Fig. 1: A proposed algorithm for the treatment of acromegaly in patients inadequately controlled with first-generation somatostatin receptor ligands lanreotide autogel and octreotide long-acting release.

In partial responders (≥50% decrease in growth hormone (GH) and/or insulin-like growth factor 1 (IGF1)), increase somatostatin receptor ligand (SRL) dose and/or dose frequency. If IGF1 remains modestly elevated during SRL administration, add cabergoline to SRL. If disease control is not achieved, patients should be switched to the second-generation SRL pasireotide if there is clinically relevant residual tumour on imaging and/or clinical concern of tumour growth (tumour concern). Patients with impaired glucose tolerance should be switched to the GH antagonist pegvisomant. Patients with impaired glucose tolerance and tumour concern should be treated with a combination of a first-generation SRL and pegvisomant. Those who remain uncontrolled despite second-line medical therapy should be considered for stereotactic radiosurgery (SRS) or surgical intervention.