Impact of central nervous system metastasis after complete resection of lung adenocarcinomas harboring common EGFR mutation - A real-world database study in Japan: The CReGYT-01 EGFR study.

OBJECTIVES: To clarify the impact of central nervous system (CNS) metastasis on performance status (PS) at relapse, on subsequent treatment(s), and on survival of patients with lung adenocarcinoma harboring common epidermal growth factor receptor (EGFR) mutation. METHODS: We conducted the multicenter real-world database study for patients with radical resections for lung adenocarcinomas between 2015 and 2018 at 21 centers in Japan. EGFR mutational status was examined at each center. RESULTS: Of 4181 patients enrolled, 1431 underwent complete anatomical resection for lung adenocarcinoma harboring common EGFR mutations. Three-hundred-and-twenty patients experienced disease relapse, and 78 (24%) had CNS metastasis. CNS metastasis was significantly more frequent in patients with conventional adjuvant chemotherapy than those without (30% vs. 20%, P = 0.036). Adjuvant chemotherapy did not significantly improve relapse-free survival at any pathological stage (adjusted hazard ratio for stage IA2-3, IB, and II-III was 1.363, 1.287, and 1.004, respectively). CNS metastasis did not affect PS at relapse. Subsequent treatment, mainly consisting of EGFR-tyrosine kinase inhibitors (TKIs), could be equally given in patients with or without CNS metastasis (96% vs. 94%). Overall survival after relapse was equivalent between patients with and without CNS metastasis. CONCLUSION: The efficacy of conventional adjuvant chemotherapy may be limited in patients with lung adenocarcinoma harboring EGFR mutations. CNS metastasis is likely to be found in practice before deterioration in PS, and may have little negative impact on compliance with subsequent EGFR-TKIs and survival after relapse. In this era of adjuvant TKI therapy, further prospective observational studies are desirable to elucidate the optimal management of CNS metastasis.

A Multi-Institutional, Randomized, Phase III Trial Comparing Anatomical Segmentectomy and Lobectomy for Clinical Stage IA3 Pure-Solid Non-Small-Cell Lung Cancer: West Japan Oncology Group Study WJOG16923L (STEP UP Trial).

INTRODUCTION: Although the standard treatment for patients with resectable early-stage non-small-cell lung cancer (NSCLC) is pulmonary lobectomy, recent clinical trials have demonstrated the efficacy of anatomical segmentectomy for small-sized early-stage NSCLC measuring ≤2 cm. Segmentectomy is gaining attention as an alternative procedure to lobectomy for early-stage NSCLC. PATIENTS AND METHODS: In January 2024, we have initiated a randomized phase III trial in Japan to confirm the noninferiority of anatomical segmentectomy to lobectomy in patients with peripheral clinical stage IA3 pure-solid NSCLC (tumor measuring >2 cm and ≤3 cm; consolidation-to-tumor ratio = 1.0). We plan to enroll 520 patients from 61 institutions over a period of 5 years. The primary endpoint is overall survival, and the secondary endpoints include relapse-free survival, postoperative respiratory function, proportion of patients with respiratory failure and cerebrovascular disease, cumulative incidence of death from other diseases, cumulative incidence of local recurrence, proportion of patients who undergo segmentectomy, number of resected segments, operative time, blood loss, and adverse events. This trial has been registered in the UMIN Clinical Trials Registry under the code UMIN000052064. CONCLUSIONS: This trial will help establish a novel treatment strategy for patients with peripheral clinical stage IA3 pure-solid NSCLC.

Secondary Mutations of the EGFR Gene That Confer Resistance to Mobocertinib in EGFR Exon 20 Insertion.

INTRODUCTION: Approximately 10% of mutations in the EGFR gene in NSCLC are in-frame insertions in exon 20 (X20ins). These tumors usually do not respond to conventional EGFR tyrosine kinase inhibitors (TKIs). Several novel EGFR TKIs active for X20ins are in clinical development, including mobocertinib, which was recently approved by the U.S. Food and Drug Administration. However, acquired resistance during treatment with these TKIs still occurs as in the case of EGFR TKIs of earlier generations. METHODS: We chronically exposed murine pro-B-cell line cells transduced with the five most common X20ins (A763_Y764insFQEA, V769_D770insASV, D770_N771insSVD, H773_V774insNPH and H773_V774insH) to mobocertinib in the presence of N-ethyl-N-nitrosourea and searched for secondary EGFR mutations. We evaluated the efficacies of several EGFR X20ins inhibitors, including zipalertinib and sunvozertinib, against cells with acquired resistant mutations. RESULTS: All secondary mutations resulting in acquired resistance to mobocertinib were exclusively C797S in insFQEA and insSVD. However, in the case of other X20ins (insASV, insNPH, and insH), T790M or C797S secondary mutations contributed to acquired resistance to mobocertinib. The emergence of T790M was more frequent in cells treated with lower drug concentrations. Sunvozertinib exhibited good activity against resistant cells with T790M. Cells with C797S were refractory to all EGFR TKIs, except for erlotinib, which was active for insFQEA with C797S. CONCLUSIONS: T790M or C797S, depending on the original X20ins mutations, conferred acquired resistance to mobocertinib. Sunvozertinib may be the treatment of choice for patients with tumors resistant to mobocertinib because of T790M.

Segmentectomy for patients with early-stage pure-solid non-small cell lung cancer.

For decades, lobectomy has been the recommended surgical procedure for non-small cell lung cancer (NSCLC), including for small-sized lesions. However, two recent pivotal clinical trials conducted by the Japanese Clinical Oncology Group/West Japan Oncology Group (JCOG0802/WJOG4607L) and the Cancer and Leukemia Group B (CALGB140503), which compared the survival outcomes between lobectomy and sublobar resection (the JCOG0802/WJOG4607L included only segmentectomy, not wedge resection), demonstrated the efficacy of sublobar resection in patients with early-stage peripheral lung cancer measuring ≤ 2 cm. The JCOG0802/WJOG4607L demonstrated the superiority of segmentectomy over lobectomy with respect to overall survival, implying the survival benefit conferred by preservation of the lung parenchyma. Subsequently, the JCOG1211 also demonstrated the efficacy of segmentectomy, even for NSCLC, measuring up to 3 cm with the predominant ground-glass opacity phenotype. Segmentectomy has become the standard of care for early-stage NSCLC and its indications are expected to be further expanded to include solid lung cancers > 2 cm. However, local control is still a major concern for segmentectomy for higher-grade malignant tumors. Thus, the indications of segmentectomy, especially for patients with radiologically pure-solid NSCLC, remain controversial due to the aggressive nature of the malignancy. In this study, we reviewed previous studies and discussed the efficacy of segmentectomy for patients with such tumors.

Recent Advances in Perioperative Immunotherapies in Lung Cancer.

Several clinical trials have been revolutionizing the perioperative treatment of early-stage non-small cell lung cancer (NSCLC). Many of these clinical trials involve cancer immunotherapies with antibody drugs that block the inhibitory immune checkpoints programmed death 1 (PD-1) and its ligand PD-L1. While these new treatments are expected to improve the treatment outcome of NSCLC patients after pulmonary resection, several major clinical questions remain, including the appropriate timing of immunotherapy (neoadjuvant, adjuvant, or both) and the identification of patients who should be treated with neoadjuvant and/or adjuvant immunotherapies, because some early-stage NSCLC patients are cured by surgical resection alone. In addition, immunotherapy may induce immune-related adverse events that will require permanent treatment in some patients. Based on this fact as well, it is desirable to select appropriate patients for neoadjuvant/adjuvant immunotherapies. So far, data from several important trials have been published, with findings demonstrating the efficacy of adjuvant atezolizumab (IMpower010 trial), neoadjuvant nivolumab plus platinum-doublet chemotherapy (CheckMate816 trial), and several perioperative (neoadjuvant plus adjuvant) immunotherapies (AEGEAN, KEYNOTE-671, NADIM II, and Neotorch trials). In addition to these key trials, numerous clinical trials have reported a wealth of data, although most of the above clinical questions have not been completely answered yet. Because there are so many ongoing clinical trials in this field, a comprehensive understanding of the results and/or contents of these trials is necessary to explore answers to the clinical questions above as well as to plan a new clinical trial. In this review, we comprehensively summarize the recent data obtained from clinical trials addressing such questions.

Clinical Relevance of Patient-Derived Organoid of Surgically Resected Lung Cancer as an In Vitro Model for Biomarker and Drug Testing.

Introduction: Lung tumor organoids (LTOs) have attracted attention as in vitro preclinical models; however, their clinical and experimental applications have not been fully established. Methods: We attempted to establish LTOs from resected specimens of patients with lung cancer who underwent lung resection. Clinicopathologic characteristics related to the establishment of LTOs were evaluated. Histologic assessment and genetic analysis were conducted for both LTOs and their parental tumors. Organoid-derived xenografts were generated in immunocompetent mice. Drug sensitivity was assessed using cell proliferation assays. Results: We established 53 LTOs from 79 lung cancer samples, including 10 long-term culture models. The establishment rate was significantly lower in squamous cell carcinomas than in other histologic types (48% versus 75%, p = 0.034). Histologic similarities were confirmed among LTOs, the parental tumors, and organoid-derived xenografts. Seven mutations, including two EGFR L858R and one EGFR exon 20 H773delinsYNPY mutations, were detected in both LTO and parental tumors; the other four mutations were detected in either LTO or parental tumors. The extensive culture ability of LTO (passaged >10 times) correlated with poor patient prognosis. LTO9 cells harboring EGFR H773delinsYNPY were sensitive to osimertinib. The parental patient, who had new metastatic lesions, was treated with osimertinib and exhibited a remarkable response. Conclusions: The establishment and growth rates of LTOs were associated with the histologic subtype and tumor size. LTOs derived from resected specimens have become preclinical models that can be used to predict drug responses and accelerate the development of treatment strategies for patients with rare mutations.

Prognostic role of preoperative fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography with an image-based harmonization technique: A multicenter retrospective study.

Objectives: Despite the prognostic impacts of preoperative fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography examination, fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography-based prognosis prediction has not been used clinically because of the disparity in data between institutions. By applying an image-based harmonized approach, we evaluated the prognostic roles of fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography parameters in clinical stage I non-small cell lung cancer. Methods: We retrospectively examined 495 patients with clinical stage I non-small cell lung cancer who underwent fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography examinations before pulmonary resection between 2013 and 2014 at 4 institutions. Three different harmonization techniques were applied, and an image-based harmonization, which showed the best-fit results, was used in the further analyses to evaluate the prognostic roles of fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography parameters. Results: Cutoff values of image-based harmonized fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography parameters, maximum standardized uptake, metabolic tumor volume, and total lesion glycolysis were determined using receiver operating characteristic curves that distinguish pathologic high invasiveness of tumors. Among these parameters, only the maximum standardized uptake was an independent prognostic factor in recurrence-free and overall survivals in univariate and multivariate analyses. High image-based maximum standardized uptake value was associated with squamous histology or lung adenocarcinomas with higher pathologic grades. In subgroup analyses defined by ground-glass opacity status and histology or by clinical stages, the prognostic impact of image-based maximum standardized uptake value was always the highest compared with other fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography parameters. Conclusions: The image-based fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography harmonization was the best fit, and the image-based maximum standardized uptake was the most important prognostic marker in all patients and in subgroups defined by ground-glass opacity status and histology in surgically resected clinical stage I non-small cell lung cancers.

Novel fungicide quinofumelin shows selectivity for fungal dihydroorotate dehydrogenase over the corresponding human enzyme.

The species selectivity of class 2 dihydroorotate dehydrogenase (DHODH), a target enzyme for quinofumelin, was examined. The Homo sapiens DHODH (HsDHODH) assay system was developed to compare the selectivity of quinofumelin for fungi with that for mammals. The IC50 values of quinofumelin for Pyricularia oryzae DHODH (PoDHODH) and HsDHODH were 2.8 nM and >100 µM, respectively. Quinofumelin was highly selective for fungal over human DHODH. Additionally, we constructed recombinant P. oryzae mutants where PoDHODH (PoPYR4) or HsDHODH was inserted into the PoPYR4 disruption mutant. At quinofumelin concentration of 0.01-1 ppm, the PoPYR4 insertion mutants could not grow, but the HsDHODH gene-insertion mutants thrived. This indicates that HsDHODH is a substitute for PoDHODH, and quinofumelin could not inhibit HsDHODH as in the HsDHODH enzyme assay. Comparing the amino acid sequences of human and fungal DHODHs indicates that the significant difference at the ubiquinone-binding site contributes to the species selectivity of quinofumelin.

The target site of the novel fungicide quinofumelin, Pyricularia oryzae class II dihydroorotate dehydrogenase.

The target site of the novel fungicide quinofumelin was investigated in the rice blast fungus Pyricularia oryzae. Quinofumelin-induced mycelial growth inhibition was reversed by orotate but not by dihydroorotate. Recovery tests suggested that the target site of quinofumelin was dihydroorotate dehydrogenase (DHODH), which catalyzes the oxidation of dihydroorotate to orotate. Quinofumelin strongly inhibited P. oryzae class 2 DHODH (DHODH II) (IC50: 2.8 nM). The inhibitory activities of mycelial growth and DHODH II were strongly positively correlated, indicating that DHODH II inhibition by quinofumelin lead to antifungal activity. A P. oryzae DHODH II gene (PoPYR4) disruption mutant (ΔPopyr4), showing the same tendency as the quinofumelin-treated wild strain in recovery tests, was constructed, and disease symptoms were not observed in rice plants infected by ΔPopyr4. Thus, DHODH II, which plays an important role in pathogenicity and mycelial growth, is found to be the target site of quinofumelin.

Psychometric assessment of individual differences in second language reading anxiety for identifying struggling students in classrooms.

Assessing learners' individual differences helps identify students who need teacher support in classrooms. Previous studies have examined second language (L2) achievement based on reading anxiety because reading is an input-based activity essential for successful L2 learning. This study applied a latent rank model to identify L2 learners who are likely to be struggling or successful in classrooms according to their L2 reading anxiety symptoms. Moreover, a psychometric function was developed to determine the cutoff anxiety scores that discriminate against their substantial differences. The model was applied to responses from the Foreign Language Reading Anxiety Scale (FLRAS) provided by 335 Japanese learners of English. The results showed that the FLRAS classified students into three ranked groups with ordinal information regarding L2 reading anxiety. Rank 1 exhibited good conditions in L2 reading anxiety. Rank 2 reported high anxiety toward unfamiliar grammar during L2 reading. Rank 3 had even higher anxiety levels, especially for vocabulary and grammatical knowledge deficits and reading difficulty. The cutoff anxiety scores estimated by the model detected students who failed their L2 class with 79% accuracy. Theoretical, methodological, and pedagogical issues in language anxiety were discussed in terms of diagnosis and different approaches to teaching L2 reading.

Foretinib can overcome common on-target resistance mutations after capmatinib/tepotinib treatment in NSCLCs with MET exon 14 skipping mutation.

BACKGROUND: Capmatinib and tepotinib are guideline-recommended front-line treatments for non-small-cell lung cancer (NSCLC) patients with MET exon 14 skipping mutations (METex14). However, the emergence of acquired resistance to capmatinib/tepotinib is almost inevitable partially due to D1228X or Y1230X secondary mutations of the MET. In this study, we explored agents that are active against both D1228X and Y1230X MET to propose an ideal sequential treatment after capmatinib/tepotinib treatment failure in NSCLC patients with METex14. METHODS: The inhibitory effects of 300 drugs, including 33 MET-TKIs, were screened in Ba/F3 cells carrying METex14 plus MET D1228A/Y secondary mutations. The screen revealed four-candidate type II MET-TKIs (altiratinib, CEP-40783, foretinib and sitravatinib). Therefore, we performed further growth inhibitory assays using these four MET-TKIs plus cabozantinib and merestinib in Ba/F3 cells carrying MET D1228A/E/G/H/N/V/Y or Y1230C/D/H/N/S secondary mutations. We also performed analyses using Hs746t cell models carrying METex14 (with mutant allele amplification) with/without D1228X or Y1230X in vitro and in vivo to confirm the findings. Furthermore, molecular dynamics (MD) simulations were carried out to examine differences in binding between type II MET-TKIs. RESULTS: All 6 type II MET-TKIs were active against Y1230X secondary mutations. However, among these 6 agents, only foretinib showed potent activity against D1228X secondary mutations of the MET in the Ba/F3 cell and Hs746t in vitro model and Hs746t in vivo model, and CEP-40783 and altiratinib demonstrated some activity. MD analysis suggested that the long tail of foretinib plays an important role in binding D1228X MET through interaction with a residue at the solvent front (G1163). Tertiary G1163X mutations, together with L1195F/I and F1200I/L, occurred as acquired resistance mechanisms to the second-line treatment foretinib in Ba/F3 cell models. CONCLUSIONS: The type II MET-TKI foretinib may be an appropriate second-line treatment for NSCLCs carrying METex14 after campatinib/tepotinib treatment failure by secondary mutations at residue D1228 or Y1230.

Presence of a Ground-Glass Opacity Component Is the True Prognostic Determinant in Clinical Stage I NSCLC.

Introduction: Recent studies have suggested that including presence or absence of ground-glass opacity (GGO) may improve the tumor descriptor (T descriptor) classification in clinical stage I NSCLC. In this study, we analyzed prognostic implications of presence or absence of GGO, size of the solid component, and predominant histology to identify the true prognostic determinant for early-stage NSCLC. Methods: We retrospectively examined 384 patients with clinical stage I NSCLC (solid: 242, part solid: 142) who underwent complete resection between 2009 and 2013. Results: Survival curves of the whole cohort revealed good separation using the current TNM classification. Nevertheless, the part-solid group had a favorable prognosis irrespective of solid component size. Conversely, patients in the solid tumor group with tumors between 3 and 4 cm had a worse prognosis than patients whose tumors were less than or equal to 3 cm. Thus, we propose the following novel T descriptor classification: IA, part-solid tumors; IB, solid tumors less than or equal to 3 cm; and IC, solid tumors between 3 and 4 cm. This novel classification system stratified patient prognosis better than the current classification. On pathologic evaluation, the part-solid group always had better prognoses than the solid group in each subgroup divided by pathologic grade. Conclusions: These results suggest that presence of GGO is the true prognostic determinant of stage I NSCLC, irrespective of the size of the solid component. Our novel T descriptor classification system could more accurately predict prognoses of clinical stage I NSCLC cases.

Intra-tumor and Inter-tumor Heterogeneity in MET Exon 14 Skipping Mutations and Co-mutations in Pulmonary Pleomorphic Carcinomas.

BACKGROUND: MET exon 14 skipping mutation is a driver mutation in lung cancer and is highly enriched in pulmonary pleomorphic carcinomas (PPCs). Whether there is intratumor or intertumor heterogeneity in MET exon 14 skipping status or in co-occurring genetic alterations in lung cancers driven by MET exon 14 skipping is unknown. METHODS: We analyzed tumor specimens obtained from 23 PPC patients (10 autopsied and 13 surgically resected). MET exon 14 skipping was detected by RT-PCR. For patients with MET exon 14 skipping mutation, further analyses were performed. Genomic DNA (gDNA) was extracted from various histological components for each patient who underwent surgical resection (to assess intratumor heterogeneity). In autopsied patients, gDNA and total RNA were extracted from all metastatic lesions (to assess intertumor heterogeneity). RESULTS: MET exon 14 skipping mutation was detected in 4 patients (4/23, 17.4%): two surgically resected and two autopsied patients. We found no intratumor or intertumor heterogeneity in MET exon 14 skipping mutation status in these patients. We observed intratumor and intertumor heterogeneity in the copy number variations and/or mutational status of cancer-related genes; some of these differences may have an impact on MET tyrosine kinase inhibitor (TKI) efficacy. CONCLUSION: In our exploratory analysis of four cases, we observed that MET exon 14 skipping mutations are distributed homogeneously throughout histological components and between metastatic lesions. Our results also suggest that there is marked intertumor and intratumor heterogeneity in co-occurring genetic alterations, and therapeutic implications of such heterogeneity should be evaluated in future studies.

Outcome of thoracoscopic anatomical sublobar resection under 3-dimensional computed tomography simulation.

BACKGROUND: Previous studies have reported the feasibility and efficacy of thoracoscopic anatomical sublobar resection under three-dimensional computed tomography (3DCT) simulation; however, its long-term outcomes have not been clearly established in primary lung cancer. This study aimed to evaluate the long-term outcomes of this technique. METHODS: We retrospectively reviewed data from 112 consecutive patients with selected clinical stage IA non-small cell lung cancer (NSCLC) who underwent thoracoscopic anatomical sublobar resection from 2004 to 2014. This procedure was planned using preoperative 3DCT simulation to ensure sufficient surgical margins and enabled tailor-made surgery for each patient. Patients who had predominantly ground glass opacity lung cancers underwent anatomical sublobar resection as a curative-intent resection. Other patients who were high-risk candidates for lobectomy underwent anatomical sublobar resection as a compromised limited resection. RESULTS: Of the 112 cases, 82 had a curative-intent resection, while 30 had a compromised limited resection. Recurrence occurred in only 2 cases (1.8%), both of which were in the compromised limited group. A second primary lung cancer was observed in 5 cases (4.5%). Of the 5 patients, 4 underwent surgery for a second cancer and had no recurrence. The 5-year overall survival, lung cancer-specific overall survival, and recurrence-free survival rates were 92.5%, 100%, and 98.2%, respectively, for all cases; 97.6%, 100%, and 100%, respectively, in the curative-intent group; and 75.8%, 100% and 92.6%, respectively, in the compromised limited group. CONCLUSIONS: Thoracoscopic anatomical sublobar resection under 3DCT simulation may be an acceptable alternative treatment in selected patients with NSCLC. TRIAL AND CLINICAL REGISTRY: Clinical registration number: IRB No. 2020-98 (Dated: 2020.6.30).

Frequent EGFR Mutations and Better Prognosis in Positron Emission Tomography-Negative, Solid-Type Lung Cancer.

BACKGROUND: The differential diagnosis of a solitary solid-type lung nodule is diverse. 18F-fluorodeoxyglucose positron emission tomography (PET) has a high sensitivity in the diagnosis of solid-type lung cancers; however, PET-negative, solid-type lung cancers are rarely observed. In this study, we analyzed the clinical/genetic features and prognosis of PET-negative, solid-type lung cancers. PATIENTS AND METHODS: Between January 2007 and February 2020, 709 patients with solid-type lung cancers (tumor size ≥2.0 cm) underwent pulmonary resection. Clinical, genetic, and prognostic features were evaluated in 27 patients (3.8%) with tumors showing negative PET results defined as SUVmax <2.0. RESULTS: All 27 patients had lung adenocarcinoma; 23 had invasive adenocarcinomas and 4 had invasive mucinous adenocarcinomas. The PET-negative group showed high frequencies of females and never-smokers. Recurrence-free survival was significantly better in the PET-negative group compared with PET-positive counterparts extracted using propensity score matching from patients who underwent pulmonary resection during the same period (P = .0052). Furthermore, 83% of PET-negative, solid-type invasive lung adenocarcinoma patients harbored EGFR mutation, which was significantly higher than that of PET-positive, solid-type invasive lung adenocarcinoma patients (38%, n = 225) who received EGFR mutation testing in our cohort (P < .0001). PET-negative, solid-type lung adenocarcinoma patients with EGFR mutations had significantly better recurrence-free survival compared with PET-positive, solid-type lung adenocarcinoma patients with EGFR mutations extracted using propensity score matching (P = .0030). CONCLUSION: PET-negative, solid-type lung cancers are characterized with a high incidence of EGFR mutation and a better prognosis compared with PET-positive, solid-type lung cancer.

In vitro validation study of HER2 and HER4 mutations identified in an ad hoc secondary analysis of the LUX-Lung 8 randomized clinical trial.

OBJECTIVES: The LUX-Lung 8 randomized trial (LL8) demonstrated a prolonged progression-free survival (PFS) in patients with metastatic squamous cell carcinoma (SCC) of the lung after treatment with afatinib compared with erlotinib. A secondary analysis of the LL8 reported that the presence of rare HER2/HER4 mutations may be partly responsible for this result. Patients with HER2 (hazard ratio [HR] 0.06/p-value 0.02) or HER4 (HR 0.21/p-value unreported) mutations had longer PFS after treatment with afatinib. However, the biological function of these mutations is unclear. MATERIALS AND METHODS: Ten HER2 and 13 HER4 point mutations that were detected in the secondary analysis were transduced into the mouse pro-B cell line (Ba/F3) to determine changes in interleukin-3 (IL-3) dependence and sensitivity to six EGFR or pan-HER tyrosine kinase inhibitors (TKIs), including afatinib and erlotinib. The efficacy of the six TKIs was compared using a sensitivity index, defined as the 50% inhibitory concentration divided by trough concentration of each drug at clinically recommended doses. RESULTS: Seven out of 10 Ba/F3 clones expressing HER2 mutations and all 13 Ba/F3 clones expressing HER4 mutations did not grow in the absence of IL-3, indicating these mutations were non-oncogenic. Three Ba/F3 clones expressing the HER2 mutations E395K, G815R, or R929W acquired IL-3-independent growth. The sensitivity indices for afatinib were ≤ one-fifth of those for erlotinib in all three lines. Other second/third-generation (2G/3G) TKIs showed high efficacy against clones expressing these HER2 mutations. CONCLUSIONS: The majority of HER2/4 mutations detected in lung SCC from LL8 were not oncogenic in the Ba/F3 models, suggesting that the presence of HER2/4 mutations were not responsible for the superior outcomes of afatinib in the LL8 study. However, SCC of the lung in some patients may be driven by rare HER2 mutations, and these patients may benefit from 2G/3G pan-HER-TKI treatment.

Activity and mechanism of acquired resistance to tarloxotinib in HER2 mutant lung cancer: an in vitro study.

BACKGROUND: HER2 (ERBB2) activating mutations are present in 2-3% of lung adenocarcinomas; however, no targeted therapy is approved for HER2-altered lung cancers. A novel pan-HER inhibitor, tarloxotinib, is designed to release the active form (tarloxotinib-E) under hypoxic conditions in tumor tissues after being administered as a prodrug. Following the evaluation of the in vitro activity of tarloxotinib-E in HER2-mutant cells, we explored the mechanisms of resistance to tarloxotinib-E in these cells. METHODS: Growth inhibitory assays were performed with tarloxotinib-E and its prodrug using Ba/F3 cells expressing one of six HER2 mutations or wild-type (WT) HER2, in addition to H1781 cells with HER2 exon 20 insertions. Resistant clones were established from N-ethyl-N-nitrosourea (ENU)-treated HER2-mutant Ba/F3 cells and H1781 cells by chronic exposure to tarloxotinib-E. RESULTS: Tarloxotinib-E showed potent activity against HER2-mutant Ba/F3 cells and H1781 cells. Furthermore, the half maximal inhibitory concentration (IC50) of tarloxotinib (inactive form) for WT HER2 was 180 times higher than that of tarloxotinib-E, indicating a wide therapeutic window of tarloxotinib. We established 30 resistant clones with secondary mutations of HER2 by ENU mutagenesis, all of which harbored C805S in exon 20. In the analysis of H1781 cells that acquired resistance to tarloxotinib-E, we found that increased HER3 expression was the molecular mechanism of tarloxotinib-E resistance. CONCLUSIONS: Tarloxotinib-E exhibited potent activity against cell line models with HER2 mutations. We identified a secondary C805S HER2 mutation and HER3 overexpression as the mechanisms of acquired resistance to tarloxotinib-E.

Perioperative Therapy for Non-Small Cell Lung Cancer with Immune Checkpoint Inhibitors.

The emergence of immune checkpoint inhibitors (ICIs) has dramatically changed the treatment landscape for patients with metastatic non-small cell lung cancer (NSCLC). These achievements inspired investigators and pharmaceutical companies to conduct clinical trials in patients with early-stage NSCLC because both adjuvant and neoadjuvant platinum-based doublet chemotherapies (PT-DCs) showed only a 5% improvement in 5-year overall survival. IMpower010, a phase 3 trial (P3), showed that adjuvant PT-DC followed by maintenance atezolitumab significantly prolonged disease-free survival over adjuvant PT-DC alone (hazard ratio, 0.79; stage II to IIIA). Since conventional therapies, including chemotherapy and radiotherapy, can promote immunogenic cell death, releasing tumour antigens from dead tumour cells, ICI combination therapies with conventional therapies are widely proposed. The Checkmate 816 trial (P3) indicated a significantly higher pathological complete response rate of neoadjuvant nivolumab/PT-DC combination therapy than of neoadjuvant PT-DC alone (odds ratio, 13.9, for stage IB to IIIA). Detection of circulating tumour DNA is highly anticipated for the evaluation of minimal residual disease. Multimodal approaches and new ICI agents are being attempted to improve the efficacy of ICI treatment in phase 2 trials. This review presents the development of perioperative treatment using ICIs in patients with NSCLC while discussing problems and perspectives.

Phase II Study of Neoadjuvant Concurrent Chemo-immuno-radiation Therapy Followed by Surgery and Adjuvant Immunotherapy for Resectable Stage IIIA-B (Discrete N2) Non-small-cell Lung Cancer: SQUAT trial (WJOG 12119L).

INTRODUCTION: We describe our ongoing multicenter, prospective, single-arm, phase II trial of neoadjuvant concurrent chemo-immuno-radiation therapy followed by surgical resection and adjuvant immunotherapy for resectable stage IIIA-B (discrete N2) non-small-cell lung cancer (NSCLC) (registered at the Japan Pharmaceutical Information Center, Clinical Trials Information-195069). PATIENTS AND METHODS: Key inclusion criteria include (1) clinical T1-3/T4 (tumor size) N2 stage IIIA-B NSCLC, and (2) pathologically confirmed N2 without extranodal invasion (based on diagnostic imaging). Patients will receive concurrent chemoradiotherapy (carboplatin [area under the curve = 2] and paclitaxel [40 mg/m2] on days 1, 8, 15, 22, and 29, with involved-field radiation therapy [RT] [dose 50 Gy] on days 1-25) and neoadjuvant immunotherapy (durvalumab [1500 mg] on days 1 and 29). Surgical resection with mediastinal lymph node dissection is performed within 2 to 6 weeks after RT. Consolidation therapy with durvalumab is administered for up to 1 year after surgery. The primary endpoint is major pathologic response (MPR) (≤10% residual viable tumor) according to the central pathological assessment. Secondary endpoints are progression-free survival, overall survival, and safety. The sample size is planned to be 31 patients based on the exact binomial distribution with a 1-sided significance level of 5% and a power of 80%, and assuming a threshold MPR rate of 40% and an expected MPR rate of 65%. CONCLUSION: This trial will help establish a novel treatment strategy for resectable N2-positive NSCLC.