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Dive into the research topics where Koichi Amano is active.

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Featured researches published by Koichi Amano.


Modern Rheumatology | 2009

Japan College of Rheumatology 2009 guidelines for the use of tocilizumab, a humanized anti-interleukin-6 receptor monoclonal antibody, in rheumatoid arthritis

Ryuji Koike; Masayoshi Harigai; Tatsuya Atsumi; Koichi Amano; Shinichi Kawai; Kazuyoshi Saito; Tomoyuki Saito; Masahiro Yamamura; Tsukasa Matsubara; Nobuyuki Miyasaka

The introduction of biological agents targeting tumor necrosis factor-alpha (TNF-α) has brought about a paradigm shift in the treatment of rheumatoid arthritis (RA). Although these anti-TNF agents have excellent efficacy against RA, a substantial number of patients still show inadequate responses. In Western countries, such patients are already being treated with new classes of antirheumatic drugs such as abatacept and rituximab. Tocilizumab (TCZ) is a humanized monoclonal antibody developed in Japan against the human interleukin-6 (IL-6) receptor. TCZ does not only alleviate the signs and symptoms of RA but also seems to prevent progressive bone and joint destruction. However, there is a concern that TCZ might increase the risk of adverse events such as infections since IL-6 plays a pivotal role in the immune system. Calculating the relative risks of specific adverse outcomes with TCZ use remains difficult, due to insufficient patient numbers enrolled in clinical trials to date. This review presents tentative guidelines for the use of TCZ for RA patients prepared by the Japan College of Rheumatology and based on results of clinical trials in Japan and Western countries. The guidelines are intended as a guide for postmarketing surveillance and clinical practice, and will be revised periodically based on the surveillance.


Rheumatology | 2011

Clinical, radiographic and functional effectiveness of tocilizumab for rheumatoid arthritis patients—REACTION 52-week study

Tsutomu Takeuchi; Yoshiya Tanaka; Koichi Amano; Daisuke Hoshi; Masao Nawata; Hayato Nagasawa; Eri Sato; Kazuyoshi Saito; Yuko Kaneko; Shunsuke Fukuyo; Takahiko Kurasawa; Kentaro Hanami; Hideto Kameda; Hisashi Yamanaka

Objectives. To evaluate the effectiveness and safety of tocilizumab in RA patients in clinical practice. Methods. We observed 232 consecutive RA patients who began tocilizumab in three rheumatology centres in Japan for 52 weeks. Clinical, radiographic and functional status and safety were evaluated. Results. Mean age of the 232 patients was 59.1 years, mean duration of disease was 12.4 years and average DAS using the 28-joint count (DAS-28) was 5.6. Although 62.8% of the patients had been treated previously with anti-TNF biologics, clinical remission at Week 52 was achieved in 43.7%, radiographic non-progression in 62.8% and functional remission in 26.4%. Retention rate at Week 52 was 71.1%, and the same for those with or without previous anti-TNF treatment. Adverse drug reactions leading to tocilizumab discontinuation were observed in 15.5% of patients, the most frequent adverse drug reaction being pneumonia in eight cases. On multivariate logistic regression analysis, DAS-28, HAQ-disability index (HAQ-DI), concomitant MTX and concomitant glucocorticoids (GCs) were predictive variables for clinical remission at Week 52 of tocilizumab treatment. In particular, HAQ-DI was found to be a predictive variable for remission of all three types—clinical, radiographic and functional—at Week 52 of tocilizumab treatment. Conclusions. In daily clinical practice, tocilizumab exhibited excellent effectiveness in established RA patients, some of whom had failed to respond to previous anti-TNF treatment. Although further detailed safety findings are required, this study provides valuable real-world findings on the management of RA with tocilizumab.


Arthritis Care and Research | 2012

Time‐dependent increased risk for serious infection from continuous use of tumor necrosis factor antagonists over three years in patients with rheumatoid arthritis

Ryoko Sakai; Yukiko Komano; Michi Tanaka; Toshihiro Nanki; Ryuji Koike; Hayato Nagasawa; Koichi Amano; Atsuo Nakajima; Tatsuya Atsumi; Takao Koike; Atsushi Ihata; Yoshiaki Ishigatsubo; Kazuyoshi Saito; Yoshiya Tanaka; Satoshi Ito; Takayuki Sumida; Shigeto Tohma; Naoto Tamura; Takahiko Sugihara; Atsushi Kawakami; Noboru Hagino; Yukitaka Ueki; Akira Hashiramoto; Kenji Nagasaka; Nobuyuki Miyasaka; Masayoshi Harigai

To investigate associations between continuous treatments with tumor necrosis factor (TNF) antagonists and risk for developing serious infections (SIs) over 3 years in Japanese patients with rheumatoid arthritis (RA) enrolled in the Registry of Japanese RA Patients for Long‐Term Safety (REAL) database.


Annals of the Rheumatic Diseases | 2012

Drug retention rates and relevant risk factors for drug discontinuation due to adverse events in rheumatoid arthritis patients receiving anticytokine therapy with different target molecules

Ryoko Sakai; Michi Tanaka; Toshihiro Nanki; Kaori Watanabe; Hayato Yamazaki; Ryuji Koike; Hayato Nagasawa; Koichi Amano; Kazuyoshi Saito; Yoshiya Tanaka; Satoshi Ito; Takayuki Sumida; Atsushi Ihata; Yoshiaki Ishigatsubo; Tatsuya Atsumi; Takao Koike; Atsuo Nakajima; Naoto Tamura; Hiroaki Dobashi; Shigeto Tohma; Takahiko Sugihara; Yukitaka Ueki; Akira Hashiramoto; Atsushi Kawakami; Noboru Hagino; Nobuyuki Miyasaka; Masayoshi Harigai

Objective To compare reasons for discontinuation and drug retention rates per reason among anticytokine therapies, infliximab, etanercept and tocilizumab, and the risk of discontinuation of biological agents due to adverse events (AE) in patients with rheumatoid arthritis (RA). Method This prospective cohort study included Japanese RA patients who started infliximab (n=412, 636.0 patient-years (PY)), etanercept (n=442, 765.3 PY), or tocilizumab (n=168, 206.5 PY) as the first biological therapy after their enrolment in the Registry of Japanese Rheumatoid Arthritis Patients for Long-term Safety (REAL) database. Drug retention rates were calculated using the Kaplan–Meier method. To compare risks of drug discontinuation due to AE for patients treated with these biological agents, the Cox proportional hazard model was applied. Results The authors found significant differences among the three therapeutic groups in demography, clinical status, comorbidities and usage of concomitant drugs. Development of AE was the most frequent reason for discontinuation of biological agents in the etanercept and tocilizumab groups, and the second most frequent reason in the infliximab group. Discontinuation due to good control was observed most frequently in the infliximab group. Compared with etanercept, the use of infliximab (HR 1.69; 95% CI 1.14 to 2.51) and tocilizumab (HR 1.98; 95% CI 1.04 to 3.76) was significantly associated with a higher risk of discontinuation of biological agents due to AE. Conclusions Reasons for discontinuation are significantly different among biological agents. The use of infliximab and tocilizumab was significantly associated with treatment discontinuation due to AE compared with etanercept.


Rheumatology | 2015

Biologic-free remission of established rheumatoid arthritis after discontinuation of abatacept: a prospective, multicentre, observational study in Japan

Tsutomu Takeuchi; Tsukasa Matsubara; Shuji Ohta; Masaya Mukai; Koichi Amano; Shigeto Tohma; Yoshiya Tanaka; Hisashi Yamanaka; Nobuyuki Miyasaka

Objective. The aim of this study was to determine whether biologic-free remission of RA is possible with discontinuation of abatacept. Methods. Japanese RA patients in 28-joint DAS with CRP (DAS28-CRP) remission (<2.3) after >2 years of abatacept treatment in a phase II study and its long-term extension entered this 52 week, multicentre, non-blinded, prospective, observational study. At enrolment, the patients were offered the option to continue abatacept or not. The primary endpoint was the proportion of patients who remained biologic-free at 52 weeks after discontinuation. Clinical, functional and structural outcomes were compared between those who continued and those who discontinued abatacept. Results. Of 51 patients enrolled, 34 discontinued and 17 continued abatacept treatment. After 52 weeks, 22 of the 34 patients (64.7%) remained biologic-free. Compared with the continuation group, the discontinuation group had a similar remission rate (41.2% vs 64.7%, P = 0.144) although they had a significantly higher mean DAS28-CRP score at week 52 (2.9 vs 2.0, P = 0.012). The two groups were also similar with regard to mean HAQ Disability Index (HAQ-DI) score (0.6 for both, P = 0.920), mean change in total Sharp score (ΔTSS; 0.80 vs 0.32, P = 0.374) and proportion of patients in radiographic remission (ΔTSS ≤ 0.5) at the endpoint (64.3% vs 70.6%, P = 0.752). Those attaining DAS28-CRP < 2.3 or < 2.7 without abatacept at the endpoint had significantly lower HAQ-DI score and/or CRP at enrolment. Non-serious adverse events occurred in three patients who continued or resumed abatacept. Conclusion. Biologic-free remission of RA is possible in some patients after attaining clinical remission with abatacept. Lower baseline HAQ-DI or CRP may predict maintenance of remission or low disease activity after discontinuation of abatacept. Trial registration: UMIN Clinical Trials Registry, http://www.umin.ac.jp/ctr/ (UMIN000004137).


Leukemia & Lymphoma | 2012

Clinicopathological analyses in patients with other iatrogenic immunodeficiency-associated lymphoproliferative diseases and rheumatoid arthritis

Michihide Tokuhira; Reiko Watanabe; Tomoe Nemoto; Morihiko Sagawa; Tatsuki Tomikawa; Jun Ichi Tamaru; Shinji Itoyama; Hayato Nagasawa; Koichi Amano; Hideto Kameda; Tsutomu Takeuchi; Shigehisa Mori; Masahiro Kizaki

Abstract Despite numerous attempts to uncover the mechanism of other iatrogenic immunodeficiency-associated lymphoproliferative diseases (OIIA-LPDs), this mechanism remains poorly understood, especially in rheumatoid arthritis (RA) patients. We analyzed the data on 23 patients with LPDs and RA. Patients were categorized into three groups according to whether they had methotrexate (MTX); MTX-regressive LPDs, MTX-persistent LPDs or other drugs-mediated LPDs. The LPDs seen in OIIA-LPDs-RA might have a unique behavior to think about several rare phenotypes. The overall survival of all patients was 74% at 5 years, and those of the three groups were 100%, 64% and 60%, respectively. Among the 6 patients who died, 4 had LPDs that were detected late, and thus adequate treatment was not given. In addition, several patients with diffuse large B cell lymphoma with a complex karyotype achieved complete remission (CR). Only one among the 17 patients who achieved CR relapsed. OIIA-LPDs-RA appeared to have a better prognosis than other more common types of lymphomas. Regarding RA treatment, various anti-RA drugs were given to the patients after developing LPDs, including MTX, but no recurrent patients were documented.


Annals of the Rheumatic Diseases | 2016

Comparison of adding tocilizumab to methotrexate with switching to tocilizumab in patients with rheumatoid arthritis with inadequate response to methotrexate: 52-week results from a prospective, randomised, controlled study (SURPRISE study)

Yuko Kaneko; Tatsuya Atsumi; Yoshiya Tanaka; Masayuki Inoo; Hitomi Kobayashi-Haraoka; Koichi Amano; Masayuki Miyata; Yohko Murakawa; Hidekata Yasuoka; Shintaro Hirata; Hayato Nagasawa; Eiichi Tanaka; Nobuyuki Miyasaka; Hisashi Yamanaka; Kazuhiko Yamamoto; Tsutomu Takeuchi

Objective To compare the efficacy and safety between tocilizumab added to methotrexate and tocilizumab switched from methotrexate in patients with active rheumatoid arthritis (RA). Methods This is a 2-year randomised, controlled study. RA patients with moderate or high disease activity despite methotrexate were randomly assigned either to tocilizumab added to methotrexate (add-on) or tocilizumab switched from methotrexate (switch). The primary endpoint was the DAS28 remission rate at week 24. Secondary objectives included other clinical efficacy indices, radiological outcomes assessed with the van der Heijde-modified total Sharp scoring system (mTSS), and safety. Results Of 223 randomised patients, 83% completed 52 weeks. DAS28 remission rates at week 24 were 70% for add-on and 55% for switch (p=0.02), but they became comparable at week 52 (72% vs 70%, p=0.86). Structural remission rates (mTSS≤0.5) at week 52 were not different (66% vs 64%, p=0.92). However, clinically relevant radiographic progression rates (CRRP; mTSS≥3) tended to be higher with the switch than with the add-on (15% vs 7%, p=0.07). Radiographic progression in the CRRP patients was larger with the switch than with the add-on (9.0/year vs 5.0/year, p=0.04). The difference in the mean C-reactive protein of the CRRP patients was significant for the first 24 weeks (1.56 vs 0.49, p=0.001) but not for the following 28 weeks (0.10 vs 0.04, p=0.1). Overall safety was preferable in the switch group. Conclusions In RA patients with inadequate response to methotrexate, tocilizumab added to methotrexate more rapidly suppressed inflammation than tocilizumab switched from methotrexate, leading to superior clinical efficacy and prevention of joint destruction. Trial registration number NCT01120366.


The Journal of Rheumatology | 2015

Longterm Safety and Efficacy of Subcutaneous Tocilizumab Monotherapy: Results from the 2-year Open-label Extension of the MUSASHI Study

Atsushi Ogata; Koichi Amano; Hiroaki Dobashi; Masayuki Inoo; Tomonori Ishii; Tsuyoshi Kasama; Shinichi Kawai; Atsushi Kawakami; Tatsuya Koike; Hisaaki Miyahara; Toshiaki Miyamoto; Yasuhiko Munakata; Akira Murasawa; Noriyoshi Ogawa; Tomohiro Ojima; Hajime Sano; Kenrin Shi; Eisuke Shono; Eiichi Suematsu; Hiroki Takahashi; Yoshiya Tanaka; Hiroshi Tsukamoto; Akira Nomura

Objective. To evaluate the longterm safety and efficacy of subcutaneous tocilizumab (TCZ-SC) as monotherapy in patients with rheumatoid arthritis (RA). Methods. Of 346 patients who received 24 weeks of double-blind treatment with either TCZ-SC monotherapy, 162 mg every 2 weeks (q2w); or intravenous TCZ (TCZ-IV) monotherapy, 8 mg/kg every 4 weeks; 319 patients continued to receive TCZ-SC q2w in the 84-week open-label extension (OLE) of the MUSASHI study (JAPICCTI-101117). Efficacy, safety, and immunogenicity were evaluated for all patients treated with TCZ during 108 weeks. Results. The proportions of patients who achieved American College of Rheumatology 20/50/70 responses, low disease activity [28-joint Disease Activity Score (DAS28) ≤ 3.2], or remission (DAS28 < 2.6) at Week 24 were maintained until Week 108. The incidences of adverse events and serious adverse events were 498.3 and 16.9 per 100 patient-years (PY), respectively. The overall safety of TCZ-SC monotherapy was similar to that of TCZ-IV monotherapy. Rates of injection site reactions (ISR) through 108 weeks remained similar to rates through 24 weeks. ISR were mild and did not cause any patient withdrawals. No serious hypersensitivity events (including anaphylactic reactions) occurred. Anti-TCZ antibodies were present in 2.1% of patients treated with TCZ-SC monotherapy. Conclusion. TCZ-SC monotherapy maintained a favorable safety profile and consistent efficacy throughout the 108-week study. Like TCZ-IV, TCZ-SC could provide an additional treatment option for patients with RA.


Modern Rheumatology | 2014

A nationwide survey on the epidemiology and clinical features of eosinophilic granulomatosis with polyangiitis (Churg-Strauss) in Japan

Ken Ei Sada; Koichi Amano; Ritei Uehara; Masahiro Yamamura; Yoshihiro Arimura; Yoshikazu Nakamura; Hirofumi Makino

Abstract Objective. We conducted a cross-sectional nationwide survey to determine eosinophilic granulomatosis with polyangiitis (Churg-Strauss) (EGPA) prevalence and clinical features in Japan. Methods. Data for EGPA patients in 2008 were collected from 1,564 hospitals. In total, 965 patients were reported from 365 departments. In a second survey, clinical data for 473 patients were obtained. Results. We estimated that 1,866 (95% CI: 1,640–2,092) patients have EGPA in Japan (prevalence, 17.8/1,000,000). Of the 473 patients in the second survey, 315 fulfilled American College of Rheumatology (ACR) criteria or Lanhams criteria for EGPA. The mean age (± SD) of the 315 at onset was 55 ± 14 years, male to female ratio 1:2. 93% of patients had neurological manifestations, which were the organ system most frequently involved. Among 277 patients tested for myeloperoxidase (MPO)-/p anti-neutrophil cytoplasmic antibody (ANCA), 139 (50%) were positive, while only 6 of 238 were positive for proteinase3 (PR3)-/cANCA. MPO-ANCA-positive patients had renal involvement, mucous membrane or ophthalmological symptoms, and ENT symptoms more frequently, whereas cutaneous lesions and cardiovascular involvement were less common. Conclusion. The prevalence of EGPA and the frequency of MPO-/p-ANCA-positivity in Japanese EGPA patients were mostly similar to those of Western countries. However, female predominance and a high frequency of neurological manifestations characterized Japanese patients.


Arthritis Research & Therapy | 2015

Head-to-head comparison of the safety of tocilizumab and tumor necrosis factor inhibitors in rheumatoid arthritis patients (RA) in clinical practice: results from the registry of Japanese RA patients on biologics for long-term safety (REAL) registry

Ryoko Sakai; Soo-Kyung Cho; Toshihiro Nanki; Kaori Watanabe; Hayato Yamazaki; Michi Tanaka; Ryuji Koike; Yoshiya Tanaka; Kazuyoshi Saito; Shintaro Hirata; Koichi Amano; Hayato Nagasawa; Takayuki Sumida; Taichi Hayashi; Takahiko Sugihara; Hiroaki Dobashi; Shinsuke Yasuda; Tetsuji Sawada; Kazuhiko Ezawa; Atsuhisa Ueda; Kiyoshi Migita; Nobuyuki Miyasaka; Masayoshi Harigai

IntroductionThe objective of this study was to directly compare the safety of tocilizumab (TCZ) and TNF inhibitors (TNFIs) in rheumatoid arthritis (RA) patients in clinical practice.MethodsThis prospective cohort study included RA patients starting TCZ [TCZ group, n = 302, 224.68 patient-years (PY)] or TNFIs [TNFI group, n = 304, 231.01 PY] from 2008 to 2011 in the registry of Japanese RA patients on biologics for long-term safety registry. We assessed types and incidence rates (IRs) of serious adverse events (SAEs) and serious infections (SIs) during the first year of treatment. Risks of the biologics for SAEs or SIs were calculated using the Cox regression hazard analysis.ResultsPatients in the TCZ group had longer disease duration (P <0.001), higher disease activity (P = 0.019) and more frequently used concomitant corticosteroids (P <0.001) than those in the TNFI group. The crude IR (/100 PY) of SIs [TCZ 10.68 vs. TNFI 3.03; IR ratio (95% confidence interval [CI]), 3.53 (1.52 to 8.18)], but not SAEs [21.36 vs. 14.72; 1.45 (0.94 to 2.25)], was significantly higher in the TCZ group compared with the TNFI group. However, after adjusting for covariates using the Cox regression hazard analysis, treatment with TCZ was not associated with higher risk for SAEs [hazard ratio (HR) 1.28, 95% CI 0.75 to 2.19] or SIs (HR 2.23, 95% CI 0.93 to 5.37).ConclusionsThe adjusted risks for SAEs and SIs were not significantly different between TCZ and TNFIs, indicating an influence of clinical characteristics of the patients on the safety profile of the biologics in clinical practice.

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Hayato Nagasawa

Saitama Medical University

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Hideto Kameda

Saitama Medical University

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Hirofumi Takei

Saitama Medical University

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Masayoshi Harigai

Tokyo Medical and Dental University

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Yoshiya Tanaka

University of Occupational and Environmental Health Japan

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Ayumi Okuyama

Saitama Medical University

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Kazuyoshi Saito

University of Occupational and Environmental Health Japan

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