In total , 512 patients were randomly assigned 1:1 to receive intravenous temsirolimus 25 mg once weekly ( n = 259 ) or oral sorafenib 400 mg twice per day ( n = 253 ) , with stratification according to duration of prior sunitinib therapy ( or > 180 days ) , prognostic risk , histology ( clear cell or non-clear cell ) , and nephrectomy status .