To describe the frequency of ocular flares in patients with noninfectious uveitis who were switched from the originator infliximab to a biosimilar infliximab.

Retrospective case series.

All patients with noninfectious uveitis who were switched from the originator infliximab to biosimilar infliximab-abda for nonmedical reasons were reviewed. Patients were excluded if they had less than 3 months of follow-up on either drug. Data included patient demographics, infliximab dosage information, additional immunosuppression medications, and numbers of and times to flares. The main study outcome was frequency of flares, defined as new or worsening inflammatory activity on examination or imaging.

A total of 17 patients met the inclusion criteria. There were no statistical differences between the duration of follow-up while on the originator and the duration while on the biosimilar infliximab (12.0 vs. 10.1 months, respectively; P = .307). Patients experienced more flares per person-years after switching to infliximab-abda (.92), than on the originator infliximab (0.19; P = .028). Four of the 6 patients (66.7%) who experienced flare after switching to infliximab-abda did so within 90 days. Only 1 patient had flares while on originator infliximab went on to develop a single flare on infliximab-abda. The final normalized dosage for patients who flared and remained on infliximab-abda (1.301 mg/kg/week) was higher than that for those who did not flare (1.186 mg/kg/week) but was not statistically significant (P = .417).

Patients who were switched to biosimilar infliximab-abda experience more flares than when previously treated with the originator infliximab. Providers should closely observe patients who switch to biosimilar infliximab, especially within the first 90 days. Patients who do have flares after switching may achieve quiescence with increased biosimilar dosage.