Pasireotide: A Review of Its Use in Cushing’s Disease

Abstract

Pasireotide (Signifor(®)) is a new subcutaneous somatostatin analogue that acts via somatostatin receptors to inhibit the secretion of corticotropin from the pituitary adenoma in patients with Cushing's disease. Pasireotide has a receptor binding profile that is distinct from that of other somatostatin analogues, binding with high affinity to somatostatin receptor subtype 5, which is strongly over expressed in corticotroph adenoma cells. Pasireotide is the first pituitary-directed agent to be approved for use in Cushing's disease. In a phase III clinical trial in patients with Cushing's disease, twice-daily pasireotide 600 or 900μg for 6months led to normalization of urinary free cortisol (UFC) levels in up to a quarter of all patients (primary endpoint) and significantly reduced mean UFC levels. The reduction in UFC levels is rapid (within one to two months) and sustained (up to 24months). Most patients who do not have an early response to pasireotide do not respond at a later time point. Decreases in UFC levels achieved during pasireotide treatment are accompanied by decreases in serum and salivary cortisol levels, as well as improvements in clinical signs and symptoms, including body weight, blood pressure and health-related quality-of-life. Pasireotide has a generally similar tolerability profile to that of other somatostatin analogues, but is associated with a relatively high incidence of hyperglycaemia, requiring the addition or intensification of glucose-lowering medication in a substantial proportion of patients. Thus, pasireotide, together with on-going patient monitoring, provides a promising new option for the medical management of Cushing's disease.