Switching Australian patients with moderate to severe inflammatory bowel disease from originator to biosimilar infliximab: a multicentre, parallel cohort study.

OBJECTIVE

To examine whether non-medical switching of patients with inflammatory bowel disease (IBD) from originator infliximab to a biosimilar (CT-P13, Inflectra) is safe and clinically non-inferior to continued treatment with originator infliximab.

DESIGN

Prospective, open label, multicentre, parallel cohort, non-inferiority study in seven Australian hospitals over 48 weeks, May 2017 - October 2019.

PARTICIPANTS

Adults (18 years or older) with IBD receiving maintenance originator infliximab (Remicade) who had been in steroid-free clinical remission for at least 12 weeks.

INTERVENTION: Managed program for switching patients in four hospitals from originator to biosimilar infliximab (CT-P13); patients in three other hospitals continued to receive originator infliximab (control).

MAIN OUTCOME MEASURES: Clinical disease worsening requiring infliximab dose escalation or change in therapy.

RESULTS

The switch group included 204 patients, the control group 141 patients with IBD. Ten patients in the control group (7%) and 16 patients switched to CT-P13 (8%) experienced clinical deterioration; the adjusted risk difference (control v switch group) was -1.1 percentage points (95% CI, -6.1 to 8.2 percentage points), within our pre-specified non-inferiority margin of 15 percentage points. Serious adverse events leading to infliximab discontinuation were infrequent in both the switch (six, 3%) and control (six, 4%) groups.

CONCLUSION

Switching patients with IBD from originator to biosimilar infliximab is safe and non-inferior to continuing treatment with originator infliximab. Moreover, the introduction of biosimilar infliximab, by increasing market competition, has resulted in substantial cost savings for the Pharmaceutical Benefits Scheme.