Control of IGF-I levels with titrated dosing of lanreotide Autogel over 48 weeks in patients with acromegaly

BACKGROUND: An essential criterion for control of acromegaly is normalization of IGF-I levels. Somatostatin analogues act to suppress IGF-I and GH levels. OBJECTIVE: To assess the efficacy and safety of 48 weeks titrated dosing of lanreotide Autogel. DESIGN: Open-label, multicentre, phase III, 48-week trial. METHODS: Patients with active acromegaly (IGF-I levels > 1·3 times upper limit of age-adjusted normal range) were recruited. Twelve injections of lanreotide Autogel were given at 28-day intervals: during the 16-week fixed-dose phase, patients received 90 mg; in the 32-week dose-titration phase, patients received 60, 90 or 120 mg according to GH and IGF-I levels. Intention-to-treat analysis was performed to determine the proportion of patients with normalized age-adjusted IGF-I levels at study end. Secondary evaluations included GH levels, clinical acromegaly signs and safety. RESULTS: Fifty-seven of 63 patients completed the study. Lanreotide Autogel resulted in normalized age-adjusted IGF-I levels in 27 patients (43%, 95% CI 31–55). Mean GH levels decreased from 6·2 to 1·5 µg/l at study end, with 53 of 62 patients (85%) having GH levels ≤ 2·5 µg/l (95% CI 76·7–94·3) and 28 of 62 patients (45%) with levels < 1 µg/l (95% CI 32·8–57·6). Twenty-four (38%) had both normal IGF-I levels and GH levels ≤ 2·5 µg/l. Acromegaly symptoms reduced significantly in most patients throughout the study. The most common adverse events were gastrointestinal, as expected for somatostatin analogues. CONCLUSIONS: Using IGF-I as primary end-point, 48 weeks lanreotide Autogel treatment, titrated for optimal hormonal control, controlled IGF-I and GH levels effectively, reduced acromegaly symptoms and was well tolerated.