2022 Volume 34 Issue 4 Pages 298-306
Objective: The retrospective study investigated the effects of switching from etanercept reference product（ETN-RP）to etanercept biosimilar（ETN-BS）on disease activity, physical function, and patient reported outcome（PRO）regarding a self-injection device in patients with well-controlled RA.
Method: We retrospectively investigated Disease Activity Score 28- C-reactive protein（DAS28-CRP）, modified health assessments questionnaire（mHAQ）, Simplified Disease Activity Index（SDAI）and patient characteristics in 42 RA patients that switched from ETN-RP to ETN-BS at least 6 months prior. Patients were also requested to answer the Toyohashi Self-Injection Assessment Questionnaire（T-SAQ）, originally designed to assess PRO.
Results: The mean age, RA duration, and ETN-RP treatment duration were 63.1 years, 18.3 years, and 3107 days, respectively. Mean disease activity and mean mHAQ after switching were as follows（baseline, 3 months, 6 months）: DAS28-CRP（1.86, 2.00, 2.03）, SDAI（4.3, 5.0, 5.3）, and mHAQ（0.43, 0.44, 0.46）. Low disease activity was maintained for 6 months. Tender joints count at 3 months and patients’ global assessment at 6 months after switching are significantly increased compared to baseline（p<0.05, p<0.001, respectively）. Total T-SAQ scores before and after switching were 1.3 and 1.1（p<0.01）, respectively. Ease of use, mental tension, and pain were especially improved after switching to ETN-BS.
Conclusion: Switching from ETN-RP to ETN-BS maintained low disease activity for 6 months in our clinical practice.
Although some cases worsened subjective complaint, nocebo effect might be one of the reasons to explain the results. On the other hand, the PRO regarding the injection device was improved.
