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Featured researches published by Yasuo Iwamoto.


Journal of Clinical Oncology | 2010

Phase III Study Comparing Second- and Third-Generation Regimens With Concurrent Thoracic Radiotherapy in Patients With Unresectable Stage III Non–Small-Cell Lung Cancer: West Japan Thoracic Oncology Group WJTOG0105

Nobuyuki Yamamoto; Kazuhiko Nakagawa; Yasumasa Nishimura; Kayoko Tsujino; Miyako Satouchi; Shinzoh Kudo; Toyoaki Hida; Masaaki Kawahara; Koji Takeda; Nobuyuki Katakami; Toshiyuki Sawa; Soichiro Yokota; Takashi Seto; Fumio Imamura; Hideo Saka; Yasuo Iwamoto; Hiroshi Semba; Yasutaka Chiba; Hisao Uejima; Masahiro Fukuoka

PURPOSE This phase III trial of concurrent thoracic radiotherapy (TRT) was conducted to compare third-generation chemotherapy with second-generation chemotherapy in patients with unresectable stage III non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Eligible patients received the following treatments: A (control), four cycles of mitomycin (8 mg/m(2) on day 1)/vindesine (3 mg/m(2) on days 1, 8)/cisplatin (80 mg/m(2) on day 1) plus TRT 60 Gy (treatment break for 1 week); B, weekly irinotecan (20 mg/m(2))/carboplatin (area under the plasma concentration-time curve [AUC] 2) for 6 weeks plus TRT 60 Gy, followed by two courses of irinotecan (50 mg/m(2) on days 1, 8)/carboplatin (AUC 5 on day 1); C, weekly paclitaxel (40 mg/m(2))/carboplatin (AUC 2) for 6 weeks plus TRT 60 Gy, followed by two courses of paclitaxel (200 mg/m(2) on day 1)/carboplatin (AUC 5 on day 1). RESULTS The median survival time and 5-year survival rates were 20.5, 19.8, and 22.0 months and 17.5%, 17.8%, and 19.8% in arms A, B, and C, respectively. Although no significant differences in overall survival were apparent among the treatment arms, noninferiority of the experimental arms was not achieved. The incidences of grade 3 to 4 neutropenia, febrile neutropenia, and gastrointestinal disorder were significantly higher in arm A than in arm B or C (P < .001). Chemotherapy interruptions were more common in arm B than in arm A or C. CONCLUSION Arm C was equally efficacious and exhibited a more favorable toxicity profile among three arms. Arm C should be considered a standard regimen in the management of locally advanced unresectable NSCLC.


Journal of Clinical Oncology | 2010

Randomized Phase III Trial of Platinum-Doublet Chemotherapy Followed by Gefitinib Compared With Continued Platinum-Doublet Chemotherapy in Japanese Patients With Advanced Non–Small-Cell Lung Cancer: Results of a West Japan Thoracic Oncology Group Trial (WJTOG0203)

Koji Takeda; Toyoaki Hida; Tosiya Sato; Masahiko Ando; Takashi Seto; Miyako Satouchi; Yukito Ichinose; Nobuyuki Katakami; Nobuyuki Yamamoto; Shinzoh Kudoh; Jiichiro Sasaki; Kaoru Matsui; Koichi Takayama; Tatsuhiko Kashii; Yasuo Iwamoto; Toshiyuki Sawa; Isamu Okamoto; Takayasu Kurata; Kazuhiko Nakagawa; Masahiro Fukuoka

PURPOSE Gefitinib is a small molecule inhibitor of the epidermal growth factor receptor tyrosine kinase. We conducted a phase III trial to evaluate whether gefitinib improves survival as sequential therapy after platinum-doublet chemotherapy in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Chemotherapy-naïve patients with advanced stage (IIIB/IV) NSCLC, Eastern Cooperative Oncology Group performance status of 0 to 1, and adequate organ function were randomly assigned to either platinum-doublet chemotherapy up to six cycles (arm A) or platinum-doublet chemotherapy for three cycles followed by gefitinib 250 mg orally once daily, until disease progression (arm B). Patients were stratified by disease stage, sex, histology, and chemotherapy regimens. The primary end point was overall survival; secondary end points included progression-free survival, tumor response, safety, and quality of life. Results Between March 2003 and May 2005, 604 patients were randomly assigned. There was a statistically significant improvement in progression-free survival in arm B (hazard ratio [HR], 0.68; 95% CI, 0.57 to 0.80; P < .001); however, overall survival results did not reach statistical significance (HR, 0.86; 95% CI, 0.72 to 1.03; P = .11). In an exploratory subset analysis of overall survival by histologic group, patients in arm B with adenocarcinoma did significantly better than patients in arm A with adenocarcinoma (n = 467; HR, 0.79; 95% CI, 0.65 to 0.98; P = .03). CONCLUSION This trial failed to meet the primary end point of OS in patients with NSCLC. The exploratory subset analyses demonstrate a possible survival prolongation for sequential therapy of gefitinib, especially for patients with adenocarcinoma.


Investigational New Drugs | 2001

Mechanisms of action of the novel sulfonamide anticancer agent E7070 on cell cycle progression in human non-small cell lung cancer cells.

Kazuya Fukuoka; Jitsuo Usuda; Yasuo Iwamoto; Hisao Fukumoto; Takashi Nakamura; Takahiro Yoneda; Nobuhiro Narita; Nagahiro Saijo; Kazuto Nishio

E7070 is a novel sulfonamide antitumoragent that exhibits potent antitumoractivity in vitro and in vivo.This compound affects cell cycleprogression in human tumor cells. Toelucidate the mechanisms by which E7070inhibits tumor cell growth, we establishedand characterized an E7070-resistantsubline, A549/ER, from a human non-smallcell lung cancer cell line A549. Flowcytometric analyses demonstrated anincrease in G0/G1 and a decrease in S phasepopulations in cells treated with E7070 at20 or 100 μg/ml for 24 h. Longerexposure to E7070, i.e. 48 and 72 h,increased the G2/M phase fraction in A549cells. These inhibitory actions of E7070on cell cycle progression were not observedin A549/ER cells. E7070 inhibited thephosphorylation of pRb, decreasedexpressions of cyclin A, B1, CDK2, and CDC2proteins, and suppressed CDK2 catalyticactivity with the induction of p53 andp21 proteins in A549 cells but not inA549/ER cells. Taken together, theseresults suggest that E7070 exerts itsantitumor effects by disturbing the cellcycle at multiple points, including boththe G1/S and the G2/M transition, in humanlung cancer cells.


Journal of Clinical Oncology | 2015

Randomized Phase III Trial Comparing Weekly Docetaxel Plus Cisplatin Versus Docetaxel Monotherapy Every 3 Weeks in Elderly Patients With Advanced Non–Small-Cell Lung Cancer: The Intergroup Trial JCOG0803/WJOG4307L

Tetsuya Abe; Koji Takeda; Yuichiro Ohe; Shinzoh Kudoh; Yukito Ichinose; Hiroaki Okamoto; Nobuyuki Yamamoto; Hiroshige Yoshioka; Koichi Minato; Toshiyuki Sawa; Yasuo Iwamoto; Hideo Saka; Junki Mizusawa; Taro Shibata; Shinichiro Nakamura; Masahiko Ando; Akira Yokoyama; Kazuhiko Nakagawa; Nagahiro Saijo; Tomohide Tamura

PURPOSE This phase III trial aimed to confirm the superiority of weekly docetaxel and cisplatin over docetaxel monotherapy in elderly patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Chemotherapy-naïve patients with stage III, stage IV, or recurrent NSCLC age ≥ 70 years with a performance status of 0 or 1 who were considered unsuitable for bolus cisplatin administration were randomly assigned to receive docetaxel 60 mg/m(2) on day 1, every 3 weeks, or docetaxel 20 mg/m(2) plus cisplatin 25 mg/m(2) on days 1, 8, and 15, every 4 weeks. The primary end point was overall survival (OS). RESULTS In the first interim analysis, OS of the doublet arm was inferior to that of the monotherapy arm (hazard ratio [HR], 1.56; 95% CI, 0.98 to 2.49), and the predictive probability that the doublet arm would be statistically superior to the monotherapy arm on final analysis was 0.996%, which led to early study termination. In total, 276 patients with a median age of 76 years (range, 70 to 87 years) were enrolled. At the updated analysis, the median survival time was 14.8 months for the monotherapy arm and 13.3 months for the doublet arm (HR, 1.18; 95% CI, 0.83 to 1.69). The rates of grade ≥ 3 neutropenia and febrile neutropenia were higher in the monotherapy arm, and those of anorexia and hyponatremia were higher in the doublet arm. CONCLUSION This study failed to demonstrate any survival advantage of weekly docetaxel plus cisplatin over docetaxel monotherapy as first-line chemotherapy for advanced NSCLC in elderly patients.


Lung Cancer | 2001

Mechanism of the radiosensitization induced by vinorelbine in human non-small cell lung cancer cells

Kazuya Fukuoka; Hitoshi Arioka; Yasuo Iwamoto; Hisao Fukumoto; Hirokazu Kurokawa; Tomoyuki Ishida; Akira Tomonari; Toshihiro Suzuki; Jitsuo Usuda; Fumihiko Kanzawa; Nagahiro Saijo; Kazuto Nishio

Vinorelbine (Navelbine, KW-2307), a semisynthetic vinca alkaloid, is a potent inhibitor of mitotic microtubule polymerization. The aims of this study were to demonstrate radiosensitization produced by vinorelbine in human non-small cell lung cancer (NSCLC) PC-9 cells and to elucidate the cellular mechanism of radiosensitization. A clonogenic assay demonstrated that PC-9 cells were sensitized to radiation by vinorelbine with a maximal sensitizer enhancement ratio at a 10% cell survival level of 1.35 after 24-h exposure to vinorelbine at 20 nM. After 24-h exposure to vinorelbine at 20 nM, the approximately 67% of the cells that had accumulated in the G2/M-phase were cultured in the absence of vinorelbine and then irradiated at a dose of 8 Gy. Flow cytometric analyses showed prolonged G2/M accumulation concomitant with continuous polyploidization, and induction of apoptosis was observed in the cells subjected to the combination of vinorelbine-pretreatment and radiation. Polyploidization and induction of apoptosis were confirmed by morphological examination and a DNA fragmentation assay, respectively. We concluded that vinorelbine at a minimally toxic concentration moderately sensitizes human NSCLC cells to radiation by causing accumulation of cells in the G2/M-phase of the cell cycle. Prolonged G2/M accumulation concomitant with continuous polyploidization and increased susceptibility to induction of apoptosis may be associated with the cellular mechanism of radiosensitization produced by vinorelbine.


Journal of Clinical Oncology | 2016

Randomized Phase III Study Comparing Gefitinib With Erlotinib in Patients With Previously Treated Advanced Lung Adenocarcinoma: WJOG 5108L

Yoshiko Urata; Nobuyuki Katakami; Satoshi Morita; Reiko Kaji; Hiroshige Yoshioka; Takashi Seto; Miyako Satouchi; Yasuo Iwamoto; Masashi Kanehara; Daichi Fujimoto; Norihiko Ikeda; Haruyasu Murakami; Haruko Daga; Tetsuya Oguri; Isao Goto; Fumio Imamura; Shunichi Sugawara; Hideo Saka; Naoyuki Nogami; Shunichi Negoro; Kazuhiko Nakagawa; Yoichi Nakanishi

PURPOSE The epidermal growth factor receptor (EGFR) tyrosine kinase has been an important target for non-small-cell lung cancer. Several EGFR tyrosine kinase inhibitors (TKIs) are currently approved, and both gefitinib and erlotinib are the most well-known first-generation EGFR-TKIs. This randomized phase III study was conducted to investigate the difference between these two EGFR-TKIs. PATIENTS AND METHODS Previously treated patients with lung adenocarcinoma were randomly assigned to receive gefitinib or erlotinib. This study aimed to investigate the noninferiority of gefitinib compared with erlotinib. The primary end point was progression-free survival (PFS). RESULTS Five hundred sixty-one patients were randomly assigned, including 401 patients (71.7%) with EGFR mutation. All baseline factors (except performance status) were balanced between the arms. Median PFS and overall survival times for gefitinib and erlotinib were 6.5 and 7.5 months (hazard ratio [HR], 1.125; 95% CI, 0.940 to 1.347; P = .257) and 22.8 and 24.5 months (HR, 1.038; 95% CI, 0.833 to 1.294; P = .768), respectively. The response rates for gefitinib and erlotinib were 45.9% and 44.1%, respectively. Median PFS times in EGFR mutation-positive patients receiving gefitinib versus erlotinib were 8.3 and 10.0 months, respectively (HR, 1.093; 95% CI, 0.879 to 1.358; P = .424). The primary grade 3 or 4 toxicities were rash (2.2% for gefitinib v 18.1% for erlotinib) and alanine aminotransferase (ALT)/aspartate aminotransferase (AST) elevation (6.1%/13.0% for gefitinib v 2.2%/3.3% for erlotinib). CONCLUSION The study did not demonstrate noninferiority of gefitinib compared with erlotinib in terms of PFS in patients with lung adenocarcinoma according to the predefined criteria.


Annals of Oncology | 2013

Efficacy and safety analysis according to histology for S-1 in combination with carboplatin as first-line chemotherapy in patients with advanced non-small-cell lung cancer: updated results of the West Japan Oncology Group LETS study

Hiroshige Yoshioka; Isamu Okamoto; Satoshi Morita; Masahiko Ando; Koji Takeda; Takashi Seto; Noboru Yamamoto; Hideo Saka; Shinji Atagi; Tomonori Hirashima; S. Kudoh; Miyako Satouchi; Norihiko Ikeda; Yasuo Iwamoto; Toshiyuki Sawa; Yoichi Nakanishi; Kazuhiko Nakagawa

BACKGROUND A phase III study (Lung Cancer Evaluation of TS-1) previously demonstrated noninferiority in terms of overall survival (OS) at interim analysis for carboplatin-S-1 compared with carboplatin-paclitaxel for first-line treatment of advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS A total of 564 patients were randomly assigned to receive either carboplatin on day 1 plus oral S-1 on days 1-14 or carboplatin-paclitaxel on day 1 every 21 days. Updated results and post hoc subgroup analysis according to tumor histology are presented. RESULTS The updated analysis revealed a median OS of 15.2 months in the carboplatin-S-1 arm and 13.1 months in the carboplatin-paclitaxel arm, with a hazard ratio (HR) of 0.956 [95% confidence interval (CI) 0.793-1.151], consistent with the previous primary analysis. Median OS was 14.0 months in the carboplatin-S-1 arm and 10.6 months in the carboplatin-paclitaxel arm (HR 0.713; 95% CI 0.476-1.068) for patients with squamous cell carcinoma (SCC), with corresponding values of 15.5 and 13.9 months (HR 1.060; 95% CI 0.859-1.308) for those with non-SCC. CONCLUSIONS These results establish the efficacy and safety of carboplatin-S-1 in patients with advanced NSCLC regardless of tumor histology.


Lancet Oncology | 2015

Nedaplatin plus docetaxel versus cisplatin plus docetaxel for advanced or relapsed squamous cell carcinoma of the lung (WJOG5208L): a randomised, open-label, phase 3 trial.

Takehito Shukuya; Takeharu Yamanaka; Takashi Seto; Haruko Daga; Koichi Goto; Hideo Saka; Shunichi Sugawara; Toshiaki Takahashi; Soichiro Yokota; Hiroyasu Kaneda; Tomoya Kawaguchi; Seisuke Nagase; Tetsuya Oguri; Yasuo Iwamoto; Takashi Nishimura; Yoshihiro Hattori; Kazuhiko Nakagawa; Yoichi Nakanishi; Nobuyuki Yamamoto

BACKGROUND The combination of nedaplatin, a cisplatin derivative, and docetaxel showed promising activity for advanced squamous cell lung carcinoma in a previous phase 1-2 study. We compared nedaplatin plus docetaxel with cisplatin plus docetaxel in patients with previously untreated advanced or relapsed squamous cell lung carcinoma to determine effects on overall survival. METHODS We did a randomised, open-label, phase 3 study at 53 institutions in Japan. Eligibility criteria included pathologically proven squamous cell lung cancer with stage IIIB/IV or postoperative recurrence, age 20-74 years, Eastern Cooperative Oncology Group performance status of 0-1, no previous chemotherapy or recurrence more than a year after previous adjuvant chemotherapy, and adequate organ function. Patients were randomly assigned (1:1) to 100 mg/m(2) nedaplatin and 60 mg/m(2) docetaxel intravenously, or 80 mg/m(2) cisplatin and 60 mg/m(2) docetaxel, every 3 weeks for four to six cycles (at the treating oncologists discretion). Randomisation was done centrally at the West Japan Oncology Group data centre via a computer-generated allocation sequence with dynamic minimisation that balanced stage (IIIB/IV or postoperative recurrent), sex, and institution. The primary endpoint was overall survival in the modified intention-to-treat population (ie, all patients who were randomly assigned and met the inclusion criteria). Safety analyses were done in all randomly assigned patients who received at least one dose of the study regimen. This trial is registered with the UMIN Clinical Trials Registry, number UMIN000002015, and is closed to new participants. FINDINGS Between July 6, 2009, and July 26, 2012, 355 patients were randomly assigned. 349 patients were included in the modified intention-to-treat analysis (177 in the nedaplatin group and 172 in the cisplatin group). Overall survival was significantly longer in the nedaplatin group (median 13·6 months, 95% CI 11·6-15·6) than in the cisplatin group (11·4 months,10·2-12·2; hazard ratio 0·81, 95% CI 0·65-1·02; p=0·037, one-sided stratified log-rank test). Grade 3 or worse nausea (seven of 177 patients in the nedaplatin group and 25 of 175 in the cisplatin group), fatigue (six vs 20), hyponatraemia (24 vs 53), and hypokalaemia (four vs 15) were more frequent in the cisplatin group than in the nedaplatin group, whereas grade 3 or worse leucopenia (98 vs 77), neutropenia (146 vs 123), and thrombocytopenia (16 vs none) were more frequent in the nedaplatin group than in the cisplatin group. Treatment-related deaths occurred in four and three patients in nedaplatin and cisplatin groups, respectively. INTERPRETATION Overall survival was significantly longer with nedaplatin plus docetaxel than with cisplatin plus docetaxel, and the regimens had different safety profiles. Nedaplatin plus docetaxel could be a new treatment option for advanced or relapsed squamous cell lung cancer. FUNDING West Japan Oncology Group and Sanofi.


Japanese Journal of Cancer Research | 1998

Preferential binding of E7010 to murine β3-tubulin and decreased β3-tubulin in E7010-resistant cell lines

Yasuo Iwamoto; Kazuto Nishio; Hisao Fukumoto; Kentaro Yoshimatsu; Michio Yamakido; Nagahiro Saijo

N‐[2‐[(4‐Hydroxyphenyl)amino]‐3‐pyridyl]‐4‐methoxybenzenesulfonamide (E7010) is a novel sulfonamide antimitotic agent, which is active against mouse and human tumors. E7010 binds to β‐tubulin and inhibits polymerization of microtubules. In order to clarify the mechanisms of E7010‐resistance, two murine leukemic P388 subclones resistant to E7010, 0.5r‐D and 4.0r‐M, were characterized. The two clones showed approximately 10‐ and 100‐fold resistance to E7010‐induced growth‐inhibitory effects, respectively, compared with the parental cells in 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. These cell lines showed no cross‐resistance to other anticancer agents such as taxanes, vinca alkaloids, mitomycin C, cisplatin and irinotecan hydrochloride (CPT‐11). Increased α‐ and β‐tubulin protein and mRNA levels were observed in 0.5r‐D and 4.0r‐M cells as compared with the parental cells. We examined the isotype‐specific expression of β‐tubulin in these E7010‐resistant cells by a competitive reverse transcription‐polymerase chain reaction method. Although a 50% increase in β5 isotype mRNA levels was observed in 4.0r‐M cells, the levels of β3 isotype message in the two resistant clones were approximately 50% less than the parental cells. To elucidate the binding properties of E7010 with β‐tubulin isotypes, we prepared isotype‐specific fusion proteins of β‐tubulins. Direct photoaffinity labelling of the isotype‐specific fusion proteins with [14C]E7010 revealed that E7010 preferentially binds to the β3 isotype rather than β2, β4, and β5 isotype proteins. Therefore, altered expression of β‐tubulin isotypes, especially β3 isotype, to which E7010 binds with high affinity, may account for the decreased sensitivity of these resistant clones to E7010.


Respirology | 2006

Intrapleural cisplatin and OK432 therapy for malignant pleural effusion caused by non-small cell lung cancer

Atsuko Ishida; Teruomi Miyazawa; Yuka Miyazu; Yasuo Iwamoto; Mika Zaima; Koji Kanoh; Hidetaka Sumiyoshi; Masao Doi

Objective:  To evaluate the efficacy of combined intrapleural therapy with cisplatin, an antineoplastic agent, and OK432, a sclerosing agent, in controlling malignant pleural effusions, when compared with monotherapy with either agent.

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Koji Takeda

Columbia University Medical Center

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