Somatostatin is a naturally occurring hormone that has many biological actions because its receptors are found throughout the body. Some actions of somatostatin include inhibiting the secretion of growth hormones (GH), vasoactive intestinal peptide (VIP), gastrin, secretin, motilin, serotonin, pancreatic polypeptide, and insulin. Because somatostatin has a short half-life and targets many different hormones, somatostatin analogs were created, including octreotide acetate (Sandostatin, Sandostatin LAR Depot). Somatostatin analogs have a much longer half-life, so they can be dosed less often, and have greater inhibitory selectivity of GH secretion over insulin secretion.
Octreotide acetate (Sandostatin) is a fast-acting formulation with a short half-life, so it needs to be administered two to four times a day subcutaneously. In contrast, the long-acting formulation, octreotide acetate (Sandostatin LAR Depot), is administered every four weeks, but it takes 10 to 14 days for the levels of the drug to achieve therapeutic levels in the body because it is not a fast-acting formulation. Hence, it is recommended that individuals with chronic conditions who require octreotide acetate initially receive octreotide acetate (Sandostatin), followed by octreotide acetate (Sandostatin LAR Depot) for continued therapy.
Because somatostatin receptors have been found throughout the whole gastrointestinal tract, octreotide acetate (Sandostatin LAR Depot) aids in the long-term treatment of flushing and severe diarrhea associated with metastatic carcinoid tumors, as well as diarrhea associated with vasoactive intestinal peptide secreting tumors (VIPomas). These conditions cause the secretion of excessive amounts of vasoactive substances, such as histamine, bradykinin, serotonin, and prostaglandins. Octreotide acetate (Sandostatin LAR Depot) works by blocking the release of serotonin and many of these other active peptides, as well as suppressing the secretion of gastrin, glucagon, and secretin.
Octreotide acetate (Sandostatin LAR Depot) has been successful at reducing the signs and symptoms of acromegaly, a rare condition characterized by abnormal enlargement of bones in the extremities and head, as well as thickening of soft tissues, such as the heart, lips, and tongue. Acromegaly occurs when the pituitary gland produces too much GH, which in turn causes excess secretion of insulin-like growth factor-1 (IGF-1). The long-term use of this medication suppresses the secretion of GH and IGF-1 in individuals who have had inadequate response to, or cannot be treated with, other therapies, including surgery or radiotherapy.
Octreotide acetate (Sandostatin LAR Depot) is approved by the US Food and Drug Administration (FDA) for long-term treatment in individuals with acromegaly who have had an inadequate response to surgery and/or radiotherapy, or for whom surgery and/or radiotherapy is not an option; long-term treatment for individuals with severe diarrhea and flushing episodes associated with metastatic carcinoid tumors; and long-term treatment of profuse watery diarrhea associated with VIP-secreting tumors.
CLINICAL STUDIES
ACROMEGALY
The efficacy of octreotide acetate (Sandostatin LAR Depot) was evaluated in 101 individuals with acromegaly who achieved growth hormone (GH) levels less than 5 ng/mL while on subcutaneous octreotide acetate (Sandostatin) injections in two clinical studies. Individuals were switched to 10 mg, 20 mg, 30 mg, or 40 mg of octreotide acetate (Sandostatin LAR Depot) once every 4 weeks for up to 27 to 28 injections. Of the 101 individuals, only 88 individuals received all of the 27 to 28 injections. A mean GH level of less than 5.0 ng/mL was observed in 83% of the individuals who completed all 27 or 28 injections. GH and insulin-like growth factor-1 (IGF-1) levels were at least as well controlled with octreotide acetate (Sandostatin LAR Depot) as they had been on octreotide acetate (Sandostatin) injections and retained the level of control for the duration of the clinical trials.
The efficacy of octreotide acetate (Sandostatin LAR Depot) was evaluated in a third study of 151 individuals with acromegaly who achieved GH levels less than 10 ng/mL on octreotide acetate (Sandostatin) injections. Individuals were switched to 10 mg, 20 mg, or 30 mg of octreotide acetate (Sandostatin LAR Depot) once every 4 weeks for up to 12 injections. Only 122 individuals received all 12 injections; a mean GH level of less than 5.0 ng/mL was observed in 97% of the individuals. Growth hormone and IGF-1 levels were at least as well controlled with octreotide acetate (Sandostatin LAR Depot) as they had been on octreotide acetate (Sandostatin) injections and retained the level of control for the duration of the clinical trial.
CARCINOID SYNDROME
In a 6-month double-blind clinical study, the efficacy of octreotide acetate (Sandostatin LAR Depot) was evaluated in 93 individuals with malignant carcinoid syndrome who had previously been responsive to octreotide acetate (Sandostatin) injections. Sixty-seven individuals were randomized to receive 10 mg, 20 mg, or 30 mg of octreotide acetate (Sandostatin LAR Depot) every 28 days, and 26 individuals remained on octreotide acetate (Sandostatin) injections (100-300 mcg three times daily) unblinded. Over the 6-month period, approximately 50-70% of octreotide acetate (Sandostatin LAR Depot) group required octreotide acetate (Sandostatin) injections as supplemental therapy to control exacerbations of carcinoid symptoms, although steady-state serum octreotide acetate (Sandostatin LAR Depot) levels had been reached. The mean daily stool frequency was as well controlled on octreotide acetate (Sandostatin LAR Depot) as on octreotide acetate (Sandostatin) injections.
Seventy-eight individuals with malignant carcinoid syndrome who participated in the 6-month study also participated in a 12-month extension study in which they received 12 injections of octreotide acetate (Sandostatin LAR Depot) at 4-week intervals. During the extension study, diarrhea and flushing were as well controlled as during the 6-month study.
OFF-LABEL INDICATIONS
There may be additional indications contained in the Policy section of this document due to evaluation of criteria highlighted in the Company’s off-label policy, and/or review of clinical guidelines issued by leading professional organizations and government entities.