The present invention relates to methods for treating cancer by administeringa therapeutically effective amount ofcompound of formula (I), such as selective NPY5R antagonist MK-0557( trans -N-[1-(2-fluorophenyl)-3-pyrazolyl]-3-oxospiro[6-azaisobenzofuran-1(3H), 1'- cyclohexane]-4'-carboxamide ), or apharmaceutically acceptable salt thereof, to a subject in needthereof The methods can further comprise administering a chemotherapeuticagent to the subject in need thereof.