The present invention provides a method for treating a cancer in a subject in need thereof, comprising administering a specific MDM2 inhibitor to the subject according to a specific dosage regimen and a pharmaceutical composition for use in treating a cancer according to the dosage regimen. The present invention also provides a method for treating liposarcoma in a subject in need thereof, comprising administering a specific MDM2 inhibitor to the subject and a pharmaceutical composition for use in treating liposarcoma, comprising the MDM2 inhibitor.
