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.