The Nocebo Effect in a Non-Medical Switching Program from Originator to Biosimilar Infliximab in Inflammatory Bowel...

Despite growing awareness of the nocebo effect, few studies have evaluated the nocebo effect using combined assessment of patient-reported outcome measures (PROMs), clinical indices, and objective biomarkers in inflammatory bowel disease (IBD) patients switching from originator to biosimilar medicines.

This study aimed to compare these outcomes across switch and non-switch cohorts to evaluate the nocebo effect in patients with IBD.

Parallel cohorts of IBD patients who (1) switched from originator to biosimilar (CT-P13) infliximab and (2) continued biosimilar (CT-P13) infliximab were evaluated over 32 weeks. Clinical disease activity, objective biomarkers and PROMs were assessed at baseline, and weeks 16 and 32 across both cohorts. The PROM of interest was patient-perceived disease activity evaluated using a 0-100 visual analogue scale (VAS) per the IBD-Control Questionnaire.

Of 81 patients, 47 switched from originator to biosimilar (CT-P13) infliximab. A negative change from baseline patient-reported disease control was observed across the switch cohort compared with the non-switch cohort at week 16 (mean VAS - 8.21 vs. 1.26; p = 0.03), but not at week 32 (mean VAS - 1.21 vs. 1.38; p = 0.58). Corresponding clinical and objective biomarker assessments over these timepoints were comparable across both cohorts.

This study demonstrated a temporary yet discernible nocebo effect in the first 16 weeks following non-medical switching that was not sustained at week 32. Negative patient perceptions may be overcome by a patient-inclusive approach to non-medical switching in conjunction with close clinical follow-up and disease monitoring.