Rates of medication persistence are similar for subcutaneous TNF inhibitors in a range of inflammatory rheumatic disorders, a ‘real world’ Australian study has shown.
After four years there were no significant differences in the proportion of patients persisting with different TNF inhibitors, data from 3749 biologic-naïve patients with RA, ankylosing spondylitis, psoriatic arthritis or undifferentiated arthritis found.
The findings come from a retrospective cohort study of new users of TNF inhibitors between 2010 and 2016, derived from the Australian Optimising Patient outcome in Australian RheumatoLogy (OPAL) registry.
Median treatment persistence rates were 33.6 months for adalimumab, 24.8 months for certolizumab, 27.6 months for etanercept and 30.3 months for golimumab.
Analysis showed no difference in persistence rates in the overall population or in a propensity matched population.
A small drop in persistence seen at three months likely reflected the effect of PBS continuation criteria to show an adequate treatment response. Another drop in persistence rates noticeable at nine months probably reflected primary failure, according to the study authors led by rheumatologist Associate Professor Kathleen Tymms of Canberra Rheumatology.
The findings contrasted with some recent reports that had suggested persistence with golimumab was better than with adalimumab and etanercept. However they were consistent with other real world studies showing no difference in persistence rates between different agents.
“Persistence rates in these real-world evidence studies are lower than those reported in clinical trials,” they noted.
“The reasons for this are not clear, but may reflect difficulty in accessing TNFi if certain efficacy criteria are not met, or due to factors associated with the clinical trial itself, such as easier access to health care. Loss to follow-up is also problematic in real-world studies.”
The study was sponsored by Janssen-Cilag, manufacturer of golimumab, and is published in Clinical Rheumatology.