Tocilizumab for the Management of Glucocorticoid-Refractory Idiopathic Orbital Inflammation

Abstract

Abstract Background: To demonstrate the efficacy of the anti-interleukin-6 receptor monoclonal antibody tocilizumab in patients with glucocorticoid-refractory idiopathic orbital inflammation (IOI). Patients and Methods: A retrospective, observational case series study on 16 (10 females, 6 male) consecutive patients treated with TCZ for glucocorticoid-refractory IOI between September 2020 and January 2022. Median follow-up was 14.0±4.68 months (range, 9-24 months). The mean age of the patients was 34.5±9.93 years (range, 19-60 years), All patients had been treated with glucocorticoid but condition is repeatedly reactivated when steroid tapering for 0.5-3 years. Each patient underwent ophthalmological examinations, laboratory tests, CT/MRI of orbit, and received the initiated treatment with a monthly dose of 8 mg/kg TCZ for 2 to 6 cycles. TCZ was withdrawn due to low disease activity. Patient-reported outcomes, clinician-reported outcomes, and CT/MRI findings of the orbit after treatment were collected at the follow-up to assess the response. Results: Among the patients, 7 (44%) had myositis, 5 (31%) had diffuse IOI, 2 (13%) had dacryoadenitis, and 2 (13%) had anterior IOI. All patients (100%) had eyelid swelling and oppressive orbital pain, 12 (75%) had diplopia and ocular motility restriction, 9 (56%) had ptosis, and 1 (6%) had vision decline. After one treatment with TCZ, the eyelid swelling, ptosis, and orbital pain improved in all patients and completely relieved after all treatments. The average numeric pain rating scale score of all patients was 4.88±2.18 (range, 2-9) and dropped to 0 before and after TCZ treatment respectively (P<0.01). At the last TCZ treatment, the diplopia had resolved in 67% (8/12) patients and significantly reduced in 33% (4/12) patients who had orbital biopsy operations or external beam radiotherapy history; the vision of the patient with the most serious diffuse IOI was improved from 0.1 to 1.0; 11 patients with single or multiple enlarged extraocular muscles showed a significant CT/MRI reduction of the orbital lesion and a stable clinical improvement for the follow-up time of observation. To date, no recurrence was occurred and no side effects of TCZ have been reported. Conclusion: TCZ can reduce orbital pain, eyelid swelling, muscle enlarge, ocular motility limitation of glucocorticoid-refractory IOI. Treatment with TCZ appears to offer another therapeutic option in cases of recalcitrant or recurrent IOI in which conventional treatment fails or contraindications to intravenous glucocorticoid pulse therapy.