Efficacy and safety of rituximab in Japanese patients with acquired thrombotic thrombocytopenic purpura refractory to conventional therapy

Yoshitaka Miyakawa, Kazunori Imada, Tatsuo Ichinohe, Kenji Nishio, Takayuki Abe, Mitsuru Murata, Yasunori Ueda, Yoshihiro Fujimura, Masanori Matsumoto, Shinichiro Okamoto

Research output: Contribution to journalArticle

4 Citations (Scopus)


Thrombotic thrombocytopenic purpura (TTP), while rare, is a potentially life-threatening disorder. Plasma exchange (PE) is considered the primary treatment for TTP. In Western countries, rituximab, an anti-CD20 antibody, is recommended with PE for the treatment of refractory/relapsed TTP, and as up-front therapy in newly diagnosed TTP with neurological/cardiac pathology. The present open-label, single-arm, multicenter study evaluated the efficacy and safety of rituximab in Japanese patients with refractory/relapsed TTP. Patients received rituximab 375 mg/m2 intravenously, once weekly for a total of four treatments, with PE and steroids. Of six evaluable patients in the full analysis set, two met the primary efficacy endpoint (platelet count >150 × 109/L at week 4), yielding a 33.3 % response rate (95 % confidence interval: 4.3–77.7). While the lower confidence limit of the primary efficacy endpoint failed to reach the pre-specified threshold of 30 %, clinically significant recovery of platelet count with discontinuation of PE, increase of ADAMTS13 activity, disappearance of ADAMTS13 inhibitor, and improvement of TTP-associated clinical manifestations were observed after rituximab therapy in all patients. No safety concerns were identified in this study; therefore, rituximab is considered a useful treatment option in Japanese TTP patients who are refractory to conventional therapy. Trial registration JMA-IIA00160.

Original languageEnglish
Pages (from-to)1-8
Number of pages8
JournalInternational Journal of Hematology
Publication statusAccepted/In press - 2016 May 17



  • ADAMTS13
  • Rituximab
  • Thrombotic thrombocytopenic purpura

ASJC Scopus subject areas

  • Hematology

Cite this