OBJECTIVES: Sirolimus was found to be associated with a better outcome of Graves' orbitopathy (GO) at 24 weeks compared to methylprednisolone. We conducted a retrospective study to investigate its efficacy and safety over a longer period. METHODS: Data from 40 consecutive patients with moderate-to-severe, active GO, 20 treated with sirolimus and 20 with methylprednisolone, were collected. PRIMARY OUTCOME: overall outcome (composite evaluation) of GO at 48 weeks. SECONDARY OUTCOMES: (1) GO outcome at 24 weeks, and, at 24 and 48 weeks: (2) outcome of single eye features
(3) quality of life (GO-QoL)
(4) TSH-receptor antibodies
(5) GO relapse at 48 weeks
(6) adverse events. RESULTS: The overall GO outcome at 48 weeks did not differ between the two groups (responders: 55% vs 55%). At 24 weeks, prevalence of responders was greater in sirolimus group (65% vs 25%
P = 0.01). A reduction ≥ 1 point in clinical activity score (CAS) was more frequent in sirolimus patients at 24 (85% vs 40%
P = 0.005) and 48 weeks (75% vs 60%
P = 0.03). The proportion of GO-QoL responders (appearance subscale) at 24 weeks was greater in sirolimus group (62.5% vs 26.3%
P = 0.03). No difference was observed for the remaining outcome measures. CONCLUSIONS: Treatment with sirolimus is followed by a greater overall response of GO compared with methylprednisolone at 24 weeks, but not at 48 weeks, when only CAS is affected. A more prolonged period of treatment may be required for a better outcome to be observed over a longer period.