Efficacy of a slow-release formulation of lanreotide (Autogel) 120 mg) in patients with acromegaly previously treated with octreotide long acting release (LAR): an open, multicentre longitudinal study

Objective: Lanreotide Autogel® 120 mg (ATG120; Ipsen S.p.A, Milan, Italy) is a high-dose, sustained-release aqueous gel formulation, supplied in a prefilled syringe and given by deep subcutaneous injection. The aim of this study was to compare efficacy and tolerability of ATG120 given every 4-8 weeks with those of octreotide LAR (o-LAR) given every 4 weeks. Design patients and intervention: A phase III multicentre Italian open clinical study of 23 acromegalic patients (15 female, 8 male). All patients had received o-LAR for 6-18 months and, after 3 months wash out, ATG120 was given every 6 weeks for a total of four injections (Period 1). Then the interval between ATG120 injections was adjusted according to three different schemes: every 4, 6 or 8 weeks depending on GH levels (GH > 2.5 μg/l; 1 < GH ≤ 2.5 μg/l; GH ≤ 1 μg/l, respectively). ATG120 was given for a further two to three doses, with a final assessment (Period 2) at Week 34, 36 or 42. Measurements: Hormonal (GH and IGF-I) and clinical efficacy and tolerability. Results: ATG120 induced a significant GH decrease from 9.9 ± 11.3 at baseline (Visit 1) to 3.5 ± 5.7 at the end of Period 1 (P < 0.01) and to 3.8 ± 5.7 μg/l at the final visit (P < 0.01). IGF-I also decreased from 544 ± 312 at baseline (Visit 1) to 318 ± 181 at Period 1 and to 356 ± 187 μg/l at the final visit (both P < 0.05 vs. baseline). The frequency of ATG120 administrations was adjusted to every 4 weeks in 12 patients, every 6 weeks in 4 patients and every 8 weeks in 6 patients; 1 patient withdrew before the dose adjustment. Serum GH and IGF-I achieved at the end of Period 1 and Period 2 were similar to those reached with o-LAR. The number of patients who achieved GH < 2.5 μg/l was comparable between o-LAR (43%) and ATG120 at Period 1 (48%) and at Period 2 (62%). Normal IGF-I levels were recorded in 8 patients during o-LAR (35%), 11 during ATG Period 1 (48%) and 10 at the final visit (43%). Last, 4 patients showed a better response to ATG120 and 2 to o-LAR. Conclusions: Lanreotide Autogel 120 mg is an effective and well-tolerated therapy for acromegaly. In approximately half of patients ATG120 may be administered every 6-8 weeks, instead of every 4 weeks, without lost of efficacy.