This Phase II extension study showed that, following 9 months of pasireotide therapy (3 months in the core study and 6 months in the extension study), 23 % (6/26) of patients with acromegaly achieved biochemical control (defined as GH ≤ 2.5 μg/L and IGF-1 within age- and sex-matched limits).The response rate observed in the extension is similar to that seen in the core study (27 %) after 3 months’ pasireotide treatment [12] and is consistent with the results of earlier studies of somatostatin analogues that used this definition of biochemical control [15–17]. This evidence concerns the gene IGF1 and acromegaly.