Objectives Transition from originator biological medicines to their biosimilar equivalents is now part of routine clinical practice, but there is little understanding of patient experiences, which influence adherence and overall satisfaction with care. Understanding this will help ensure future switches adequately address patients’ concerns and expectations leading to better outcomes for all stakeholders.

Method 35 patients participating in a clinical trial including an open-label transition event from originator to biosimilar adalimumab, mimicking what would be encountered in a real-world setting, took part in semi-structured interviews exploring their experience of biosimilar transition.

Results Opinions expressed were often heterogeneous, but common experiences and themes were identified. Five themes were identified following thematic analysis. (1) Understanding and awareness of biosimilars: prior awareness of biosimilars and knowledge of the biosimilar concept was low, indicating a disparity between healthcare professionals and patients. (2) Motivation to undertake transition: patients accept a biosimilar transition to minimise drug expenditure. (3) Initial concerns: before undertaking biosimilar transition away from the brand they had experienced, anticipated loss of efficacy and adverse effects from the biosimilar were common concerns for patients. (4) Reassuring factors: trust in the healthcare team is critical to patient acceptance of biosimilars. Important reassurances include a point of contact, education about biosimilars and monitoring. (5) Experiences during the transition: on reflection, participants described consistent efficacy and tolerability (although 22 participants specifically mentioned injection pain) following brand transition.

Conclusion The majority of patients felt comfortable with future transition to another adalimumab biosimilar. Injection experience was an important component of patient satisfaction.