- The patient must have histological-proven primary or recurrent extremity melanoma (or other skin cancer including but not limited to Merkel cell carcinoma) or sarcoma, stage IIIB, IIIC, or IV (American Joint Committee on Cancer [AJCC] staging must be documented in patient's medical record, as determined by computed tomography [CT] of the chest, abdomen and pelvis, and/or whole body positron emission tomography [PET] scan, within six weeks prior to administration of study drug)