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

Background 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. Aims 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. Methods 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. Results 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. Conclusion 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.