Bayer HealthCare Pharmaceuticals said the FDA has approved Gadavist (gadobutrol) injection, a macrocyclic gadolinium-based contrast agent (GBCA), for intravenous use in diagnostic magnetic resonance imaging (MRI) in adults and children (2 years and older) to detect and visualize areas with disrupted blood brain barrier (BBB) and/or abnormal vascularity of the central nervous system (CNS).

Patients referred for MRI of the central nervous system with contrast were enrolled in two clinical trials (study A and study B) that evaluated the visualization characteristics of lesions. In both studies, patients underwent a baseline, pre-contrast MRI prior to administration of Gadavist at a dose of 0.1 mmol/kg, followed by a post-contrast MRI. In study A, patients also underwent an MRI before and after the administration of gadoteridol. The studies were designed to demonstrate superiority of Gadavist MRI to non-contrast MRI for lesion visualization. For both studies, pre-contrast and pre-plus-post contrast images (paired images) were independently evaluated by three readers for contrast enhancement and border delineation using a scale of 0 to 4, and for internal morphology using a scale of 0 to 3.  Lesion counting was also performed to demonstrate non-inferiority of paired Gadavist image sets to pre-contrast MRI. Readers were blinded to clinical information.

Gadavist provided a statistically significant improvement for each of the three lesion visualization parameters when averaged across three independent readers for each study.  For both studies, the improvement of visualization endpoints in paired Gadavist images compared to pre-contrast images resulted in improved assessment of normal and abnormal CNS anatomy.