Statins for Graves' orbitopathy (STAGO): a phase 2, open-label, adaptive, single centre, randomised clinical trial.

BACKGROUND: A protective action of statins on development of Graves' orbitopathy suggests that statins might be used for treatment of the disease. We aimed to assess the efficacy of the addition of a statin, atorvastatin, to intravenous glucocorticoids (ivGCs) on Graves' orbitopathy outcomes in patients with hypercholesterolaemia.

METHODS: We did a randomised, open-label, phase 2, adaptive, clinical trial at a single, tertiary, referral hospital in Pisa, Italy. Patients with moderate-to-severe, active Graves' orbitopathy, with a low-density lipoprotein cholesterol concentration between 2·97 and 4·88 mmol/L were eligible for inclusion. Patients were randomly assigned (1:1) in 11 blocks of eight, using a computer-based system, to the ST group or the NST group. The ST group received ivGCs (methylprednisolone 500 mg once a week for 6 weeks followed by 250 mg once a week for an additional six weeks) for 12 weeks and oral atorvastatin (20 mg once a day) for 24 weeks. The NST group only received the ivGC regimen. Patients were unmasked to group allocation; however, the ophthalmological investigator was masked to randomisation. The primary endpoint was the Graves' orbitopathy outcome (composite evaluation of exophthalmos, clinical activity score, eyelid aperture, and diplopia) at 24 weeks in the modified intention-to-treat (ITT) population (patients who attended the week 12 visit). Patients were considered responders when at least two of the following criteria were fulfilled in the most affected eye, without worsening in any of the same measures in both eyes: (1) reduction in exophthalmos of 2 mm or more, with no increase by 2 mm or more in the other eye; (2) reduction of clinical activity score by two or more points; (3) reduction in eyelid aperture by 2 mm or more, with no increase by 2 mm or more in the other eye; and (4) disappearance or improvement (change from constant to inconstant, intermittent, or absent, or from inconstant to intermittent or absent) of diplopia, and (5) improvement in visual acuity by 0·2 decimals or more. The trial is registered with EUDRACT, 2018-001317-33, and ClinicalTrials.gov, NCT03110848.

FINDINGS: Between June 1, 2020, and Nov 30, 2020, 119 patients were screened for inclusion, of whom 88 (74%) patients were enrolled and randomly assigned to one of the two treatment groups (44 [50%] to the ST group and 44 [50%] to the NST group). Eight (9%) patients did not attend the 12 week visit; 80 (91%) patients (18 [23%] men and 62 [78%] women) were included in the modified ITT population (41 [51%] in the ST group and 39 [49%] in the NST group]. The proportion of Graves' orbitopathy composite evaluation responders at 24 weeks was higher in the ST group (21 [51%] of 41 patients) than the NST group (11 [28%] of 39 patients; attributable risk 0·23 [95% CI 0·02-0·44]; p=0·042). 26 adverse events occurred in 21 (24%) of 88 patients in the safety population. One (2%) of 44 patients in each group required treatment discontinuation, with no serious adverse events and no difference between groups.

INTERPRETATION: Addition of oral atorvastatin to an ivGC regimen improved Graves' orbitopathy outcomes in patients with moderate-to-severe, active eye disease who were hypercholesterolaemic. Future phase 3 studies, which could potentially recruit patients regardless of low-density lipoprotein cholesterol concentration, are required to confirm this association.

FUNDING: Associazione Allievi Endocrinologia Pisana.