Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are standard therapies for EGFR-mutated non-small-cell lung cancer (NSCLC); however, their efficacy is inconsistent. Secondary mutations in the EGFR or other genes that lead to resistance have been identified, but resistance mechanisms have not been fully identified. Chromosomal instability (CIN) is a hallmark of cancer and results in genetic diversity. In this study, we demonstrated by transcriptomic analysis that CIN activates the cGAS-STING signaling pathway, which leads to EGFR-TKI refractoriness in a subset of EGFR-mutated NSCLC patients. Furthermore, EGFR-mutated H1975dnMCAK cells, which frequently underwent chromosomal mis-segregation, demonstrated refractoriness to the EGFR-TKI osimertinib compared to control cells. Second, H1975dnMCAK cells exhibited activation of cGAS-STING signaling and its downstream signaling, including tumor-promoting cytokine IL-6. Finally, chromosomally unstable EGFR-mutated NSCLC exhibited enhanced epithelial-mesenchymal transition (EMT). Blockade of cGAS-STING-TBK1 signaling reversed EMT, resulting in restored susceptibility to EGFR-TKIs in vitro and in vivo. These results suggest that CIN may lead to the activation of cGAS-STING signaling in some EGFR-mutated NSCLC, resulting in EMT-associated EGFR-TKI resistance.

BACKGROUNDPrecise stratification of patients with non-small cell lung cancer (NSCLC) is needed for appropriate application of PD-1/PD-L1 blockade therapy.METHODSWe measured soluble forms of the immune-checkpoint molecules PD-L1, PD-1, and CTLA-4 in plasma of patients with advanced NSCLC before PD-1/PD-L1 blockade. A prospective biomarker-finding trial (cohort A) included 50 previously treated patients who received nivolumab. A retrospective observational study was performed for patients treated with any PD-1/PD-L1 blockade therapy (cohorts B and C), cytotoxic chemotherapy (cohort D), or targeted therapy (cohort E). Plasma samples from all patients were assayed for soluble immune-checkpoint molecules with a highly sensitive chemiluminescence-based assay.RESULTSNonresponsiveness to PD-1/PD-L1 blockade therapy was associated with higher concentrations of these soluble immune factors among patients with immune-reactive (hot) tumors. Such an association was not apparent for patients treated with cytotoxic chemotherapy or targeted therapy. Integrative analysis of tumor size, PD-L1 expression in tumor tissue (tPD-L1), and gene expression in tumor tissue and peripheral CD8+ T cells revealed that high concentrations of the 3 soluble immune factors were associated with hyper or terminal exhaustion of antitumor immunity. The combination of soluble PD-L1 (sPD-L1) and sCTLA-4 efficiently discriminated responsiveness to PD-1/PD-L1 blockade among patients with immune-reactive tumors.CONCLUSIONCombinations of soluble immune factors might be able to identify patients unlikely to respond to PD-1/PD-L1 blockade as a result of terminal exhaustion of antitumor immunity. Our data suggest that such a combination better predicts, along with tPD-L1, for the response of patients with NSCLC.TRIAL REGISTRATIONUMIN000019674.FUNDINGThis study was funded by Ono Pharmaceutical Co. Ltd. and Sysmex Corporation.

BACKGROUND: Immune-related adverse events (irAEs) have been found to predict PD-L1 inhibitor efficacy in metastatic NSCLC. However, the relation of irAEs to clinical outcome for nonmetastatic NSCLC has remained unknown. METHODS: In this multicenter prospective study of Stage III NSCLC treated with PACIFIC regimen, the relation of irAEs to PFS was evaluated by 8-week landmark analysis to minimise lead-time bias as well as by multivariable analysis adjusted for baseline factors. irAEs were categorised as mild or nonmild according to whether they were treated with systemic steroid. RESULTS: Median PFS was 16.0 months, not reached, and 9.7 months for patients without (85 cases) or with mild (21 cases) or nonmild (21 cases) irAEs, respectively. Multivariable analysis indicated that nonmild irAEs were associated with poor PFS, with HRs of 3.86 (95% CI, 1.31-11.38) compared with no irAEs and 11.58 (95% CI, 2.11-63.63) compared with mild irAEs. This pattern was consistent after irAE grade, the number of durvalumab doses and immune profiles (PD-L1 score, CD8+ tumour-infiltrating lymphocyte density, and tumour mutation burden) were taken into consideration. CONCLUSIONS: The development of mild irAEs might predict a better survival outcome, whereas immunosuppressive steroid-treated irAEs were associated with a worse outcome, regardless of baseline clinical and immune profiles.

BACKGROUND: Immune checkpoint inhibitors have been reported to have excellent therapeutic effects on various malignant tumors. However, immune-related adverse events can occur, targeting various organs. CASE PRESENTATION: A 49-year-old male with lung carcinoma was started on carboplatin + pemetrexed + nivolumab (every 3 weeks) + ipilimumab (every 6 weeks), and nivolumab/ipilimumab was administered in the 3rd course. Subsequently, fever and fatigue developed, and grade 3 liver damage was also noted, so he was admitted to Kindai University Hospital. A bone marrow aspirate examination was performed on the third day of illness, and a definitive diagnosis of hemophagocytic lymphohistiocytosis (HLH) was made. It was determined that immediate therapeutic intervention was necessary, and pulse therapy with methylprednisolone was started on the third day of illness. After 3 days of pulse treatment, a rapid recovery of platelet values, a decrease in ferritin levels, and a decrease in lactate dehydrogenase were observed. Subjective symptoms such as fever and fatigue also quickly improved. CONCLUSION: Early diagnosis and treatment for HLH resulted in a positive response. The number of HLH cases may increase in the future due to the expansion of immune checkpoint inhibitor indications.

Abstract Small amounts of epidermal growth factor receptor (EGFR) T790M mutation (micro-T790M), which is detected using droplet digital PCR (ddPCR) but not conventional PCR, in formalin-fixed and paraffin-embedded (FFPE) samples have been investigated as a predictive factor for the efficacy of EGFR-tyrosine kinase inhibitors (TKIs). However, the predictive value of micro-T790M remains controversial, possibly owing to the failure to examine artificial T790M in FFPE specimens. Therefore, we examined the predictive value of micro-T790M in first-generation (1G), second-generation (2G), and third-generation (3G) EGFR-TKI efficacy using a new method to exclude FFPE-derived artificial mutations in our retrospective cohort. The primary objective was time to treatment failure (TTF) of 1G, 2G, and 3G EGFR-TKIs according to micro-T790M status. In total, 315 patients with EGFR-positive non-small cell lung cancer treated with 1G, 2G, and 3G EGFR-TKIs were included in this study. The proportion of patients positive for micro-T790M in the 1G, 2G, and 3G EGFR-TKI groups was 48.2%, 47.1%, and 47.6%, respectively. In the micro-T790M-positive group, the TTF was significantly longer in the 2G and 3G EGFR-TKI groups than in the 1G TKI group. No differences in the micro-T790M-negative group were observed. Micro-T790M status detected using ddPCR, eliminating false positives, may be a valuable predictor of EGFR-TKI efficacy.

There have been few studies on predictive biomarkers that may be useful to select the most suitable opioids to optimize therapeutic efficacy in individual patients with cancer pain. We recently investigated the efficacy of morphine and oxycodone using single nucleotide polymorphisms (SNPs) of the catechol-O-methyltransferase (COMT) rs4680 gene as a biomarker (RELIEF study). To explore additional biomarkers that may enable the selection of an appropriate opioid for individual patients with cancer pain, three SNPs were examined: C-C motif chemokine ligand 11 (CCL11; rs17809012), histamine N-methyltransferase (HNMT; rs1050891) and transient receptor potential V1 (TRPV1; rs222749), which were screened from 74 pain-related SNPs. These SNPs, which were identified as being significantly associated with the analgesic effect of morphine, were then used to genotype the 135 patients in the RELIEF study who had been randomized into a morphine group (n=69) or an oxycodone group (n=66). The present study then assessed whether the SNPs could also be used as selective biomarkers to predict which opioid(s) might be the most suitable to provide pain relief for patients with cancer. Oxycodone tended to provide superior analgesic effects over morphine in patients carrying the genotype AA for the CCL11 rs17809012 SNP (P=0.012 for interaction), suggesting that it could serve as a potential biomarker for personalized analgesic therapy for patients suffering with cancer pain.

INTRODUCTION: The PACIFIC regimen of consolidation therapy with the programmed cell death-ligand 1 (PD-L1) inhibitor durvalumab after definitive concurrent chemoradiation therapy has become a standard of care for individuals with unresectable stage III non-small cell lung cancer (NSCLC). However, about half of treated patients experience disease progression within 1 year, with the mechanisms of treatment resistance being poorly understood. We here performed a nationwide prospective biomarker study to explore the resistance mechanisms (WJOG11518L/SUBMARINE). METHODS: A total of 135 patients with unresectable stage III NSCLC who received the PACIFIC regimen were included for comprehensive profiling of the tumor microenvironment by immunohistochemistry, transcriptome analysis, and genomic sequencing of pretreatment tumor tissue as well as flow cytometric analysis of circulating immune cells. Progression-free survival (PFS) was compared based on these biomarkers. RESULTS: The importance of preexisting effective adaptive immunity in tumors were revealed for treatment benefit regardless of genomic features. We also identified CD73-expression by cancer cells as a mechanism of resistance to the PACIFIC regimen. Multivariable analysis of immunohistochemistry data with key clinical factors as covariables indicated that low CD8+ tumor-infiltrating lymphocytes (TILs) density and the high CD73+ cancer cells were independently associated with poor durvalumab outcome (HRs, 4.05 [95% CI, 1.17-14.04] for CD8+ TILs; 4.79 [95% CI, 1.12-20.58] for CD73). In addition, whole-exome sequencing of paired tumor samples suggested that cancer cells eventually escaped immune pressure as a result of neoantigen plasticity. CONCLUSIONS: Our study emphasizes the importance of functional adaptive immunity in stage III NSCLC, and implicates CD73 as a promising treatment target, thus providing insight forming a basis for development of a new treatment approach in NSCLC.

BACKGROUND: Some lung cancer patients have preexisting interstitial lung disease (ILD), which is considered a risk factor for lung cancer treatment. This study investigated the safety and efficacy of durvalumab consolidation therapy for patients with stage III non-small-cell lung cancer (NSCLC) and preexisting ILD. METHODS: Fifty consecutive patients who were judged to be tolerable to concurrent chemoradiotherapy (CCRT) for stage III NSCLC were enrolled. Differences in the incidence rate of radiation pneumonitis (RP) and progression-free survival (PFS) were assessed in patients with or without ILD of which CT showed non-usual interstitial pneumonia pattern between the durvalumab consolidation group and chemotherapy (combination of carboplatin and paclitaxel [CP]) consolidation group. RESULTS: The incidence of RP was higher in patients with preexisting ILD (40% and 20% in the durvalumab and CP groups, respectively) than in those without ILD (26% and 8% in the durvalumab and CP groups, respectively). Univariate analysis showed that durvalumab therapy tended to increase the incidence of RP; however, preexisting ILD did not significantly increase the incidence of RP. The condition of all patients who developed RP improved with the administration of oral prednisolone. Among patients without ILD, the median PFS was 17 and 16 months in the durvalumab and CP groups, respectively. Among patients with preexisting ILD, median PFS was not achieved in the durvalumab group and was 8 months in the CP group. CONCLUSIONS: Although durvalumab consolidation therapy tended to increase the incidence of RP, it might be tolerable in stage III NSCLC patients with preexisting ILD.

Introduction: Despite a considerable benefit of adding immune checkpoint inhibitors (ICIs) to platinum-based chemotherapy for patients with extensive-stage SCLC (ES-SCLC), a durable response to ICIs occurs in only a small minority of such patients. Methods: A total of 135 patients with ES-SCLC treated with chemotherapy either alone (chemo-cohort, n = 71) or together with an ICI (ICI combo-cohort, n = 64) was included in this retrospective study. Tumors were classified pathologically as inflamed or noninflamed on the basis of programmed death-ligand 1 expression and CD8+ tumor-infiltrating lymphocyte density. Immune-related gene expression profiling was performed, and predicted neoantigen load was determined by whole-exome sequencing. Results: Among patients in the ICI combo-cohort, median progression-free survival was 10.8 and 5.1 months for those with inflamed (n = 7) or noninflamed (n = 56) tumors, respectively (log-rank test p = 0.002; hazard ratio of 0.26). Among the 89 patients with immune-related gene expression profiling data available, inflamed tumors had a higher T cell-inflamed GEP score than did noninflamed tumors (-0.18 versus -0.58, p < 0.001). The 12-month progression-free survival rate was 16.1% and 0% for patients in the ICI combo-cohort harboring tumors with a high (n = 26) or low (n = 18) frameshift neoantigen load, respectively. A high-frameshift neoantigen load was associated with up-regulation of gene signatures related to antigen presentation and costimulatory signaling. A durable clinical benefit of ICI therapy was observed only in patients with inflamed tumors and a high-frameshift neoantigen load. Conclusions: Expression of programmed death-ligand 1, CD8+ T cell infiltration, and a high-frameshift neoantigen load are associated with clinical benefit of ICI therapy in ES-SCLC. Clinical trial registration: UMIN000041056.

PURPOSE: Although the efficacy of programmed cell death-1 (PD-1) blockade is generally poor for non-small cell lung cancer (NSCLC) with activating mutations of the epidermal growth factor receptor (EGFR) gene, EGFR tyrosine kinase inhibitors (TKIs) may improve the tumor immune microenvironment. We performed a randomized study to assess whether nivolumab improves outcome compared with chemotherapy in such patients previously treated with EGFR-TKIs. PATIENTS AND METHODS: Patients with EGFR-mutated NSCLC who acquired EGFR-TKI resistance not due to a secondary T790M mutation of EGFR were randomized 1:1 to nivolumab (n = 52) or carboplatin-pemetrexed (n = 50). The primary endpoint was progression-free survival (PFS). RESULTS: Median PFS and 1-year PFS probability were 1.7 months and 9.6% for nivolumab versus 5.6 months and 14.0% for carboplatin-pemetrexed [log-rank P < 001; hazard ratio (HR) of 1.92, with a 60% confidence interval (CI) of 1.61-2.29]. Overall survival was 20.7 and 19.9 months [HR, 0.88 (95% CI, 0.53-1.47)], and response rate was 9.6% and 36.0% for nivolumab and carboplatin-pemetrexed, respectively. No subgroup including patients with a high tumor mutation burden showed a substantially longer PFS with nivolumab than with carboplatin-pemetrexed. The T-cell-inflamed gene expression profile score (0.11 vs. -0.17, P = 0.036) and expression of genes related to cytotoxic T lymphocytes or their recruitment were higher in tumors that showed a benefit from nivolumab. CONCLUSIONS: Nivolumab did not confer a longer PFS compared with carboplatin-pemetrexed in the study patients. Gene expression profiling identified some cases with a favorable tumor immune microenvironment that was associated with nivolumab efficacy.

INTRODUCTION: The real-world effectiveness of combination treatment with cytotoxic chemotherapy and programmed cell death protein-1 or programmed death-ligand 1 inhibitor for NSCLC, especially for the elderly (aged ≥75 y) or those with poor performance status (≥2), has not been fully elucidated. We investigated the real-world effectiveness and safety of this combination therapy in these populations. METHODS: This multicenter retrospective study evaluated patients who are chemo-naïve with advanced NSCLC who received a combination of platinum, pemetrexed, and pembrolizumab between December 2018 and June 2019. This was an updated prespecified secondary analysis with the primary objective of investigating the safety and effectiveness in this cohort. RESULTS: Overall, 299 patients were included. Multivariate analysis identified performance status (0-1) and programmed death-ligand 1 tumor proportion score (≥50%) as significant independent predictors of progression-free survival (p = 0.007, and p = 0.003, respectively). The incidence of severe adverse events (AEs) was higher in the elderly and those with poor performance status than in their younger and good performance status counterparts. A total of 71 patients developed AEs that led to treatment discontinuation, and AE-related treatment discontinuation occurred at a significantly higher rate in older patients (median [range]) (70 [46-82] y) than in younger patients (68 [31-84] y) (p <0.001). CONCLUSIONS: Combination treatment with pembrolizumab plus chemotherapy had low real-world effectiveness for poor performance status patients. Severe AEs occurred at a higher rate in the elderly and poor performance status patients, and the AE-related treatment discontinuation rate increased with age. Physicians should be cautious about using this regimen, especially in the elderly and poor performance status patients.

BACKGROUND: Cancer of unknown primary (CUP) has a poor prognosis. Given the recent approval of immune checkpoint inhibitors for several cancer types, we carried out a multicenter phase II study to assess the efficacy of nivolumab for patients with CUP. PATIENTS AND METHODS: Patients with CUP who were previously treated with at least one line of systemic chemotherapy constituted the principal study population. Previously untreated patients with CUP were also enrolled for exploratory analysis. Nivolumab (240 mg/body) was administered every 2 weeks for up to 52 cycles. The primary endpoint was objective response rate in previously treated patients as determined by blinded independent central review according to RECIST version 1.1. RESULTS: Fifty-six patients with CUP were enrolled in the trial. For the 45 previously treated patients, objective response rate was 22.2% [95% confidence interval (CI), 11.2% to 37.1%], with a median progression-free survival and overall survival of 4.0 months (95% CI, 1.9-5.8 months) and 15.9 months (95% CI, 8.4-21.5 months), respectively. Similar clinical benefits were also observed in the 11 previously untreated patients. Better clinical efficacy of nivolumab was apparent for tumors with a higher programmed death-ligand 1 expression level, for those with a higher tumor mutation burden, and for microsatellite instability-high tumors. In contrast, no differences in efficacy were apparent between tumor subgroups based on estimated tissue of origin. Adverse events were consistent with the known safety profile of nivolumab. No treatment-related death was observed. CONCLUSIONS: Our results demonstrate a clinical benefit of nivolumab for patients with CUP, suggesting that nivolumab is a potential additional therapeutic option for CUP.

PURPOSE: EGFR-tyrosine kinase inhibitor (TKI) is a standard first-line therapy for activated EGFR-mutated non-small cell lung cancer (NSCLC). Treatment options for patients with acquired EGFR-TKI resistance are limited. HER3 mediates EGFR-TKI resistance. Clinical trials of the HER3-targeting antibody-drug conjugate patritumab deruxtecan (HER3-DXd) demonstrated its anticancer activity in EGFR-mutated NSCLC; however, the mechanisms that regulate HER3 expression are unknown. This study was conducted with the aim to clarify the mechanisms underlying HER3 regulation in EGFR-mutated NSCLC tumors and explored the strategy for enhancing the anticancer activity of HER3-DXd in EGFR-mutated NSCLC. EXPERIMENTAL DESIGN: Paired tumor samples were obtained from 48 patients with EGFR-mutated NSCLC treated with EGFR-TKI(s). HER3 expression was immunohistochemically quantified with H-score, and genomic alteration and transcriptomic signature were tested in tumors from pretreatment to post-EGFR-TKI resistance acquisition. The anticancer efficacy of HER3-DXd and osimertinib was evaluated in EGFR-mutated NSCLC cells. RESULTS: We showed augmented HER3 expression in EGFR-mutated tumors with acquired EGFR-TKI resistance compared with paired pretreatment samples. RNA sequencing revealed that repressed PI3K/AKT/mTOR signaling was associated with HER3 augmentation, especially in tumors from patients who received continuous EGFR-TKI therapy. An in vitro study also showed that EGFR-TKI increased HER3 expression, repressed AKT phosphorylation in multiple EGFR-mutated cancers, and enhanced the anticancer activity of HER3-DXd. CONCLUSIONS: Our findings help clarify the mechanisms of HER3 regulation in EGFR-mutated NSCLC tumors and highlight a rationale for combination therapy with HER3-DXd and EGFR-TKI in EGFR-mutated NSCLC.

Considering the increasing number of identified driver oncogene alterations, additional genetic tests are required to determine the treatment for advanced non-small-cell lung cancer (NSCLC). Next-generation sequencing can detect multiple driver oncogenes simultaneously, enabling the analysis of limited amounts of biopsied tissue samples. In this retrospective, multicenter study (UMIN ID000039523), we evaluated real-world clinical data using the Oncomine Dx Target Test Multi-CDx System (Oncomine DxTT) as a companion diagnostic system. Patients with NSCLC who were tested for a panel of 46 genes using the Oncomine DxTT between June 2019 and January 2020 were eligible for enrollment. Patients from 19 institutions affiliated to the West Japan Oncology Group were recruited. The primary endpoint of the study was the success rate of genetic alteration testing in four driver genes (EGFR, ALK, ROS1, and BRAF) using the Oncomine DxTT. In total, 533 patients were enrolled in the study. The success rate of genetic alteration testing for all four genes was 80.1% (95% CI 76.5%-83.4%). Surgical resection was associated with the highest success rate (88.0%), which was significantly higher than that for bronchoscopic biopsy (76.8%, P = .005). Multivariate analysis revealed a significant difference for surgical resection alone (P = .006, 95% CI 1.36-6.18, odds ratio 2.90). Although the success rate of genetic alteration testing immediately after Oncomine DxTT induction was not sufficient in this study, optimizing specimen quantity and quality may improve the use of driver gene testing in clinical settings.

BACKGROUND: Tumour burden (TB) is implicated in resistance to programmed cell death-1/PD-L1 inhibitor (immune checkpoint inhibitor [ICI]) therapy. However, whether TB contributes to such resistance in non-small-cell lung cancer (NSCLC) has remained unknown. METHODS: A total of 260 treatment-naïve patients with advanced NSCLC who started ICI monotherapy (ICI cohort), platinum-doublet therapy (Chemo cohort) or ICI and platinum-doublet therapy (ICI+Chemo cohort) as first-line treatment were consecutively included. TB was estimated on the basis of the sum of the diameters of measurable target lesions as per Response Evaluation Criteria in Solid Tumours. Progression-free survival (PFS) in the ICI cohort was evaluated as per TB as a preplanned primary objective, with the analysis based on propensity score-weighted survival curves and estimation of restricted mean survival time (RMST). The Chemo cohort served as a control to determine whether TB is predictive of ICI treatment outcomes. The ICI+Chemo cohort was exploratory. The relation of TB to tumour immune status was assessed by immune-related gene expression profiling (irGEP) of pretreatment tumour tissue. RESULTS: In the ICI cohort, patients with a low TB showed a significantly longer PFS than did those with a high TB (median, 17.9 vs 4.3 months; weighted hazard ratio, 0.32 [95% confidence interval, 0.19-0.53]). No such difference was apparent in the other cohorts. A significant difference in overall survival was also observed only in the ICI cohort. RMST-based analysis confirmed these results. The irGEP analysis implicated M2-type macrophages, angiogenesis and transforming growth factor-β as well as protumourigenic signalling pathways in ICI resistance conferred by a high TB. CONCLUSION: A high TB was associated with a poor outcome of ICI therapy for advanced NSCLC as a result of immunosuppressive phenotypes. Development of combination or novel treatment strategies for such disease is thus warranted.

PURPOSE: Treatment with KRAS G12C inhibitors such as sotorasib can produce substantial regression of tumors in some patients with non-small cell lung cancer (NSCLC). These patients require alternative treatment after acquiring resistance to the inhibitor. The mechanisms underlying this acquired resistance are unclear. The purpose of this study was to identify the mechanisms underlying acquired sotorasib resistance, and to explore potential treatments for rescuing patients with sotorasib-resistant KRAS G12C NSCLC cells. EXPERIMENTAL DESIGN: Clones of sotorasib-sensitive KRAS G12C NSCLC H23 cells exposed to different concentrations of sotorasib were examined using whole-genomic transcriptome analysis, multiple receptor kinase phosphorylation analysis, and gene copy number evaluation. The underlying mechanisms of resistance were investigated using immunological examination, and a treatment aimed at overcoming resistance was tested in vitro and in vivo Results: Unbiased screening detected subclonal evolution of MET amplification in KRAS G12C NSCLC cells that had developed resistance to sotorasib in vitro MET knockdown using siRNA restored susceptibility to sotorasib in these resistant cells. MET activation by its amplification reinforced RAS cycling from its inactive form to its active form. In addition to RAS-mediated MEK-ERK induction, MET induced AKT activation independently of RAS. Crizotinib, a MET inhibitor, restored sensitivity to sotorasib by eliminating RAS-MEK-ERK as well as AKT signaling. MET/KRAS G12C dual inhibition led to tumor shrinkage in sotorasib-resistant xenograft mice. CONCLUSIONS: MET amplification leads to the development of resistance to KRAS G12C inhibitors in NSCLC. Dual blockade of MET and KRAS G12C could be a treatment option for MET amplified, KRAS G12C-mutated NSCLC.

BACKGROUND: The utility of bronchoscopy for patients with suspected immune checkpoint inhibitor (ICI)-related pneumonitis is currently debatable. The purpose of this study was to examine the findings of bronchoalveolar lavage (BAL) analysis and transbronchial lung biopsy (TBLB) in non-small cell lung cancer (NSCLC) patients with ICI-related pneumonitis, and to elucidate the clinical significance of bronchoscopy for this health condition. PATIENTS AND METHODS: Consecutive NSCLC patients treated with ICIs, diagnosed with ICI-related pneumonitis after undergoing bronchoscopy between October 2015 and March 2019 were retrospectively screened. Findings of BAL fluid analysis and/or TBLB specimen histology were reviewed. RESULTS: Twelve patients underwent bronchoscopy for the diagnosis of ICI-related pneumonitis, ten of whom underwent BAL. An increase in the proportion of lymphocytes higher than 20% was observed in all ten patients. An increase in the proportion of neutrophils (> 10%) and eosinophils (> 10%) was observed in two and one patient, respectively. TBLB specimens were analyzed for eight patients. Major histologic findings included alveolitis in seven (87.5%) and organizing pneumonia (OP) in five (62.5%) patients. Other findings included acute lung injury and fibrosis. All twelve patients demonstrated favorable outcomes. CONCLUSION: A major characteristic of BAL analysis in ICI-related pneumonitis with NSCLC was an increased proportion of lymphocytes. The histologic features of lung tissue included alveolitis and/or OP. Acute lung injury and fibrosis were observed. Although the necessity of bronchoscopy should be determined on a case-by-case basis, it is necessary to assess these parameters when proper differential diagnosis is needed.

Patients with NSCLC in East Asia, including Japan, frequently contain EGFR mutations. In 2018, we published the latest full clinical practice guidelines on the basis of those provided by the Japanese Lung Cancer Society Guidelines Committee. The purpose of this study was to update those recommendations, especially for the treatment of metastatic or recurrent EGFR-mutated NSCLC. We conducted a literature search of systematic reviews of randomized controlled and nonrandomized trials published between 2018 and 2019 that multiple physicians had reviewed independently. On the basis of those studies and the advice from the Japanese Society of Lung Cancer Expert Panel, we developed updated guidelines according to the Grading of Recommendations, Assessment, Development, and Evaluation system. We also evaluated the benefits of overall and progression-free survival, end points, toxicities, and patients' reported outcomes. For patients with NSCLC harboring EGFR-activating mutations, the use of EGFR tyrosine kinase inhibitors (EGFR TKIs), especially osimertinib, had the best recommendation as to first-line treatment. We also recommended the combination of EGFR TKI with other agents (platinum-based chemotherapy or antiangiogenic agents); however, it can lead to toxicity. In the presence of EGFR uncommon mutations, except for an exon 20 insertion, we also recommended the EGFR TKI treatment. However, we could not provide recommendations for the treatment of EGFR mutations with immune checkpoint inhibitors, including monotherapy, and its combination with cytotoxic chemotherapy, because of the limited evidence present in the literature. The 2020 Japanese Lung Cancer Society Guidelines can help community-based physicians to determine the most appropriate treatments and adequately provide medical care to their patients.

PURPOSE: The impact of EGFR tyrosine kinase inhibitors (TKI) on the tumor immune microenvironment (TME) in non-small cell lung cancer (NSCLC) is unclear. EXPERIMENTAL DESIGN: We retrospectively identified 138 patients with EGFR-mutated NSCLC who underwent rebiopsy after progression during EGFR-TKI treatment. PD-L1 and CD73 expression in tumor cells and tumor-infiltrating lymphocyte (TIL) density at baseline and after progression were determined by IHC. Tumor mutation burden (TMB) was determined by next-generation sequencing. RESULTS: The proportion of patients with a PD-L1 expression level of ≥50% (high) increased from 14% before to 28% after EGFR-TKI (P = 0.0010). Whereas CD8+ and FOXP3+ TIL densities were significantly lower after EGFR-TKI treatment than before, CD8+ TIL density was maintained in tumors with a high PD-L1 expression level. Expression of CD73 in tumor cells after EGFR-TKI treatment was higher than that before in patients with a high PD-L1 expression level. TMB tended to be higher after EGFR-TKI treatment than before (3.3→4.1 mutations/Mbp, P = 0.0508). Median progression-free survival for subsequent treatment with antibodies to PD-1 was longer for patients with a high than for those with a low PD-L1 expression after EGFR-TKI (7.1 vs. 1.7 months, P = 0.0033), and two of five patients whose PD-L1 expression level changed from low to high after EGFR-TKI treatment achieved a PFS of >6 months. CONCLUSIONS: EGFR-TKI treatment was associated with changes in the TME of EGFR-mutated NSCLC, and such changes may provide clues for optimization of subsequent PD-1 inhibitor treatment.

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are standard therapy for EGFR-mutant non-small cell lung cancer (NSCLC). Preclinically, HER3 ligand heregulin induces resistance to EGFR-TKIs, whereas the pan-human EGFR family inhibitor afatinib remains effective. Here, we examined whether soluble heregulin levels have clinical implications for EGFR-mutant NSCLC treated with EGFR-TKIs. Soluble heregulin was immunologically measured in plasma from EGFR-mutant NSCLC patients. Cutoff values were determined by 1-year PFS ROC curve. The relationship between soluble heregulin and PFS following EGFR-TKI therapy was analyzed by Cox proportional hazards model. Seventy-three patients were enrolled: 44 were treated with 1st-generation and 29 with 2nd-generation EGFR-TKIs. Soluble heregulin levels varied (range: 274-7,138 pg/mL, median: 739 pg/mL). Among patients treated with 1st-generation EGFR-TKIs, those with high heregulin (n = 20, >800 pg/mL) had a tendency for shorter PFS than those with low heregulin (n = 24, <800 pg/mL), with median PFS of 322 and 671 days, respectively. Cox proportional hazards model also indicated a trend toward resistance against 1st-generation EGFR-TKIs (HR: 1.825, 95% CI: 0.865-4.318) but not against 2nd-generation EGFR-TKIs. Soluble heregulin potentially correlates with resistance to EGFR-TKIs but not 2nd-generation EGFR-TKIs in patients with EGFR-mutant NSCLC.

HER2-targeted therapy, especially the anti-HER2 antibody trastuzumab, is standard for HER2-positive breast cancer; however, its efficacy is limited in a subpopulation of patients. HER3 ligand (heregulin)-dependent HER2-HER3 interactions play a critical role in the evasion of apoptosis and are therefore a target for oncotherapy to treat HER2-positive breast cancer. The anti-HER2 antibody pertuzumab and anti-HER3 antibody patritumab both target this heregulin-HER3-HER2 complex in different ways. This study examined the anticancer efficacy of dual HER2 and HER3 blockade in trastuzumab-resistant HER2-positive breast cancer. HER2-positive SKBR3 or BT474 cells overexpressing heregulin (SKBR3-HRG, BT474-HRG) were used to evaluate the efficacy of trastuzumab, pertuzumab, and patritumab in vitro by performing cell viability, immunoblotting, and clonogenic assays. The effects of these agents were then evaluated in vivo using BT474-HRG and an intrinsic heregulin-expressing and HER2-positive JIMT-1 xenograft models. SKBR3-HRG and BT474-HRG cells lost sensitivity to trastuzumab, which was accompanied by Akt activation. Unexpectedly, trastuzumab in combination with pertuzumab or patritumab also showed limited efficacy toward these cells. In contrast, trastuzumab/pertuzumab/patritumab triple treatment demonstrated potent anticancer efficacy, concomitant with strong repression of Akt. Finally, in heregulin-expressing BT474-HRG and JIMT-1 xenograft models, the addition of pertuzumab and patritumab to trastuzumab also enhanced antitumor efficacy leading to tumor regression. The current study found that triple blockade of HER2 and HER3 using trastuzumab, pertuzumab, and patritumab could overcome resistance to trastuzumab therapy in heregulin-expressing and HER2-positive breast cancer, which could be exploited clinically.

BACKGROUND: Overexpression of heregulin, a HER3 ligand, is one mechanism that confers resistance to the anti-HER2 agents trastuzumab and lapatinib. We investigated the impact of heregulin expression on the efficacy of HER2-targeted therapeutic agents, including trastuzumab, trastuzumab emtansine (T-DM1) and lapatinib, in vitro and in vivo and evaluated the heregulin messenger RNA (mRNA) levels in specimens from patients with HER2-positive breast or gastric cancer. RESULTS: Cell proliferation and apoptosis assays demonstrated that heregulin conferred robust resistance to lapatinib and trastuzumab via HER3-Akt pathway activation followed by survivin overexpression; however, heregulin conferred minimal or no resistance to T-DM1 and paclitaxel. The heregulin mRNA level of one of 10 patients was up-regulated after the acquisition of resistance to trastuzumab-based therapy. MATERIALS AND METHODS: SK-BR-3, NCI-N87, BT-474, MDA-MB-453, HCC1954, SNU-216 and 4-1ST cells were pharmacologically treated with recombinant heregulin or transfected with the heregulin gene. We also assessed the expression of heregulin mRNA in HER2-positive breast or gastric cancer samples before and after trastuzumab-based therapy using a RT-PCR-based method. CONCLUSIONS: mRNA up-regulation of heregulin was observed in clinical breast cancer specimens during trastuzumab-based treatment, but heregulin overexpression had a limited effect on the sensitivity to T-DM1 in vitro and in vivo.

Extramammary Paget's disease is a malignant intraepithelial carcinoma, which constitutes less than 1 % of all vulvar malignancies. Surgical resection is the first treatment of choice and standard chemotherapy has not been established for advanced or recurrent disease. Experimental and clinical studies have identified human epidermal growth receptor 2 as a potential therapeutic target. A 63-year-old male was referred for recurrent extramammary Paget's disease after surgery. Human epidermal growth receptor 2 was shown to be overexpressed and amplified by immunohistochemical analysis and fluorescence in situ hybridization analysis, respectively. After two cycles of trastuzumab monotherapy, all lymph node metastases decreased in size. However, he experienced recurrence in the lymph nodes during the seven courses of trastuzumab. As a subsequent treatment, trastuzumab was administered in combination with docetaxel and pertuzumab; clinical response was sustained for 12 months without significant adverse events.

We conducted a phase I study of a weekly nab-paclitaxel and S-1 combination therapy in patients with human epidermal growth factor receptor type 2-negative metastatic breast cancer. The primary objective was to estimate the maximum tolerated and recommended doses. Each treatment was repeated every 21 days. Levels 1, 2a, 2b, and 3 were set depending on the S-1 dose (65 or 80 mg/m(2) ) and nab-paclitaxel infusion schedule (days 1 and 8 or days 1, 8, and 15). Fifteen patients were enrolled. Dose-limiting toxicity was observed in one patient at Level 3 (100 mg/m(2) nab-paclitaxel on days 1, 8, and 15 with 80 mg/m(2) S-1 daily for 14 days, followed by 7 days of rest). Although the maximum tolerated dose was not reached, the recommended dose was determined to be Level 3. Neutropenia was the most frequent grade 3-4 treatment-related adverse event. For patients with measurable lesions, the response rate was 50.0% and the median time to treatment failure and median progression-free survival was 13.2 and 21.0 months, respectively. The present results show the feasibility and potential for long-term administration of this combination therapy.

Certain genetically defined cancers are dependent on a single overactive oncogene for their proliferation and survival, a phenomenon known as "oncogene addiction". A new generation of drugs that selectively target such "driver oncogenes" manifests a clinical efficacy greater than that of conventional chemotherapy in appropriate genetically defined patients. MET is a proto-oncogene that encodes a receptor tyrosine kinase, and aberrant activation of MET signaling occurs in a subset of advanced cancers as result of various genetic alterations including gene amplification, polysomy, and gene mutation. Our preclinical studies have shown that inhibition of MET signaling either with the small-molecule MET inhibitor crizotinib or by RNA interference targeted to MET mRNA resulted in marked antitumor effects in cancer cell lines with MET amplification both in vitro and in vivo. Furthermore, patients with non-small cell lung cancer or gastric cancer positive for MET amplification have shown a pronounced clinical response to crizotinib. Accumulating preclinical and clinical evidence thus suggests that MET amplification is an "oncogenic driver" and therefore a valid target for treatment. However, the prevalence of MET amplification has not been fully determined, possibly in part because of the difficulty in evaluating gene amplification. In this review, we provide a rationale for targeting this genetic alteration in cancer therapy.

BACKGROUND: Eribulin is a recently approved new therapeutic option for patients with metastatic breast cancer. According to several reports, eribulin has limited ability to cross the blood brain barrier. Recently, capecitabine and eribulin have been recognized as drugs with similar application for patients with advanced breast cancer. Although there have been several case reports describing the efficacy of capecitabine against brain metastases, no report of eribulin demonstrating efficacy for brain metastases exists today. CASE PRESENTATION: We describe a case of a 57-year-old Japanese woman who was diagnosed with breast cancer stage IV metastasized to multiple organs including liver and lung. After she received 3 regimens, she showed evidence of brain metastases, and whole brain radiation therapy was performed. Lapatinib and capecitabine was then administered as fourth-line chemotherapy, but the patient was hospitalized due to the exacerbation of interstitial pneumonitis and progression of brain and liver metastases. To control the systemic disease, eribulin was commenced as fifth-line chemotherapy. One month later, a significant response of brain metastases had been achieved, and this response has persisted for the last 4 months. We now describe a remarkable antitumor effect of eribulin against brain metastases from breast cancer. This case is the first report which indicates potential treatment of brain metastases using this medication. CONCLUSION: This report suggests that eribulin treatment may be beneficial for breast cancer patients with brain metastases progressing after whole brain radiation therapy. However, further clinical studies are warranted to determine the clinical effect of eribulin in brain metastases.