Endocrine Abstracts

Introduction: Graves’ orbitopathy (GO) is the most common extrathyroidal manifestation of Graves’ disease. The first-line treatment are intravenous corticoids in active moderate-severe GO. Tocilizumab is a humanized monoclonal antibody against the IL-6 receptor which has been approved for the treatment of rheumatoid arthritis and is in its research stage for patients with corticosteroid-refractory GO.

Objectives: To assess the experience with tocilizumab in patients with GO at the University Clinical Hospital of Salamanca.

Material and methods: Retrospective analysis of four patients treated with tocilizumab for GO since 2014. The CAS was ≥3 and TSI antibodies were positive. An intravenous dose of 8 mg/kg was administered every month. The end of the treatment was dependent on clinical improvement (CAS≤2) or negative results for TSI antibodies.

Results: The average age was 45±9.5 years, and 50% of the patients were male. Half of the patients were active smokers and the rest were ex-smokers. Two of them were diabetic. They all presented bilateral moderate-severe GO and three of them had previously received corticoids (4.5 g doses) without any improvement. One patient had received treatment with rituximab, with no results. The average time from the last dose of corticosteroids and the administration of tocilizumab was 5 months. After 6.5±2.6 cycles all the patients showed an improvement of the CAS (6±2.3 before the treatment and 2.3±0.5 after the last cycle (P=0.036)). All the patients showed an improvement of exophthalmos, visual acuity and ocular motility. Two patients required decompression surgery and one patient required radiotherapy. TSI antibodies returned to normal values in all cases. The follow-up since the last dose was 18.3±6.3 months, without any recurrence. None of the described secondary effects were observed, although two of the patients showed asymptomatic CK elevation.

Conclusions: Tocilizumab may be an alternative to corticoids in patients with GO who do not respond to them or who have a contraindication. More studies are necessary to assess the effectiveness and safety of this drug.