Somatostatin is a naturally occurring hormone that has many biological actions because its receptors are found throughout the entire body. Some actions of somatostatin include inhibiting the secretion of growth hormones (GH), prolactin, glucagon, and insulin. Because somatostatin has a short half-life and targets many different hormones, somatostatin analogs were created (e.g., lanreotide [Somatuline® Depot]). Somatostatin analogs have a long half-life so they can be dosed less often, as well as greater inhibitory selectivity of GH secretion over insulin secretion.
Lanreotide (Somatuline® Depot) is indicated for the long-term treatment 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). Lanreotide (Somatuline® Depot) 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, by binding to somatostatin receptors.
Lanreotide (Somatuline® Depot) is also indicated for the treatment of unresectable, well- or moderately differentiated, locally advanced or metastatic gastroenteropancreatic neuroendocrine tumors. Data have shown that lanreotide (Somatuline® Depot) exhibits antiproliferative effects on these tumors, and improves progression-free survival. Neuroendocrine tumors are a heterogeneous group of neoplasms that arise from neuroendocrine cells and their precursors located throughout the body. Individuals with metastases from neuroendocrine tumors often become symptomatic due to hormone hypersecretion rather than tumor bulk. Lanreotide (Somatuline® Depot) is highly effective in controlling the symptoms associated with neuroendocrine tumors, such as flushing and diarrhea.
CLINICAL STUDIES
ACROMEGALY
The efficacy of lanreotide (Somatuline® Depot) on reducing growth hormone and IGF-1 was evaluated in two trials. The first was a three-phase trial which included a 4-week, double-blind, placebo-controlled phase; a 16-week, single-blind, fixed-dose phase; and a 32-week, open-label dose titration phase. A total of 107 patients completed the placebo-controlled phase, 105 completed the fixed-dose phase, and 99 completed the dose-titration phase. In the first (double-blind) phase of the trial, 52 of 83 (63 percent) of the lanreotide (Somatuline® Depot)–treated individuals had greater than 50 percent decrease in mean GH from baseline to week four, compared to 0 in the placebo group. In the fixed-dose phase, 72 percent of the 107 lanreotide (Somatuline® Depot)–treated individuals had a decrease from baseline in mean GH of greater than 50 percent. This efficacy was maintained for the duration of the trial.
The second trial was a 48-week, open-label, uncontrolled, multicenter study that enrolled individuals with an IGF-1 level equal to or greater than 1.3 times the upper limit of normal. This trial began with a 4-month fixed-dose phase in which individuals received four deep subcutaneous injections of lanreotide (Somatuline® Depot) at 4-week intervals. This was followed by a dose-titration phase in which the dose of lanreotide (Somatuline® Depot) was adjusted based on GH and IGF-1 levels. Sixty-three individuals started the fixed-dose phase and 57 completed 48 weeks of treatment. At the completion (48 weeks) of the trial, 43 percent (27/63) achieved normal age-adjusted IGF-1 levels, 38 percent (24/63) individuals achieved both normal IGF-1 levels and GH levels less than or equal to 2.5 ng/mL, and 27 percent (17/63) had both normal IGF-1 levels and GH levels less than 1 ng/mL.
GASTROENTEROPANCREATIC NEUROENDOCRINE TUMORS
Efficacy of lanreotide (Somatuline® Depot) in the treatment of gastroenteropancreatic neuroendocrine tumors was evaluated in a multicenter, randomized, double-blind, placebo-controlled trial of 204 individuals. Individuals received either lanreotide (Somatuline® Depot) or placebo every 4 weeks until disease progression, unacceptable toxicity, or a maximum of 96 weeks. Primary outcome was progression-free survival. Individuals in the lanreotide (Somatuline® Depot) arm had statistically significant improvement in progression-free survival compared to those in the placebo arm. Median progression-free survival was not reached in the lanreotide (Somatuline® Depot) group, and was 16.6 months in the placebo group.
OFF-LABEL INDICATION
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.