Table 1.

A summary of evidence supporting nocebo effects in biosimilar switching studies in patients with rheumatic disease. Adapted from Kristensen LE et al. BioDrugs. 2018 Oct;32(5):397-404 (Kristensen et al., 2018).

Interventions	Study (year)/study design	Evidence
Infliximab/ CT-P13	(Nikiphorou et al., 2015) Observational, single-center	11/39 (28%) patients discontinued CT-P13 6/39 (15%) patients discontinued CT-P13 for subjective reasons No objective worsening of disease activity
	(Glintborg et al., 2017b) Observational registry	117/792 (15%) patients discontinued CT-P13 Main reasons for discontinuation: perceived loss of efficacy [51/792 (6%)] and adverse events [34/792 (4%)] Majority of patients had no change in disease activity
	(Tweehuysen et al., 2017) Observational, multicenter, prospective cohort	44/192 (23%) patients discontinued CT-P13 Main reasons for discontinuation: perceived loss of efficacy [35/192 (8%)] and adverse events [23/192 (12%)] No changes in efficacy, safety, or immunogenicity
	(Scherlinger et al., 2018); (Germain et al., 2018) Observational, single-center	64/89 (72%) patients continued CT-P13 for 33 weeks (median) 25/89 (28%) patients asked to be switched back to originator Reasons for switch back: clinical disease activity [13/25 (52%)]; serum sickness [1/25 (4%)]; no objective disease activity [11/25 (44%)]
Etanercept/ SB4	(Glintborg et al., 2017a) Observational registry (n = 1548)	129/1548 (8%) patients discontinued SB4 during 5-month follow-up Reasons for discontinuation: perceived lack of efficacy [59/1548 (4%)]; adverse events [42/1548 (3%)]; remission [2/1548 (< 1%)]; cancer [4/1548 (< 1%)]; death [1/1548 (< 1%)]; and other/unknown [21/1548 (1%)] Disease activity was unaffected in most patients (3 months pre-switch vs. 3 months post-switch)