Rituximab for treatment of non-infectious and non-malignant orbital inflammatory disease.

Purpose: To provide a comprehensive review of rituximab use for the treatment of non-infectious/non-malignant orbital inflammation.

Methods: Review of literature through January 2021.

Results: Individual data was available for 167 patients with refractory non-infectious/non-malignant orbital inflammation who received treatment with rituximab (RTX). Rituximab was generally utilized as third-line or later treatment (108/149, 72.5%) at a mean of 44.6 months following the diagnosis of orbital inflammation (range = 0 to 360 months; median = 13.7 months). Patients with non-infectious/non-malignant orbital inflammation either received prior treatment with corticosteroids only (27/122, 22.1%), or with one (31/122, 25.4%), two (25/122, 20.5%), or three or more (25/122, 20.5%) corticosteroid-sparing immunosuppressive agents with or without corticosteroids before initiation of RTX treatment. The rheumatologic protocol (two infusions of 1 gram of RTX separated by 14 days) was utilized most frequently (80/144, 55.6%), followed by the oncologic protocol (four weekly infusions of 375 mg/m RTX; 51/144, 35.4%). Various other off-label regimens were used infrequently (13/144, 9.0%). Rituximab treatments resulted in a positive therapeutic response for the majority of patients with orbital inflammation (146/166, 88.0%). Commonly treated diagnoses included granulomatosis with polyangiitis (99/167, 59.3%), IgG-4 related disease (36/167, 21.6%), and orbital inflammation of indeterminate cause (25/167, 15.0%). No side effects were reported in 83.3% (55/66) of cases. The most common RTX-induced adverse event was an infusion-related temporary exacerbation of orbital disease (4/66, 6.1%), which occurred prior to the routine use of systemic corticosteroids as pre-conditioning.

Conclusions: Overall, RTX appears to be both efficacious and well-tolerated as second- or third-line therapy for patients with non-infectious/non-malignant orbital inflammation.