Objective: To evaluate extended dosing intervals (EDIs) with lanreotide Autogel 120 mg in patients with acromegaly previously biochemically controlled with octreotide LAR 10 or 20 mg. Design and methods: Patients with acromegaly had received octreotide LAR 10 or 20 mg/4 weeks for R6 months and had normal IGF1 levels. Lanreotide Autogel 120 mg was administered every 6 weeks for 24 weeks (phase 1); depending on week-24 IGF1 levels, treatment was then administered every 4, 6 or 8 weeks for a further 24 weeks (phase 2). Hormone levels, patient-reported outcomes and adverse events were assessed. Primary endpoint: proportion of patients on 6- or 8-week EDIs with normal IGF1 levels at week 48 (study end). Results: 107/124 patients completed the study (15 withdrew from phase 1 and two from phase 2). Of 124 patients enrolled, 77.4% were allocated to 6- or 8-week EDIs in phase 2 and 75.8% (95% CI: 68.3-83.3) had normal IGF1 levels at week 48 with the EDI (primary analysis). A total of 88.7% (83.1-94.3) had normal IGF1 levels after 24 weeks with 6-weekly dosing. GH levels were ≤2.5 mg/l in >90% of patients after 24 and 48 weeks. Patient preferences for lanreotide Autogel 120 mg every 4, 6 or 8 weeks over octreotide LAR every 4 weeks were high. Conclusions: Patients with acromegaly achieving biochemical control with octreotide LAR 10 or 20 mg/4 weeks are possible candidates for lanreotide Autogel 120 mg EDIs. EDIs are effective and well received among such patients.