Abstract
Objectives: To prospectively evaluate the efficacy and tolerability of a six-week extended dosing interval with tocilizumab (TCZ) in patients with rheumatoid arthritis (RA) in sustained remission.
Methods: Patients who received over six doses of intravenous TCZ in clinical remission (disease activity score [DAS] 28 – erythrocyte sedimentation rate [ESR] ≤ 2.6) maintained over 3 months between December 2013 and December 2015 were included. Flare was defined as DAS28-ESR >3.2 at two consecutive visits.
Results: Twenty-five patients were enrolled; 87.5% achieved clinical remission at week 54 after six-week extension and 95.5% achieved a van der Heijde modified total Sharp score (ΔmTSS) ≤0.5. The Health Assessment Questionnaire Disability Index (HAQ-DI) did not increase during 54 weeks. HAQ-DI at baseline and ΔDAS28-ESR at week six positively correlated with increase in DAS28-ESR at week 54. ΔSwollen joint count at week six positively correlated with ΔmTSS at week 54. A total of 12 adverse events occurring in 10 patients did not lead to cessation of TCZ except for one case of recurrent lymphoproliferative disorder at week five.
Conclusion: A six-week extended dosing interval of TCZ for patients with RA in sustained remission is proposed as an acceptable treatment option for maintaining efficacy and tolerability.
Acknowledgements
The authors wish to thank all clinical research assistants in the Department of Rheumatology and Clinical Immunology, Saitama Medical Center, Saitama Medical University, including Izumi Ohshima, Masami Sato, Mayumi Suzuki, Miyuki Suzuki, Takashi Kukita, Machiko Kawamura, and Megumi Sawada for the support to conduct the study.
Conflict of interest
J.K. has received fees for speaking from Bristol-Myers Squibb, Chugai Pharmaceutical Co. Ltd., Eisai Co. Ltd., Pfizer Japan Inc. K.A. has received fees for speaking from Pfizer Japan Inc., Mitsubishi Tanabe Pharma Corp. All other authors have no conflicts of interest to declare.