Chemical Identity

Property	Value
Chemical Formula	C54H69N11O10S2
Molecular Weight	1096.3 Da
CAS Number	108736-35-2
Peptide Class	Somatostatin Analog (Cyclic Octapeptide)
Route	Deep subcutaneous injection

Structure

Lanreotide is a synthetic cyclic octapeptide analog of somatostatin containing D-tryptophan, L-lysine, L-threonine, D-cysteine, and L-cysteine residues in a disulfide-bridged ring structure. The Autogel formulation provides sustained release over 28 days from a supersaturated aqueous solution.

Mechanism of Action

Lanreotide binds preferentially to somatostatin receptor subtype 2 (SSTR2) and to a lesser extent SSTR5, inhibiting growth hormone, TSH, and various gastrointestinal hormone secretion. In neuroendocrine tumors, it suppresses tumor growth through anti-proliferative and anti-angiogenic effects.

Clinical Applications

• Acromegaly: Control of GH and IGF-1 excess (Somatuline)
• Neuroendocrine tumors: Carcinoid syndrome symptom control
• Thyrotropinoma: TSH-secreting pituitary adenomas
• Hepatocellular carcinoma: TACE combination therapy

Pharmacokinetics

• Half-life: 23-30 days (Autogel)
• Tmax: 6-24 hours (Autogel)
• Duration: 28 days per injection
• Protein binding: 78%
• Route: Deep SC (Autogel)

Safety and Side Effects

GI disturbances (diarrhea, steatorrhea, abdominal pain), gallstones (20-30%), bradycardia, hyperglycemia, injection site reactions, and vitamin B12 malabsorption with long-term use.

References

• Chanson, P., et al. (2001). Lanreotide Autogel for acromegaly. European Journal of Endocrinology, 144, 501-508.
• Caplin, M.E., et al. (2014). Lanreotide for neuroendocrine tumors. New England Journal of Medicine, 371, 224-233.