Long-term safety and efficacy of long-acting pasireotide in acromegaly

Background Pasireotide long acting (LAR) can be effective in normalizing insulin-like growth factor (IGF)-1 level in acromegaly patients inadequately controlled by octreotide or lanreotide. Objective Determine the long-term efficacy and safety of pasireotide, including time to biochemical control and time to best response, and risk for diabetes mellitus. Methods A retrospective multicenter study investigating the efficacy and safety of pasireotide LAR treatment in patients with active acromegaly treated for >12 months. Results The study included 19 patients (10 men; mean age ± SD, 48.0 ± 12.9 years) treated with pasireotide for a mean of 50 ± 36 months. During the follow-up, 4 patients discontinued pasireotide treatment. Pasireotide LAR produced a tolerable and long-term significant biochemical response in 15 of 19 patients (79.0%). Mean time to IGF-1 normalization from pasireotide LAR initiation was 13.6 ± 16.9 months with early biochemical normalization (<12 months) evident in 11 (64.7%) patients and delayed IGF-1 normalization in 6 (35.2%) patients. Nadir IGF-1 values were recorded within the first 12 months in 6 patients (35.3%), while in 11 patients (64.7%) lowest values were reported after >12 months of treatment, including 4 of 11 patients with early IGF-1 normalization. New-onset diabetes was documented in 5 of 7 patients with pre-diabetes and in 1 of 5 patients with normal glucose homeostasis at baseline. Among patients with pre-diabetes or diabetes mellitus prior to initiating pasireotide, mean HbA1c increase was 0.56 ± 1.0%. Conclusions The results support the long-term efficacy and safety of pasireotide LAR for acromegaly and support the potential delayed effect of treatment on IGF-1 normalization.