Efficacy and tolerance of osilodrostat in patients with severe Cushing’s syndrome due to non-pituitary cancers

To the editor Severe hypercortisolism (SH) is a rare life-threatening endocrine emergency, mainly caused by ectopic ACTH syndrome (EAS), which requires a rapid normalization of cortisol concentrations (1, 2). Due to their rapidity of action, steroidogenesis inhibitors, such as ketoconazole and metyrapone, given in monotherapy or in association, are recommended in this situation (1, 3, 4). Osilodrostat is a recently developed inhibitor of adrenal 11B-hydroxylase (5) which has been shown to be effective, using a progressive titration of the drug dosage, in the treatment of Cushing's disease (5, 6, 7). Limited data are available on the use of osilodrostat in SH induced by EAS (8). Following the shortage of metyrapone in 2019, a temporary authorization for the use of osilodrostat was given by French authorities. We report herein our experience with osilodrostat in the treatment of three patients with severe Cushing's syndrome due to EAS and adrenal carcinoma (ACC).