Guidelines on the diagnosis and treatment of acromegaly were published in February 2021 by the Pituitary Society in Pituitary.
Acromegaly is abnormally high linear growth due to excessive action of insulin-like growth factor I (IGF-I) that occurs after the growth plate cartilage fuses in adulthood. (Gigantism is the same disorder of IGF-1 but occurs while the epiphyseal growth plates are open during childhood.)
The guidelines include the following:
Biochemical control is the strongest predictor of patient outcome, reflecting improvements in glucose metabolism, obstructive sleep apnea, cardiovascular disease, and vertebral fractures.
Insulin-like growth factor I (IGF-I) levels 6 weeks after surgery can assess remission, but normalization of levels may still occur by 3-6 months.
Predictors of a more favorable response to lanreotide, 120 mg therapy every 4 weeks, include older age, female sex, lower IGF-I levels, and hypointensity of tumor T2-weighted MRI images at baseline.
Oral octreotide capsules (OOC), which received US FDA approval in June 2020 for long-term maintenance in acromegaly patients who respond to treatment with octreotide or lanreotide, are suitable for patients who have had a complete or partial response on injectable octreotide or lanreotide.
OOC is not recommended for patients with octreotide-resistant tumors.
OOC is initiated at a dose of 40 mg/day, given as 20 mg capsules twice per day taken 1 hr before or 2 hr after a meal.
OOC dose can be increased by 20 mg every 2-4 wk on the basis of IGF-I levels and clinical symptoms. (Injectable somatostatin receptor ligand [SRL] doses are often increased every 3 mo.)
Pegvisomant in patients with diabetes mellitus improves glucose metabolism independent of IGF-I control.
Higher doses of pegvisomant and a more rapid increase in dose are necessary for patients with diabetes mellitus and those with a higher body mass index to achieve normal IGF-I levels.
For patients who require combination therapy, low-dose octreotide long-acting release or lanreotide plus weekly pegvisomant is a good option.
The combination of pasireotide and pegvisomant can achieve control rates above 70%, but the addition of pegvisomant does not reduce the high rates of pasireotide-induced hyperglycemia.
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