Avouac J, et al. - An inquiry was set up with regard to the effectiveness of systematic switching the treatment from innovator infliximab to biosimilar infliximab, and its associated factors. There did not appear to be any variations in drug trough levels or objective parameters, after the switch. Variations were reported only in the patient-reported outcomes. This, in turn, [pointed out towards attribution effects rather than pharmacological differences.

Methods

• The scheme of this trial was a prospective observational study.
• Herein, all adult patients receiving maintenance therapy with innovator infliximab in Cochin University Hospital were systematically switched to biosimilar infliximab.
• An examination was performed of the effectiveness through the retention rate of biosimilar infliximab at the time of the third infusion.
• Sensitivity analyses for effectiveness comprised of the variations of the disease activity parameters and infliximab trough levels between baseline and the last visit.
• It also included the occurrence of adverse events leading to drug discontinuation.
• This study also inspected the factors related to biosimilar infliximab discontinuation at the last visit.

Results

• The eligible candidates were 260 in number, including 31 rheumatoid arthritis (RA), 131 axial spondyloarthritis (axSpA) and 64 inflammatory bowel diseases.
• At the time of the third biosimilar infusion, the retention rate was 85% (221/260 patients).
• 59 patients (23%) discontinued biosimilar infliximab, between baseline and the last visit (mean follow-up of 34 weeks).
• This was attributed to experienced inefficacy (n=47, 80%).
• There was no connection between the clinical or biological factors with biosimilar discontinuation.
• There were no reports of serious adverse events.
• The data did not disclose any change in the objective disease activity parameters or infliximab trough levels.
• A substantial increase of BASDAI (2.94±2.20 vs. 3.18±2.21, p=0.046, before vs. after switch, respectively) was brought to light, in patients with axSpA.
• Re-establishment was carried out of the innovator infliximab in 47/59 patients (80%).