Adalimumab biosimilars compared to originator: impact on uveitic macular edema

To evaluate the effect of originator or biosimilar adalimumab on uveitic macular edema (UME) in refractory non-infectious uveitis.

Multicenter retrospective cohort study of non-infectious uveitis patients who received either originator or biosimilar adalimumab. Serial optical coherence tomography monitored UME over 24 months. Main outcomes were time to UME resolution in eyes with baseline UME, and time to UME onset in eyes without baseline UME.

The study included 94 patients (146 eyes): 56 patients (84 eyes) received originator adalimumab and 38 (62 eyes) biosimilars. Median follow-up was 24.0 (IQR 24.0, 24.0) and 12.0 (IQR 6.0, 24.0) months, respectively. Baseline UME was present in 27/84 originator (32.1%) and 22/62 biosimilar eyes (35.5%; p = 0.84). Among eyes with baseline UME, mean CRT decreased in both groups (originator 379.5 ± 68.3 to 304.8 ± 55.1 μm; biosimilar 440.3 ± 125.2 to 267.6 ± 162.4 μm; p < 0.0001) and remained stable in eyes without baseline UME (p = 0.78). UME resolved in 24/27 originator (88.9%) and 13/22 biosimilar eyes (59.1%; p = 0.02). Median time to resolution was 3 and 6 months, respectively; in multivariable analysis, biosimilar use (HR 0.44, 95% CI 0.25-0.77, p = 0.003) and bilateral UME (HR 0.48, 95% CI 0.31-0.76, p = 0.001) were independently associated with delayed resolution. Relapse after resolution occurred in 15/37 eyes (40.5%). New UME developed in 15/57 originator (26.3%) and 7/40 biosimilar eyes (17.5%), with no significant difference in risk (HR 0.99, 95% CI 0.37-2.64).

Treatment with either originator or biosimilar adalimumab is associated with improvement in UME among non-infectious uveitis patients. Treatment with biosimilars resulted in delayed resolution of UME.