Published papers

Objectives: Several preclinical data proposed a potential efficacy of osimertinib, a third-generation EGFR tyrosine kinase inhibitor, for EGFR exon 20 insertion (EGFR ex20ins)-positive non-small cell lung cancer (NSCLC). However, reported case series and a retrospective study proposed controversial efficacy. The efficacy of osimertinib in EGFR ex20ins-positive NSCLC have not been well evaluated in prospective clinical trials. In this study, we performed a prospective, single-arm, multi-center, open-label, non-randomized phase I/II study to evaluate efficacy of osimertinib for EGFR ex20ins-positive NSCLC. Materials and methods: From August 2018 to January 2020, 14 NSCLC patients with EGFR ex20ins were enrolled, of whom 2 were excluded because they did not meet the inclusion criteria. Efficacy and safety of 80 mg osimertinib were evaluated. In addition, we performed a translational exploratory study to clarify the association of mutation type-specific drug sensitivity, osimertinib pharmacokinetic data, and clinical efficacy. Results: Of the evaluated patients, none experienced objective response, 7 experienced stable disease (58.3%), and 5 experienced disease progression (41.7%). The median progression free survival (PFS) was 3.8 months, and the median overall survival was 15.8 months. Interestingly, the exploratory study demonstrated statistically significant positive correlation between plasma osimertinib concentration/in vitro IC50 ratio and PFS (R = 0.9912, P = 0.0001), highlighting the mutation type-specific concentration-dependent efficacy of osimertinib for EGFR ex20ins-positive NSCLC. Conclusions: Regular dose, 80 mg/day, of osimertinib has limited clinical activity in NSCLC patients with EGFR ex20ins. The translational study proposed the potential efficacy of higher dose osimertinib in a subgroup of EGFR ex20ins-positive NSCLC.

In 2004, several groups reported the correlation between EGFR mutations and sensitivity to EGFR tyrosine kinase inhibitors (EGFR-TKIs). Since then, multiple EGFR-TKIs have been developed, improving the prognosis of advanced EGFR-mutated lung cancer patients. However, most patients with advanced EGFR mutation-positive lung cancer die of lung cancer in less than five years, highlighting the need for the further development of effective therapies. To develop effective inhibitors or treatment strategies, a basic understanding of EGFR-mutated lung cancer is essential. In particular, the knowledge of how EGFR mutations activate EGFR kinase and how sensitivity to EGFR-TKIs is determined is important. In this review, I will summarize the knowledge and propose clinical insight on how to translate this basic knowledge into a clinical setting.

Although the main cellular target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is thought to be alveolar cells, the absence of their tractable culture system precludes the development of a clinically relevant SARS-CoV-2 infection model. Here, we establish an efficient human alveolosphere culture method and sphere-based drug testing platform for SARS-CoV-2. Alveolospheres exhibit indolent growth in a Wnt- and R-spondin-dependent manner. Gene expression, immunofluorescence, and electron microscopy analyses reveal the presence of alveolar cells in alveolospheres. Alveolospheres express ACE2 and allow SARS-CoV-2 to propagate nearly 100,000-fold in 3 days of infection. Whereas lopinavir and nelfinavir, protease inhibitors used for the treatment of human immunodeficiency virus (HIV) infection, have a modest anti-viral effect on SARS-CoV-2, remdesivir, a nucleotide prodrug, shows an anti-viral effect at the concentration comparable with the circulating drug level. These results demonstrate the validity of the alveolosphere culture system for the development of therapeutic agents to combat SARS-CoV-2.

Background: Accurate prognostic understanding in patients with advanced cancer is essential for shared decision making; however, patients may experience psychological burden through knowing the incurable nature of advanced cancer. It has been unclear how their prognostic understanding fluctuates and whether accurate prognostic understanding is associated with psychological distress from the time of diagnosis over time. Materials and Methods: We longitudinally investigated prognostic understanding in 225 patients with newly diagnosed advanced lung cancer at 16 hospitals in Japan until 24 months after diagnosis. We examined associated factors with being consistently accurate in prognostic understanding, especially focusing on its association with psychological well-being. Results: The proportion of patients with an inaccurate prognostic understanding remained approximately 20% over time with the presence of patients with inconsistent understanding. Patients with consistently accurate prognostic understanding showed a significantly lower Emotional Well-Being subscale score at both 3 and 6 months after diagnosis (p =.010 and p =.014, respectively). In multivariate analyses, being consistently accurate in prognostic understanding was significantly associated with female gender and higher lung cancer–specific symptom burden at 3 months (p =.008 and p =.005, respectively) and lower emotional well-being at 6 months (p =.006). Conclusion: Although substantial proportions of patients with advanced lung cancer had inaccurate prognostic understanding from the time of diagnosis over time, patients with consistently accurate prognostic understanding experienced greater psychological burden. Our findings highlight the importance of continuous psychological care and support for patients who understand their severe prognosis accurately. Implications for Practice: This study demonstrated that approximately 20% of patients with advanced lung cancer had an inaccurate understanding about their prognosis, not only at the time of diagnosis but also at the later time points. Being consistently accurate in prognostic understanding was significantly associated with elevated levels of psychological distress. Although accurate prognostic understanding is essential for decision making for treatment and advance care planning, health care providers should be aware of psychological burdens in patients that accept their severe prognosis accurately. Appropriate care and support for such patients are warranted from diagnosis over time.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes the disease COVID-19 can lead to serious symptoms, such as severe pneumonia, in the elderly and those with underlying medical conditions. While vaccines are now available, they do not work for everyone and therapeutic drugs are still needed, particularly for treating life-threatening conditions. Here, we showed nasal delivery of a new, unmodified camelid single-domain antibody (VHH), termed K-874A, effectively inhibited SARS-CoV-2 titers in infected lungs of Syrian hamsters without causing weight loss and cytokine induction. In vitro studies demonstrated that K-874A neutralized SARS-CoV-2 in both VeroE6/TMPRSS2 and human lung-derived alveolar organoid cells. Unlike other drug candidates, K-874A blocks viral membrane fusion rather than viral attachment. Cryo-electron microscopy revealed K-874A bound between the receptor binding domain and N-terminal domain of the virus S protein. Further, infected cells treated with K-874A produced fewer virus progeny that were less infective. We propose that direct administration of K-874A to the lung could be a new treatment for preventing the reinfection of amplified virus in COVID-19 patients.

Background: Both advanced cancer patients and their family caregivers experience distress and have a range of concerns after cancer diagnosis. However, longitudinal studies on this topic have been lacking. Aim: To investigate concerns in both patients with advanced lung cancer and their family caregivers longitudinally from diagnosis. Design: A multi-center prospective questionnaire-based study. Setting/participants: We recruited patients with newly diagnosed advanced lung cancer and their family caregivers at 16 hospitals in Japan. We prospectively assessed the prevalence of their concerns using the Concerns Checklist and investigated the associations between their concerns and mental status as well as quality of life until 24 months after diagnosis. Results: A total of 248 patients and their 232 family caregivers were enrolled. The prevalence of serious concerns was highest at diagnosis (patients: 68.3%, family caregivers: 65.3%). The most common serious concern was concern about the future in both groups at diagnosis (38.2% and 40.5%, respectively) and this remained high in prevalence over time, while the high prevalence of concern about lack of information improved 3 months after diagnosis in both groups. Approximately one-third of patient-family caregiver dyads had discrepant reports of serious concerns. The presence of serious concerns was significantly associated with anxiety and depression continuously in both groups. Conclusions: The majority of advanced lung cancer patients and their family caregivers have serious concerns from diagnosis, which is associated with their psychological distress. The spectrum of concerns alters over the disease trajectory, warranting efficient tailored care and support for both groups immediately after diagnosis.

Transdifferentiation of lung adenocarcinoma to small cell lung cancer (SCLC) has been reported in a subset of lung cancer cases that bear EGFR mutations. Several studies have reported the prerequisite role of TP53 and RB1 alterations in transdifferentiation. However, the mechanism underlying transdifferentiation remains understudied, and definitive additional events, the third hit, for transdifferentiation have not yet been identified. In addition, no prospective experiments provide direct evidence for transdifferentiation. In this study, we show that FGF9 upregulation plays an essential role in transdifferentiation. An integrative omics analysis of paired tumor samples from a patient with transdifferentiated SCLC exhibited robust upregulation of FGF9. Furthermore, FGF9 upregulation was confirmed at the protein level in four of six (66.7%) paired samples. FGF9 induction transformed mouse lung adenocarcinoma-derived cells to SCLC-like tumors in vivo through cell autonomous activation of the FGFR pathway. In vivo treatment of transdifferentiated SCLC-like tumors with the pan-FGFR inhibitor AZD4547 inhibited growth. In addition, FGF9 induced neuroendocrine differentiation, a pathologic characteristic of SCLC, in established human lung adenocarcinoma cells. Thus, the findings provide direct evidence for FGF9-mediated SCLC transdifferentiation and propose the FGF9–FGFR axis as a therapeutic target for transdifferentiated SCLC.

© 2020 The Authors The development of molecular targeted therapy has improved clinical outcomes in patients with life-threatening advanced lung cancers with driver oncogenes. However, selective treatment for KRAS-mutant lung cancer remains underdeveloped. We have successfully characterised specific molecular and pathological features of KRAS-mutant lung cancer utilising newly developed cell line models that can elucidate the differences in driver oncogenes among tissues with identical genetic backgrounds. Among these KRAS-mutation-associated specific features, we focused on the IGF2-IGF1R pathway, which has been implicated in the drug resistance mechanisms to AMG 510, a recently developed selective inhibitor of KRAS G12C lung cancer. Experimental data derived from our cell line model can be used as a tool for clinical treatment strategy development through understanding of the biology of lung cancer. The model developed in this paper may help understand the mechanism of anticancer drug resistance in KRAS-mutated lung cancer and help develop new targeted therapies to treat patients with this disease.

Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Cancer-associated fibroblasts (CAFs) are known to promote tumourigenesis through various mechanisms. Fibroblast growth factor (FGF)/FGF receptor (FGFR)-dependent lung cancers have been described. We have developed a mouse model of lung adenocarcinoma that was constructed through the induction of Fgf9 overexpression in type 2 alveolar cells. The expression of Fgf9 in adult lungs resulted in the rapid development of multiple adenocarcinoma-like tumour nodules. Here, we have characterised the contribution of CAFs and the Fgf/Fgfr signalling pathway in maintaining the lung tumours initiated by Fgf9 overexpression. We found that CAF-secreted Fgf2 contributes to tumour cell growth. CAFs overexpressed Tgfb, Mmp7, Fgf9, and Fgf2; synthesised more collagen, and secreted inflammatory cell-recruiting cytokines. CAFs also enhanced the conversion of tumour-associated macrophages (TAMs) to the tumour-supportive M2 phenotype but did not influence angiogenesis. In vivo inhibition of Fgfrs during early lung tumour development resulted in significantly smaller and fewer tumour nodules, whereas inhibition in established lung tumours caused a significant reduction in tumour size and number. Fgfr inhibition also influenced tumour stromal cells, as it significantly abolished TAM recruitment and reduced tumour vascularity. However, the withdrawal of the inhibitor caused a significant recurrence/regrowth of Fgf/Fgfr-independent lung tumours. These recurrent tumours did not possess a higher proliferative or propagative potential. Our results provide evidence that fibroblasts associated with the Fgf9-induced lung adenocarcinoma provide multiple means of support to the tumour. Although the Fgfr blocker significantly suppressed the tumour and its stromal cells, it was not sufficient to completely eliminate the tumour, probably due to the emergence of alternative (resistance/maintenance) mechanism(s). This model represents an excellent tool to further study the complex interactions between CAFs, their related chemokines, and the progression of lung adenocarcinoma; it also provides further evidence to support the need for a combinatorial strategy to treat lung cancer. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. Background: No consensus has been reached regarding the treatment order and timing of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) and cytotoxic chemotherapy administration for EGFR mutation-positive non-small cell lung cancer (NSCLC) patients. Methods: In this phase II trial, chemotherapy-naïve patients harboring activating EGFR mutations with stage IIIB/IV or post-surgical recurrent non-squamous NSCLC were enrolled. Patients were treated with erlotinib induction at 150 mg/day for 3 months. This was followed by cytotoxic chemotherapy with platinum plus pemetrexed, with or without bevacizumab, when the induction erlotinib achieved a CR or PR. The primary end point was the 1-year progression-free survival (PFS) rate, while the secondary end points were the response rate (RR), PFS, safety, and overall survival (OS). Results: Twenty patients were enrolled in this study. The median age was 63 years. Eighteen patients had stage IV disease, and 2 patients had recurrent disease. Eleven patients achieved a PR after induction of erlotinib and 9 out of 11 patients were switched to chemotherapy. The 1-year PFS rate was 45.0% (90% CI 26.8–63.2), the overall RR was 55.0%, and the median PFS was 10.7 months in the intention-to-treat (ITT) population. Grade 3–4 adverse events were reported for 40% of the patients, including patients with leukopenia (10%), neutropenia (20%), and interstitial pneumonitis, bacterial pneumonia, rash, and nausea (all 5%). Conclusions: The primary end point of this study was not achieved. However, the therapy was well tolerated and may be a treatment option for a future study with patients responsive to short-term erlotinib treatment. Clinical trials registration number: UMIN ID: 000013125.

© AlphaMed Press 2018 Background: Prognostic understanding in advanced cancer patients and their caregivers may have an impact on the delivery of effective care. The aims of this study were to explore prognostic understanding at diagnosis in both patients with advanced lung cancer and their caregivers and to investigate correlates of their understanding. Subjects, Materials, and Methods: A total of 193 patients with newly diagnosed advanced lung cancer and their 167 caregivers were enrolled at 16 hospitals in Japan. We assessed their perceptions of prognosis and goals of therapy and examined their associations with their sociodemographic characteristics, clinical status, quality of life, mood symptoms, and the status of disclosure of information by their treating physicians. Results: One fifth of patients and caregivers (21.7% and 17.6%, respectively) mistakenly believed that the patients’ cancer was “completely curable.” Substantial proportions of them (16.9% and 10.3%, respectively) mistakenly believed that the primary goal of therapy was to remove all the cancer. Levels of anxiety and depression in both patients and caregivers were significantly higher among those who had accurate understanding of prognosis. In multivariate analyses, inaccurate perceptions of prognosis in patients were associated with sex, better emotional well-being, and lower lung cancer-specific symptom burden. Caregivers’ inaccurate perceptions of patients’ prognoses were associated with better performance status and better emotional well-being of patients. Conclusion: Substantial proportions of advanced lung cancer patients and their caregivers misunderstood their prognosis. Interventions to improve their accurate prognostic understanding should be developed with careful attention paid to its associated factors. Implications for Practice: This study demonstrated that substantial proportions of patients with newly diagnosed advanced lung cancer and their caregivers had misunderstandings about their prognosis. Accurate perceptions of prognosis, which are indispensable in the delivery of effective care, were associated with elevated levels of anxiety and depression in both patients and caregivers, warranting psychosocial care and support for them immediately after diagnosis. Inaccurate perceptions of prognosis in patients were associated with better emotional well-being and lower lung cancer-specific symptom burden. Illness understanding in caregivers was associated with patients’ physical and mental status. Those findings provide insight into how they obtain accurate illness understanding.

© 2019 American Association for Cancer Research. Despite the worldwide approval of three generations of EGFR tyrosine kinase inhibitors (TKI) for advanced non- small cell lung cancers with EGFR mutations, no TKI with a broad spectrum of activity against all clinically relevant mutations is currently available. In this study, we sought to evaluate a covalent mutation-specific EGFR TKI, TAS6417 (also named CLN-081), with the broadest level of activity against EGFR mutations with a prevalence of ≥1%. Lung cancer and genetically engineered cell lines, as well as murine xenograft models were used to evaluate the efficacy of TAS6417 and other approved/in-development EGFR TKIs (erlotinib, afatinib, osimertinib, and poziotinib). We demonstrate that TAS6417 is a robust inhibitor against the most common EGFR mutations (exon 19 deletions and L858R) and the most potent against cells harboring EGFR-T790M (first/second-generation TKI resistance mutation). In addition, TAS6417 has activity in cells driven by less common EGFR-G719X, L861Q, and S768I mutations. For recalcitrant EGFR exon 20 insertion mutations, selectivity indexes (wildtype EGFR/mutant EGFR ratio of inhibition) favored TAS6417 in comparison with poziotinib and osimertinib, indicating a wider therapeutic window. Taken together, we demonstrate that TAS6417 is a potent EGFR TKI with a broad spectrum of activity and a wider therapeutic window than most approved/in-development generations of EGFR inhibitors.

© 2020 American Association for Cancer Research. EGFR-mutated lung cancer accounts for a significant proportion of lung cancer cases worldwide. For these cases, osimertinib, a thirdgeneration EGFR tyrosine kinase inhibitor, is extensively used as a first-line or second-line treatment. However, lung cancer cells acquire resistance to osimertinib in 1 to 2 years. Thus, a thorough clarification of resistance mechanisms to osimertinib is highly anticipated. Recent next-generation sequencing (NGS) of lung cancer samples identified several genetically defined resistance mechanisms to osimertinib, such as EGFR C797S or MET amplification. However, nongenetically defined mechanisms are not well evaluated. For a thorough clarification of osimertinib resistance, both genetic and nongenetic mechanisms are essential. By using our comprehensive protein phosphorylation array, we detected IGF1R bypass pathway activation after EGFR abolishment. Both of our established lung cancer cells and patient-derived lung cancer cells demonstrated IGF2 autocrine-mediated IGF1R pathway activation as a mechanism of osimertinib resistance. Notably, this resistance mechanism was not detected by a previously performed NGS, highlighting the essential roles of living cancer cells for a thorough clarification of resistance mechanisms. Interestingly, the immunohistochemical analysis confirmed the increased IGF2 expression in lung cancer patients who were treated with osimertinib and met the established clinical definition of acquired resistance. The findings highlight the crucial roles of cell-Autonomous ligand expression in osimertinib resistance. Here, we report for the first time the IGF2 autocrine-mediated IGF1R activation as a nongenetic mechanism of osimertinib resistance in lung cancer at a clinically relevant level.