Background and purpose: In acromegaly, growth hormone (GH) excess and pituitary tumours are typically managed through transsphenoidal surgery, often in combination with somatostatin receptor ligands (SRLs) given either before or following surgery. Although first-generation SRLs (lanreotide and octreotide) are efficacious in many patients, some exhibit resistance.
Methods: We present the efficacy of the second-generation SRL, pasireotide, in six patients anticipated to be resistant to first-generation SRLs. The patients had large, hyperintense tumors on T2-weighted MRI and sparse granulation pattern by histology.
Results: Over three to eight months, pasireotide reduced tumour volume in all patients and improved GH and IGF-1 levels. Visual field defects normalised. Despite hyperglycemia, requiring antidiabetic treatment in two patients, pasireotide proved effective as a first pharmacological therapy.
Conclusion: This series supports the use of pasireotide for rapid tumour control and GH reduction, in selected patients with complex and large tumours, likely to be resistant to first-generation SRLs. This approach expands the therapeutic options for managing the most challenging cases enhancing the potential for other subsequent treatment modalities.
Keywords: Octreotide test; Pituitary; Somatostatin analogue; Somatostatin receptor ligand.
© 2025. The Author(s).