Recurrence rates of inflammation after switching from originator infliximab to biosimilar infliximab-abda for non-infectious uveitis

Abstract: Purpose To describe the frequency of ocular flares in patients with non-infectious uveitis who switch from originator infliximab to biosimilar infliximab. Design Retrospective case series Methods We reviewed all patients with non-infectious uveitis who were switched from originator infliximab to biosimilar infliximab-abda for non-medical reasons. Patients were excluded if they had less than three months of follow-up on either drug. Data was collected including patient demographics, infliximab dosing information, additional immunosuppression medications, number and time to flare. The main study outcome was frequency of flares, defined as new or worsening inflammatory activity on exam or imaging. Results 17 patients met the inclusion criteria. There was no statistical difference in the duration of follow-up reviewed while on originator or biosimilar infliximab (12.0 vs 10.1 months, P=0.307). Patients experienced more flares per person-years after switching to infliximab-abda (0.92), than when on originator infliximab (0.19, P=0.028). Four of the six patients (66.7%) who flared after switching to infliximab-abda did so within 90 days. Only one patient who flared on originator infliximab went on to develop a single flare on infliximab-abda. The final normalized dose of patients who flared and remained on infliximab-abda (1.301 mg/kg/week) was higher than those who didn’t flare (1.186 mg/kg/week), but was not statistically significant (P=0.417). Conclusions Patients who switch to biosimilar infliximab-abda experience more flares than when previously treated with originator infliximab. Providers should closely observe patients who switch to biosimilar infliximab, especially within the first 90 days. Those who do flare after switching may achieve quiescence with increased biosimilar dosing.