(B-045) Uptake and use of biologic medicines in paediatric immune-mediated inflammatory diseases: An Australian population-based study

Monday, August 25, 2025

11:30 AM - 1:00 PM ET

Presenting Author(s)

JH

Jun Ni Ho, BPharm (Hons)

PhD Candidate
Quality Use of Medicines and Pharmacy Research Centre, Clinical and Health Sciences, University of South Australia, Adelaide, Australia, Australia

Co-Author(s)

NP

Nicole Pratt, PhD

Professor
Quality Use of Medicines and Pharmacy Research Centre, Clinical and Health Sciences, University of South Australia, Adelaide, Australia, Australia
JH

Jodie Hillen, PhD

Senior Research Fellow
School of Pharmacy and Pharmaceutical Sciences, Faculty of Health, Medicine and Behavioural Sciences, The University of Queensland, Brisbane, Australia, Australia
NN

Natasha Nassar, PhD

Professor
Child Population and Translational Health Research, Children's Hospital at Westmead Clinical School, Faculty of Medicine and Health, Charles Perkins Centre, The University of Sydney, New South Wales, Australia, Australia
HZ

Helga Zoega, PhD

Professor
Centre of Public Health Sciences, Faculty of Medicine, University of Iceland, Reykjavik, Iceland, Iceland
RL

Renly Lim, PhD

Senior Research Fellow
Quality Use of Medicines and Pharmacy Research Centre, Clinical and Health Sciences, University of South Australia, Adelaide, Australia
Adelaide, South Australia, Australia
BD

Benjamin Daniels, PhD

Senior Research Fellow
Medicines Intelligence Research Program, School of Population Health, University of New South Wales, Sydney, Australia, Australia

Background: The extent of use of biologic medicines in paediatric immune-mediated inflammatory diseases (IMIDs) is poorly understood. These medicines often have missing safety information at market launch and the real-world evidence on the extent of exposure in children is lacking.

Objectives: To describe the uptake, use and characteristics of children initiating biologic medicines.

Methods: We used Australian Pharmaceutical Benefits Scheme dispensing claims from a random 15% sample (2013 – 2017) and 30% sample (2017 – 2020) of young Australians ( < 18 years). We examined nine biologic medicines used to treat severe asthma, inflammatory arthropathies, inflammatory skin diseases and inflammatory bowel diseases (IBD). We estimated annual incidence (number dispensed a medicine of interest during each calendar year with no previous dispensing in the preceding 12 months) and prevalence (number dispensed a medicine of interest during each calendar year) per 1,000,000 population < 18 years using Australian Bureau of Statistics population estimates. We described patient and treatment characteristics at the time of first biologic medicine dispensing.

Results: A total of 1,131 children from the samples were dispensed at least one biologic medicine during the study period. Nearly 80% of children were exposed to infliximab, adalimumab or etanercept. Between 2014 and 2020, the annual incidence of children using infliximab, adalimumab and etanercept increased from 66.0, 17.6, and 13.2/1,000,000, respectively, to 88.4, 49.6 and 19.4/1,000,000. Prevalence for all medicines increased over time across the study period. Mean age at first biologic dispensing was 14 years (s.d.: 3 years); 51% of children were male. 55% children were first dispensed biologic medicines for IBD, 29% for inflammatory arthropathies, and 10% for inflammatory skin diseases. 15% children were dispensed two or more unique biologic medicines and 3% three or more over the study period.

Conclusions: Uptake and use of biologic medicines for paediatric IMIDs increased steadily over time, suggesting children were staying on treatment for extended periods of time. Long-term safety remains largely unknown, despite several medicines having more than 10 years of market histories. Future real-world studies should prioritise post-market surveillance in children, particularly the safety of use of multiple biologic medicines and longer-term safety.