Abstract

Background/Objectives: Acromegaly is a chronic endocrine disorder caused mainly by GH-secreting pituitary adenomas, leading to excess GH and elevated IGF-1. Although surgery is first-line therapy, many patients require medical treatment, and remission is often not achieved with first-generation somatostatin receptor ligands (SRLs). Pasireotide, a second-generation SRL, offers superior biochemical and tumor control but is associated with hyperglycemia. This study aimed to evaluate real-world outcomes associated with pasireotide treatment in patients with acromegaly inadequately controlled on first-generation SRLs, with IGF-1 normalization as the primary endpoint. Secondary outcomes included GH control, tumor response, and glycemic safety. Methods: We conducted a historical cohort study of adults with acromegaly treated at Clínica Imbanaco (Cali, Colombia) between 2017 and 2024. Eligible patients had residual tumors and persistently elevated GH and/or IGF-1 levels above the age-adjusted upper limit of normal despite treatment with clinically adequate doses of first-generation SRLs, as well as 12 months of continuous pasireotide treatment and follow-up after pasireotide initiation. Demographic, biochemical, imaging, and glycemic data were collected. Statistical analysis included paired and independent Student’s t-tests, Wilcoxon signed-rank tests, McNemar’s test, and Fisher’s exact test, with significance set at p < 0.05. Results: Fourteen patients (50% female; mean age 52.1 ± 14.5 years) were included. After 12 months, mean IGF-1 decreased from 2.73 ± 0.73 to 0.99 ± 0.56 × ULN, and 50% achieved IGF-1 normalization. Additionally, 35.7% achieved GH <1 ng/mL, and 14.3% achieved combined control. Mean tumor diameter decreased by −3.26 mm (95% CI −4.56 to −1.95; p < 0.001). HbA1c increased from 5.56% to 6.05%, while type 2 diabetes mellitus prevalence rose from 14.3% to 35.7%. No patient discontinued pasireotide due to metabolic adverse events. Conclusions: Pasireotide was associated with favorable biochemical and tumor responses in patients with acromegaly inadequately controlled on first-generation SRLs under real-world conditions. Although treatment was associated with higher HbA1c and increased diabetes incidence, proactive monitoring and early management of hyperglycemia may have supported treatment persistence.

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