12 Apr 2023 Health impacts of BC policy switch to biosimilar infliximab for inflammatory bowel disease
On September 5, 2019, British Columbia announced a new policy to switch from originator to biosimilar infliximab for patients with inflammatory bowel diseases (IBD). Subsequently, Dr. Anat Fisher and colleagues in the TI’s Pharmacoepidemiology Working Group analyzed BC administrative health data to assess the impact of this policy. The findings are now published in Gastroenterology Research and Practice and available here: https://doi.org/10.1155/2023/2794220
The analysis involves a “policy cohort” of 1,893 IBD patients (both children and adults) who were affected by the policy because they had been treated with originator infliximab (Remicade) before the new provincial drug benefit policy was announced. Three historical cohorts consisted of similar patients (1,994 to 2,368 patients per cohort) identified in the BC administrative database 1, 2 and 3 years before the new biosimilar substitution policy was implemented.
The historical cohorts showed prescribing trends expected in the absence of a reimbursement policy impact. However, in the year following the policy announcement, 92.3% of users of originator infliximab (Remicade) in the “policy cohort” switched to biosimilar infliximab (brand names: Inflectra, Renflexis).
Dr. Fisher’s study reports an increase in the frequency of infliximab dispensing in the policy cohort, and an increase in dose. However, about half of the patients who increased the infliximab dose had yet to switch to the biosimilar infliximab. The team also reported that after policy implementation, patients visited physicians more commonly (especially gastroenterologists). Dose escalation of infliximab might result from changes in clinical practice and new 2019 guideline recommendations for optimizing infliximab treatment.
The observed decrease in hospitalizations, emergency department visits, and prescriptions for antibiotics and prednisone suggest that patients with inflammatory bowel disease achieved better disease control following the new guideline recommendations.
The TI pharmacoepidemiologists conclude that the results support previous findings of minimal or no harmful effects on patient health of switching from an “originator” biological drug to a “biosimilar” – see also: Biosimilars or Biologics: What’s the difference? Therapeutics Letter 123 (September-October 2019).
This study is one in a series of monitoring studies conducted by the TI’s Pharmacoepidemiology Working Group.
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