ObjectiveTo 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 methodsPatients with acromegaly had received octreotide LAR 10 or 20 mg/4 weeks for ≥6 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).Results107/124 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 μg/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.ConclusionsPatients 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.