Urinary Retention Suggesting Aseptic Meningitis: Meningitis-Retention Syndrome Without Physical Signs of Meningeal Irritation

Meningitis-retention syndrome (MRS) is the combination of aseptic meningitis and acute urinary retention that occurs in the absence of other neurological diseases. The cause(s) of MRS remain unclear. A 57-year-old Japanese woman was referred to our hospital for the evaluation of persistent fever and headache. The fever's cause was initially unclear, but the presence of urinary retention raised concern about possible aseptic meningitis despite no physical indications of meningeal irritation. Only typical cases of MRS have been reported thus far to our knowledge, and it is important that clinicians are aware of MRS when it presents in this atypical form.

VEGFR2 blockade augments the effects of tyrosine kinase inhibitors by inhibiting angiogenesis and oncogenic signaling in oncogene-driven non-small-cell lung cancers

Molecular agents targeting the epidermal growth factor receptor (EGFR)-, anaplastic lymphoma kinase (ALK)- or c-ros oncogene 1 (ROS1) alterations have revolutionized the treatment of oncogene-driven non-small-cell lung cancer (NSCLC). However, the emergence of acquired resistance remains a significant challenge, limiting the wider clinical success of these molecular targeted therapies. In this study, we investigated the efficacy of various molecular targeted agents, including erlotinib, alectinib, and crizotinib, combined with anti-vascular endothelial growth factor receptor (VEGFR) 2 therapy. The combination of VEGFR2 blockade with molecular targeted agents enhanced the anti-tumor effects of these agents in xenograft mouse models of EGFR-, ALK-, or ROS1-altered NSCLC. The numbers of CD31-positive blood vessels were significantly lower in the tumors of mice treated with an anti-VEGFR2 antibody combined with molecular targeted agents compared with in those of mice treated with molecular targeted agents alone, implying the antiangiogenic effects of VEGFR2 blockade. Additionally, the combination therapies exerted more potent antiproliferative effects in vitro in EGFR-, ALK-, or ROS1-altered NSCLC cells, implying that VEGFR2 inhibition also has direct anti-tumor effects on cancer cells. Furthermore, VEGFR2 expression was induced following exposure to molecular targeted agents, implying the importance of VEGFR2 signaling in NSCLC patients undergoing molecular targeted therapy. In conclusion, VEGFR2 inhibition enhanced the anti-tumor effects of molecular targeted agents in various oncogene-driven NSCLC models, not only by inhibiting tumor angiogenesis but also by exerting direct antiproliferative effects on cancer cells. Hence, combination therapy with anti-VEGFR2 antibodies and molecular targeted agents could serve as a promising treatment strategy for oncogene-driven NSCLC.

Dacomitinib as a retreatment for advanced non-small cell lung cancer patient with an uncommon EGFR mutation

In non‐small cell lung cancer (NSCLC), uncommon epidermal growth factor receptor (EGFR) mutations are mutations other than Ex19 deletion and Ex21 L858R, which are common mutations highly sensitive to EGFR‐tyrosine kinase inhibitors. Afatinib, a second‐generation EGFR‐tyrosine kinase inhibitor, has been shown to be effective in patients with uncommon mutations. Dacomitinib, another second‐generation EGFR‐tyrosine kinase inhibitor, has not previously been shown to be effective in patients with uncommon mutations. Here, we report the efficacy of dacomitinib for uncommon EGFR mutations in a 71‐year‐old woman diagnosed with metastatic lung adenocarcinoma with uncommon EGFR mutation (Ex18 G719A). Afatinib was administered as the first‐line treatment, and a remarkable antitumor effect was observed. However, the tumor grew after 14 months. Pemetrexed plus carboplatin followed by pemetrexed, docetaxel, atezolizumab and S‐1 were performed in sequence. Although approximately four years had passed since the start of treatment, her physical condition was good. The patient started dacomitinib as the sixth‐line treatment. Lesions were markedly reduced and treatment with dacomitinib was continued for 7.8 months. Dacomitinib is a possible treatment option for NSCLC with uncommon mutations.

Beneficial effect of erlotinib and trastuzumab emtansine combination in lung tumors harboring EGFR mutations

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) is the standard therapy for non-small cell lung cancer (NSCLC) harboring EGFR mutations, but the resistance is inevitable. The drug-tolerant persister cancer cells are thought to be involved in the resistance. We recently reported that HER2 expression had a negative impact on time-to-treatment-failure in patients with EGFR mutant NSCLC. In this study, we hypothesized that HER2 might be a potential target for alternative combination therapy in NSCLC harboring EGFR mutations. In vitro study showed that the level of HER2 expression had no correlation with the sensitivity to EGFR-TKI, erlotinib but showed some correlation with HER2-inhibitor, ado-trastuzumab emtansine (T-DM1) in multiple EGFR-mutant lung cancer cell lines. In addition, HER2 expression was increased in persister cancer cells in 11-18 cell line harboring EGFR L858R or HCC827 cell line harboring EGFR exon 19 deletion after the exposure to erlotinib in vitro and in vivo. The combination of erlotinib and T-DM1 showed a superior inhibitory effect on cell proliferation compared with those of the erlotinib or T-DM1 alone in either 11-18 or HCC827 cells in vitro. The combination therapy also induced a significantly greater inhibitory effect on tumor growth in xenograft model in mice transplanted with either 11-18 or HCC827 cells compared with erlotinib alone or T-DM1 alone. No body weight loss was observed in these mice. These results suggested that the combination therapy with EGFR-TKI and T-DM1 might be a potentially promising strategy for treating lung cancer harboring EGFR mutations.

Utility of immune checkpoint inhibitors in non-small-cell lung cancer patients with poor performance status

Most clinical trials of non‐small‐cell lung cancer (NSCLC) exclude patients with poor ECOG performance status (PS). Thus, the efficacy of immune checkpoint inhibitors (ICIs) in patients with poor PS remains unclear. Herein, we used data from a retrospective cohort to assess the potential clinical benefits of ICIs in NSCLC patients with poor PS. Data from NSCLC patients who received ICI monotherapy at 9 institutions between December 2015 and May 2018 were retrospectively analyzed. After excluding 4 patients who lacked PS data, a total of 527 ICI‐treated patients, including 79 patients with PS 2 or higher, were used for our analyses. The progression‐free survival (PFS) and overall survival (OS) of patients with PS 2 or higher were significantly shorter compared with those of PS 0‐1 patients (median PFS, 4.1 vs 2.0 months; P < .001 and median OS, 17.4 vs 4.0 months; P < .001). Among NSCLC patients with programmed cell death protein‐ligand 1 (PD‐L1) expression of 50% or higher who were treated with pembrolizumab as first‐line therapy, the median PFS times of patients with PS 2 and 0‐1 were 7.3 and 8.1 months, respectively. There was no significant difference in PFS between patients with PS 2 and 0‐1 (P = .321). Although poor PS was significantly associated with worse outcomes in NSCLC patients treated with ICIs, pembrolizumab as a first‐line treatment in NSCLC patients expressing high levels of PD‐L1 could provide a clinical benefit, even in patients with PS 2.

Deterioration of high-resolution computed tomography findings predicts disease progression after initial decline in forced vital capacity in idiopathic pulmonary fibrosis patients treated with pirfenidone

BACKGROUND

Pirfenidone suppresses the decline of forced vital capacity (FVC) in patients with idiopathic pulmonary fibrosis (IPF). However, IPF progresses in some patients despite treatment. We analyzed patients with meaningful FVC declines during pirfenidone treatment and explored the factors predictive of disease progression after FVC decline.

METHODS

This study was a retrospective, multicenter, observational study conducted by the Okayama Respiratory Disease Study Group. We defined initial decline in %FVC as 5% or greater per 6-month period during pirfenidone treatment. IPF patients who were treated with pirfenidone and experienced an initial decline from December 2008 to September 2017 were enrolled.

RESULTS

We analyzed 21 patients with IPF. After the initial decline, 4 (19.0%) patients showed improvement in disease, 11 (52.4%) showed stable disease, and 6 (28.6%) showed progressive disease. There was no significant correlation between %FVC reduction on initial decline and subsequent %FVC change (p = 0.475). Deterioration of high-resolution computed tomography (HRCT) findings on initial decline was observed significantly more often in the progressive versus improved/stable disease groups (100% vs 20.0%, p = 0.009).

CONCLUSIONS

We revealed that deterioration of HRCT findings may predict disease progression after the initial decline in %FVC in IPF patients treated with pirfenidone.

Rapidly Progressive Acute Kidney Injury Associated with Nivolumab Treatment

A 63-year-old man with pulmonary adenocarcinoma was treated with nivolumab. High fever developed within several hours after the first administration of nivolumab; subsequently, serum creatinine levels kept increasing daily. We diagnosed acute kidney injury (AKI) as an immune-related adverse event; the patient was initially treated with 50 mg prednisolone, and the dose was then tapered. Renal biopsy pathologically revealed tubulointerstitial inflammation with strong infiltration of only T cells that were CD3⁺, CD4⁺, and CD8⁺. The infiltration of CD163⁺ M2 macrophage was also observed. AKI within 1 week after the administration of nivolumab seems to be rare; therefore, the present case provides important findings useful in daily clinical practice.

Pilot evaluation of a HER2 testing in non-small-cell lung cancer

AIMS

HER2-positivity pattern in the specimens of immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH) has been hardly reported in non-small-cell lung cancer (NSCLC).

METHODS

We evaluated the characteristics of HER2-positivity pattern in formalin-fixed paraffin-embedded samples using IHC and FISH in 15 patients enrolled in a larger prospective cohort study to survey a HER2-positive NSCLC.

RESULTS

As for the immunostaining pattern, most specimens (79%) demonstrated incomplete or mixed-typed membranous immunoreactivity with heterogeneity, resembling that observed in gastric cancer rather than breast cancer. Concordance between IHC-positivity and FISH-positivity was 87.5% according to the criteria for breast cancer scoring system. On application of the gastric cancer scoring system to the examined tumours, the IHC score increased in the seven (43.8%) specimens, and the concordance between IHC positivity and FISH positivity rose to 93.8%.

CONCLUSIONS

In our pilot series, the pattern of IHC reactivity closely resembled that observed in gastric cancer rather than breast cancer.

TRIAL REGISTRATION NUMBER

000017003.

Clinical Characteristics of Severe Refractory Asthma Associated with the Effectiveness of Bronchial Thermoplasty

We investigated the clinical characteristics of refractory asthma associated with the effectiveness of bronchial thermoplasty (BT). We retrospectively evaluated data from 10 patients who underwent BT between June 2016 and December 2017 at Okayama Medical Center. The following were measured before and 6 months post-BT: forced expiratory volume in 1.0 s (FEV1), fractional exhaled nitric oxide (FeNO), immunoglobulin E (IgE) level, blood eosinophil counts (Eosi), Asthma Quality of Life Questionnaire (AQLQ) score, and preventive medication use. At baseline, the mean post-bronchodilator FEV1 was 80.9% of the predicted value (range 45.6-115.7%). All patients were being treated with moderate- or high-dose inhaled corticosteroids and long-acting β2 agonists. The AQLQ improved from 4.26±1.67 at baseline to 5.59±0.94 at 6 months post-BT (p<0.05). The %FEV1, FeNO, IgE, and Eosi did not change significantly between baseline and 6 months post-BT. No severe complications were reported. BT was effective for non-allergic and non-eosinophilic in 3 patients, and allergic or eosinophilic in 4 patients. Their AQLQ improved by > 0.5 points post-BT. For both allergic and eosinophilic asthmatics following mepolizumab, BT was not useful. BT was effective for non-allergic and non-eosinophilic or allergic asthmatics, but insufficient for both allergic and eosinophilic following mepolizumab.

Bilateral Testicular Metastases from Lung Adenocarcinoma Showing an Objective Response to Nivolumab: A Case Report and Review of the Literature

A 69-year-old man who had undergone chemoradiotherapy for advanced pulmonary adenocarcinoma had bilateral testicular and adrenal gland masses on a routine follow-up examination. We performed left orchiectomy, and the histopathological examination confirmed metastatic pulmonary adenocarcinoma involving the extracted testis. He was treated for disease progression with nivolumab after unsuccessful cytotoxic chemotherapy, which resulted in regression of recurrent adrenal and right testicular tumors. We reviewed the existing literature on metastatic testicular tumors and found that testicular metastasis from lung cancer is rare and poses a chemotherapeutic challenge. Based on our experience, immune checkpoint inhibitors seem to have good efficacy for treating testicular metastasis.

EGFR-TKI acquired resistance in lung cancers harboring EGFR mutations in immunocompetent C57BL/6J mice

OBJECTIVES

Lung cancers harboring epidermal growth factor receptor (EGFR) mutations inevitably develop resistance to EGFR tyrosine-kinase inhibitors (EGFR-TKIs). Therefore, we sought to establish clinically relevant lung-cancer mouse models to achieve deep remission of cancers.

MATERIALS AND METHODS

We previously established two transgenic lung-cancer mouse models harboring human EGFR exon 21 L858R substitution (hLR) and mouse Egfr exon 19 deletion (mDEL) in the C57BL/6 J background. Lung tumors from these two transgenic mouse strains were transplanted subcutaneously into BALB/c-nunu mice or C57BL/6 J mice.

RESULTS

The transplanted tumors developed the ability to grow on the subcutaneous tissue, peritoneum, or lung of C57BL/6 J mice. While hLR tumors could grow only in C57BL/6 J mice carrying the transgene, mDEL tumors could grow in wild-type C57BL/6 J mice. The tumors maintained EGFR-dependency, and, thus, the EGFR-TKI gefitinib inhibited tumor growth; however, similar to human lung cancers, hLR and mDEL tumors acquired resistance in 60 and 200 days, respectively, following gefitinib administration. Secondary EGFR T790 M mutation in hLR tumors and secondary Egfr T792I mutation in mDEL tumors developed; however, no MET activation was detected. Accordingly, the third-generation EGFR-TKI osimertinib effectively inhibited gefitinib-resistant tumors in vivo. Furthermore, gefitinib-resistant tumors developed resistance to osimertinib in 100 days.

CONCLUSION

These syngeneic lung-cancer mouse models harboring EGFR mutations are suitable for studying the drug-resistance mechanisms and the role of the tumor microenvironment. Further investigation with these mouse models is warranted for developing next-generation treatment strategies for lung cancer.

Transoesophageal ultrasound-guided bronchoscopic aspiration of a superior mediastinal tumour using the BF-UC290F instrument

A 46-year-old male with a superior mediastinal mass presented with a one-month history of hoarseness and chest pain and was referred to our hospital. Although endobronchial, ultrasound-guided, transbronchial needle aspiration (EBUS-TBNA) was initially performed, we could not obtain an adequate specimen because of his severe cough and an inadequate EBUS view. During the same endoscopic session, we performed endoscopic, ultrasound-guided, bronchoscopic fine-needle aspiration (EUS-B-FNA) via a transoesophageal approach using the BF-UC290F (Olympus, Tokyo, Japan), a third-generation EBUS-TBNA endoscope. The BF-UC290F enabled smooth access through the oesophagus and a clear EBUS view of the mass, attributable, respectively, to the compact distal tip and the powerful angulation. Rapid on-site cytology revealed that an adequate specimen had been obtained, and we terminated the procedure without inducing a severe cough. Histologically, the mass was a squamous cell carcinoma. EUS-B-FNA employing the BF-UC290F was useful to diagnose the superior mediastinal mass.

Impact of HER2 aberrations on EGFR-TKI treatment outcomes in lung tumors harboring EGFR mutations: A HER2-CS STUDY subset analysis

9056

Background: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are a key treatment for EGFR-mutated non-small-cell lung carcinoma (NSCLC). To date, a biomarker to predict whether NSCLC will exhibit a short- or long-term response to first- or second-generation EGFR-TKIs has not been established for clinical use. Human epidermal growth factor receptor-2 (HER2) aberrations are mechanisms for acquired resistance to EGFR-TKIs; however, their impact on EGFR-TKI therapy outcomes in EGFR-mutant NSCLC has not yet been systematically evaluated. Methods: Patients with advanced NSCLC were prospectively registered from more than 35 institutes (HER2-CS STUDY UMIN 000017003). EGFR mutations or anaplastic lymphoma kinase gene translocations were assessed at each institution using a commercially approved test. HER2 protein expression levels were determined by immunohistochemistry (IHC) using the Ventana I-VIEW PATHWAY anti-HER-2/neu (4B5). The IHC status scoring system applied to gastric cancer was used. Results: Of 1,126 screened patients with NSCLC, 354 (31.8%) had EGFR-mutated tumors, and the HER2 protein statuses were as follows: IHC0 (n = 71, 26%), IHC1+ (n = 148, 53%), IHC2+ (n = 51, 18%), and IHC3+ (n = 7, 3%). The patients’ demographics were almost identical in those with lung tumors harboring EGFR mutations and HER2-IHC2+/3+ (group P) or EGFR mutations and HER2-IHC0/1 (group N). The EGFR-TKI response rates were not different between these groups (Table). However, group P showed significantly shorter time to EGFR-TKI treatment failure than group N (median 19.1 vs. 13.3 months; log rank p = 0.038). Conclusions: These data from a large prospective cohort show that HER2 protein expression in EGFR-mutant NSCLC may have a negative impact on the effect of EGFR-TKIs. A clinical trial of EGFR/HER2-TKIs (e.g., afatinib) is warranted for this population. [Table: see text]

Rapidly Progressive Multiple Cavity Formation in Necrotizing Pneumonia Caused by Community-acquired Methicillin-resistant Staphylococcus aureus Positive for the Panton-Valentine Leucocidin Gene

A 66-year-old man was transferred to our hospital for pneumonia that was resistant to sulbactam/ampicillin and levofloxacin therapy. Chest computed tomography showed the rapidly progressive formation of multiple cavities. Methicillin-resistant Staphylococcus aureus (MRSA) was isolated, and the patient was diagnosed with necrotizing pneumonia caused by community-acquired MRSA (CA-MRSA). The MRSA strain had type IV staphylococcus cassette chromosome mec and genes encoding Panton-Valentine leucocidin (PVL). CA-MRSA necrotizing pneumonia with the PVL gene is rare; only three cases have been previously reported in Japan. We administered anti-MRSA antibiotics and the patient achieved complete clinical and radiological improvement.

Success of Crizotinib Combined with Whole-Brain Radiotherapy for Brain Metastases in a Patient with Anaplastic Lymphoma Kinase Rearrangement-Positive Non-Small-Cell Lung Cancer

Although crizotinib shows marked antitumor activity in anaplastic lymphoma kinase (ALK) rearrangement-positive non-small-cell lung cancer (NSCLC) patients, all treated patients ultimately develop resistance to this drug. Isolated central nervous system failure without progression at extracranial sites is a common progression pattern in ALK rearrangement-positive NSCLC patients treated with crizotinib. Here, we report the success of crizotinib combined with whole-brain radiotherapy in an ALK rearrangement-positive NSCLC patient who developed leptomeningeal carcinomatosis and progression of multiple brain metastases. Additionally, we focused on the mechanism involved by examining the plasma and cerebrospinal fluid concentrations of crizotinib in the present case.

Effectiveness of benralizumab for allergic and eosinophilic predominant asthma following negative initial results with omalizumab

A 64-year-old woman, who had presented with a 30-year history of refractory asthma, and been treated with anti-allergic drug therapy, inhaled corticosteroids, a long-acting beta-agonist, and a long-acting muscarinic antagonist. She had been characterized as an allergic, eosinophilic asthmatic. Although omalizumab was tried initially, it was found to be insufficient. We began treatment with benralizumab. The asthma symptom control and sinusitis were improved immediately. Benralizumab was effective for overlapping patient population following negative initial results with omalizumab.

Pembrolizumab-induced Autoimmune Hemolytic Anemia and Hemophagocytic Lymphohistiocytosis in Non-small Cell Lung Cancer

We herein report a 78-year old man with squamous cell carcinoma of the lungs treated with pembrolizumab. At 10 days after the administration of pembrolizumab, he showed progressive anemia and increased levels of bilirubin. Because the findings of a direct coombs test and cold hemagglutinin were positive, we diagnosed the patient with autoimmune hemolytic anemia and treated him with prednisolone. Subsequently, he was admitted to our hospital owing to fatigue, a high fever, and jaundice. His clinical findings met the diagnostic criteria of hemophagocytic lymphohistiocytosis, and he was rescued with a high dose of glucocorticoids. Marked tumor regression was obtained and has been maintained since then.

Comparing the Clinical Performance of the New 19-G ViziShot FLEX and 21- or 22-G ViziShot 2 Endobronchial Ultrasound-guided Transbronchial Needle Aspiration Needles

Objective Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive procedure for pulmonary and mediastinal diseases. This study compared the performance of a novel 19-G needle with a 21- or 22-G needle. Patients and Methods Eleven patients at Okayama Medical Center were enrolled retrospectively between April and December 2017. Enlarged lymph nodes and a pulmonary nodule were sampled with both 19-G and 21- or 22-G needles in nine patients. Two patients underwent biopsies for suspected lymphoma with only the 19-G needle. We examined their medical records on the diagnosis, size of the lymph nodes and pulmonary nodule, and complications. Results The median longest diameter of the 13 lymph nodes (8 #7, 4 #4R, and 1 #11) and 1 pulmonary nodule (right segment 6) in the 11 patients was 31.6 mm (range, 10.4-45.0 mm). Definitive diagnoses were made using the 19-G needle in nine patients. EBUS-TBNA with a 19-G needle resulted in successful diagnoses of one case of retinal hemangioblastoma, one case of tuberculous lymphadenitis, and one case of lung adenocarcinoma, as well as the evaluation of the programmed death-ligand 1 (PD-L1) expression following initial negative findings after a 21- or 22-G biopsy. A small pulmonary nodule (lung squamous cell carcinoma) with negative findings after a 19-G biopsy was diagnosed with a 22-G biopsy. Two suspected lymphoma patients were diagnosed with a 19-G needle: one had lymphoma and the other sarcoidosis. Three patients were diagnosed with sarcoidosis using both the 19-G and 21- or 22-G needles. Conclusion EBUS-TBNA with a 19-G needle was useful for diagnosing retinal hemangioblastoma and tuberculous lymphadenitis as well as for PD-L1 testing after 21- and 22-G biopsies were unsuccessful.

Abstract 1160: The novel osimertinib resistant lung cancer mice model harboring EGFR mutations driven by the SP-C promoter

Background: Discovery of driver mutations has drastically changed clinical practice in patients with lung tumors. Management of lung tumors with appropriated oncoprotein inhibitors is a key for longer survival. Osimertinib is an irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) and the new compound changed the standard treatment for non-small-cell lung cancer (NSCLC) harboring EGFR T790M. We previously established two strains of transgenic lung cancer mice model harboring mice Egfr ex19 deletion(mDEL) or human EGFR L858R(hLR) driven by an SP-C promoter (Ohashi Cancer sci 2008, Ohashi Cancer res 2009). The mice develop EGFR dependent lung adenocarcinoma multifocally, so it detaches to clinical primary lung cancers which usually occur mono-focally. In addition, the tumors develop from type II pneumocyte one after another. The more clinically relevant lung cancer mice model is warranted.

Material and Methods: The lung tumors from each of transgenic mice, mDEL or hLR, were transplanted subcutaneously into C57BL/6J mice. The each of engrafted tumors was able to be serially transplanted and grew in subcutaneous of other C57BL/6J mice. In addition, the tumor engraftment was succeeded in peritoneum by intraperitoneal administration or lung by tail vein injection. Gefitinib (50mg/kg) or Osimertinib (5 or 15 mg/kg) were orally administrated. Results These tumors maintained the EGFR dependency in novel syngenic xenograft models, thus EGFR-TKI, gefitinib inhibited the tumor growth significantly. However, same as human lung tumors, these tumors eventually acquired resistance and re-grew. mDEL tumors got the resistance for five months and hLR tumors acquired the resistance for two months after gefitinib treatment. Interestingly secondary mutation Egfr T790I on mDEL tumors and secondary mutation EGFR T790M on hLR tumors were detected. Strikingly, third-generation EGFR-TKI, osimertinib inhibited the tumor growth in vivo in each of gefitinib-resistant tumors harboring secondary mutations in vivo. Resembling human lung cancer, these tumors again acquired the resistance to osimertinib and re-grew two months after of treatment with osimertinib. The resistant mechanisms are under investigation.

Conclusion: We established clinically relevant novel EGFR-TKI resistant mice model. The strength of the model is 1) syngenic model, 2) the mice have a normal immune system and 3) the model presented a clinically relevant resistant mechanism. We are assessing an alternative treatment including combination therapies or immunotherapy in this mice model. (This work was supported by KAKEN 16K19454, KAKEN 15H04830)

Citation Format: Kadoaki Ohashi, Hisao Higo, Go Makimoto, Kenichiro Kudo, Kazuya Nishii, Kiichiro Ninomiya, Hiroe Kayatani, Takashi Ninomiya, Toshio Kubo, Kammei Rai, Eiki Ichihara, Katsuyuki Hotta, Masahiro Tabata, Katsuyuki Kiura. The novel osimertinib resistant lung cancer mice model harboring EGFR mutations driven by the SP-C promoter [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1160.

Abstract 4818: In vivo efficacy of triplet therapy with osimertinib, cetuximab and bevacizumab for lung cancer cells harboring EGFR T790M

Background

Osimertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), is the standard treatment for patients with lung cancer harboring EGFR T790M (Mok T et al. N Engl J Med. 2017). However, acquired resistance to osimertinib is inevitable, and alternative strategies are needed. We recently reported that triplet therapy with afatinib, cetuximab and bevacizumab induced deep remission in lung tumors with EGFR T790M in vivo (Kudo K, et al. Mol Oncol. 2017). Therefore, we hypothesized that the combination of osimertinib with cetuximab and/or bevacizumab is a more effective treatment than osimertinib monotherapy for lung tumors harboring EGFR T790M.

Materials and Methods

RPC-9 cells (5 × 106) harboring EGFR 19DEL+T790M were injected subcutaneously into nude mice as xenograft models. The mice were treated with osimertinib (5 mg/kg, 5 times/week), cetuximab (1 mg/mouse, twice/week) and/or bevacizumab (5 mg/kg, twice/week) for 1 month, and observed for an additional month without treatment. The efficacy and toxicity of the triplet therapy (osimertinib, cetuximab, and bevacizumab) were compared with each of the single and double therapies.

Results

The cell proliferation assay confirmed that RPC-9 cells were sensitive to osimertinib in vitro. In the xenograft model, the doublet therapies (osimertinib plus bevacizumab or osimertinib plus cetuximab) had stronger antitumor effects than osimertinib monotherapy 56 days after drug administration (i.e., 28 days after discontinuation of the treatment). However, no significant differences were observed in inhibitory or CR ratios between mice receiving triplet therapy and those receiving doublet therapies

(osimertinib plus bevacizumab or cetuximab). No intolerable toxicity was observed with the doublet or triplet therapies.

Conclusions

Doublet therapy (osimertinib plus bevacizumab or osimertinib plus cetuximab), induced a significant reduction in lung tumors with EGFR T790M in vivo compared with osimertinib monotherapy. We were not able to prove the superiority of the triplet therapy over the doublet therapy. In future studies, we will examine the effects of the doublet and triplet therapies in other models, including an EGFR-driven transgenic lung cancer mice model.

Citation Format: Kazuya Nishii, Kadoaki Ohashi, Go Makimoto, Hisao Higo, Kiichiro Ninomiya, Hiroe Kayatani, Takashi Ninomiya, Toshio Kubo, Kammei Rai, Eiki Ichihara, Katsuyuki Hotta, Masahiro Tabata, Katsuyuki Kiura. In vivo efficacy of triplet therapy with osimertinib, cetuximab and bevacizumab for lung cancer cells harboring EGFR T790M [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4818.

MET or NRAS amplification is an acquired resistance mechanism to the third-generation EGFR inhibitor naquotinib

As a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), osimeritnib is the standard treatment for patients with non-small cell lung cancer harboring the EGFR T790M mutation; however, acquired resistance inevitably develops. Therefore, a next-generation treatment strategy is warranted in the osimertinib era. We investigated the mechanism of resistance to a novel EGFR-TKI, naquotinib, with the goal of developing a novel treatment strategy. We established multiple naquotinib-resistant cell lines or osimertinib-resistant cells, two of which were derived from EGFR-TKI-naïve cells; the others were derived from gefitinib- or afatinib-resistant cells harboring EGFR T790M. We comprehensively analyzed the RNA kinome sequence, but no universal gene alterations were detected in naquotinib-resistant cells. Neuroblastoma RAS viral oncogene homolog (NRAS) amplification was detected in naquotinib-resistant cells derived from gefitinib-resistant cells. The combination therapy of MEK inhibitors and naquotinib exhibited a highly beneficial effect in resistant cells with NRAS amplification, but the combination of MEK inhibitors and osimertinib had limited effects on naquotinib-resistant cells. Moreover, the combination of MEK inhibitors and naquotinib inhibited the growth of osimertinib-resistant cells, while the combination of MEK inhibitors and osimertinib had little effect on osimertinib-resistant cells. Clinical assessment of this novel combination (MEK inhibitors and naquotinib) is worth considering in osimertinib-resistant lung tumors.

Abstract 3164: A comprehensive analysis of autopsied specimens and patient-derived cell lines in ALK-positive lung cancers with rapid acquired resistance to alectinib

Background

Alectinib, a highly selective anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI), demonstrated a stunning disease control rate (95.7%) and unprecedented median progression-free survival (not reached: 95% CI: 20.3-) (Lancet Oncology 2013, ASCO 2016, Abstract #9008). However, acquired resistance to alectinib is inevitable; some ALK-positive lung tumors rapidly acquire alectinib resistance. Therefore, we sought to investigate the mechanism of the rapid resistance to alectinib using clinical samples and patient-derived ALK-positive cell lines.

Materials and Methods

Autopsied samples (primary lung tumors and metastatic tumors from the esophagus, liver, and bilateral kidney) were obtained from a 51-year-old male with advanced ALK-positive lung cancer. The lung tumors acquired resistance to first-line treatment of alectinib in three months, and subsequent treatment with ceritinib or crizotinib showed only a moderate and temporary effect. We established novel ALK-positive cell lines; ABC-14 was established from a pleural effusion after alectinib treatment, and ABC-17 was established from patient-derived xenograft (PDX) tumors of autopsied liver metastases. Western blot analysis, immunostaining, a receptor tyrosine kinase assay, fluorescence in situ hybridization (FISH), and next-generation sequencing were performed.

Results

ALK overexpression was confirmed in all autopsied samples by immunostaining. PCR revealed that ABC-14 harbored the EML-4/ALK fusion variant 3. An in vitro cell proliferation assay showed that ABC-14 exhibited resistance to alectinib (IC50 &gt; 1 µM), but was sensitive to crizotinib (IC50 = 98 nM). The receptor tyrosine kinase assay revealed the activation of MET and EGFR in ABC-14. Quantitative RT-PCR and FISH confirmed MET gene amplification. Quantitative RT-PCR also indicated the overexpression of an EGFR ligand, EGF, TGF-α but no EGFR mRNA overexpression. The combination of crizotinib (dual ALK/MET-TKI) and an EGFR-TKI, gefitinib, showed an additive inhibitory effect on cell growth compared with each drug alone in vitro. ABC-17 showed resistance to both alectinib and crizotinib; consistently showed no activation of MET and no MET gene amplification. Interestingly, ABC-17 showed metastatic ability in the lung in NOG mouse PDX models.

Conclusion

The mechanism of rapid resistance to alectinib may be complicated and heterogeneous. Crizotinib combined with gefitinib, which inhibits the ALK, EGFR, and MET pathways, may represent one potent strategy against alectinib resistance. Further next-generation sequencing of clinically relevant samples should provide deeper insights into its resistance. (This work was supported by KAKEN 16K19454 and KAKEN 15H04830.)

Citation Format: Go Makimoto, Kadoaki Ohashi, Kazuya Nishii, Shuta Tomida, Hiroe Kayatani, Tomoki Tamura, Hisao Higo, Kiichiro Ninomiya, Takashi Ninomiya, Toshio Kubo, Eiki Ichihara, Akiko Sato, Katsuyuki Hotta, Masahiro Tabata, Katsuyuki Kiura. A comprehensive analysis of autopsied specimens and patient-derived cell lines in ALK-positive lung cancers with rapid acquired resistance to alectinib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3164. doi:10.1158/1538-7445.AM2017-3164

Abstract 3152: Acquired resistance to the third-generation EGFR inhibitor ASP8273 is associated with MET or NRAS gene amplifications in preclinical models

Background. Third-generation EGFR tyrosine kinase inhibitors (TKIs) such as osimertinib and ASP8273 demonstrated biologic activity in patients with non-small cell lung cancer (NSCLC) harboring the EGFR T790M mutation; however, acquired resistance inevitably develops and the mechanisms of have not been fully elucidated. This study evaluated potential mechanisms of resistance to ASP8273.

Materials and Methods. ASP8273 was kindly provided by Astellas Pharma Inc. PC-9 cells harboring EGFR 19del and RPC-9 cells harboring EGFR 19del +T790M were used as cell models to explore alternative molecular mechanisms of acquired resistance to ASP8273. Resistant cell lines (PC-9ASR and RPC-9ASR) were established from each cell line after continuous exposure to ASP8273 for 6 months.

Results. Other EGFR-TKIs, including osimertinib, afatinib, or gefitinib, did not inhibit cell growth and acquired EGFR mutations were not detected in either of ASP8273 resistant cell lines. The PC-9-based model was first analyzed. The 50% inhibitory concentration (IC50) of ASP8273 was 45-fold higher in PC-9ASR cells (1,216 nmol/L) than in the parental PC-9 cells (27 nmol/L). A receptor tyrosine kinase array showed that MET phosphorylation was increased in PC-9ASR cells relative to PC-9 cells. Single-cell cloning revealed that PC-9ASRc2 cells harbored MET gene amplification, but other clones (c1, c3, c4, and c5) did not; these results suggest that heterogeneous cells comprised the resistant cell lines. Consistently, the combination of EGFR inhibitors (ASP8273 or gefitinib) with MET inhibitors (crizotinib or SGX-523) inhibited cell proliferation in vitro. In vivo, concomitant dosing of ASP8273 with crizotinib consistently inhibited this resistant tumor xenograft model. The RPC-9-based model was then assessed. The IC50 of ASP8273 was 40-fold greater in RPC-9ASR cells (1,393 nmol/L) than in the parental RPC-9 cells (32 nmol/L). Next-generation sequencing showed significant NRAS gene amplification and no NRAS mutations in RPC-9ASR cells. EGFR 19del +T790M was maintained in the resistant cells. Western blot analysis and an active RAS pull-down kit confirmed that NRAS protein was significantly overexpressed and that NRAS-GTPase activity was much higher in RPC-9ASR cells than in the RPC-9 parental cells. As expected, inhibition of RAS signaling using a MEK inhibitor (selumetinib or trametinib) in addition to ASP8273 overcame the resistance in vitro. Interestingly, a combination of MEK inhibitors with another third-generation EGFR-TKI, osimertinib, had no effect on the RPC-9 resistant cells.

Conclusions. These studies suggest that a bypass signaling pathway, such as MET gene amplification, or activation of the RAS signaling pathway plays a role in ASP8273 resistance in lung cancer cells harboring EGFR mutations. (This work was supported by KAKEN 16K19454 and 15H04830.)

Citation Format: Kiichiro Ninomiya, Kadoaki Ohashi, Shuta Tomida, Hiroe Kayatani, Tomoki Tamura, Hisao Higo, Go Makimoto, Takashi Ninomiya, Toshio Kubo, Eiki Ichihara, Akiko Sato, Katsuyuki Hotta, Masahiro Tabata, Katsuyuki Kiura. Acquired resistance to the third-generation EGFR inhibitor ASP8273 is associated with MET or NRAS gene amplifications in preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3152. doi:10.1158/1538-7445.AM2017-3152

Triplet therapy with afatinib, cetuximab, and bevacizumab induces deep remission in lung cancer cells harboring EGFR T790M in vivo

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have changed the treatment strategy for EGFR‐mutant lung cancers; however, resistance usually occurs due to a secondary mutation, T790M, in EGFR. Combination therapy using afatinib and cetuximab has had good results in lung tumors harboring EGFR^T790M mutations in clinical trials. The effect of bevacizumab, an antivascular endothelial growth factor (VEGF) antibody, combined with EGFR‐TKIs has also been investigated. We hypothesized that the dose of afatinib and cetuximab could be reduced by combination with bevacizumab and that the triplet therapy may result in better tumor inhibition with tolerable toxicity. Using a xenograft mouse model with H1975‐harboring EGFR^L858R+T790M and RPC‐9‐harboring EGFR^19DEL+T790M, we tested the efficacy of the triplet therapy with a modified dose of afatinib, cetuximab, and bevacizumab, and compared this therapy to single and double therapies. Triplet therapy with afatinib, cetuximab, and bevacizumab induced pathological complete remission in xenograft tumors with H1975 and RPC‐9 cells versus tumors treated with single or double therapies. We saw no body weight loss in the mice. The triple therapy induced a significant reduction in CD31‐positive vascular endothelial cells and increased cleaved caspase‐3‐positive cells in the tumors. This suggests that one mechanism underlying the deep remission could be suppression of neovascularization and induction of apoptosis by intensive inhibition of driver oncoproteins and VEGF. These results highlight the potential of afatinib, cetuximab, and bevacizumab to induce deep remission in tumors harboring EGFR^T790M mutations. Therefore, clinical trials of this combination therapy are warranted.

Abstract 2103: Activating alternative receptor tyrosine kinases induced alectinib-resistance in ALK rearranged non-small cell lung cancer cells

Background

The second-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI), alectinib, demonstrated high response rate, long response duration and a favorable toxic profile in patients with ALK-rearranged advanced non-small cell lung cancer in a phase II study (Lancet Oncol 14:590-8, 2013). However, even this promising drug is predicted to develop acquired resistance. Therefore, we investigated the mechanisms of resistance using two alectinib-resistant cell lines.

Methods

We established alectinib-resistant cell lines, H2228/CHR and ABC-11/CHR, from H2228 (EML4-ALK fusion genes variant 3a/b E6) and ABC-11 (EML4-ALK fusion genes variant 3b E6) respectively, by continuous exposure to alectinib. They were characterized using MTT assay, Western blotting, receptor tyrosine kinase array, ELISA, FISH, RT-PCR, and xenograft models.

Results

H2228/CHR and ABC-11/CHR cells were 117- and 40-fold more resistant than the parental lines, respectively, and maintained downstream AKT and ERK phosphorylation even in the presence of 10 μM alectinib. There were no ALK secondary mutations in those resistant cell lines. H2228/CHR lost the EML4-ALK fusion gene, and exhibited increased activation of insulin-like growth factor-1 receptor (IGF-1R) and human epidermal growth factor receptor 3 (HER3) with overexpression of the HER3 ligand neuregulin 1. Accordingly, pharmacologic inhibition of IGF-1R and HER3 signaling overcame the resistance. In ABC-11/CHR, MET was activated by stimulated hepatocyte growth factor (HGF) autocrine signaling. We found HGF gene translocation underlying the HGF autocrine system. Anti-HGF antibody suppressed the MET activation and combined treatment with alectinib and anti-HGF antibody or a MET inhibitor suppressed downstream signaling in ABC-11/CHR cells. Finally, crizotinib, which targets both ALK and MET, most effectively inhibited the growth of ABC-11/CHR both in vitro and in vivo.

Conclusions

We identified novel alectinib resistance mechanisms caused by the activation of alternative tyrosine kinase receptors. Our findings provide new insights into constructing a therapeutic strategy for ALK-positive lung cancer.

Citation Format: Hideko Isozaki, Eiki Ichihara, Masayuki Yasugi, Nagio Takigawa, Kadoaki Ohashi, Toshio Kubo, Takashi Ninomiya, Nobuaki Ochi, Daisuke Minami, Kenichiro Kudo, Yuka Kato, Hiroe Kayatani, Tomoki Tamura, Kiichiro Ninomiya, Toshio Higo, Tsuyoshi Makimoto, Akiko Sato, Katsuyuki Hotta, Kunio Matsumoto, Toshiaki Sendo, Mitsune Tanimoto, Katsuyuki Kiura. Activating alternative receptor tyrosine kinases induced alectinib-resistance in ALK rearranged non-small cell lung cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2103.

Abstract 4667: pCR induced by triplet therapy with low-dose afatinib, cetuximab and bevcizumab in lung cancer cells harboring EGFR T790M

Background. EGFR T790M plays a major role on the resistance for 1st or 2nd-generation EGFR-TKIs (e.g. erlotinib, afatinib) in lung tumors with activating EGFR mutations. 3rd generation EGFR-TKIs (e.g. AZD9291) show an excellent response in lung tumors with EGFR T790M, while the acquired resistance is inevitable (NEJM 2015). The combination of afatinib and cetuximab also induced significant response in the lung cancers in clinical trial (Cancer Discov. 2014). However, there is clearly still room for improvement in the combination therapy. Bevacizumab, a key drug in lung cancer treatment, is thought to have a wide variety of effects, including anti-vascularization and improved drug delivery. Thus, we hypothesized that the dosage of afatinib and cetuximab could be reduced by combining with bevacizumab, and that the triple therapy might produce better tumor inhibition with tolerable toxicity.

Methods. Two lung cancer cell lines, H1975, with EGFR L858R and T790M, and RPC-9, with EGFR exon 19 deletion and T790M, were injected subcutaneously into nude mice as xenograft models. Mice were divided into four groups 10 days after tumor cell inoculation (vehicle, afatinib, afatinib + cetuximab, afatinib + cetuximab + bevcacizumab). Compared with previous reports (afatinib 25 mg/kg, 5 times/week, cetuximab 1 mg/mouse, every 3 days; J. Clin. Invest. 2009), the low dose of afatinib (10 mg/kg, 5 times/week; i.e., 60% less drug) or cetuximab (0.1 mg/mouse, once/week; i.e., 90% less drug) were administered to the mice for 1 month. Bevacizumab was injected at 2 mg/kg twice/week. Following the therapies, the mice were observed for 1 month without treatment.

Results. Surprisingly, the triple therapy induced a pathological complete response (pCR) in H1975 and RPC-9 cell xenograft tumors; in contrast, the tumors treated with single or double therapy were inhibited only partially. AZD9291 monotherapy did not reproduce pCR. Furthermore pCR was maintained during the observation period in the triple therapy group. There was no body weight loss in any group. Frozen tumors were obtained from RPC-9 xenograft models after 1 week treatment with each regimen. Expression levels of pEGFR, pAKT, and pERK were decreased in the triple therapy group. CD31-positive blood vessels and Ki-67-positive cells in tumors with triple therapy were reduced significantly versus the tumors in other groups. Cleaved caspase-3 expression in the tumors with triple therapy was positive in a higher number of tumor cells than in the other groups. There were no difference of afatinib concentration among the tumors.

Conclusions. We demonstrated that a low-dose of afatinib and cetuximab combined with bevacizumab induced pCR in EGFR T790M mutated cell xenograft tumors with no obvious adverse events. We suggest that the suppression of neovascularization and induction of apoptosis may play important roles in the triple therapy.

This project is supported by KAKEN(No26893155)

Citation Format: Kadoaki Ohashi, Kenichiro Kudo, Eiki Ichihara, Hiroe Kayatani, Hisao Higo, Yuka Kato, Yasuko Kurata, Daisuke Minami, Takashi Ninomiya, Toshio Kubo, Katsuyuki Hotta, Mitsune Tanimoto, Katsuyuki Kiura. pCR induced by triplet therapy with low-dose afatinib, cetuximab and bevcizumab in lung cancer cells harboring EGFR T790M. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4667.

Abstract 1889: AXL and EGFR signaling mediate resistance to Crizotinib in non-small cell lung cancer cells harboring the ROS1 fusion gene

Background: The multi-tyrosine kinase inhibitor (TKI) crizotinib elicits a dramatic response in patients with non-small cell lung cancer (NSCLC) harboring the c-ros oncogene 1 (ROS1) fusion gene (Shaw et al. NEJM 2014); however, these patients inevitably develop resistance to crizotinib within a year, which limits the efficacy of crizotinib. Although reported molecular changes include ROS1 tyrosine kinase mutations, epidermal growth factor receptor (EGFR) activation, and epithelial-to mesenchymal transition, the detailed mechanism of crizotinib resistance has not been elucidated.

Methods: To explore the molecular mechanisms of acquired crizotinib resistance in detail, we used a cell line model. HCC78 cells harboring the SLC34A2-ROS1 fusion gene, which are sensitive to crizotinib, were exposed continuously to increasing concentrations of crizotinib in a step-wise manner. A crizotinib-resistant cell line designated HCC78R was established and assessed by MTT assay, Western blotting, a receptor tyrosine kinase (RTK) array, quantitative PCR (RT-PCR), ELISA, and an RNA kinome targeted kinome panel (612 genes) with next-generation sequencing.

Results: Crizotinib-resistant HCC78R (50% inhibitory concentration [IC50] 4085.9 nmol/L) was 47-fold more resistant to crizotinib than was parental HCC78 (IC50 85.8 nmol/L) (p = 0.0145) according to MTT assay. The RTK array revealed that EGFR phosphorylation was upregulated in HCC78R cells. Western blotting confirmed the activation of EGFR and its downstream signaling pathways. RT-PCR screening of EGFR ligand family member expression showed increased heparin-binding EGF-like growth factor (HB-EGF) in HCC78R compared with HCC78 cells. Consistently, addition of the HB-EGF or conditioned medium from HCC78R cells rendered the HCC78 parental cells moderately resistant to crizotinib. EGFR overexpression or activating mutations were not detected. Furthermore, RNA kinome sequencing revealed 16-fold higher AXL mRNA expression and 1.68-fold lower ROS1 fusion gene expression in HCC78R compared with HCC78. Overexpression of the AXL protein and downregulation of the ROS1 protein were confirmed by Western blotting. Monotherapy with gefitinib (EGFR-TKI) or R428 (AXL inhibitor) or cabozantinib (AXL inhibitor) moderately inhibited the growth of HCC78R cells, while combined therapy suppressed proliferation more significantly compared with each monotherapy.

Conclusions: AXL and EGFR signaling mediate resistance to crizotinib, and combination treatment of an EGFR-TKI and AXL inhibitor may be an alternative strategy in ROS1 fusion gene-driven lung cancer cells.

Citation Format: Yuka Kato, Kadoaki Ohashi, Eiki Ichihara, Shuuta Tomida, Hiroe Kayatani, Kenichiro Kudo, Daisuke Minami, Takashi Ninomiya, Toshio Kubo, Toshiyuki Kozuki, Katsuyuki Hotta, Nagio Takigawa, Mitsune Tanimoto, Katsuyuki Kiura. AXL and EGFR signaling mediate resistance to Crizotinib in non-small cell lung cancer cells harboring the ROS1 fusion gene. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1889.

Abstract 5198: Combination effect of anti-VEGFR-2 antibody with erlotinib on EGFR mutant non-small cell lung cancer

Background: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have excellent effects on non-small cell lung cancer (NSCLC) harboring EGFR mutations. However, EGFR mutant NSCLC inevitably acquires resistance to EGFR-TKIs such as gefitinib, erlotinib, or afatinib. Previously, we found that bevacizumab, an anti-vascular endothelial growth factor-A (VEGF-A) antibody, enhanced the antitumor effects of gefitinib and afatinib in preclinical lung cancer models (Ichihara et al., Caner Res 2009; Ninomiya et al., Mol Cancer Ther 2013). In a phase II trial of OLCSG1001, we demonstrated relatively longer progression-free survival by adding bevacizumab to gefitinib in the treatment of patients harboring an EGFR exon 19 deletion. Seto et al. (Lancet Oncol 2015) also reported that adding bevacizumab to erlotinib in patients harboring EGFR mutations significantly prolonged progression-free survival. A new anti-angiogenic agent, the anti-human VEGF receptor-2 (VEGFR-2) antibody ramucirumab, has also been used clinically (Garon et al., Lancet 2014). We investigated the effect of an anti-VEGFR-2 antibody combined with erlotinib on the growth of lung cancers harboring EGFR mutations.

Materials and Methods: NSCLC cell lines PC-9, which harbors EGFR exon 19 deletion and H3255, which harbors EGFR L858R mutation, were used in this study. Ramucirumab and the anti-murine VEGFR-2 antibody DC101 were kindly provided by Eli Lilly (Indianapolis, IN, USA). BALB/c nu/nu or transgenic mice expressing the delE748-752 mutant version of mouse Egfr driven by the SP-C promoter, which is equivalent to the delE746-A750 mutation of humans (C57BL/6/Egfr15DEL) (Ohashi et al. Cancer Sci 2009), were used for in vivo experiments. For xenograft models, PC-9 or H3255 cells were injected subcutaneously into BALB/c mice. The mice were divided into four treatment groups: vehicle, erlotinib, DC101, or erlotinib combined with DC101.

Results: DC101 alone moderately inhibited the growth of PC-9 or H3255 tumor in the xenograft mouse models or suppressed lung cancers in C57BL/6/Egfr15DEL mice. Combined erlotinib and DC101 therapy inhibited the growth of PC-9 tumor in the xenograft mouse models more markedly than did erlotinib or DC101 alone. There were no differences in toxicity between monotherapy and combination therapy.

Conclusion: Combination therapy with erlotinib and an anti-VEGFR-2 antibody had a stronger antitumor effect than those of the respective monotherapies in lung cancers harboring EGFR mutations in vivo.

Citation Format: Hiroe Kayatani, Kadoaki Ohashi, Takeshi Imao, Kenichiro Kudo, Yuka Kato, Takashi Ninomiya, Toshio Kubo, Akiko Sato, Ktsuyuki Hotta, Mitsune Tanimoto, Katsuyuki Kiura. Combination effect of anti-VEGFR-2 antibody with erlotinib on EGFR mutant non-small cell lung cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5198.

Trastuzumab Emtansine in HER2+ Recurrent Metastatic Non-Small-Cell Lung Cancer: Study Protocol

The treatment outcome has been unsatisfactory for patients with non-small-cell lung cancer (NSCLC) refractory to standard first-line chemotherapy. Trastuzumab emtansine (T-DM1), an anti-HER2 antibody conjugated with a vinca alkaloid, has been approved for clinical use in HER2+ breast cancer in many countries. Approximately 5% of NSCLC tumors possess HER2 alterations, and T-DM1 has shown excellent antitumor effects against HER2+ lung cancer cell lines in preclinical models. Therefore, we hypothesized that T-DM1 could significantly inhibit the growth of HER2+ lung cancers. We have launched a nonrandomized phase II trial of T-DM1 monotherapy for patients with HER2+ lung cancers. The major eligibility criteria are as follows: age ≥ 20 years, pathologically diagnosed NSCLC with documented HER2 positivity (immunohistochemistry 3+, both immunohistochemistry 2+ and fluorescence in situ hybridization positive, or exon 20 insertion mutation), and previous chemotherapy. Thirty patients will receive T-DM1 3.6 mg/kg every 3 weeks. The primary endpoint is the overall response rate. This trial will provide information on whether T-DM1 monotherapy is effective against HER2+ lung cancer.

Magnitude of the benefit of progression-free survival as a potential surrogate marker in phase 3 trials assessing targeted agents in molecularly selected patients with advanced non-small cell lung cancer: systematic review

Background

In evaluation of the clinical benefit of a new targeted agent in a phase 3 trial enrolling molecularly selected patients with advanced non-small cell lung cancer (NSCLC), overall survival (OS) as an endpoint seems to be of limited use because of a high level of treatment crossover for ethical reasons. A more efficient and useful indicator for assessing efficacy is needed.

Methods and Findings

We identified 18 phase 3 trials in the literature investigating EGFR-tyrosine kinase inhibitor (TKIs) or ALK-TKIs, now approved for use to treat NSCLC, compared with standard cytotoxic chemotherapy (eight trials were performed in molecularly selected patients and ten using an “all-comer” design). Receiver operating characteristic analysis was used to identify the best threshold by which to divide the groups. Although trials enrolling molecularly selected patients and all-comer trials had similar OS-hazard ratios (OS-HRs) (0.99 vs. 1.04), the former exhibited greater progression-free survival-hazard ratios (PFS-HR) (mean, 0.40 vs. 1.01; P<0.01). A PFS-HR of 0.60 successfully distinguished between the two types of trials (sensitivity 100%, specificity 100%). The odds ratio for overall response was higher in trials with molecularly selected patients than in all-comer trials (mean: 6.10 vs. 1.64; P<0.01). An odds ratio of 3.40 for response afforded a sensitivity of 88% and a specificity of 90%.

Conclusion

The notably enhanced PFS benefit was quite specific to trials with molecularly selected patients. A PFS-HR cutoff of ∼0.6 may help detect clinical benefit of molecular targeted agents in which OS is of limited use, although desired threshold might differ in an individual trial.

Pulmonary tumor thrombotic microangiopathy diagnosed antemortem and treated with combination chemotherapy

A 29-year-old man developed a persistent dry cough. Chest high-resolution computed tomography (HRCT) revealed centrilobular ultrafine granular shadows scattered in all lung fields. A lung biopsy with video-assisted thoracoscopic surgery revealed findings compatible with pulmonary tumor thrombotic microangiopathy (PTTM). However, the primary tumor was not identified. Combination chemotherapy with S-1 and cisplatin decreased his cough and improved the chest HRCT findings. The illness, however, gradually became difficult to control. He eventually developed pulmonary hypertension and died. Typically, an antemortem diagnosis of PTTM cannot be made. In this case, the diagnosis of PTTM and combination chemotherapy improved the chest HRCT findings, respiratory symptoms, and prognosis.

[A case of small cell lung cancer that presented with paraneoplastic syndrome]

A 65-year-old man had suffered from systemic erythema from November 2008 and had noticed gradually progressing weakness in the upper and lower limbs. He received medical treatment in another hospital but his symptoms did not improve. He was admitted to our hospital for treatment of diabetes in June 2009, and his chest X-ray images and CT scans showed a mass shadow in the right upper lobe with hilar and mediastinal lymphadenopathy. We performed bronchoscopy, and diagnosed small cell lung cancer (T2N2M1, stage IV). However, he had hand grip weakness and continuing upper and lower limb muscle weakness, and therefore electromyography was performed, which showed the presence of waxing in the right leg. Subsequently, a diagnosis of Lambert-Eaton myasthenic syndrome was made. As he also showed ataxia of the left lower extremity, we also diagnosed paraneoplastic cerebellar degeneration. We gave the patient chemotherapy consisting of carboplatin and etoposide which resulted in the disappearance of his waxing, and his grip strength and erythema immediately improved with regression of the tumor after 1 course of chemotherapy. We report a case of small cell lung cancer associated with Lambert-Eaton myasthenic syndrome, paraneoplastic cerebellar degeneration and erythema which presented as paraneoplastic syndrome, which improved with chemotherapy.

An autopsy case of fetal Gaucher disease

BACKGROUND

A case of fetal form of Gaucher disease in a Japanese fetus is presented.

RESULTS

A macerated baby showing hydrops fetalis was dissected at 29 weeks of gestation. The fetus was heavier in the body, liver and spleen than a normal fetus at the same gestation period. It also suffered from pericardial effusion and ascites. The diagnosis of Gaucher disease was made by histological and biochemical findings. In microscopical examinations 'Gaucher cells', which were periodic acid-Shiff (PAS)-positive, alcian blue-positive and CD68-positive, existed in the lungs, liver, spleen, thymus, adrenal glands, bone marrow and brain. In thin layer chromatography, a large quantity of glucocerebroside was seen to have accumulated in the patient's organs.