Context: Short and long-acting somatostatin (SRIF) analogs are approved for clinical use in acromegaly. Recent analysis of the relative efficacy of octreotide LAR and lanreotide SR on the GH – IGF-I axis in acromegaly favoured octreotide LAR, in secondary treatment of patients not pre-selected by SRIF responsiveness. A novel aqueous formulation of lanreotide, Lanreotide Autogel (ATG), has recently been approved and is the predominant (and only in USA) formulation of lanreotide used clinically.

Objective: We performed a critical review of SRIF analog treatment, to establish the relative efficacy of three clinically available SRIF analog preparations, Octreotide LAR, Lanreotide SR, and Lanreotide ATG (somatuline depot in USA) in control of the GH – IGF-I axis in acromegaly.

Data Sources: Data were drawn from Medline, and from the bibliography of analyses of long-acting SRIF analogs.

Data Collection: We reviewed the largest studies of subcutaneous octreotide, octreotide LAR, and lanreotide SR; all that included biochemical end-point data for Lanreotide ATG; studies which directly compared efficacy of octreotide LAR and lanreotide SR.

Data Synthesis: Caveats considered included differences in baseline GH and IGF-I values, patient selection, and inter and intra-assay variability, confounding the analysis. Studies comparing patients treated contiguously with lanreotide SR and octreotide LAR are fraught with methodological problems, however, are suggestive of marginally greater efficacy in control of the GH – IGF-I axis for octreotide LAR. Lanreotide ATG shows non-inferiority to lanreotide SR. Five small studies directly comparing octreotide LAR and lanreotide ATG suggest no significant differences between these preparations in control of biochemical end-points.

Conclusion: Lanreotide ATG and octreotide LAR are equivalent in control of symptoms and biochemical markers in patients with acromegaly.