Vol.23 No.2

Original Article

Phase II dose-response study of abatacept in Japanese patients with active rheumatoid arthritis with an inadequate response to methotrexate

Authors

Tsutomu Takeuchi1 , Tsukasa Matsubara2 , Taisuke Nitobe3 , Eiichi Suematsu4 , Syuji Ohta5 , Shigeru Honjo6 , Tohru Abe7 , Ami Yamamoto8 , Nobuyuki Miyasaka9 , The Japan Abatacept Study Group

  • Division of Rheumatology, Department of Internal Medicine, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
  • Department of Orthopedics, Matsubara Mayflower Hospital, Hyogo, Japan 944-25 Fujita, Kato, Hyogo, 673-1462, Japan
  • Department of Rheumatology, Seihoku Chuo Hospital, Aomori, Japan 41 Nunoyacho, Gosyogawara, Aomori, 037-0053, Japan
  • Department of Internal Medicine and Rheumatology, National Hospital Organization Kyushu Medical Center, Fukuoka, Japan 1-8-1 Jigyohama, Chuo-ku, Fukuoka, 810-8563, Japan
  • Department of Rheumatology, Taga General Hospital, Ibaraki, Japan 2-1-2 Kokubun-cho, Hitachi, Ibaraki, 316-0035, Japan
  • Honjo Rheumatism Clinic, Toyama, Japan 387-1 Futatsuka, Takaoka, Toyama, 933-8525, Japan
  • Division of Rheumatology, Clinical Immunology, Saitama Medical Center/School, Saitama, Japan 1981 Kamoda, Kawagoe, Saitama, 350-8550, Japan
  • Bristol-Myers KK, Tokyo, Japan 6-5-1, Nishi-shinjuku, Shinjuku-ku, Tokyo, 163-1328, Japan
  • Department of Medicine and Rheumatology and Global Center of Excellence, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yusima, Bunkyo-ku, Tokyo, 113-8519, Japan
Received:

15 March 2012

Accepted:

24 April 2012

Published online:

9 June 2012

Full Text

PDF　(member's only)

Abstract

Objective The objective of this study was to assess the response to abatacept at doses of 2 mg/kg and 10 mg/kg compared to placebo in patients with active rheumatoid arthritis (RA) with an inadequate clinical response to methotrexate (MTX).
Methods In this multicenter, placebo-controlled, doubleblind, parallel-group, dose-response study, 195 Japanese patients with active RA with an inadequate response to MTX were randomized 1:1:1 to receive 10 mg/kg or 2 mg/kg abatacept plus MTX, or placebo plus MTX, for 24 weeks.
Results Abatacept demonstrated a dose-response relationship when given at 2 and 10 mg/kg. Based on the American College of Rheumatology criteria (20, 50, and 70 %), the responses to 10 mg/kg abatacept were significantly greater than those to placebo at week 24 (p<0.001). Smaller yet statistically significant responses were also seen in the 2 mg/kg abatacept group. Overall rates of adverse events, serious adverse events, and treatment discontinuations because of adverse events were comparable in all three groups.
Conclusions Abatacept (2 mg/kg and 10 mg/kg) showed a dose-response relationship in Japanese patients with active RA with an inadequate clinical response to MTX. Administration of abatacept in combination with MTX for 24 weeks was well tolerated.

Key words

Abatacept - Active rheumatoid arthritis - Clinical response - Japan - Methotrexate