The main purpose of this study is to estimate the proportion of patients with a type of skin
cancer called melanoma who are progression free, (that is, the cancer has not gotten
substantially worse), when treated with Anti-CD137 (4-1BB) (BMS-663513) at 0.1 mg/kg, 1 mg/kg
or 5 mg/kg every 3 weeks or 1 mg/kg every 6 weeks