Safety of long-term treatment with Pegvisomant: analysis of Spanish patients included in global ACROSTUDY

To evaluate the long-term safety of Pegvisomant (PEG) in the Spanish cohort of ACROSTUDY. As of July 2013, 199 Spanish patients were included in ACROSTUDY, a global non interventional safety PEG surveillance study. Patients were observed for safety, biochemical outcome and magnetic resonance imaging evaluations. PEG was administered during an average period of 6.7 +/- A 2.1 years and a mean daily dose of 15.5 +/- A 7.5 mg. 48.2 % of patients received PEG monotherapy. 90.9 % of patients had received other medical treatment before PEG start. 195 adverse events (AEs) were reported in 88 patients (44.2 %), and serious AEs were described in 31 patients (15.6 %). There were no cases of liver tests > 10 ULN, or permanent liver damage. Tumor size changes were locally reported in 61 cases (33.5 %), with increases observed in 11 patients (6 %). In acromegalic patients with diabetes mellitus a decrease in fasting serum glucose value was reported, reaching statistical significance after 1 and 4 years of treatment (-24.6 and -25.9 mg/dl, p = 0.04). After 60 months, normal or lower limit of normal (LLN) IGF-I levels were found in 67.9 % of patients. 85.5 % of patients showed an IGF-I normal or < LLN at any time after PEG start. Most patients with uncontrolled IGF-I levels were on submaximal PEG doses. ACROSTUDY carried out with the Spanish cohort confirmed that PEG has a favorable safety and efficacy profile. The percentage of patients considered under control was similar to data reported globally and in other local ACROSTUDY results.