Endocrine Abstracts

Objective: Graves’ orbitopathy (GO) is an autoimmune disease that affects about 25% of the patients with Graves’ disease. The thyrotropin receptor (TSHR) is the main autoantigen of GO. Somatostatin receptors (SSR) are expressed by orbital fibroblasts (OB) of GO patients. Pasireotide (SOM230) is a somatostatin analog that has a great affinity for the type 1 and type 5 SSRs and inhibits both orbital human lymphocyte and OB proliferation in vitro. Therefore it is interesting to investigate the effect of SOM230 on predefined endpoints in patients with active moderate to severe GO (MSGO).

Methods: This pilot study evaluated 10 patients with active MSGO treated with SOM230 compared to 10 patients with MSGO treated with methylprednisolone (MPNS). They received 4500 mg of intravenous MPNS or 180 mcg of SOM230 for 12 weeks. Clinial endpoints and quality of life (GOQUOL) were evaluated at time 0 and at 12 weeks. GO activity scored by clinical activity score (CAS) was evaluated at time 0, after they received about half of SOM230 or MPNS total dose and at 12 weeks.

Results: The efficacy of SOM230 and MPNS was similar accordig to overall clinical criteria evaluation and GOQUOL: in both groups 50% and 60% of patients improved respectively. Eyelid aperture improved in the SOM230 group compared to the MPNS group althougth not significantly: −0.7(−2–4.5) vs. −0.15(−3–2), P=0.7. Hertel absolute decrement was not different in the MPNS group compared with the SOM230 group: 0.75±0.8 vs 0.67±0.7, P=0.7, Hertel improved in 3(30%) patients of MNPS group, no patients improved in SOM230 group according to a single point clinical evaluation. CAS absolute decrement at 12 weeks was not different between the groups: −2 (3.2) vs −2 (1.2), P=0.6.

Conclusions: SOM230 showed to be as effective as MPNS to improve GO clinical signs and symptoms in MSGO patients when evaluated by overall clinical criteria.