Gadobutrol in the central nervous system at three doses: results from a phase II, randomized, multicenter trial.

Purpose: To investigate the efficacy and safety of three doses of gadobutrol and determine the minimum effective dose for contrast-enhanced MRI of the central nervous system (CNS).

Materials And Methods: This was a Phase II, multicenter, double-blind, parallel-group controlled study in subjects referred for contrast-enhanced MRI of the CNS. Subjects were randomized to receive gadobutrol 0.03, 0.1, or 0.3 mmol/kg body weight, and underwent unenhanced, gadobutrol-enhanced, and comparator-enhanced MRI scans. Three blinded readers assessed the images. Primary efficacy variables were number of lesions detected, border delineation, contrast enhancement, and internal morphology.

Results: Of the 229 randomized subjects, 173 were evaluated for efficacy. Clinically meaningful improvements in lesion border delineation, contrast enhancement, and internal morphology were observed for 0.1 mmol/kg gadobutrol. Pair-wise comparisons of a composite score of the four primary variables showed the 0.1 mmol/kg dose to be statistically superior to the 0.03 mmol/kg dose (P = 0.003). The 0.3 mmol/kg dose showed no statistically significant difference with the 0.1 mmol/kg dose. Twenty-two (9.8%) subjects reported at least one treatment-emergent adverse event (TEAE). No TEAE was reported at an incidence >3.5%.

Conclusion: The 0.1 mmol/kg dose of gadobutrol was effective and well tolerated for contrast-enhanced MRI of the CNS.