著者

矢船 明史 竹内 正弘 成川 衛

出版者

日本臨床薬理学会

雑誌

臨床薬理 (ISSN:03881601)

巻号頁・発行日

vol.31, no.6, pp.705-713, 2000-11-30 (Released:2010-06-28)

参考文献数

20

被引用文献数

1

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Since nonlinear mixed effects model is statistically quite complicated, it is not possible to obtain the analytical forms of the marginal mean and its corresponding covariance matrix for observations. To circumvent this issue, a first-order Taylor series expansion is generally employed to approximate a nonlinear model with a linear form additive in inter-subject random effects. This linear approximation is based on the assumption that the parameter variation among subjects is negligible, which is quite hard to satisfy in actual clinical data analyses. Consequently, the linear approximation probably leads to inconsistent estimators. This paper describes the statistical issues regarding the first-order linear approximation in nonlinear mixed effects models.

著者

還田 悠平 髙山 茜 成川 衛

出版者

一般社団法人 日本臨床薬理学会

雑誌

臨床薬理 (ISSN:03881601)

巻号頁・発行日

vol.48, no.1, pp.9-14, 2017-01-31 (Released:2017-02-17)

参考文献数

13

被引用文献数

1 1

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Background: In Japan, delay in marketing approval of new drugs, known as “drug lag”, was believed to hinder patient access to innovative treatments. The Japanese government took several corrective measures, and the median review time for new drugs was shortened. However, in many cases, new drugs are developed in the United States (US) and European Union (EU) , and these drugs are usually approved first in the US and EU prior to approval in Japan. Increase of drugs approved in Japan before the rest of the world or simultaneous with other countries is expected to further improve patient access to innovative drugs.Method: For all New Active Substances (NASs)that were approved in Japan between January 2008 and December 2014 , detailed information including the regions where the new drugs were developed and the countries of first global approval were identified. We also collected information about safety concerns that were identified before approval.Result: Two hundred and thirty-nine NASs obtained Japanese approval during the study period. Of the 239 NASs, 44 (18.4%) were approved in Japan before the rest of the world. Drugs that obtained Japanese approval first in the world were more often developed in Japan from the early stage. Furthermore, the data suggested that these drugs were launched with relatively limited safety information. Conclusion: For better patient access to new drugs, it is important to facilitate early development of new drugs in Japan and at the same time to ensure further strengthening of post-marketing safety measures.

著者

還田 悠平 髙山 茜 成川 衛

出版者

一般社団法人 日本臨床薬理学会

雑誌

臨床薬理 (ISSN:03881601)

巻号頁・発行日

vol.48, no.1, pp.9-14, 2017

被引用文献数

1

---

<p><b>Background</b>: In Japan, delay in marketing approval of new drugs, known as &ldquo;drug lag&rdquo;, was believed to hinder patient access to innovative treatments. The Japanese government took several corrective measures, and the median review time for new drugs was shortened. However, in many cases, new drugs are developed in the United States (US) and European Union (EU) , and these drugs are usually approved first in the US and EU prior to approval in Japan. Increase of drugs approved in Japan before the rest of the world or simultaneous with other countries is expected to further improve patient access to innovative drugs.</p><p><b>Method</b>: For all New Active Substances (NASs)that were approved in Japan between January 2008 and December 2014 , detailed information including the regions where the new drugs were developed and the countries of first global approval were identified. We also collected information about safety concerns that were identified before approval.</p><p><b>Result</b>: Two hundred and thirty-nine NASs obtained Japanese approval during the study period. Of the 239 NASs, 44 (18.4%) were approved in Japan before the rest of the world. Drugs that obtained Japanese approval first in the world were more often developed in Japan from the early stage. Furthermore, the data suggested that these drugs were launched with relatively limited safety information.</p><p></p><b>Conclusion</b>: For better patient access to new drugs, it is important to facilitate early development of new drugs in Japan and at the same time to ensure further strengthening of post-marketing safety measures.

著者

高山 茜 成川 衛

出版者

一般社団法人 レギュラトリーサイエンス学会

雑誌

レギュラトリーサイエンス学会誌 (ISSN:21857113)

巻号頁・発行日

vol.6, no.2, pp.119-126, 2016 (Released:2016-05-31)

参考文献数

4

被引用文献数

1

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本研究では, わが国の薬価算定における補正加算などの適用状況を提示し, 有用性加算および営業利益率の加算的補正の取得に影響を与え得る要因を検討した. 2004年10月から2014年12月の期間に, 464の新薬が薬価収載され, うち285医薬品 (61.4%) が類似薬効比較方式で, 135医薬品 (29.1%) が原価計算方式で薬価算定された. 類似薬効比較方式で算定された285品目のうち, 89品目 (31.2%) が有用性加算を取得した. 原価計算方式で算定された135品目のうち, 33品目 (24.4%) が営業利益率の加算的補正を受けた. 類似薬効比較方式 (Ⅰ) で算定された品目において, 新規の作用機序を有する品目では, その他の品目と比べ, 有用性加算を取得した品目割合は大きく (p<0.0001), さらに, 実薬を対照として優越性が検証された品目では, 非劣性が示された品目 (p=0.0013), プラセボを対照として有効性が検証された品目 (p=0.0046) と比べ, 有用性加算を取得した品目の割合は大きかった. 同様に, 原価計算方式で算定された品目において, 実薬を対照とし有効性が検証された品目では, 単群試験のみが実施された品目と比べ, 営業利益率の加算的補正を受ける品目の割合は大きかった (p=0.0021). 一方, 適用された加算率および加算的補正率の大きさについては一定の傾向はみられなかった.

著者

盛岡 一輝 髙山 茜 成川 衛

出版者

一般社団法人 レギュラトリーサイエンス学会

雑誌

レギュラトリーサイエンス学会誌 (ISSN:21857113)

巻号頁・発行日

vol.7, no.3, pp.151-162, 2017 (Released:2017-09-30)

参考文献数

25

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本研究では, 我が国で現在もなお臨床現場で活用されている古くからある医薬品に着目し, 臨床上の有用性および利便性の観点からその特性を分析した. 1999年以前に我が国で承認され, 2013年国内売上高100億円以上の医療用医薬品を 「ロングセラー医薬品」 と定義し, 併せて, 各ロングセラー医薬品の競合品を2013年時点で製造販売されていた医薬品から選出した. 2013年国内売上高100億円以上であった154医薬品のうち, 58医薬品 (38%) がロングセラー医薬品であった. ロングセラー医薬品では, その競合品に比べて, 適応症に係る治療ガイドラインで第一選択として推奨される作用機序をもつ医薬品の占める割合が大きかった. また, 作用機序が同一の医薬品群における検討では, ロングセラー医薬品の添付文書には, その競合品の添付文書に比べて豊富な臨床成績が記載されており, さらに, 競合品に比べて適応症に係る治療ガイドラインで引用された市販後臨床成績をもつ医薬品の占める割合が大きかった. また, ロングセラー医薬品の1日投与回数は, その競合品の1日投与回数に比べて少なかった. 豊富な臨床上の有用性に係るエビデンスを有し, 新薬に比べて相対的に安価なロングセラー医薬品の活用は, 質の高い効率的な医療の提供および医療費の適正化の面から重要と考える.

著者

竹内 正弘 矢船 明史 成川 衛

出版者

日本臨床薬理学会

雑誌

臨床薬理 (ISSN:03881601)

巻号頁・発行日

vol.31, no.5, pp.659-665, 2000-09-30 (Released:2010-06-28)

参考文献数

26

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Nonlinear mixed effects models are often used for the analysis of repeated measure ments in clinical trials. A typical example is population pharmacokinetic analysis. Due to the statistical complexity, careful attention must be paid to some statistical issues in order to obtain reliable and robust results. This paper provides a description of the notes on the use of nonlinear mixed effects models for the analysis of repeated measurements in clinical trials. Three main issues are discussed in this paper: 1) a first-order lineariza tion, 2) a missing data, and 3) a measurement error.

著者

成川 衛

出版者

一般社団法人 日本臨床薬理学会

雑誌

臨床薬理 (ISSN:03881601)

巻号頁・発行日

vol.40, no.3, pp.101-104, 2009 (Released:2009-08-12)

参考文献数

4