OBJECTIVES: Acromegaly is a rare disease with an estimated incidence of 2.5 cases per million (cpm) and a prevalence of 50-60 (cpm) per year according to Spanish national data. Somatuline Autogel (Ipsen property) and Sandostatin LAR (Novartis property) are associated with similar efficacy and together they represent more than 90% of long-acting somatostatin analogs sales in Spain. Somatuline Autogel has been approved of an injection extended dosing interval for 6 or 8 weeks with the dose of 120mg. This study is aimed to estimate the potential budgetary consequences of increasing the use of Somatuline Autogel in the treatment of acromegaly in Spain. METHODS: A budget impact model was developed to compare annual treatment costs of acromegaly patients with either Somatuline Autogel and Sandostatin LAR, including drug acquisition costs and administration costs. Disease prevalence and IMS sales data were used to estimate total number of patients using both treatments, and the potential budget impact of increasing Somatuline Autogel was calculated under different scenarios based on the proportion of patients using different dose ranges. RESULTS: Overall treatment costs were 11,857€ and 12,165€ per patient/year for Somatuline Autogel and Sandostatin LAR respectively (monthly treatment), as a result of the higher acquisition cost and administration costs of the latter. Furthermore, assuming that 30% of patients with Somatuline Autogel may benefit of the extended dose interval (every 6 or 8 weeks), mean cost savings per patient may rise to 2,019€ (10,147€ vs. 12,165€). When applying these patient-level cost savings with Somatuline Autogel to total treated patients, acromegaly treatment costs could be reduced by 0.3 M€ to 1.