Imaging Study to Compare Effects of Darolutamide and Enzalutamide With Respect to Placebo on the Blood Flow in the Brain in Healthy Male Volunteers.

The current study would investigate the effects of a single dose of darolutamide and enzalutamide compared with placebo and compared to each other on human brain blood flow using arterial spin labeling magnetic resonance imaging (ASL-MRI), a non-invasive MRI technique. The change in cerebral blood flow was an indirect measure of brain penetration. The risk of drug-associated CNS-related adverse events was likely to be correlated with the concentration of the drug in the brain. In contrast to enzalutamide, preclinical studies of darolutamide indicate that its brain penetration was much lower. The aim of this study was to determine whether there was a difference between darolutamide and enzalutamide compared to placebo in cerebral blood flow and thus in brain penetration.