That could be a key query if long-run drug costs are going to return down for biologic merchandise. We are able to decompose this query into 3 sub-questions:
- What share sufferers initiating remedy begin on a biosimilar?
- What share of sufferers already utilizing a biologic merchandise change to a biosimilar?
- Do affected person of doctor components drive biosimilar prescribing patterns?
A paper by Roberts et al. (2024) goals to reply these questions utilizing the remedy infliximab as a case research. Infliximab is indicated for quite a lot of auto-immune illnesses (e.g., rheumatoid arthritis, Crohn’s illness, psoriatic arthritis).
Strategies
The authors use information from the American School of Rheumatology’s Rheumatology Informatics System for Effectiveness (RISE) registry. RISE is drawn from digital well being data information from >1000 US rheumatologists. The authors run a multilevel logistic regression mannequin clustering sufferers by apply to look at the share of biosimilar prescribing depending on affected person vs. doctor apply components.
Outcomes
- Biosimilar initiation: The authors discovered that for sufferers initiating remedy, 21.6% acquired an infliximab biosimilar between 2017 and 2022. Nevertheless, whereas <10% of sufferers initiated a biosimilar in 2017, by 2022 37% of Medicare sufferers, 51% of commercially insured and 55% of Medicaid sufferers initiated a biosimilar model of infliximab. Sufferers within the lowest socioeconomic standing (as measured by Space Deprivation Index) had been extra prone to provoke a biosimilar (RR = 1.29, 95percentCI 1.01–1.66).
- Biosimilar switching. Whereas there was an rising development to extra biosimilar remedy initiation, switching from biologic to biosimilar was much less frequent. “86.4% of customers who acquired at the very least two doses of infliximab stayed with the formulation they had been initially prescribed.” A lot of the switchers switched from biologic to biosimilar (11.5%) with 1% switching from biosimilar to biologic and <1% switching between biosimilar variations of infliximab.
- Observe stage impacts. The creator’s multi-level modelled revealed that 34% of the variation in switching was defined by variation between practices (as measured by the intraclass correlation coefficient [ICC]). “The median new begins on a biosimilar was 16% (IQR: 6%–27%) throughout practices. Nineteen practices had >40% of latest begins on a biosimilar…The median % of sufferers switched from bio-originator to biosimilar was 11% (IQR = 5–20%) however 14 practices switched >40% of their sufferers.”
https://onlinelibrary.wiley.com/doi/abs/10.1111/1475-6773.14410
Total, we see a development in the direction of elevated biosimilar prescribing however nonetheless vital variability by affected person socioeconomic standing and insurance coverage sort with giant variability in biosimilar use throughout rheumatology practices.
