Octreotide Long-Acting Repeatable in Acromegaly: Achieving Optimal Control

An open-label dose-escalation study of once-daily and twice-daily pasireotide in healthy volunteers: safety, tolerability, and effects on glucose, insulin, and glucagon levels

Pasireotide is a multireceptor-targeted somatostatin analogue that has high affinity for 4 of the 5 somatostatin receptor subtypes (sst1,2,3 and sst5) and has therapeutic potential in conditions with tumors of neuroendocrine origin, such as Cushing disease, acromegaly, and neuroendocrine tumors. This phase 1, open-label, dose-escalation study assessed the overall safety and tolerability of once-daily and twice-daily pasireotide and its effects on glucose, insulin, and glucagon levels in healthy volunteers. Eleven cohorts (n = 6 for each) received subcutaneous pasireotide 150, 300, 600, 900, 1200, or 1500 μg once daily, or 150, 300, 450, 600, or 750 μg twice daily, for 8 days. Pasireotide was generally well tolerated at all doses; adverse events were predominantly mild-to-moderate gastrointestinal disorders. All participants experienced fasting and postprandial plasma glucose elevations after all doses of pasireotide; increases in blood glucose level seemed to be dose dependent. Hyperglycemia was associated with a marked suppression of insulin secretion and a mild inhibition of glucagon secretion. In conclusion, pasireotide showed good overall tolerability at doses up to 1500 μg once daily and 750 μg twice daily for 8 days. Both fasting and postprandial hyperglycemia occurred after all doses of pasireotide, which was related to the suppression of insulin secretion.

Octreotide long-acting release (LAR): a review of its use in the management of acromegaly

Octreotide long-acting release (LAR) [Sandostatin LAR] is a somatostatin analogue with a well established clinical profile in patients with acromegaly. It binds to somatostatin receptor subtypes 2 and 5 with high potency to reduce the production and secretion of growth hormone (GH) and insulin-like growth factor (IGF)-I. Octreotide LAR is administered intramuscularly once every 28 days, in contrast to the subcutaneous formulation which requires administration two to three times daily. In several noncomparative trials, octreotide LAR was effective as primary therapy in normalizing GH and IGF-I levels and reducing tumour volume in patients with acromegaly. In addition, no significant difference was seen between octreotide LAR and surgery or lanreotide long-acting (LA) or lanreotide Autogel(R) (ATG) in small, randomized or observational, primary therapy trials. In another small, randomized trial, preoperative octreotide LAR followed by surgery was no more effective than surgery alone in terms of normalizing IGF-I levels, except in patients with macroadenoma. Octreotide LAR has also demonstrated good efficacy as postoperative adjuvant therapy, alone or in combination with pegvisomant, in randomized or noncomparative trials. In patients with different treatment histories (mixed populations), the efficacy of octreotide LAR appears to be generally similar to that of lanreotide ATG and greater than that of lanreotide LA, according to data from switching or crossover studies. Also in mixed populations, the efficacy of octreotide LAR was not significantly different to that of pegvisomant in terms of normalizing IGF-I levels in a randomized trial, and octreotide LAR demonstrated good efficacy in combination with cabergoline in a small, sequential-treatment trial. Octreotide LAR was generally well tolerated in clinical trials, with the most commonly occurring adverse events being gastrointestinal or hepatobiliary in nature. Thus, octreotide LAR continues to be a valuable option in the treatment of acromegaly.

Management of acromegaly in Latin America: expert panel recommendations

Although there are international guidelines orienting physicians on how to manage patients with acromegaly, such guidelines should be adapted for use in distinct regions of the world. A panel of neuroendocrinologists convened in Mexico City in August of 2007 to discuss specific considerations in Latin America. Of major discussion was the laboratory evaluation of acromegaly, which requires the use of appropriate tests and the adoption of local institutional standards. As a general rule to ensure diagnosis, the patient's GH level during an oral glucose tolerance test and IGF-1 level should be evaluated. Furthermore, to guide treatment decisions, both GH and IGF-1 assessments are required. The treatment of patients with acromegaly in Latin America is influenced by local issues of cost, availability and expertise of pituitary neurosurgeons, which should dictate therapeutic choices. Such treatment has undergone profound changes because of the introduction of effective medical interventions that may be used after surgical debulking or as first-line medical therapy in selected cases. Surgical resection remains the mainstay of therapy for small pituitary adenomas (microadenomas), potentially resectable macroadenomas and invasive adenomas causing visual defects. Radiotherapy may be indicated in selected cases when no disease control is achieved despite optimal surgical debulking and medical therapy, when there is no access to somatostatin analogues, or when local issues of cost preclude other therapies. Since not all the diagnostic tools and treatment options are available in all Latin American countries, physicians need to adapt their clinical management decisions to the available local resources and therapeutic options.