A biosimilar is a biological medicine that shows no clinically meaningful differences with another already approved biological medicine (the ‘reference medicine’). A new study in Arthritis and Rheumatology found that one-quarter of patients with rheumatoid arthritis, psoriatic arthritis, or ankylosing spondylitis who switched from reference infliximab to biosimilar infliximab (called CT-P13) stopped taking CT-P13 during six months follow-up, mainly due to subjective health complaints.
The substantial discontinuation rate of CT-P13 after open-label transitioning might be explained by the awareness of clinicians and patients of the transition. This awareness might induce negative expectations about transitioning to a biosimilar, resulting in negative symptoms during treatment (nocebo effect) and/or incorrect causal attributions.
“As a result, communication between clinicians and patients seems to be the determining factor of the success of transitioning to a biosimilar in daily practice”, said lead author Dr. Lieke Tweehuysen, of Sint Maartenskliniek, in the Netherlands.