Pasireotide (Signifor): Uses, Evidence, and Side Effects

Key takeaways

• Pasireotide is approved under the brand name Signifor as a treatment for adult Cushing's disease.
• It works by binding somatostatin receptors, particularly the SSTR5 subtype overexpressed in corticotroph tumor cells.
• It is reserved for patients for whom pituitary surgery is not an option or has not been curative.
• Across 88 registered trials, researchers have studied pasireotide in Cushing's disease and in other tumor-related settings.
• Reported side effects most often involve blood sugar changes and gastrointestinal symptoms, based on FAERS reports.

What Pasireotide Is

Pasireotide is a cyclohexapeptide somatostatin analogue given by injection. It is classified in the somatostatin analog drug class.

The compound works by binding to somatostatin receptors (SSTRs), a family of five known subtypes found throughout the body. Corticotroph tumor cells in Cushing's disease frequently overexpress the SSTR5 subtype, while other subtypes are often less present on these cells. By engaging these receptors, pasireotide affects hormone-related tumor activity tied to the disease.

What Pasireotide Is Approved For

Pasireotide, sold as Signifor, is approved for adult patients with Cushing's disease. It is indicated specifically for those for whom pituitary surgery is not an option or has not achieved a cure. No boxed warning is listed on the label.

What the Evidence Shows

Pasireotide has been studied across 88 registered clinical trials. One completed Phase 2 trial extended earlier work to assess its long-term safety and efficacy in participants with Cushing's disease. Other research has explored different applications, including a completed Phase 1 trial combining pasireotide with everolimus and selective internal radioembolization for unresectable hepatic metastases, and a Phase 4 trial in neuroendocrine tumor that was withdrawn.

Reported Side Effects

FAERS data reflect reported reactions, not confirmed incidence or causation. The most frequently reported reactions relate to blood sugar regulation: blood glucose increased (262 reports), hyperglycaemia (249), and diabetes mellitus (246). Gastrointestinal and general symptoms were also common, including nausea (230), diarrhoea (210), fatigue (205), and headache (179). Off label use was reported 173 times.