Certain compounds, or pharmaceutically acceptable salts or prodrugs thereof, pharmaceutical compositions comprising the same and methods of treating patients suffering from certain diseases and disorders responsive to the inhibition of KMO activity are described, which comprise administering to such patients an amount of at least one compound, or pharmaceutically acceptable salt or prodrug thereof described herein, effective to reduce signs or symptoms of the disease or disorder. These diseases include neurodegenerative disorders such as Huntington's disease. The application also provides a method for screening a compound capable of inhibiting KMO activity.