Generation EGFR-TKI Research Articles

P3.12D.02 Phase 1/2 Clinical Trial of JIN-A02, a 4th Generation EGFR-TKI in EGFR Mutated Advanced/metastatic Non-Small Cell Lung Cancer (NSCLC)

P3.12D.02 Phase 1/2 Clinical Trial of JIN-A02, a 4th Generation EGFR-TKI in EGFR Mutated Advanced/metastatic Non-Small Cell Lung Cancer (NSCLC)

FLAIR: A Phase II, Open Label, Randomized Study of Osimertinib Plus Bevacizumab Versus Osimertinib in Recurrent or Metastatic Treatment-Naïve NSCLC Patients Harboring EGFR 21L858R Mutation

IntroductionOsimertinib, the 3rd generation EGFR-TKI, has emerged as standard first-line treatment for patients with advanced EGFR mutated nonsmall cell lung cancer (NSCLC). Patients with exon 21 L858R mutation showed lower efficacy with EGFR-TKIs than those with 19Del mutation, even with osimertinib, it remains an unmet medical need to further improve the efficacy in L858R population. We present the rationale and design for FLAIR (NCT04988607), which will investigate the efficacy and safety of osimertinib plus bevacizumab versus osimertinib monotherapy in treatment-naïve recurrent or metastatic NSCLC patients harboring EGFR exon 21 L858R mutation. Materials and MethodsFLAIR is a prospective, multicenter, randomized, open label study, which is initiated by Chinese Thoracic Oncology Group (CTONG2002). Patients age ≥18 years with primary recurrent or metastatic nonsquamous NSCLC who are treatment-naïve with documented EGFR exon 21 L858R mutation is eligible. Patients will be randomized 1:1 to receive osimertinib 80 mg once daily plus bevacizumab 15mg/kg every 3 weeks or osimertinib monotherapy 80 mg once daily until progression or another discontinuation criterion is met. The primary endpoint is investigator-assessed progression free survival (PFS). Secondary endpoints include: overall survival rate at 24 months, time to treatment failure (TTF), overall response rate (ORR), disease control rate (DCR), duration of response (DoR), central nervous system (CNS) PFS, CNS ORR and safety. ResultsFLAIR has completed the enrollment, and results are expected in the fourth quarter of 2025 (depending on the actual event rate). ConclusionsThis study will offer better perspectives on the efficacy and safety of osimertinib plus bevacizumab combination therapy in treatment-naïve recurrent or metastatic NSCLC patients harboring EGFR exon 21 L858R mutation, providing valuable guidance for clinical practice.

2277: Effect of intervention timing of CRT combined non-third generation EGFR-TKIs in EGFR-mutant NSCLC

2277: Effect of intervention timing of CRT combined non-third generation EGFR-TKIs in EGFR-mutant NSCLC

Advances in Diagnosis and Targeted Therapy of G719X/L861Q/S768I Mutant Non-small Cell Lung Cancer

Lung cancer accounts for the highest proportion of cancer deaths in the world and poses a great threat to human health. About 30% to 40% of non-small cell lung cancer (NSCLC) is caused by point mutations, exon insertion and exon deletion of the epidermal growth factor receptor (EGFR). In addition to the common exon 19 deletion mutation and exon 21 L858R mutation, exon 18 G719X mutation, exon 21 L861Q mutation and exon 20 S768I mutation are the most important rare mutations. At present, the diagnostic methods for major rare mutations are mainly next-generation sequencing (NGS), digital polymerase chain reaction (dPCR), droplet digital PCR (ddPCR), etc. Regarding the targeted therapy of G719X/L861Q/S768I mutant NSCLC, the first generation EGFR-tyrosine kinase inhibitors (TKIs) have poor efficacy, while the second and third generation EGFR-TKIs have similar efficacy. The novel third generation EGFR-TKIs and combination therapy show a good therapeutic prospect. This article summarized the progress in the diagnosis and targeted therapy of G719X/L861Q/S768I mutant NSCLC, so as to provide reference for subsequent clinical drug use and research. .

Strong PD-L1 affect clinical outcomes in advanced NSCLC treated with third-generation EGFR-TKIs.

Background: In first/second generation EGFR-TKIs, strong PD-L1 expression contributes to primary resistance, significantly affecting patient prognosis. The relationship between PD-L1 expression levels and third-generation TKIs remains unclear.Methods: This study analyzed advanced NSCLC who received third-generation EGFR-TKIs as first-line systemic therapy from March 2019 to June 2022. The EGFR and PD-L1 status of the patients was also assessed.Results: Overall, 150 patients were included in this study. PD-L1 expression was negative (PD-L1 tumor proportion score <1%) in 89 cases, weak (1-49%) in 42 cases, and strong (≥50%) in 19 cases. mPFS for patients with negative, weak and strong PD-L1 expressions was 23.60, 26.12 and 16.60months, respectively. The mPFS for strong PD-L1 expression was significantly shorter than that for with weak PD-L1 expression but was not associated with negativity. The same conclusions were shown in subgroup analyses of mutation types and TKI kinds. In addition, Relative to PD-L1-negative patients, resistance to TKIs may be associated with early progression for patients with strong PD-L1 expression.Conclusion: PD-L1 expression in tumor cells influenced the clinical outcomes of patients with advanced NSCLC treated with third-generation EGFR-TKIs. Stronger PD-L1 expression in TKIs-treated patients with advanced first-line EGFR-mutated NSCLC was associated with worse PFS.

NGS and FISH for MET amplification detection in EGFR TKI resistant non-small cell lung cancer (NSCLC) patients: A prospective, multicenter study in China

ObjectivesComprehensive data using Next-Generation Sequence (NGS) and fluorescence in situ hybridization (FISH) for detecting MET amplification is limited in Chinese patients, we evaluating NGS performance both in tissue and plasma samples using FISH as reference. We also sought to find optimal thresholds value for NGS in detecting MET amplification via bioinformatics methods. MethodPatients progressed after 1st-, 2nd-, or 3rd-generation (G) EGFR-TKIs were enrolled. Tissue biopsy samples were performed for MET amplification detection via both NGS and FISH. Paired plasma samples were collected for MET amplification detection by NGS. The sensitivity, specificity and agreement were analyzed between NGS and FISH. Results116 eligible patients were analyzed. 44 patients were male. 82 patients were after 3rd generation EGFR-TKI. MET amplification was detected in 43 (37.1 %) patients by FISH, including 19 (16.4 %) polysomy and 24 (20.7 %) focal amplification. The positive rate of MET amplification in post 3rd generation EGFR-TKI and post 1st/2ndgeneration EGFR-TKI resistant patients was 42.7 % (35/82), and 23.5 % (8/34).The sensitivity, specificity and agreement of detecting MET amplification by NGS in tissue were 39.5 % (17/43), 98.6 % (72/73) and 76.7 % (89/116), respectively, 66.7 % (16/24), 98.6 % (72/73) and 90.7 % (88/97) for focal MET amplification in tissue and 29.2 % (7/24), 94.5 % (69/73), 78.4 % (76/97) for focal amplification in plasma. Results were shown in the table below. ConclusionNGS is an alternative method for MET focal amplification detection in tissue. While the sensitivity of NGS testing in plasma needs further improvement to maximize identification of patients with potential benefit from dual-targeted therapy.

Phase 1/2 clinical trial of JIN-A02, a 4th generation EGFR-TKI, in patients with 3rd generation EGFR-TKI resistance in EGFR mutated advanced/metastatic non-small cell lung cancer (NSCLC).

TPS8658 Background: Epidermal growth factor receptor (EGFR) mutations are the most common driver mutations in NSCLC. EGFR tyrosine kinase inhibitors (TKIs) are the recommended front-line option for EGFR-mutant advanced NSCLC patients, but patients invariably develop acquired resistance and face disease progression. JIN-A02, a 4th generation EGFR-TKI intended for oral administration, selectively and reversibly binds to EGFR mutations, including the C797S and/or T790M mutation that causes resistance to 3rd generation of EGFR-TKIs. Pre-clinical studies with EGFR C797S and/or T790M mutated cell lines showed that JIN-A02 can inhibit cell growth in a dose dependent manner and has a high degree of selectivity over wild-type EGFR. In vivo studies showed that administration of JIN-A02 dose-dependently inhibited tumor growth in the C797S+ xenograft mice model. Moreover, JIN-A02 shown to penetrate blood-brain barrier and exhibit anti-tumor activity in an intracranial tumor model. The strong potency and high selectivity of JIN-A02 for mutant EGFR may offer improved therapeutic window in the clinical setting vs available EGFR-TKIs. Methods: JIN-A02 is being evaluated in this Phase 1/2, multicenter, an open-label trial (NCT05394831) for subjects with advanced NSCLC harboring C797S and/or T790M mutation as a monotherapy. The primary object of this study is to assess safety, tolerability, pharmacokinetics, and anti-tumor effect for determining the recommended phase 2 dose (RP2D) of JIN-A02. The inclusion criteria are that the subject (≥ 18 years) must have an advanced or metastatic NSCLC showed progress disease (PD) after receiving approved standard EGFR-TKI therapies and/or platinum-based anticancer chemotherapy is allowed up to 1 time after using EGFR-TKI treatment with ECOG status 0 or 1. Before enrollment in the study, the EGFR mutation status is determined using either tumor tissue and/or plasma ctDNA. This study comprises three parts, dose escalation (Part A), dose exploration (Part B), and dose expansion (Part C). In Part A, dose escalation, comprised of 5 cohorts ranged from a starting dose of 12.5 mg P.O, QD to a top dose of 150 mg P.O, QD with every three subjects, is carried out where the maximum tolerated dose (MTD) is evaluated in subjects with 28-day cycles. Dose-limiting toxicities (DLT) are evaluated for 21 days. In Part B, dose exploration is carried out to evaluate the safety of JIN-A02 further and to determine the RP2D using 2 preliminary effective dose levels from Part A in subjects. In Part C dose-expansion study, subjects (n=36 for each cohort) are divided into 5 different cohorts based on the EGFR mutation (both or single positive of C797S and T790M), and the anti-tumor activity of JIN-A02 is evaluated according to RECIST v1.1 at RP2D. Clinical trial information: NCT05394831 .

Immune infiltrate characterization and differential gene expression by RNA-sequencing analysis in patients with oncogene-addicted NSCLC with early progression under targeted therapy.

8535 Background: Despite remarkable advances with tyrosine kinase inhibitors (TKI), patients (pts) with oncogene addicted advanced non-small cell lung cancer (aNSCLC) eventually face resistance. Moreover, some pts exhibit early TKI resistance, often linked to a reduced response subsequent TKIs. These pts might have unique biology, and identifying post-resistance treatments for them is an unmet need. Here, we explore the transcriptomic profile of pts with aNSCLC and early TKI progression, as compared to long responders. Methods: We included pts with aNSCLC harboring EGFR mutations or oncogenic fusions ( ALK, ROS1, RET, NTRK), treated with TKI at Gustave Roussy and enrolled in the prospective MATCH R trial (NCT02517892). Clinical data on treatment outcomes and survival were collected. Pts with PFS &lt; 6 months were considered as having early progression (EP), pts with PFS &gt; 18 months as long responders (LR). At least one tissue biopsy was performed at PD, on which bulk RNA sequencing was carried out. We explored the transcriptomic differences between pts with EP and LR. Differential gene expression (DESeq2), pathway enrichment studies and identification with MSigDb were performed and compared between groups. Immune cell type contents were evaluated by CIBERSORT deconvolution method. Results: From 2015 to 2022, 37 pts were included. 68% were females, median age was 55 (IQR43-83). 18 carried EGFR mutations (EP N=5, 28%; LR N=13, 72%), 19 had fusions (EP N=10, 52%; LR N=9, 48%). All pts had progressed to targeted TKI (7 first generation EGFR-TKI, 11 osimertinib, 8 crizotinib, 7 second generation ALK-TKI, 2 lorlatinib, 2 pralsetinib, 1 repotrectinib). Immune suppressive macrophages were the most represented immune cells in EGFR+ and fusion+ PD samples (33.5% and 33.2% of immune cells). The composition of the immune infiltrate was not significantly different between EP and LR in EGFR+ and fusion+ pts. DESeq2 showed that EGFR+ EP had significantly lower EPCAM(log2FC: 1.60, padj=0.01), higher SOS1 (log2FC: -1.18, padj=0.01), higher JAK2(log2FC: -1.56, padj=0.02) expression, as compared to EGFR+ LR. In the fusion+ group, EP had higher FGFR3/4 (log2FC: -3.5, padj=0.02) and lower MTAP expression (log2FC: 1.75, padj=0.03). Hallmark analysis in the EGFR+ showed higher activation of TNFα, IFNγ response, and KRAS pathways in EP (NES: -1.72, p=0.03; NES=-1.78,p=0.02; NES:-2.07, p=0.01) versus LR. No differential activation was observed in the fusion+ group. Conclusions: Immune suppressive macrophages are the most represented immune cells at PD to TKI, irrespective of the treatment duration. Pts with EP seem to have a different biology, with transcriptomic features of stemness and immune suppression in the EGFR+ pts, and lower MTAP expression in the fusion+ group. This should be further explored for the development of novel therapeutics.

Effect of strong programmed cell death ligand-1 (PD-L1) expressions on clinical outcomes in advanced non-small cell lung cancer treated with third-generation epidermal growth factor receptor-tyrosine kinase inhibitors.

e20500 Background: Third-generation tyrosine kinase inhibitors (TKIs) are the standard treatment for advanced epidermal growth factor receptor (EGFR) mutation-positive lung adenocarcinoma. In first/second generation EGFR-TKIs, strong programmed death ligand 1 (PD-L1) expression contributes to primary resistance, significantly affecting patient prognosis. Despite this, the relationship between PD-L1 expression levels and third-generation TKIs remains unclear. Methods: This retrospective cohort study reviewed patients with advanced NSCLC who received third-generation EGFR-TKIs as first-line systemic therapy at the Shandong Cancer Hospital between March 2019 and June 2022. The EGFR status of the patients was assessed using amplification refractory mutation system fluorescence quantitative polymerase chain reaction, and the PD-L1 expression level was evaluated using Dako 22 C3 immunohistochemical staining. The Kaplan–Meier method was used for survival analysis. The log-rank test was used to compare differences in survival curves between the two groups. Results: Overall, 150 patients were included in this study. PD-L1 expression was negative (PD-L1 tumor proportion score &lt; 1%) in 89 cases, weak (1–49%) in 42 cases, and strong (≥50%) in 19 cases. The median follow-up period for the entire cohort was 22.12 months (median progression-free survival [mPFS]: 24.33 months); the median overall survival was not reached. mPFS for patients with negative, weak, and strong PD-L1 expressions was 23.60, 26.12, and 16.60 months, respectively. The mPFS for strong PD-L1 expression was significantly shorter than that for with weak PD-L1 expression but was not associated with negativity, particularly in the 19DEL and 21L858R subgroups. PFS was significantly shorter in patients with strong PD-L1 expression in both subgroups (19DEL and 21L858R) than in those with weak PD-L1 expression. Conclusions: Strong PD-L1 expression in tumor cells influenced the clinical outcomes of patients with advanced NSCLC treated with third-generation EGFR-TKIs. Stronger PD-L1 expression in TKI-treated patients with advanced first-line EGFR-mutated NSCLC was associated with worse PFS.

Ivonescimab combined with chemotherapy in patients with EGFR-mutant non-squamous non-small cell lung cancer who progressed on EGFR tyrosine-kinase inhibitor treatment (HARMONi-A): A randomized, double-blind, multi-center, phase 3 trial.

8508 Background: Ivonescimab (AK112/SMT112) is a anti-PD-1/VEGF bispecific antibody. Previous phase I/II clinical studies have shown potential efficacy of ivonescimab in NSCLC patients with EGFR mutations who had failed prior EGFR-TKIs therapies. This phase 3 study aimed to evaluate and confirm the efficacy and safety of ivonescimab combined with chemotherapy versus chemotherapy alone in this population. Methods: Patients were randomized 1:1 to receive ivonescimab (20 mg/kg) plus pemetrexed (500 mg/m2) and carboplatin (AUC 5) or placebo plus chemotherapy once every 3 weeks for four cycles, with stratification according to the third-generation EGFR-TKI (received vs not received) and brain metastases (presence vs absence), followed by maintenance therapy of ivonescimab and pemetrexed or placebo and pemetrexed. The primary endpoint was progression-free survival (PFS) in intention-to-treat (ITT) population assessed by independent radiographic review committee (IRRC) per RECIST v1.1. Here we report the results of the first planned interim analysis. Results: Total 322 patients were randomized (161 to the ivonescimab plus chemotherapy arm, 161 to the placebo plus chemotherapy arm). 86.3% versus 85.1% of patients had received the third generation EGFR-TKIs treatment, 21.7% versus 23.0% of patients had brain metastases. As of March 10, 2023, median follow up time was 7.89 months. PFS was significantly improved in the ivonescimab plus chemotherapy arm (HR 0.46 [0.34, 0.62], P &lt; 0.0001). Median PFS (95%CI) by IRRC were 7.06m (5.85, 8.74) in the ivonescimab arm versus 4.80m (4.21, 5.55) in chemotherapy arm. The prespecified subgroup analysis showed PFS benefit favoring patients receiving ivonescimab over placebo across almost all subgroups, including in patients who progressed on the third-generation EGFR-TKIs therapy (HR 0.48, 95% CI 0.35-0.66), those with brain metastases (HR 0.40, 0.22-0.73), those with EGFR mutation of deletion 19 (HR 0.48, 0.32-0.73), and individuals with T790M mutation positive (HR 0.22, 0.09-0.54). The ORR were 50.6% and 35.4%, respectively. Grade ≥3 TEAEs occurred in 99 (61.5%) patients versus 79 (49.1%) patients, the most common grade ≥3 TEAEs were chemotherapy related adverse events. Grade ≥3 immune-related adverse events occurred in 10 (6.2%) patients versus 4 (2.5%). Grade ≥3 VEGF blocking related adverse events occurred in 5 patients (3.1%) versus 4 patients (2.5%). Conclusions: Ivonescimab plus chemotherapy significantly improved PFS while maintaining a manageable safety profile in patients who had failed EGFR-TKIs treatments. Clinical trial information: NCT05184712 .

Case report: NSCLC with pulmonary embolism after treatment with almonertinib

Rationale: Almonertinib is the first independently developed third generation epidermal growth factor receptor tyrosine kinase inhibitors in China. It can be used not only for epidermal growth factor receptor (EGFR) sensitive mutation patients but also for T790M (+) resistant patients, and has better safety and survivability compared to the first and second generation EGFR-TKIs. The previous literature and case studies have reported significant treatment-related adverse reactions in non-small cell lung cancers patients treated with almonertinib, including elevated blood creatine phosphatase, prolonged cardiac QT interval, altered myocardial contractility, interstitial lung disease, eye disease, and hematological events. But there are few individual reports of pulmonary embolism events. Patient concerns: A 55-year-old female with no history of smoking visited a local hospital with mild cough and lower sacrococcygeal pain without obvious cause. Diagnosis: She was diagnosed with right lung adenocarcinoma with multiple bone metastases (T2bN1M1c, stage IVB) after image and histological examination, with EGFR 21 exon L858R sensitive mutation. Interventions: She initially underwent surgical treatment due to the discovery of a sacral tumor, and the pathology of the surgery indicated metastatic lung adenocarcinoma. Genetic testing results showed EGFR 21 exon L858R sensitive mutation. Combined with positron emission tomography/computed tomography imaging results and sacral tumor surgical pathology results, it was considered that the patient had lung adenocarcinoma with multiple bone metastases. Treatment plan: targeted treatment with almonertinib which is the third-generation EGFR-TKIs. After only 1 month of targeted treatment, chest enhanced computed tomography revealed pulmonary embolism imaging, combined with coagulation indicators, considering pulmonary embolism. As the thromboembolic site is located at the end of the pulmonary artery branch and imaging shows that tumor lesions are stable. Consider continuing targeted treatment with almonertinib and adjuvant oral anticoagulant therapy with rivaroxaban for treatment. Outcomes: Two months later, the patient’s condition was followed up and it was found that the imaging manifestations of pulmonary embolism disappeared, but the coagulation indicators remained in a hypercoagulable state. The patient’s treatment plan remained unchanged, and the patient was hospitalized for follow-up every 6 to 8 weeks to closely observe changes in the condition. Lessons: There are many reasons for the occurrence of hypercoagulable blood in tumor patients, and there are very few reports of treatment-related pulmonary embolism events in patients who are treated with almonertinib targeted therapy. It is particularly important to determine whether the hypercoagulable blood in such patients is related to targeted therapy drugs in clinical practice, as this will affect the clinical benefits of patients in epidermal growth factor receptor tyrosine kinase inhibitors treatment and the clinical indicators which need to pay more attention in follow-up observation, to avoid serious pulmonary embolism events and thus affect the patient’s survival status and quality of life.

2307: Effect of intervention timing of CRT combined with third generation EGFR-TKIs in EGFR-mutant NSCLC.

2307: Effect of intervention timing of CRT combined with third generation EGFR-TKIs in EGFR-mutant NSCLC.

Abstract CT154: Phase 1/2 clinical trial of JIN-A02, a 4th generation EGFR-TKI, in patients with 3rd generation EGFR-TKI resistance in EGFR mutated advanced/metastatic non-small cell lung cancer (NSCLC)

Abstract Background: Epidermal growth factor receptor (EGFR) mutations are the most common driver mutations in NSCLC. EGFR tyrosine kinase inhibitors (TKIs) are the recommended front-line option for EGFR-mutant advanced NSCLC patients, but patients invariably develop acquired resistance and face disease progression. JIN-A02, a 4th generation EGFR-TKI intended for oral administration, selectively and reversibly binds to EGFR mutations, including the C797S and/or T790M mutation that causes resistance to 3rd generation of EGFR-TKIs. Pre-clinical studies with EGFR C797S and/or T790M mutated cell lines showed that JIN-A02 can inhibit cell growth in a dose dependent manner and has a high degree of selectivity over wild-type EGFR. In vivo studies showed that administration of JIN-A02 dose-dependently inhibited tumor growth in the C797S+ xenograft mice model. Moreover, JIN-A02 shown to penetrate blood-brain barrier and exhibit anti-tumor activity in an intracranial tumor model. The strong potency and high selectivity of JIN-A02 for mutant EGFR may offer improved therapeutic window in the clinical setting vs available EGFR-TKIs. Methods: JIN-A02 is being evaluated in this Phase 1/2, multicenter, an open-label trial (NCT05394831) for subjects with advanced NSCLC harboring C797S and/or T790M mutation as a monotherapy. The primary object of this study is to assess safety, tolerability, pharmacokinetics, and anti-tumor effect for determining the recommended phase 2 dose (RP2D) of JIN-A02. The inclusion criteria are that the subject (≥ 18 years) must have an advanced or metastatic NSCLC showed progress disease (PD) after receiving approved standard EGFR-TKI therapies and/or platinum-based anticancer chemotherapy is allowed up to 1 time after using EGFR-TKI treatment with ECOG status 0 or 1. Before enrollment in the study, the EGFR mutation status is determined using either tumor tissue and/or plasma ctDNA. This study comprises three parts, dose escalation (Part A), dose exploration (Part B), and dose expansion (Part C). In Part A, dose escalation, comprised of 5 cohorts ranged from a starting dose of 12.5 mg P.O, QD to a top dose of 150 mg P.O, QD with every three subjects, is carried out where the maximum tolerated dose (MTD) is evaluated in subjects with 28-day cycles. Dose-limiting toxicities (DLT) are evaluated for 21 days. In Part B, dose exploration is carried out to evaluate the safety of JIN-A02 further and to determine the RP2D using 2 preliminary effective dose levels from Part A in subjects. In Part C dose-expansion study, subjects (n=36 for each cohort) are divided into 5 different cohorts based on the EGFR mutation (both or single positive of C797S and T790M), and the anti-tumor activity of JIN-A02 is evaluated according to RECIST v1.1 at RP2D. Citation Format: Sun Min Lim, Byoung Chul Cho, Ji Youn Han, Sang We Kim, Ki Hyeong Lee, Misako Nagasaka, Anna Jo, Ethan Seah, Choonok Kim, Thanyanan Reungwetwattana. Phase 1/2 clinical trial of JIN-A02, a 4th generation EGFR-TKI, in patients with 3rd generation EGFR-TKI resistance in EGFR mutated advanced/metastatic non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT154.

Abstract CT055: Efficacy of YK-029A, a novel EGFR TKI, in advanced NSCLC patients with acquired T790M mutation

Abstract In the multicenter, dose-escalation and dose-expansion phase 1 clinical trial (NCT05767866), we evaluated safety and tolerability of YK-029A in various EGFR mutated non-small-cell lung cancer (NSCLC). We have reported efficacy of YK-029A in untreated NSCLC with EGFR ex20ins mutation[1]. This time we report efficacy of YK-029A in patients with acquired EGFR T790M mutation after failure of first or second generation EGFR tyrosine kinase inhibitors (TKIs). Method: This dose-escalation and dose-expansion phase 1 trial recruited previously treated NSCLC patients with EGFR T790M mutation or patients with EGFR ex20ins or EGFR rare mutations. In dose-escalation phase, patients with EGFR T790M mutation were enrolled. YK-029A was given at doses of 50, 100, 150, 200 to 250 mg/day (3+3 design). In dose-expansion phase, patients with EGFR T790M, EGFR ex20ins, or EGFR rare mutations were enrolled. The primary objective was safety. Dose-limiting toxicity (DLT) and maximum tolerated dose (MTD) were explored. Efficacy of YK-029A in EGFR T790M mutated NSCLC was assessed by the investigators. Results: A total of 114 patients were recruited into the study. Safety profile of the first 108 patients was reported previously[1]. By the cut-off date on Sep 12, 2023, 38 patients harbored EGFR T790M mutation were included in efficacy analysis. All these patients were previously treated with first or second generation EGFR-TKIs. The objective response rate (ORR; RECIST 1.1) was 65.8% (95%CI: 48.6%-80.4%) and disease control rate (DCR) was 84.2% (95%CI: 68.7%-94.0%). With a median follow-up time of 8.2 months,the median progression free survival (PFS) was 11.0 months (95%CI: 7.75-NR). The median overall survival (OS) was not reached. Among the 8 patients with measurable brain metastases, intracranial ORR was 75% (95%CI: 35.6%-95.6%) . Conclusions: YK-029A has promising activity in previously treated NSCLC patients harboring EGFR T790M mutation. Reference[1] DUAN J, WU L, YANG K, et al. Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of YK-029A in Treatment-Naive Patients With Advanced NSCLC Harboring EGFR Exon 20 Insertion Mutations: A Phase 1 Trial [J]. J Thorac Oncol, 2023. Citation Format: Rui Wan, Yi Fung Chau, Jun Zhao, Zhe Liu, Mingfang Zhao, Yanqiu Zhao, Xiumei Dai, Yueyin Pan, Zhihong Zhang, Yu Yao, Kunyu Yang, Lin Wu, Yanyan Xie, Bi Chen, Yixuan Yang, Yongqi Guo, Jie Wang, Jianchun Duan. Efficacy of YK-029A, a novel EGFR TKI, in advanced NSCLC patients with acquired T790M mutation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT055.

Comparison between the Originator and Me-too Drugs of First- Generation EGFR-TKI in EGFR-Mutant NSCLC Patients: A Retrospective Cohort Study

Comparison between the Originator and Me-too Drugs of First- Generation EGFR-TKI in EGFR-Mutant NSCLC Patients: A Retrospective Cohort Study

Correlation Analysis between T790M Status and Clinical Characteristics of Patients with EGFR-sensitive Mutation Advanced NSCLC who Progressed after the First Generation and First-line EGFR-TKIs Administration: A Real-world Exploratory Study.

The present study is to investigate the association between T790M status and clinical characteristics of patients with EGFR-sensitive advanced non-small cell lung cancer (NSCLC) who progressed the initial epidermal growth factor receptor tyrosine kinase inhibitors (EGFRTKIs) administration. A total of 167 patients with EGFR-sensitive mutations advanced NSCLC who had successful genetic tests and progressed the initial EGFR-TKI treatment were included in this study retrospectively. The clinical and demographic characteristics of these patients were collected, which were manifested as pathological type, metastasis location, initial biopsy method, initial genetic test specimens, and baseline gene mutations status. Correlation analysis between T790M status and these characteristics was performed and prognostic analysis regarding the different subgroups was carried out accordingly. The prevalence of secondary T790M after resistance to initial EGFR-TKIs among the 167 patients was 52.7%. Correlation analysis indicated that the median progression-free Survival (PFS) to initial EGFR-TKIs >12 months were more likely to develop secondary T790M in univariate analysis. However, the conclusion failed to show statistically significant in multivariate analysis. Additionally, patients with intracranial progression of initial EGFR-TKIs therapy were associated with secondary EGFR-T790M. However, it should be noted that those whose best overall response was partial response (PR) during the EGFR-TKI therapy were relevant to secondary T790M. Furthermore, The median PFS of the initial EGFR-TKIs administration was longer among patients with T790M positive mutation and patients with PR reaction than those without T790M mutation and patients with stable disease (SD), respectively (median PFS: 13.6 vs. 10.9 months, P=0.023) and (median PFS: 14.0 vs. 10.1 months, P=0.001). This retrospective study highlighted the real-world evidence that the best efficacy and intracranial progression with initial EGFR-TKIs therapy among patients with advanced NSCLC might be the promising indicators to predict the occurrence of EGFR-T790M. Patients with PR reaction and T790M positive mutation conferred longer PFS of the initial EGFR-TKIs administration. Also, the conclusion should be confirmed in more patients with advanced NSCLC subsequently.

Abstract 5204: Exploring the therapeutic potential of EGFR retreatment: A comprehensive analysis of T790m(+) conversion and prognosis in lung cancer patients

Abstract Background: T790M acquired resistance occurs in 30-40% of cases after first- or second-generation EGFR TKI treatment. However, some patients who did not develop T790M mutation are converted to T790M positive through EGFR TKI retreatment. We conducted a Phase II prospective study analyzing T790m (+) conversion and prognosis in patients who were not induced T790M mutation at 2nd biopsy and were re-treated with first-generation EGFR-TKI as the third-line or later therapy. Methods: We re-administered first-generation EGFR-TKI to 63 patients (gefitinib n=34 or erlotinib n=29) who had previously been treated with first- or second- generation EGFR TKIs and cytotoxic chemotherapy because they were T790M-negative at the 2nd biopsy. Results: Among the 63 patients, a new T790m (+) mutation was identified in 20 patients (32%) with EGFR TKI retreatment. The first EGFR TKI treatment period and EGFR TKI retreatment period were significantly longer in the T790m (+) group than in the T790m (-) group (P-value=0.026, P-value=0.029, respectively). The best response to retreatment was also favorable in the T790m (+) group (P-value=0.038). The median overall survival (OS) in the T790m (+) group was 29.3 months, which was significantly better than the 6.0 months observed in the T790m (-) group (P-value&amp;lt;0.001). In an additional NGS analysis conducted on stored plasma samples from the 24 patients who were negative for T790M in the tumor tissue before retreatment, T790M was detected in five patients. These patients, who were subsequently treated with a third EGFR TKI, demonstrated very favorable overall survival (OS). Conclusions: EGFR retreatment could induce T790m (+) conversion in approximately one-third of cases, and these patients exhibited favorable prognosis. Through NGS analysis using plasma samples, approximately 20% cases of T790m mutation, which were not detected through routine PCR tests at the tumor tissue, could be identified. Retreatment-EGFR TKI and NGS analysis through blood samples could improve patient prognosis through the additional discovery of T790m (+) mutation. Citation Format: Joong Jin Ahn, Jae Cheol Lee, Chang Min Choi, In Ae Kim, Kye Young Lee, Jeong Eun Lee, Seung Hoon Jang, Seong Hoon Yoon, In Jae Oh, Sang Hoon Lee, Eun Young Kim, Juwhan Choi, Sung Yong Lee. Exploring the therapeutic potential of EGFR retreatment: A comprehensive analysis of T790m(+) conversion and prognosis in lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5204.

Abstract 4756: Targeting DNA topoisomerase II to manage acquired resistance to third generation EGFR tyrosine kinase inhibitors in the treatment of EGFR mutant NSCLC

Abstract Development of effective strategies to manage the inevitable acquired resistance to osimertinib, a 3rd generation EGFR inhibitor with proven clinical efficacy in prolonging survival of patients with EGFR mutant (EGFRm) non-small cell lung cancer (NSCLC), is an urgent and critical area of unmet need in the clinic. Effort toward this direction led us to find that the DNA topoisomerase II (Topo II) inhibitors, doxorubicin and etoposide (VP-16), but not other chemotherapeutic agents, synergistically decreased the survival of osimertinib-resistant cell lines when combined with osimertinib. The combination of osimertinib with either doxorubcin or VP-16 effectively induced DNA damage and apoptosis in osimertinib-resistant cells, suppressed the growth of osimertinib-resistant tumors, and delayed the emergence of acquired resistance to osimertinib. Mechanistic studies found that osimertinib as well other EGFR-TKIs effectively decreased Topo IIα levels in EGFRm NSCLC cells by facilitating its proteasomal degradation and induced DNA damage; these effects were lost in cell lines with osimertinib acquired resistance that possessed elevated basal levels of Topo IIα. In the majority of EGFRm NSCLC tissues relapsed from EGFR-TKI treatment, Topo IIα levels were substantially increased. Enforced expression of ectopic TOP2A genes in sensitive EGFRm NSCLC cells conferred resistance to osimertinib in inducing DNA damage and apoptosis, whereas knockdown of TOP2A in osimertinib-resistant cell lines restored their responses to undergo osimertinib-induced DNA damage and apoptosis. Together, these results reveal a previously undiscovered essential role of Topo IIα modulation in regulating the responses of EGFRm NSCLC cells to osimertinib, providing scientific rationale for targeting Topo II to manage acquired resistance to osimertinib and possibly other third generation EGFR-TKIs, thus warranting clinical validation of this strategy. (This study was supported by NIH/NCI R01 CA223220 and UG1 CA233259 and Emory Winship Cancer Institute lung cancer research pilot funds). Citation Format: Zhen Chen, Karin A. Vallega, Dongsheng Wang, Zihan Quan, Songqing Fan, Qiming Wang, Ticiana A. Leal, Suresh S. Ramalingam, Shi-Yong Sun. Targeting DNA topoisomerase II to manage acquired resistance to third generation EGFR tyrosine kinase inhibitors in the treatment of EGFR mutant NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4756.

Abstract 5868: Upregulation of HER3 and MET in non-small cell lung cancer cells resistant to EGFR tyrosine kinase inhibitor

Abstract Introduction: Prior research demonstrates the importance of studying epidermal growth factor receptor (EGFR) activating mutations for better understanding the biology of non-small cell lung cancer (NSCLC), which comprises the majority (~80%) of lung cancers. EGFR-targeted tyrosine kinase inhibitors (TKIs) have been used in the clinic to treat NSCLC with EGFR activating mutations. First and second-generation EGFR-TKIs are effective in NSCLC patients with the most common EGFR mutations (exon 19 deletion (Del19) and exon 21-point mutation (L858R)). A third generation EGFR-TKI, osimertinib (AZD9291), has been developed to target the T790M resistance mutation, but patients are starting to show resistance to this line of therapy as well. Our study aims to elucidate the underlying mechanism(s) of EGFR-TKI resistance in NSCLC cells. Methods: NSCLC cell lines, including PC-9 and HCC827, which have the Del19 EGFR activating mutation, were utilized for experiments. From the parental cell lines, several cell lines resistant to the EGFR-TKIs were previously established. Cell proliferation (MTS) assays were used to confirm the resistance phenotype of the established cell lines. Western blot assays and RT-qPCR were utilized to determine changes in the expression level of several membrane receptors and their downstream effectors. Results: Our preliminary analysis showed that both human epidermal growth factor 3 (HER3) and mesenchymal-epithelial transition factor (MET) were upregulated in the EGFR-TKI-resistant cell lines as compared to their parental counterparts. Further studies revealed an increased level of phosphorylated STAT3 (p-STAT3) and ERK1/2 (p-ERK1/2) in the resistant cell lines when compared to the parental cell lines, suggesting the possible involvement of HER3 and/or MET in the activation of downstream signaling pathways. Upregulation of HER3 and MET was found at both the protein and mRNA level. Conclusion: Based on our initial findings, membrane receptors, including HER3 and MET, could be working together to continue activating downstream signaling pathways to evade the effects of osimertinib, resulting in resistance. Additional work is underway to define the role of HER3 and MET in the NSCLC cells resistant to EGFR-TKIs. Citation Format: Margaret Larsen, Hui Lyu, CongCong Tan, Yakun Wu, Bolin Liu. Upregulation of HER3 and MET in non-small cell lung cancer cells resistant to EGFR tyrosine kinase inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5868.

Abstract 1967: IN-119873, the next-generation allosteric EGFR TKI, a potent and highly selective EGFR L858R for the treatment of osimertinib-resistant NSCLC

Abstract EGFR mutations occur in approximately 50% of Asian patients and 20% of Caucasian patients with non-small cell lung cancer (NSCLC). The EGFR L858R mutation constitutes approximately half of the EGFR-mutated patients, and despite receiving first-line or second-line treatment with the 3rd generation EGFR TKI osimertinib, they continue to exhibit a poor prognosis. According to real-world analysis, the leading resistance mechanism to osimertinib is identified as EGFR C797S mutation. Furthermore, osimertinib is still associated with gastrointestinal and skin toxicity, despite its improved selectivity for EGFR WT compared to 1st-generation EGFR TKIs. Here, we show that IN-119873 can overcome C797S-mediated acquired resistance based on the results obtained by various in vitro and in vivo NSCLC models. IN-119873 binds to an EGFR allosteric site separate from the ATP-binding site with a remarkable preference for highly mutant-selective inhibition. It effectively targets EGFR L858R activating mutations while sparing the inhibition of EGFR WT, which sets it apart from ATP competitive inhibitors. Moreover, oral administration of IN-119873 showed excellent anti-tumor efficacy in a dose-dependent manner in a diverse of osimertinib-resistant CDX and PDX models. IN-119873 also demonstrated favorable blood-brain-barrier penetration with promising intracranial efficacy in the H1975-luc brain metastasis model both mono or in combination with osimertinib. As a selective, orally available, and CNS-penetrable next-generation allosteric EGFR-TKI, IN-119873 is currently undergoing IND-enabling studies and has the potential to demonstrate activity in both first-line and resistance settings, either as a monotherapy or in combination with 3rd generation EGFR TKI. Citation Format: Jong Ryoul Choi, Daseul Yoon, Seo Hyun Kim, Do Gyeong Kim, Seock Yong Kang, Seong-Il Choi, Somyi Park, Hyun Kyung Lee, Donghyun Kim, Ju Hyun Lee, Hye-Jung Kim, Bong Tae Kim. IN-119873, the next-generation allosteric EGFR TKI, a potent and highly selective EGFR L858R for the treatment of osimertinib-resistant NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1967.