Antibody-drug conjugates: A new twist to overcome EGFR-TKIs resistance in non-small cell lung cancer.

Background: NSCLC accounts for nearly 85% of all lung cancers. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are effective for EGFR mutated NSCLCs, but these drugs often stop working after EGFR acquires additional mutations. Preclinical and clinical data suggest a stronger antitumor effect with dual blockade of the EGFR and vascular endothelial growth factor (VEGF) pathways in EGFR-mutated NSCLC. RELAY, a randomized, double-blind, phase 3 trial, demonstrated superior progression-free survival (PFS) with ramucirumab (RAM) + erlotinib compared with placebo + erlotinib in patients with untreated EGFR-mutated advanced NSCLC. Additionally, RAM was tested in a Phase 1 study with the third-generation irreversible EGFR TKI osimertinib (OSI); AstraZeneca) in NSCLC patients with advanced T790M-positive EGFR mutant tumors after progression on first-line EGFR TKI therapy. OSI can be used with L858R, exon 19 del and T790M EGFR mutant tumors. We investigated the combined use of OSI+RAM in EGFR mutated NSCLC PDX mouse models. Materials and Methods: The antimurine VEGFR2 antibody DC101 (40 mg/kg, BIW) and the EGFR TKI OSI (10 mg/kg, QD) were used in this study. Twenty-seven PDX NSCLC mouse models carrying EGFR activating and/or T790M resistance mutations, commonly detected in patients with advanced NSCLC, were evaluated at 3 independent sites. Mice were divided into 4 treatment arms: vehicle (PBS), DC101, OSI and combination (DC101+OSI). Each study arm included two transplanted mice per model. Sensitivity to DC101 and OSI monotherapies, enhancement of anti-tumor activity with the combination therapy and durability of the response were evaluated. Desirability score, a weighted composite score of six features of tumor growth curves including best median % response, number of days in best response category, time to doubling, re-growth rate (last 5 observations) relative to vehicle growth rate, last observed tumor volume and last observed day, was calculated for each treatment arm. Analysis of variance was used to compare summary scores per animal across treatments. Results: OSI alone and OSI+DC101 combination therapy had stronger antitumor effects than DC101 monotherapy in significantly more models 11 vs 1 and 12 vs 0, respectively. A small but consistent shift in favor of OSI+DC101 vs OSI was observed across most of the models. Paired t-test analyses showed a moderate but significant benefit with combination OSI+DC101 vs OSI. Overall desirability score was statistically improved with OSI+DC101 compared to either single agent. Conclusions: Dual inhibition of EGFR and VEGFR2 with OSI+DC101 had a stronger antitumor effect than those of the respective monotherapies in EGFR mutated NSCLCs in vivo. Future studies will investigate the molecular mechanisms underlying the enhanced antitumor effect of OSI+DC101 combination therapy. Citation Format: Sudhakar Chintharlapalli, Anthony Fischl, Chun Ping Yu, Philip Iversen. Enhanced antitumor effect of dual EGFR and VEGFR2 inhibition in EGFR-mutated non-small cell lung cancer (NSCLC) patient-derived tumor xenograft (PDX) models [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 1675.

MTE23.02 Biomarker Characterization: Challenges and Perspectives

Oncogene-addicted metastatic non-small-cell lung cancer: ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up

Meta-Analysis of EGFR Kinase Inhibitors: Not Always Greater Than the Sum of Its Parts

MTE 10.01 Bridging the Gap between Genomics and Clinics

Lung cancer remains one of the most prevalent and deadly malignancies globally, with non-small cell lung cancer (NSCLC) comprising approximately 84% of all cases. Despite advances in treatment, the overall 5-year survival rate for NSCLC remains at 15%. Among NSCLC cases, 15-20% are driven by activating mutations (such as L858R) in the epidermal growth factor receptor (EGFR), which are treated with EGFR tyrosine kinase inhibitors (TKIs). Although three generations of TKIs have been developed, a number of genetic mutations (T790M and C797S) have been shown to evolve that confer resistance in most patients. This has spurred interest in combination therapies, particularly with PD-1 and PD-L1 immune checkpoint inhibitors (ICIs), however, these have limited efficacy in patients with EGFR-mutant NSCLC. Therefore, understanding the immune landscape of these tumors is critical. We developed a mouse model of EGFR-mutant lung cancer using a transgenic mouse model expressing an EGFR carrying L858R activating, as well as T790M and C797S resistance mutations. We demonstrate the expression of this gene after intranasal delivery of an adenovirus carrying GFP-Cre (Ad-GFP-Cre) from a CAG promoter, along with expression of Td-tomato and Luciferase to allow for tumor tracking and visualization. In a time-course experiment, we monitored tumor progression and immune infiltration. By 4-6 weeks post-Ad-GFP-Cre injection, we observed consistent and palpable tumor growth, establishing a critical window for therapeutic intervention. At 2 weeks post-injection, lung tissues showed robust infiltration of CD8+ T cells, highlighting a strong initial immune response. However, levels of regulatory T cells (Tregs) increased significantly over time. This accumulation of Tregs coincided with tumor growth and suppression of cytotoxic T cell activity, suggesting a shift toward an immunosuppressive microenvironment. CD4+ T cells remained relatively constant, underscoring the specific role of Tregs in facilitating immune evasion. Systemic adaptive immunity against EGFR was detected in all tumor bearing mice, demonstrating the potency of local immune suppression in EGFR+ tumor evolution. To evaluate the therapeutic relevance of these findings, we treated mice with a PD-1 inhibitor starting at 4 weeks post-injection. Tumor response was minimal, mirroring clinical observations of limited efficacy for ICIs in EGFR-mutant NSCLC. The early wave of cytotoxic immune activity followed by Treg-mediated suppression offers insights into potential therapeutic targets. This will be a useful model to study the impact of different EGFR TKIs, as well as the combination of these agents with different immunotherapeutic modalities to identify strategies to optimize combination therapies. This work has the potential to inform innovative approaches for treating EGFR-mutant NSCLC and improving patient outcomes. Citation Format: Anchit Bhagat, Cong-Xiao Liu, Xiao Yang, Melissa Gajda, Jason McBane, Herbert K. Lyerly, Zachary C. Hartman. Uncovering immune evasion in EGFR-mutant and treatment resistant NSCLC: insights from a novel mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2197.

BackgroundUncommon epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) is a rare subset of NSCLC. The aim of this study was to investigate the prevalence, characteristics, and clinical outcomes of metastatic NSCLC harboring uncommon EGFR mutation at Thailand’s largest national tertiary hospital. The secondary objective was to compare treatment efficacy between EGFR-tyrosine kinase inhibitor (EGFR-TKI) and chemotherapy.MethodsThis retrospective chart review included patients that were tested for EGFR-mutation NSCLC during 2014–2018. Patient demographic and clinical data, treatment data, and outcome data were collected and analyzed.ResultsOf the 681 patients that were evaluated for EGFR mutation, 317 (47.0%) had EGFR-mutant NSCLC, and 28 (8.8%) of those harbored uncommon EGFR mutations. The median follow-up was 19.1 months. History of tobacco use was reported in 50% of patients. The most common single mutation among uncommon EGFR was exon 20 insertion (n = 6), followed by L861Q (n = 5) and G719X (n = 4). Thirteen (46%) patients had compound mutations. One hundred percent of male patients with G719X mutation were smokers. Sixteen of 28 patients were treated with EGFR-TKI. Most received first-generation EGFR-TKI, and 29% were treated with chemotherapy alone. The objective response rate was 37.5% in the EGFR-TKI group. Median progression-free survival (PFS) in the EGFR-TKI group was 10.2 months. Median PFS among the 8 patients in the chemotherapy group that received first-line platinum doublet was 6.5 months. Three-year overall survival (OS) among 28 patients was 34%. Three-year OS was significantly better in patients treated with EGFR-TKI.ConclusionsUncommon EGFR mutations was detected in 8.8% of EGFR-mutant NSCLC. Exon 20 insertion was the most common mutation, and 50% of patients had history of tobacco use. First- or second-generation EGFR-TKI demonstrated greater OS benefit than platinum-doublet chemotherapy among patients harboring uncommon EGFR-mutant NSCLC. Survival outcomes were comparable to those reported from previous large cohort studies.

Waxing and Waning of MET Amplification in EGFR-Mutated NSCLC in Response to the Presence and Absence of Erlotinib Selection Pressure

Emergence of RET rearrangement co-existing with activated EGFR mutation in EGFR-mutated NSCLC patients who had progressed on first- or second-generation EGFR TKI.

Background: The 3rd-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI), like osimertinib, provide marked clinical benefit for EGFR-mutant non-small cell lung cancer (NSCLC) patients with extended overall survival vs former EGFR TKIs (e.g., gefitinib). Approximate 10%-24% of NSCLC patients acquired C797S mutation when treated with osimertinib. Unfortunately, limited treatments are available for patients after osimertinib resistance. QLH11811 is a new generation EGFR TKI designed to target the EGFR with ex19del/L858R/T790M/C797S mutations. Here, we disclosed its preclinical data to support its clinical development in EGFR-mutant NSCLC. Methods: The inhibitory activity of QLH11811 on mutated and wild-type EGFR was tested in engineered cell lines and patient-derived organoid (PDO). The in vivo antitumor activity of QLH11811 was evaluated in the patient-derived xenograft (PDX) model with cis EGFR ex19del/T790M/C797S triple mutations, and the H1975 (cis EGFR L858R/T790M/C797S and cis EGFR ex19del/T790M/C797S), PC-9 (EGFR ex19del), and Ba/F3 (EGFR ex19del/C797S) cell line-derived xenograft (CDX) models. The pharmacokinetic (PK) profile was investigated in animals, and the human PK profile was projected using allometric scaling method. Results: QLH11811 displayed potent anti-proliferation activity against Ba/F3 (EGFR ex19del/T790M/C797S, L858R/T790M/C797S, ex19del/C797S, or L858R/C797S), PC-9 (EGFR ex19del/T790M/C797S), H1975 (EGFR L858R/T790M/C797S, L858R/T790M), H3255 (L858R) and HCC827 (ex19del) with IC50 of 2.6, 3.1, 2.4, 4.1, 51, 50, 27, 21, and 11 nM, respectively. QLH11811 also showed excellent selectivity when compared the above values with its IC50 against Ba/F3 (EGFR wild-type, 61 nM) and A431 (EGFR wild-type, 440nM). QLH11811 demonstrated excellent inhibitory activities against seven osimertinib-resistant PDO models. Daily oral QLH11811 significantly inhibited tumor growth at all doses tested (P <0.001) in the PDX model, the H1975, PC-9, and Ba/F3 CDX models. QLH11811 had good PK profile in mice, rats, dogs, and monkeys, with the absolute bioavailability at 71%, 29%, 80% and 42%. The human PK parameters were obtained by allometric scaling method, and the efficacious dose in human was projected to 103 mg, daily. Conclusion: The in vitro and in vivo preclinical data demonstrated QLH11811 is a highly potent and selective 4th-generation EGFR TKI with activity against the osimertinib-resistant NSCLC with EGFR C797S mutation. The preclinical PK data supported the efficacious dose of QLH11811 in human would be 103 mg. Citation Format: Shansong Zheng, Wei Deng, Qingmei Zheng, Yingying Yang, Na Li, Tan Pang, Xueying Feng, Simon Taylor, Lina Ma, Yaqiong Wu, Ziwei Zhao. QLH11811, a selective 4th-generation EGFR inhibitor for osimertinib-resistant EGFR-mutant NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5457.

The non-small cell lung cancer (NSCLC) accounts approximately 85% of lung cancers and includes predominantly adenocarcinomas, which is the most common type and squamous cell carcinomas. The treatment options include surgery, radiation therapy, and chemotherapy and the decision depends on the patient’s medical status and stage of disease. From 1970 the standard first line treatment for most patients with unresectable NSCLC and good performance status was the use of a combination of chemotherapy regimens and usually cisplatin-based. The most common combination regimens in use at present are platinum based regimens with gemcitabine, with paclitaxel or docetaxel and with vinorelbine combinations. The addition of the recombinant humanized monoclonal antibody bevacizumab that binds to vascular endothelial growth factor (VEGF) to carboplatin and paclitaxel for the treatment of non-squamous advanced NSCLC has demonstrated to increase response rate (RR), progression free survival (PFS) and overall survival (OS) when compared to chemotherapy alone. Despite recent advances with approval of more active chemotherapeutic and anti-angiogenesis agents for stage IV NSCLC, standard therapy can provide only modest clinical benefits with significant toxicities when used in unselected patients. In 2004, the identification of somatic mutations in the epidermal growth factor receptor (EGFR) gene provided the first glimpse of a possible target for a treatment which could maximize clinical outcome in those patients who could benefit from a personalized therapy. Identifying mutations in oncogenes associated with non-squamous NSCLC can help determine which patients are more likely to benefit from a targeted therapy. Such oncogenes include EGFR, KRAS, and ALK. The presence of an EGFR mutation confers a more favorable prognosis and strongly predicts for sensitivity to EGFR tyrosine kinase inhibitors (TKIs) such as erlotinib, gefitinib, and afatinib. The use of EGFR TKIs is based upon the detection of these mutations. The incidence of EGFR mutations in tumors with non-small-cell histology ranges from ~15% in Caucasians to ~50% in East Asians; 95% of such mutations have been found in adenocarcinomas. Patients bearing EGFR mutations have shown favorable clinical outcomes even with conventional chemotherapy suggesting that EGFR may be a predictive and a prognostic factor. Activation of the EGFR protein stimulates protein tyrosine kinase, which leads to activation of signaling pathways associated with cell growth and survival. Both EGFR overexpression and activating mutations in the tyrosine kinase domain of the EGFR gene lead to tumor growth and progression. Erlotinib, gefitinib and afatinib are examples of EGFR TKIs that can prevent activation of the signaling pathways and improve RRs in selected NSCLC patients. These mutations which are associated with increased sensitivity to EGFR TKIs, predominate in never-smokers, females, and tumors with adenocarcinoma histology. The most common mutations associated with sensitivity to EGFR TKIs include exon 19 deletions and the L858R point mutation and they are associated with RRs of >70%. Other EGFR mutations like T790M and exon 20 insertion, have been associated with much lower response or acquired resistance to TKI’s. The predictive value of EGFR mutations for use of gefitinib has been strengthened by the results of three randomized phase III trials that specifically compared TKIs used as first-line therapy with traditional platinum-based chemotherapy in patients with advanced NSCLC. In 2009 the results of IRESSA Pan-Asia Study were presented. This trial included a big number of Asian ethnicity patients (1,217) who were never smokers or former light smokers with histologic diagnosis of adenocarcinoma. The trial demonstrated an improvement in PFS and RR, with no statistical difference in OS, with the use of gefitinib in EGFR-mutated tumors and better RR and PFS with standard chemotherapy in patients without mutations. The first phase III trial of gefitinib versus chemotherapy as initial treatment of recurrent or advanced NSCLC, based on selection of patients with known activating EGFR mutations was the WJTOG3405 trial, reported in 2010. This trial documented important achievements in RR and PFS with the use of TKIs. Almost the same results were confirmed by another similar Japanese phase III trial, NEJ002, with RR and PFS definitely favoring the use of gefitinib in the first-line setting of metastatic EGFR-mutated NSCLC. Based on the results of the IPASS study, gefitinib was approved for use in Europe for the initial treatment of patients with NSCLC exhibiting EGFR mutations. The positive results of the EURTAC trial, NCT00446225, which was a randomized phase III trial of erlotinib versus standard chemotherapy, suggested that responsiveness in mutation-positive patients was not a function of ethnicity. Afatinib is approved as monotherapy for the treatment of EGFR TKI—naïve adults with locally advanced or metastatic NSCLC with activating EGFR mutations in the EU, and for the first-line treatment of patients with metastatic NSCLC whose tumors have EGFR exon 19 deletions or exon 21 (L858R) substitution mutations as detected by a US FDA-approved test in the US. In two randomized, open-label, multinational phase III trials, progression-free survival was significantly prolonged with afatinib compared with pemetrexed plus cisplatin (LUX-Lung 3) or gemcitabine plus cisplatin (LUX-Lung 6) in treatment-naïve patients with advanced NSCLC with activating EGFR mutations. EGFR-TKIs as a class are generally well tolerated. The two most common toxicities include dermatologic and GI effects, which are mild to moderate, easily managed and reversible. In order to determine whether an EGFR TKI or chemotherapy is the appropriate first-line therapy, the latest guidelines recommend mutation testing for all patients with advanced NSCLC tumor. The aim of this prospective study is to compare the efficacy of gefitinib, erlotinib and afatinib in patients with advanced NSCLC harboring activating EGFR mutations in first line of treatment. These agents are recommended as first line treatments for NSCLCs with such mutations. The primary endpoint will be the PFS and the secondaries will be the OS and the record of the toxicities. In each of the 3 arms will be participate 20 patients with EGFR mutated tumors. The technique for screening NSCLC patients for driver mutations that it will be used is next-generation sequencing, which overcomes many of the shortcomings of direct sequencing. This massively parallel approach, relying heavily on automation, data storage, and computational processing, allows quantitative analysis of infrequent alleles and simultaneous evaluation of multiple genes or even whole genomes, but is not yet used routinely in clinical practice. In addition, KRAS mutation analysis will be performed in patients with known smoking history in order to determine the correlation of type and mutation frequency with smoking.

PARP inhibitor and chemotherapy combination trials for the treatment of advanced malignancies: does a development pathway forward exist?

Metastatic non-small-cell lung cancer (NSCLC): ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up

Dual inhibition of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) pathways could potentiate improved outcomes in patients with metastatic EGFR-mutated non-small cell lung cancer (NSCLC). The purpose of this systematic review and meta-analysis was to compare the efficacy of an EGFR tyrosine kinase inhibitor (TKI) plus a VEGF inhibitor with EGFR TKI alone for the treatment of EGFR-mutated NSCLC. We systematically searched for randomized controlled trials (RCT) that involved patients with EGFR-mutated metastatic NSCLC treated with combination therapy versus EGFR TKI alone. In a pooled analysis of 5 studies, treatment with the combination therapy was associated with statistically significant improvements in progression-free survival (hazard ratio [HR] 0.63, 95% CI [0.54, 0.75]) when compared with control. However, pooled data from 4 studies revealed no statistically significant differences between the 2 groups for overall survival (HR 1.00, 95% CI [0.68, 1.52]) and the objective response rate (relative risk [RR] 1.05, 95% CI [0.97, 1.14]). In patients with metastatic EGFR-mutated NSCLC, treatment with EGFR TKI plus VEGF inhibition provided significant improvements in progression-free survival, but not in overall survival or objective response rate, when compared with treatment with EGFR TKI alone.

Postoperative adjuvant epidermal growth factor receptor (EGFR) inhibitor osimertinib is the standard care for stage IB-IIIB non-small-cell lung cancer (NSCLC) with EGFR exon 19 deletions or exon 21 L858R mutation, following complete tumour resection, with or without prior platinum-based adjuvant chemotherapy. However, the role of EGFR tyrosine kinase inhibitors (TKIs) in this setting is debated, particularly concerning long-term curative effects versus recurrence delay. Uncertainties persist around treatment duration, harms, and effectiveness across disease stages, prior chemotherapy, or EGFR-sensitising mutation types. To assess the effectiveness and harms of adjuvant EGFR tyrosine kinase inhibitors (TKIs) in people with resected stage I to III non-small-cell lung cancer (NSCLC) harbouring an activating EGFR mutation. We searched major databases (CENTRAL, MEDLINE, Embase) to 9 December 2024, along with conference proceedings (from 2019) and clinical trial registries. We included randomised controlled trials (RCTs) reporting benefits or harms of adjuvant EGFR TKIs in adults with resected stage I-III NSCLC. Trials compared EGFR TKIs with platinum-based chemotherapy, placebo/best supportive care (BSC), or second-and/or third-generation EGFR TKIs versus first- and/or second-generation EGFR TKIs. Participants were adults with histologically confirmed stage I-III NSCLC. Three review authors independently assessed search results, resolving disagreements with a fourth author. Primary outcomes were overall survival (OS), disease-free survival (DFS), and adverse events (AEs); secondary outcomes included health-related quality of life (HRQoL), relapse risk during drug-off time, and brain relapse risk. We conducted meta-analyses using random-effects and fixed-effect models with hazard ratios (HRs) or risk ratios (RRs) and 95% confidence intervals (CIs). We assessed heterogeneity with the I² statistic. We included nine RCTs involving 2603 participants, and identified six ongoing trials. Five trials compared EGFR TKIs with placebo/BSC, and four compared them with chemotherapy. We found no trials comparing second-and/or third-generation to first- and/or second-generation EGFR TKIs. Six trials had low selection bias risk; most had unclear or high risk for detection or performance bias; and four were high risk for other biases. The certainty of the evidence (GRADE) ranged from moderate to very low, depending on the outcome. First-, second-, and/or third-generation EGFR TKIs versus placebo/BSC EGFR TKIs probably improve overall survival compared to placebo/BSC (HR 0.54, 95% CI 0.40 to 0.73; 3 studies, 864 participants; moderate-certainty evidence). TKIs may improve disease-free survival compared to placebo/BSC, but the evidence is very uncertain (HR 0.34, 95% CI 0.28 to 0.41; 5 studies, 1153 participants). We are uncertain if there is a difference between groups in serious adverse events (≥ grade 3) as the evidence is very uncertain, with wide confidence intervals spanning both potential harm and no effect (RR 2.52, 95% CI 0.44 to 14.37; 4 studies, 1134 participants). Mild-to-moderate adverse events (grades 1 and 2) may be more frequent with EGFR TKIs compared to placebo/BSC, but the evidence is very uncertain (RR 1.57, 95% CI 1.08 to 2.29; 4 studies, 1134 participants). One study assessed HRQoL, with no clinically meaningful decline compared to placebo/BSC (592 participants; moderate-certainty evidence). First-, second-, and/or third-generation EGFR TKIs versus chemotherapy Overall survival was similar between EGFR TKIs and chemotherapy (HR 0.79, 95% CI 0.52 to 1.18; 4 studies, 878 participants; moderate-certainty evidence). TKIs may have improved disease-free survival compared to chemotherapy (HR 0.54, 95% CI 0.35 to 0.83; 4 studies, 878 participants; low-certainty evidence). TKIs may have reduced serious adverse events (≥ grade 3) compared to chemotherapy (RR 0.31, 95% CI 0.18 to 0.52; 4 studies, 811 participants; low-certainty evidence). TKIs may have increased mild-to-moderate adverse events (grades 1 and 2) (RR 2.13, 95% CI 1.20 to 3.78; 4 studies, 811 participants; low-certainty evidence). Two studies assessed HRQoL, showing no clear difference compared to chemotherapy, as assessed with the Functional Assessment of Cancer Therapy-Lung instrument (2 studies, 399 participants) and the Lung Cancer Symptom Scale (2 studies, 400 participants), both with moderate-certainty evidence. Adjuvant EGFR TKIs may improve disease-free survival compared to both placebo/BSC and chemotherapy. There is moderate-certainty evidence that EGFR TKIs increase overall survival compared to placebo/BSC. However, they likely result in little to no difference in overall survival compared to chemotherapy. We could not rule out a potential survival benefit of adjuvant chemotherapy in people with EGFR-mutant NSCLC. Approximately 50% of participants experienced relapse or death within one year of stopping TKI therapy, indicating that the disease-free survival benefit may wane after withdrawal. This raises the possibility that prolonged adjuvant TKI therapy could be associated with improved long-term outcomes, although further research is needed to clarify this.