinib to osimertinib over osimertinib alone in terms of 2-year PFS rate in untreated advanced NSCLC patients with common EGFR mutations. Clinical trial information: 031200021 .

Clinicopathological analysis of 4 cases of lung cancer with concomitant EGFR mutation and ROS1 fusion

目的： 探讨表皮生长因子受体（EGFR）基因突变与ROS1基因融合共存型（简称“ER双突变”）肺癌患者的临床病理学特征及治疗与预后。 方法： 回顾性分析ER双突变肺癌患者的临床病理特征，并对患者进行随访，探讨其临床治疗及预后。 结果： （1）1 586例非小细胞肺癌患者的EGFR突变率为51.5%（816/1 586），ROS1融合突变率为2.4%（38/1 586），ROS1融合与患者的年龄、吸烟史、病灶部位有关。（2）38例ROS1融合非小细胞肺癌患者中，4例为ER双突变，占比10.5%（4/38）。4例均为女性、肺腺癌患者，中位年龄62岁，均无吸烟史，临床分期Ⅰ期、Ⅱ期、Ⅲ期、Ⅳ期各1例。EGFR以第19号外显子缺失突变多见，ROS1融合以R2型多见。（3）4例ER双突变患者中位随访8.5个月，其中Ⅰ期患者右上肺叶切除术后随访22个月疾病无进展；Ⅱ期患者左下肺叶切除术后辅助化疗，随访6个月疾病无进展；Ⅲ期患者右中肺癌根治术后随访6个月疾病无进展；Ⅳ期患者伴肺、肝、骨转移，第一代EGFR-酪氨酸激酶抑制剂（TKI）治疗8个月后出现脑转移，血液EGFR检测示T790M突变，二线接受第三代EGFR-TKI治疗，3个月后复查脑转移灶略缩小，疾病稳定。 结论： ER双突变肺癌在临床上较少见，多见于女性、不吸烟、肺腺癌患者，其可能从EGFR-TKI靶向治疗中获益。非小细胞肺癌患者在靶向治疗之前进行驱动基因联合检测，有助于靶向药物的选择以及预后判断。.

Liquid and tissue profiling of targetable co-mutations with KRAS in non-small cell lung cancer.

e21201 Background: The primary objective of this study was to understand the co-occurrence of KRAS with other actionable drivers in Indian lung cancers patients, and to assess the utility of liquid biopsy in this cohort. Methods: We evaluated single nucleotide alterations, copy number alterations, and fusions in 507 tumor tissue and 1271 blood specimens with targeted NGS panels in NSCLC patients. Results: In tissue-based analysis (n = 507), KRAS mutations were detected in 68 (13.4%) samples. Of these, 63 (92.6%) samples did not show the presence of any targetable co-mutations. Targetable co-mutations were detected in 5 (7.4%), with concomitant EGFR mutations in all 5 samples(100%) and BRAF mutations in 2 samples (33.3%) In the liquid biopsy (n = 1271) analysis, KRAS mutations were observed in 94 (7.4%) samples. The liquid biopsy analysis showed higher presence of targetable co-mutations in 11.7% (n = 11). EGFR was the most common co-occurring targetable gene observed in 9 samples (81.8%). Mutations in BRAF were detected in 3 (27.3%) samples. ERBB2 Exon 20 insertion was detected in 1 sample (9.1%). No ALK, RET or ROS1 fusions were seen in our KRAS positive cohort. In the tissue cohort, one newly diagnosed adenocarcinoma case showed primary co-mutations in EGFR (Exon 19del VAF 76.8%) and KRAS (G13D VAF 10.5%), impacting utility of EGFR TKI as the first line therapy. Another EGFR Exon 19 del patient developed KRAS G12D mutation as an acquired resistance mutation post Osimertinib therapy. In the liquid biopsy cohort (n = 11), the KRAS positive cohort had four newly diagnosed patients with 3 having EGFR and 1 with BRAF co-mutation. Among the patients with prior therapy, one patient at presentations had EGFR Exon 19 deletion and developed EGFR T790M at progression on Afatinib. The baseline tissue did not have coexisting KRAS mutation. Fresh tissue biopsy was performed at the progression on Osimertinib. The noteworthy finding was the KRAS G12C (VAF 0.36%) presence in liquid biopsy but absences in the simultaneous fresh tissue sample. The EGFR Exon 19 was present at lesser frequency than KRAS in the liquid (VAF 0.23%). In the patients from liquid biopsy cohort with Osimertinib therapy (n = 4), all presented with KRAS as acquired resistance mutation. One among these also showed concomitant EGFR C797S mutation. Conclusions: KRAS mutation virtually makes it unlikely for other targetable mutations to coexist. It makes it thus compelling to further study the role of liquid biopsy with KRAS first and decide if chemotherapy with IO can be started considering the standard of care is to wait for the entire targeted panel before initiating IO. Equally its important to include KRAS in the lung panel and although small the concomitant KRAS may compromise the efficacy to TKI. Liquid biopsy is a promising alternative for detection of actionable alterations, including KRAS and can be harnessed for longitudinal profiling, monitoring tumor evolution and treatment outcome.

Potential Therapeutic Strategy for EGFR-Mutant Lung Cancer With Concomitant EML4-ALK Rearrangement—Combination of EGFR Tyrosine Kinase Inhibitors and ALK Inhibitors

IntroductionAlthough driver gene mutations have been believed to be mutually exclusive, some patients with NSCLC and concomitant EGFR mutations and EML4-ALK rearrangements have been reported. In this study, we reported a case of a patient with lung cancer who harbored both EGFR mutation and the EML4-ALK rearrangement after acquiring resistance to the EGFR tyrosine kinase inhibitor treatment. EGFR-mutant and ALK fusion proteins were detected in the same tumor cells through immunohistochemical analysis. Investigation of the molecular mechanisms of concomitant EGFR mutation and the EML4-ALK rearrangement in the same tumor cell can help discover an appropriate treatment for these patients. MethodsPC-9 cells, expressing EGFR exon 19 deletion, were transfected with EML4-ALK variant 3a (v3a) and variant 3b (v3b) separately and selected, and the effect of EGFR and ALK inhibitors was evaluated in vitro and in vivo. ResultsPC-9_v3a-gef and PC-9_v3b-gef cells were resistant to gefitinib and ALK inhibitors alone, but ALK inhibitors enhanced gefitinib-induced cytotoxicity. In animal studies, gefitinib completely inhibited the tumor growth in PC-9_vector cells but not in PC-9_v3a-gef and PC-9_v3b-gef cells. A combination of ALK inhibitor and gefitinib was found to be more potent than gefitinib alone in PC-9_v3a-gef and PC-9_v3b-gef cells. Furthermore, combination treatment with osimertinib and ceritinib caused a decrease in liver tumor size of the patient with liver metastases. ConclusionsOur data suggest that combination treatment with EGFR and ALK inhibitors can be a therapeutic strategy for treating NSCLC with concomitant EGFR mutation and EML4-ALK rearrangement.

Clinicopathological analysis of 6 cases of lung adenocarcinoma with concomitant EGFR mutation and ALK fusion

目的： 探讨表皮生长因子受体（EGFR）基因突变与间变性淋巴瘤激酶（ALK）基因融合共存型肺腺癌患者的临床病理特征及治疗与预后。 方法： 回顾性分析EGFR突变与ALK融合共存的肺腺癌患者的临床病理特征，并对患者进行随访，探讨其临床治疗及预后。 结果： （1）2 803例肺腺癌患者的基因检测（ARMS法）结果显示，EGFR突变率为52.98%（1 485/2 803），EML4-ALK突变率为5.82%（163/2 803），其中6例患者EGFR与ALK双突变，占比0.21%。（2）6例EGFR与ALK双突变肺腺癌患者中，男性2例，女性4例，中位年龄55岁，仅1例有吸烟史，临床分期Ⅰ期1例，余5例均为Ⅳ期，EGFR以第19号外显子缺失和第21号外显子L858R突变多见。（3）5例Ⅳ期患者接受第一代EGFR酪氨酸酶抑制剂（TKI）治疗，4例有效，中位疾病无进展生存期为11.5个月，其中2例患者随访期间死亡，总生存期分别为9和12个月。（4）2例患者第一代EGFR-TKI治疗耐药后行二次基因检测示T790M突变，接受第三代EGFR-TKI治疗，分别继续随访16和15个月，疾病无进展。 结论： EGFR突变与ALK融合共存的肺腺癌在临床上较少见，多为年轻、女性、不吸烟、临床分期晚的患者，其可能从EGFR-TKI或ALK-TKI靶向治疗中获益，靶向治疗耐药后应行二次基因检测以指导后续治疗。.

HER2 Amplification in Advanced NSCLC Patients After Progression on EGFR-TKI and Clinical Response to EGFR-TKI Plus Pyrotinib Combination Therapy.

BackgroundHER2 (or ERBB2) amplification is an important mechanism for acquired resistance to EGFR tyrosine kinase inhibitors (TKI). The benefits of HER2-targeted therapy have been limited. Herein, we investigated the molecular and clinical patterns of HER2 amplification in non-small cell lung cancer (NSCLC) patients during progression on EGFR-TKIs and the potential of combining EGFR-TKI and pyrotinib to overcome resistance.MethodsIn this study, 1,637 NSCLC cases from Geneseeq after progression of EGFR-TKIs were screened and analyzed by next generation sequencing (NGS), in which 48 patients with HER2 amplification were eligible and enrolled. A total of 403 patients from Sun Yat-sen University Cancer Center (SYSUCC) were screened and five patients with concomitant EGFR mutations and HER2 amplification were retrospectively collected to assess the effect of afatinib or combination of EGFR-TKI and pyrotinib.ResultsIn the 48 patients from the Geneseeq cohort, 27 (56.2%) patients suffered from resistance of 1st/2nd generation EGFR-TKI, and 21 (43.8%) patients from 3rd generation. As for the five patients forming the SYSUCC cohort, three patients were treated with afatinib, one achieved partial response (PR) with progression-free survival (PFS) of 6 months and two quickly developed disease progression. Two patients were treated with EGFR-TKIs plus pyrotinib, one receiving gefitinib plus pyrotinib achieved PR with PFS of 8 months and benefited from osimertinib plus pyrotinib for 3 months till data-off; one receiving osimertinib plus pyrotinib achieved SD for 4 months till data-off. The most common co-occurring alteration was TP53 (91.7%) in the mutation profile of the 48 patients from the Geneseeq cohort, and four patients had TP53 co-mutations of the five patients from the SYSUCC cohort.ConclusionIn this study, we detected 7% HER2 amplification present in EGFR-TKIs resistance. Patients with concomitant EGFR mutation and HER2 amplification may derive clinical benefit from therapies that target both EGFR and HER2.

Mutational landscape of multiple primary lung cancers and its correlation with non-intrinsic risk factors

Multiple primary lung cancers (MPLCs) harbour various genetic profiles among the tumours, even from individuals with same non-intrinsic risk factors. Paired mutational analyses were performed to obtain a census of mutational events in MPLC and assess their relationship with non-intrinsic risk factors. Thirty-eight surgical specimens from 17 patients diagnosed as MPLC were used. Extracted DNAs were sequenced for somatic mutations in 409 cancer-associated genes from a comprehensive cancer panel. We statistically analysed the correlation between each driver mutation frequency and non-intrinsic risk factors using Fisher's exact test, and whether genetic mutations occurred concomitantly or randomly in MPLC using an exact test. Comprehensive genetic analyses suggested different mutation profiles in tumours within the same individuals, with some exceptions. EGFR, KRAS, TP53, or PARP1 mutations were concomitantly detected in some MPLC cases. EGFR mutations were significantly more frequent in never or light smokers and females. Concomitant EGFR or KRAS mutations in MPLCs were significantly more frequent than expected by chance (P = .0023 and .0049, respectively) suggesting a more prominent role of non-intrinsic risk factors in EGFR and KRAS mutations than other mutations, which occurred more randomly. Concomitant EGFR or KRAS mutations were particularly prominent in never or light smokers and males.

Treatment Patterns and Survival of Patients With Advanced Non-Small Cell Lung Cancer Guided by Comprehensive Genomic Profiling: Real-World Single-Institute Study in China.

Although the National Comprehensive Cancer Network and the Chinese Society of Clinical Oncology guidelines recommend comprehensive genomic profiling of lung adenocarcinoma, it has not been widely applied in Chinese hospitals. This observational study aimed to determine real-world evidence of whether comprehensive genomic profiling can benefit the survival of patients with lung cancer. We investigated the frequency of genomic alterations, treatment strategies, and clinical outcomes in 233 patients with advanced non-small cell lung carcinoma who were routinely screened using a 508-gene panel. The most prevalent drivers were mutations of EGFR (51%), KRAS (9%), PIK3CA (7%), ALK (7%), MET (6%), and BRAF (5%). Mutations in tumor suppressor genes included TP53, KEAP1, RB1, PTEN, and APC. Median overall survival (OS) was significantly shorter among patients harboring KRAS (mutant, n = 17; WT, n = 154) and TP53 (mutant, n = 103; WT n =68) mutations (11.3 vs. 24.0 months; P = 0.16 and 18.7 vs. 28.7 months; P = 0.018, respectively). The OS was longer among patients with tumors harboring EGFR (P = 0.069) and ALK (P = 0.51) mutations. Most patients (65.4%) with the driver gene-positive (EGFR, ALK, and ROS1) tumors were received TKI treatment, whereas those with driver gene wild tumors (53.1%) chose platinum-based therapy. Univariate and multivariate analyses associated a shorter OS among patients with tumors harboring concomitant TP53 and EGFR mutations. These findings provide additional evidence from real-world on the potential importance of targeted therapies as a treatment option in NSCLC patients harboring clinically actionable mutation.

P76.33 Concurrent EGFR and KRAS Mutations in Lung Adenocarcinoma: A Single Institution Case Series

Lung adenocarcinomas with molecular mutations in both the EGFR and KRAS genes are a distinct group of patients. EGFR mutant lung cancers most commonly occur in nonsmokers, respond well to tyrosine kinase inhibitor (TKI) therapy, and have a higher relative overall survival rate. In contrast, KRAS mutant lung cancers occur more commonly in patients with smoking history, do not respond to TKI therapy, and have a lower overall relative survival rate. Historically, EGFR and KRAS mutations were thought to be mutually exclusive however in this case series we present multiple cases of lung adenocarcinoma with both EGFR and KRAS mutations. From a single institution database of patients with non-small cell lung cancer (NSCLC) from 2010 – 2019, cases with concurrent EGFR and KRAS mutations were extracted. Clinical characteristics of these patient cases were reviewed, including sex, age, smoking history, stage, treatment. In addition, pathologic features were evaluated including mutations and histologic features. Follow up data including treatment was recorded. From this database 92 out of 1025 (9%) patients had EGFR mutations and 4 out of the 92 EGFR mutated cancers had both KRAS and EGFR mutations (4%). All 4 patients were between ages 55 and 67, and 3 out of 4 (75%) patients were male. 2 out of 4 (50%) patients presented with metastatic disease, while the remainder presented with localized disease. All 4 patients had KRAS mutations on codon 12 (c.34_35delinsAA and p.G12N, c.35G>A and p.G12D, p.G12S, c.34G>A and p.G12S), and 2 of these had additional mutations on exon 13 (c.38_39delinsCT and p.G13A, and p.G13D). Two patients had EGFR exon 21 mutation (c.2573T>G, p.L858R, and c.2573T>G, p.L858R), one patient had exon 19 mutation (c.2240_2254del, p.L747_T751del), and one patient had exon 18 mutation (c.2180A>G, p.Y727C). Two patients had an additional MET amplification. One patient (25%) had PDL-1 expression >1%. One of the 2 patients with localized disease had lobectomy, while the other patient underwent radiation therapy. Both patients are alive and have no recurrence of disease. One of the 2 patients with metastatic disease underwent resection of brain metastases and SBRT, while the other underwent conservative management for bone metastases. Due to patient preference, neither patient received chemotherapy or immunotherapy. One patient died and the other remains in hospice care. Patients with concomitant EGFR and KRAS mutations may be a distinct subset of lung adenocarcinoma. EGFR and KRAS should no longer be considered mutually exclusive mutations. Clinical questions remain on the efficacy of treating concomitant EGFR and KRAS mutations with TKI therapy. Further studies are necessary to determine the most effective therapeutic strategies to address this unique subset of lung cancer patients. KRAS inhibitors are currently under study.

Targeting FGFR in non-small cell lung cancer: implications from the landscape of clinically actionable aberrations of FGFR kinases.

Objective:Dysfunction in fibroblast growth factor receptor (FGFR) signaling has been reported in diverse cancer types, including non-small cell lung cancer (NSCLC). The frequency of FGFR aberrations in Chinese NSCLC patients is therefore of great clinical significance.Methods:A total of 10,966 NSCLC patients whose tumor specimen and/or circulating cell-free DNA (cfDNA) underwent hybridization capture-based next-generation sequencing were reviewed. Patients’ clinical characteristics and treatment histories were also evaluated.Results:FGFR aberrations, including mutations, fusions, and gene amplifications, were detected in 1.9% (210/10,966) of the population. FGFR abnormalities were more frequently observed in lung squamous cell carcinomas (6.8%, 65/954) than lung adenocarcinomas (1.3%, 128/9,596). FGFR oncogenic mutations were identified in 19 patients (∼0.17%), of which, 68% were male lung squamous cell carcinoma patients. Eleven out of the 19 patients (58%) had concurrent altered PI3K signaling, thus highlighting a potential combination therapeutic strategy of dual-targeting FGFR and PI3K signaling in such patients. Furthermore, FGFR fusions retaining the intact kinase domain were identified in 12 patients (0.11%), including 9 FGFR3-TACC3, 1 FGFR2-INA, 1 novel FGFR4-RAPGEFL1, and 1 novel fusion between the FGFR1 and SLC20A2 5′-untranslated regions, which may have caused FGFR1 overexpressions. Concomitant EGFR mutations or amplifications were observed in 6 patients, and 4 patients received anti-EGFR inhibitors, in whom FGFR fusions may have mediated resistance to anti-EGFR therapies. FGFR amplification was detected in 24 patients, with the majority being FGFR1 amplifications. Importantly, FGFR oncogenic mutations, fusions, and gene amplifications were almost always mutually exclusive events.Conclusions:We report the prevalence of FGFR anomalies in a large NSCLC population, including mutations, gene amplifications, and novel FGFR fusions.

Abstract 2333: Mutational landscape of multiple primary lung cancers and its correlation with environmental factors

Abstract Background: Multiple primary lung cancers (MPLC) are reported to occur in 0.2-20 % of all primary lung cancer cases. MPLC are considered to harbor various genetic profiling patterns among the tumors even within the same individuals, though they developed from the same occupational and environmental exposure. In this study, we performed paired mutational analyses to clarify genetic mutations in MPLC and its relationship with environmental factors. Materials and methods: We obtained 38 surgical specimens from 17 patients who were pathologically diagnosed as MPLC and underwent surgery at Osaka City University Hospital between October 2007 and March 2019. In addition to the clinicopathological features, the patients' age, sex, smoking history, body mass index, radiologic features and surgical procedures were reviewed. Four of the 17 MPLC patients had metachronous lesions, whereas 13 patients only had synchronous lesions. For genetic profiling of MPLC patients, the extracted DNAs were deep-sequenced on Ion S5 sequencer (Thermo Fisher) for somatic mutations in 409 cancer-associated genes (Ion AmpliSeq Comprehensive Cancer Panel). The study was approved by institutional review board of Osaka City University Hospital and written informed consent was obtained from all of the patients. For statistically analyses, we assumed genetic mutations occurred by chance and calculated the frequency of concomitant mutations in multiple tumors within the same individuals based on a previous study (JME study; Kawaguchi T et al, J Clin Oncol 2016). Comparing the assumed frequency of mutations with the actual data, statistically analyses whether mutations would occur concomitantly or randomly were performed using an exact test. Results: Deep sequencing was successfully performed in all of the specimens with the mean coverage of 823. Results from comprehensive genetic analyses suggested that the mutation profiles differed among the tumors within the same individuals, whereas EGFR, KRAS, TP53, and PARP1 mutations were concomitantly detected in multiple tumors within the same individuals. In this study, the frequency of EGFR mutations was significantly higher in never or light -smokers and females. The occurrence of concomitant EGFR or KRAS mutations in multiple tumors within the same individuals was significantly more frequent than expected by chance (EGFR, P = .0023; KRAS, P = .0049), suggesting environmental factors play more role in EGFR and KRAS mutations than the other mutations including TP53 which occurred more randomly in individual tumors. Concomitant EGFR or KRAS mutations were particularly prominent in never or light-smokers and males. Conclusions: Results from our MPLC study confirmed that the development of EGFR or KRAS-mutated tumors were strongly related to environmental factors such as sex and smoking history, and suggested that the other mutations may occur randomly. Citation Format: Motohiro Izumi, Jun Oyanagi, Kenji Sawa, Mitsuru Fukui, Koichi Ogawa, Yoshiya Matsumoto, Yoko Tani, Tomohiro Suzumura, Tetsuya Watanabe, Hiroyasu Kaneda, Shigeki Mitsuoka, Kazuhisa Asai, Tatsuo Kimura, Nobuyuki Yamamoto, Tomoya Kawaguchi, Yasuhiro Koh. Mutational landscape of multiple primary lung cancers and its correlation with environmental factors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2333.

Abstract 745: Landscape of FGFRactivating aberrations in Chinese non-small cell lung cancer

Abstract Background Dysfunction in fibroblast growth factor receptor (FGFR) signaling has been reported in non-small cell lung cancer (NSCLC), particularly in lung squamous cell carcinoma (LUSC). We hereby assessed the frequency of FGFR aberrations in a large Chinese NSCLC population. Methods A total of 10,966 NSCLCs whose tumor specimen and/or circulating cell-free DNA (cfDNA) underwent hybridization capture-based next-generation sequencing (NGS) of 400+ cancer-related genes were retrospectively reviewed. Patients' clinical characteristics and treatment histories were further evaluated. Results FGFR aberrations, including mutations, fusions, and gene amplifications, were detected in approximately 1.9% (210/10,966) of the population. FGFR abnormalities were more frequently observed in LUSCs (6.8%, 65/954) than lung adenocarcinomas (1.3%, 128/9596). Previously reported FGFR oncogenic mutations were identified in 19 patients (~0.17%), of which, 68% were male LUSC patients. Eleven out of the 19 patients (58%) had concurrent altered PI3K signaling, thus, highlighting an intriguing molecular characteristic and potential combination therapeutic strategy of dual-targeting FGFR and PI3K signaling in those patients. Furthermore, FGFR fusions retaining the intact kinase domain were identified in 12 patients (0.11%), including nine FGFR3-TACC3 cases, one FGFR2-INA fusion, one novel FGFR4-RAPGEFL1 rearrangement event, and one novel gene fusion between FGFR1 and the SLC20A2 5'-untranslated region, which may result in FGFR1 overexpression. Concomitant EGFR mutations or EGFR amplifications were observed in six patients, four of whom were previously treated with EGFR tyrosine kinase inhibitors, suggesting that FGFR fusions may act as acquired resistance to anti-EGFR therapies. In addition, FGFR amplification was detected in 24 patients, with FGFR1 amplification being the most common event. Notably, FGFR oncogenic mutations, fusions, and gene amplifications were almost always mutually exclusive events. Conclusion We herein report an incidence of FGFR anomalies in a large Chinese NSCLC population, including mutations, gene amplifications, and previously characterized and novel FGFR fusions involving TACC3, INA, RAPGEFL1, and SLC20A2. Keywords: FGFR, activating mutation, fusion, gene amplification, NSCLC, FGFR inhibitors Citation Format: Zhen Zhou, Zichuan Liu, Qiuxiang Ou, Xue Wu, Xiaonan Wang, Yang Shao, Hongyan Liu, Yu Yang. Landscape of FGFRactivating aberrations in Chinese non-small cell lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 745.

Clinical and patho-genomic characteristics of concomitant mutated status of TP53, EGFR, KRAS genes in Chinese patients with resected lung adenocarcinoma.

e21024 Background: Alterations of TP53, EGFR, KRAS genes are of importance in LUAD etiology, vital prognostic markers as well as therapeutic targets as recently reported. In addition, in advanced or metastatic NSCLC, concomitant mutations of TP53 with EGFR or KRAS closely associated with prognosis and TKIs’ efficacy. While, distribution of concomitant mutations of TP53, EGFR and KRAS in early stage or resectable LUAD remained to be elucidated. Methods: 434 patients with defined pathological diagnosis of LUAD were recruited from 1st.Jan.2019-31st.Dec.2019, which made 468 FFPE blocks for the study. Histology and composition were given by authorized by pathologist. Genomic DNA from FFPE samples and peripheral blood was extracted. 636 cancer-related genes were specifically captured and sequenced by MGI-seq 2000. Association of concomitant status with clinical and genomic characteristics was further analyzed. Results: Generally, TP53, EGFR and KRAS mutation rate is 26.7%, 60.9% and 10% respectively. Among these samples, Subtypes of EGFR mutations significantly differed in between tumors rising in left and right lung (P = 0.048). Tumors with KRAS mutations occurred more easily in right lung than those with TP53 or EGFR mutations (P = 0.012, P = 0.043 respectively). In addition, histology subtype and clinical stage were closely associated with TP53, EGFR and KRAS mutation status (P < 0.001). 90 samples (19.2%) carried concomitant TP53 and EGFR mutation, 14 samples (3%) were TP53/KRAS co-mutated. LUAD samples with EGFR amplification had higher rate of concomitant TP53/EGFR mutations (RR:1.1,95%CI: 1.032 to 1.159,P = 0.0009). Moreover, KRAS G13 mutated samples more easily co-mutated with TP53 mutations compared with those with mutations in G12 loci (RR:1.33,95%CI: 1.24 to 1.37,P = 0.024). Further, samples with non-concomitant TP53 mutations had highest level of tumor mutation burden (muts/Mb) (median TMB = 9.74 vs 2.05 for TP53/EGFR/KRAS wild type, P < 0.0001). Samples with concomitant TP53/EGFR mutations and TP53/KRAS mutations displayed higher TMB level than their non-concomitant compartment (P < 0.001 and P = 0.05 respectively). Conclusions: TP53,EGFR and KRAS mutations and their concomitant mutation status displayed diverse correlation with spatial, clinical and genomic characteristics in resectable LUAD patients. This correlation may indicate complex biological heterogeneity of LUAD which may need further exploration.

Influence of EGFR-activating mutations on sensitivity to tyrosine kinase inhibitors in a KRAS mutant non-small cell lung cancer cell line.

In non-small cell lung cancer (NSCLC), oncogenic driver mutations including those in KRAS and EGFR are typically mutually exclusive. However, recent reports indicate that multiple driver mutations are found in a certain percentage of cancers, and that the therapeutic responses of such cases with co-mutations of driver genes are largely unclear. Here, using CRISPR-Cas9-mediated genome editing, we generated isogenic cell lines harboring one or two copies of an EGFR-activating mutation from the human NSCLC cell line A549, which is known to harbor a homozygous KRAS gene mutation. In comparison with parent cells with KRAS mutation alone, cells with concomitant EGFR mutation exhibited higher sensitivity to EGFR-tyrosine kinase inhibitors (TKIs) but not to conventional anti-cancer drugs. In particular, cells with two copies of EGFR mutation were markedly more sensitive to EGFR-TKIs compared with parent cells. Thus, the presence of concomitant EGFR mutation can affect the TKI response of KRAS-mutated cells, implying that EGFR-TKI may represent an effective treatment option against NSCLC with EGFR/KRAS co-mutation.

1988P - Identification of novel and known FGFR gene fusions in Chinese non-small cell lung cancer

BackgroundOncogenic fibroblast growth factor receptor (FGFR) gene fusions have been described in diverse tumor histology. FGFR inhibitors including erdafitinib have demonstrated promising results in patients whose tumors harbor FGFR gene fusions or mutations. We hereby assessed the frequency of FGFR rearrangements in the Chinese non-small cell lung cancer (NSCLC) population. MethodsA total of 10,966 NSCLC patients whose tumor specimen and/or circulating cell-free DNA (cfDNA) submitted for genomic profiling by hybridization capture-based targeted next-generation sequencing (NGS) of exons and introns of cancer related genes were retrospectively reviewed. Patients’ clinical characteristics and treatment history were retrieved from the database for further evaluation. ResultsFGFR fusions retaining the intact kinase domain were identified in 0.11% (12/10966) of NSCLC cases examined, including 9 fibroblast growth factor receptor 3 (FGFR3)-transforming acidic coiled-coil containing protein 3 gene (TACC3) fusion-positive cases that was mostly reported in solid tumors, one fibroblast growth factor receptor 2 (FGFR2)-internexin neuronal intermediate filament protein α gene (INA) fusion that was previously reported in gliomas, one novel fibroblast growth factor receptor 4 (FGFR4)-Rap guanine nucleotide exchange factor like 1 gene (RAPGEFL1) fusion case, and one novel fibroblast growth factor receptor 1 (FGFR1) gene fusion involving the 5’UTR of Solute Carrier Family 20 Member 2 gene (SLC20A2) which may possibly drive the overexpression of FGFR1. Concomitant EGFR mutations or EGFR amplification were observed in 6 patients, four of which were previously treated with EGFR tyrosine kinase inhibitors (TKIs), but disease progressed prior to NGS tests. FGFR fusions may arise as resistance mechanism to EGFR TKI therapies in patients who carried founder EGFR alterations. No other known concurrent driver mutations were detected in the remaining 6 cases. ConclusionsWe hereby report a frequency of FGFR fusions of 0.11% in a large Chinses NSCLC population involving known and novel FGFR gene fusion partners including TACC3, INA, RAPGEFL1, and SLC20A2. Oncogenic FGFR fusions may arise as mechanisms of acquired resistance. Legal entity responsible for the studyGeneseeq Technology Inc. FundingHas not received any funding. DisclosureQ. Ou: Full / Part-time employment, NA: Geneseeq Technology Inc. X. Wu: Leadership role, NA: Geneseeq Technology Inc. X. Wang: Full / Part-time employment, NA: Nanjing Geneseeq Technology Inc. Y.W. Shao: Leadership role, NA: Geneseeq Technology Inc. All other authors have declared no conflicts of interest.

Abstract 4905: Comprehensive characterization of MET alterations in a large cohort of 610 advanced non-small cell lung cancer patients

Abstract Background: A variety of alterations in MET have been described in advanced non-small cell lung cancer (NSCLC) patients, including gene amplification, protein overexpression, splicing variants and point mutations. MET alterations are receiving increasing attention as targets in precision medicine, and several clinical trials of anti-MET agents are ongoing in NSCLC. Methods: A cohort of 610 patients with stage IIIb-IV NSCLC from two institutions was retrospectively analyzed for MET alterations by next-generation sequencing (NGS) (Ion Torrent PGM® or GeneReader®), nCounter, reverse transcriptase polymerase chain reaction (RT-PCR) or immunohistochemistry (IHC) during a 2-year period. Patients positive for MET amplification by NGS or MET overexpression by nCounter and/or IHC were submitted to fluorescence in situ hybridization (FISH). Representative patients positive for MET exon 14-skipping (METΔex14) mutations by nCounter and/or RT-PCR were confirmed by sequencing exons 13-15 of the METgene. Results: Overall, MET alterations were found in 116/610 patients (19%). Some patients had ≥2 MET aberrations. The most frequent finding was MET overexpression (58/333; 17.6%), followed by METΔex14 (31/610; 5.1%) and MET point mutations (3/129; 2.3%). Regarding MET amplification, it was found in 24/157 patients (15.3%). MET positivity by IHC (3+, >50%) showed a 90.8% concordance with MET mRNA overexpression by nCounter, with a 0.768 Cohen’s kappa (confidence interval, CI 95% 0.575-0.961). A moderate agreement between RT-PCR and nCounter was found for METΔex14 (Cohen’s kappa 0.629; CI 95% 0.434-0.825). METamplification by FISH was found in the subset of MET-overexpressing patients with the highest mRNA levels by nCounter. Interestingly, a patient with a concomitant EGFR mutation and MET overexpression derived two years clinical benefit from crizotinib. Conclusions: MET aberrations are present in 19% of advanced NSCLC patients and represent one of the most frequent targetable alterations in this malignancy. A comprehensive testing of MET alterations in advanced NSCLC patients, including NGS and nCounter techniques, is needed to identify a broader number of patients’ candidates for targeted therapies. Citation Format: Cristina Aguado Esteban, Cristina Teixidó, Ruth Román, Ana María Gimenez Capitán, Carlos Cabrera, Mireia García, Clara D. Mayo De Las Casas, Ainara Arcocha, Sonia Rodriguez, Roxana Reyes, Elba Marín, Ana Perez Rosado, Niki Karachaliou, Aleix Prat, Rafael Rosell, Alejandro Martinez-Bueno, Miguel Angel Molina-Vila, Noemi Reguart. Comprehensive characterization of MET alterations in a large cohort of 610 advanced non-small cell lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4905.

P3.13-16 Concomitant EML4-ALK Rearrangement and EGFR Mutation in Non-Small Cell Lung Cancer Patients: Data from Eastern Indian Hospital.

P3.13-16 Concomitant EML4-ALK Rearrangement and EGFR Mutation in Non-Small Cell Lung Cancer Patients: Data from Eastern Indian Hospital.

Abstract A59: Impact of NGS four-gene panel in screening genes with potential therapies in NSCLC

Abstract Targetable genomic mutation detection has innovated personalized medicine in non-small cell lung cancer (NSCLC) mainly through detection of EGFR activation mutations, which predicts susceptibility to tyrosine kinase inhibitors (TKIs). Although patients render positive response to TKIs initially, resistance could eventually arise, due to the secondary mutation T790M, therefore decreasing patients' survival and limiting treatment options. NSCLC patients harbors a variety of other mutated genes, despite EGFR that could potentially be treated with drugs already approved, or in ongoing clinical trials for other types of tumor. KRAS is one of the most frequently mutated genes in NSCLC and could act as a new target for lung cancer treatment. Although no targeted therapy has yet been approved for mutated-KRAS, there are multiple potential treatment strategies under investigation. BRAF is another gene described in NSCLC that offers a rational therapeutic strategy, since its pathway plays a role in the carcinogenesis of NSCLC. In the present study the prevalence of KRAS, BRAF, and EGFR was determined among patients with next-generation sequence technology. We used a custom multigene panel for Ion Platform to investigate EGFR, KRAS, and BRAF mutations in 491 NSCLC Brazilian patients. Genomic DNA libraries were prepared from FFPE-derived DNA and sequenced in the Ion PGM platform. KRAS was the most frequently mutated gene, found in 27.6% of all samples, and thus could be an appealing target for new therapy strategies as described in other studies. 111 (82.2%) samples harbored mutation in codon 12, with G12C mutation the most common one, present in 37.8%. The second most prevalent mutated gene was EGFR with 119 (24.3%) mutated samples. The most common mutations were exon 19 deletions (most frequently E746-A750), found in 42% of the samples, and L858R, found in 32% of the samples. BRAF displayed prevalence rates of 3.7%. V600E mutation was present in 55.5% of the BRAF mutated samples, followed by mutations in codon G469 (22%). We identified 17 double and coexisting mutations. EGFR T790M was the most common secondary mutation, found in six (12%) samples concomitantly with p.E746_A750del, indicating that these patients might have a reduced response to TKIs therapy. Interesting is the fact that three of these double mutant samples had prior cobas® EGFR Test results from 2-3 previous years with absence of T790M mutation, indicating that resistance may have arrived in a 2- to 3-year life span. Although EGFR gene mutations are reported as mutually exclusive with KRAS or BRAF mutations in lung cancer, we found three samples harboring concomitant EGFR and KRAS mutations. Previous studies also reported that mutations in KRAS and BRAF are mutually exclusive, but we found one sample harboring mutations in both genes, indicating that this is a rare event. In conclusion, this study shows that in development of future therapies, targeting KRAS should be prioritized. Although BRAF-mutated samples displayed short prevalence, it could be a potential target among wild-type EGFR and KRAS cancer patients. This study shows the importance of multi-gene panel screening to reduce overall turnaround time generating results in a single test. Citation Format: Carolina Bustamante, Maíra Cristina Menezes Freire, Natália Penido Lopes, Mariano Zalis. Impact of NGS four-gene panel in screening genes with potential therapies in NSCLC [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; São Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr A59.

Discovery of N-(5-((5-chloro-4-((2-(isopropylsulfonyl)phenyl)amino)pyrimidin-2-yl)amino)-4-methoxy-2-(4-methyl-1,4-diazepan-1-yl)phenyl)acrylamide (CHMFL-ALK/EGFR-050) as a potent ALK/EGFR dual kinase inhibitor capable of overcoming a variety of ALK/EGFR associated drug resistant mutants in NSCLC

Recently, more and more concomitant EGFR mutations and ALK rearrangement are observed from the clinic, which still lacks effective single-agent therapy. Starting from ALK inhibitor 14 (TAE684), we have developed a highly potent EGFR/ALK dual kinase inhibitor compound 18 (CHMFL-ALK/EGFR-050), which potently inhibited EGFR L858R, del 19 and T790M mutants as well as EML4-ALK, R1275Q, L1196M, F1174L and C1156Y mutants biochemically. Compound 18 significantly inhibited the proliferation of EGFR mutant and EML4-ALK driven NSCLC cell lines. In the cellular context it strongly affected EGFR and ALK mediated signaling pathways, induced apoptosis and arrested cell cycle at G0/G1 phase. In the in vivo studies, 18 significantly suppressed the tumor growth in H1975 cell inoculated xenograft model (40 mg/kg/d, TGI: 99%) and H3122 cell inoculated xenograft model (40 mg/kg/d, TGI: 78%). Compound 18 might be a potential drug candidate for EGFR- or ALK-individual as well as concomitant EGFR/ALK NSCLC.

Concomitant EML4-ALK rearrangement and EGFR mutation in non-small cell lung cancer patients: a literature review of 100 cases.

The discovery of EGFR mutations and EML4-ALK gene rearrangements has radically changed the therapeutic scenario for patients with advanced non-small cell lung cancer. ALK and EGFR tyrosine-kinase inhibitors showed better activity and efficacy than standard chemotherapy in the first and second line treatment settings, leading to a clear advantage in overall survival of advanced non-small cell lung cancer patients harboring these genetic alterations.Historically the coexistence of EGFR mutations and EML4-ALK rearrangements in the same tumor has been described as virtually impossible. Nevertheless many recent observations seem to show that it is not true in all cases.In this review we will discuss the available literature data regarding this rare group of patients in order to give some suggestions useful for their clinical management. Furthermore we report here two cases of concomitant presence of both alterations that will help us in the development of discussion.