After 15 days of treatment with pasireotide, 76% of patients with Cushing’s disease experienced a decrease in urinary free cortisol levels.
The researchers conducted a phase-2, open-label, single-arm study to evaluate the short-term efficacy of pasireotide (SOM230), a novel multireceptor ligand somatostatin, in 39 patients with Cushing ’s disease. They assigned patients to self-administered 600-mcg pasireotide twice per day for 15 days.
The main outcome measure — normalization of urinary free cortisol levels — was reached in five of 29 patients (17%) with Cushing’s disease who were included in the primary efficacy analysis. Mean urinary free cortisol levels decreased by 44.5% during the study period, from 1,231 nmol per 24 hours at baseline to 683 nmol per 24 hours at day 15. Patients who had normalization of urinary free cortisol levels had higher plasma glucose exposure to pasireotide compared with patients who did not reach normalization.
Pasireotide was also associated with reductions in serum cortisol and plasma adrenocorticotropic hormone levels. Seven patients had increased urinary free cortisol levels at day 15 compared with baseline, four of whom also experienced decreases in ACTH AUC. Five days of treatment produced steady-state concentrations of pasireotide. Safety analysis revealed that pasireotide was well tolerated; the most common adverse events were gastrointestinal disorders (54%), such as diarrhea (44%), nausea (23%) and abdominal pain (18%).
J Clin Endocrinol Metab. 2009;94:115-122.