An evaluation of the utilisation of biosimilar monoclonal antibody drugs in Ireland and barriers to their usage

While biologic drugs have demonstrated efficacy across a range of indications, patient access to these drugs is constrained due to their high cost. Biosimilars provide a means to increase patient access while reducing the financial burden.

The primary objective was to determine the current usage of biosimilar and reference trastuzumab and rituximab in four Irish hospitals. A secondary objective involved determining barriers to biosimilar usage.

This project involved a retrospective chart review to analyse the usage of reference and biosimilar versions of trastuzumab and rituximab. Additionally, a prospective cross-sectional study identified barriers to the usage of biosimilars via the distribution of a novel questionnaire to patients, pharmacists, doctors and students.

The utilisation of biosimilar intravenous trastuzumab and rituximab ranged from 39 to 100%, and 0 to 89%, respectively. A total of n = 479 questionnaire responses were included. Biosimilar awareness was significantly lower among ‘Doctors and Medical Students’ (45.3%; 95% [CI, 33.8–57.3%]) compared to ‘Pharmacists and Pharmacy Students’ (97.1%; 95% [CI, 94–98.8%; comparison p < 0.001]). A significant majority of healthcare professionals agreed biosimilars should have consistent nomenclature (p < 0.001). A significant majority of patients (87.3%, 95% [CI, 81.3–92%; p < 0.001]) indicated that they would agree to commence using a biosimilar medicine.

Biosimilar versions of trastuzumab and rituximab were in use to a variable extent. There remains a considerable opportunity to further increase the usage to maximise their potential benefits. A series of challenges were identified including reduced awareness among the medical profession and lack of clear nomenclature.